ORTHOPEDIC MCQS BANK WITH ANSWER PEDS 01

1.          The inheritance of the deformity shown in Figure 1 is most commonly

 

1-         autosomal-recessive.

2-         autosomal-dominant.

3-         x-linked dominant.

4-         mitochondrial.

5-         sporadic.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Cleft hand and cleft foot malformations are commonly inherited as autosomal-dominant traits and are associated with a number of syndromes.  An autosomal-recessive and an x-linked inheritance pattern have also been described, but these are much less common and are usually atypical.  In the common autosomal-dominant condition, nearly one third of the known carriers of the gene show no hand or foot abnormalities.  This is known as reduced penetrance.  The disorder may be variably expressed; affected family members often exhibit a range from mild abnormalities in one limb only to severe anomalies in four limbs.  Variable expressivity and reduced penetrance can cause difficulty in counseling families regarding future offspring in an affected family.  Many patients have a cleft hand that may be caused by the split-hand, split-foot gene (SHFM1) localized on chromosome 7q21.  

 

REFERENCE: Kay SPJ: Cleft hand, in Green DP (ed): Green’s Operative Hand Surgery. Philadelphia, Pa, Churchill Livingston, 1999, pp 402-414.

2.         Examination of a 12-year-old girl with bilateral anterior knee pain reveals excessive femoral anteversion and excessive external tibial torsion.  The patient has no patellofemoral instability.  Nonsurgical management consisting of muscle strengthening and nonsteroidal medication has failed to relieve the patient’s pain.  Treatment should now consist of

 

1-         corrective osteotomies with internal rotation of the distal part of the tibia and/or external rotation of the femur.

2-         external rotation of the distal part of the tibia.

3-         internal rotation of the distal part of the femur.

4-         arthroscopic retinacular release.

5-         a patellar realignment procedure.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Children with symptomatic severe torsional malalignment of the lower extremity and patellofemoral pathology show excessive femoral anteversion and external tibial torsion on physical examination and analysis of gait.  The functional effect of this torsional malalignment is centered about the knee joint.  If nonsurgical management fails to alleviate patellofemoral pain, definitive surgical treatment should consist of corrective osteotomies, including internal rotation of the distal part of the tibia or external rotation of the femur, or both.  Patients with surgical correction by osteotomy show an improved gait pattern and appearance of the extremity and a marked decrease in knee pain.  External rotation of the distal part of the tibia or internal rotation of the distal part of the femur worsens the torsional malalignment.  No additional soft-tissue realignment procedures, including retinacular release or patellar realignment, are required. 

 

REFERENCE: Delgado ED, Schoenecker PL, Rich MM, Capelli AM: Treatment of severe torsional malalignment syndrome.  J Pediatr Orthop 1996;16:484-488.

 

3.         Which of the following patients with cerebral palsy is considered the ideal candidate for a selective dorsal rhizotomy?

 

1-         An ambulatory 6-year-old patient with spastic diplegia

2-         An ambulatory 10-year-old patient with spastic right hemiplegia

3-         An ambulatory 16-year-old patient with spastic diplegia

4-         A nonambulatory 8-year-old patient with spastic quadriplegia

5-         A nonambulatory 18-year-old patient with rigid quadriplegia

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The enthusiasm with which dorsal rhizotomy was received led to the broadening of selection criteria with poorer results.  The ideal candidate is an ambulatory 4- to 8-year-old child with spastic diplegia who does not use assistive devices or have joint contractures.  The child must be old enough to actively participate in the rigorous postoperative physical therapy program.  The use of the procedure in an ambulatory 16-year-old patient is less desirable because joint contractures will most likely have developed to a varying degree.  The hemiplegic child is best treated by orthopaedic interventions.

 

REFERENCES: Oppenheim WL: Selective posterior rhizotomy for spastic cerebral palsy: A review.  Clin Orthop 1990;253:20-29.

Renshaw TS, Green NE, Griffin PP, Root L:  Cerebral palsy: Orthopaedic management.  J Bone Joint Surg Am 1995;77:1590-1606.

Richards BS (ed): Orthopaedic Knowledge Update: Pediatrics.   Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1996, pp 19-27.

4.         A 3-year-old boy sustains a complete paralysis following a high thoracic spinal cord injury consistent with a SCIWORA-type injury (spinal cord injury without radiographic abnormality).  Subsequent progressive spinal deformity will develop in what percent of patients with this injury?

 

1-         10%

2-         25%

3-         50%

4-         75%

5-         Greater than 75%

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Spinal cord injury in skeletally immature patients almost always leads to the development of paralytic spinal deformity.  The age at injury is the most important factor affecting the development of scoliosis.  Spinal cord injury that occurs more than 1 year prior to skeletal maturity is almost always followed by the development of scoliosis.  In one study, scoliosis developed in 100% of children who were younger than age 10 years at the time of spinal cord injury.  Scoliosis can occur after injury at any level.  Spasticity is often a contributing factor.  Up to two thirds of patients who have paralytic scoliosis prior to skeletal maturity will eventually require surgery for curve control.

 

REFERENCES: Mayfield JK, Erkkila JC, Winter RB: Spine deformity subsequent to acquired childhood spinal cord injury. J Bone Joint Surg Am 1981;63:1401-1411.

Lancourt JE, Dickson JH, Carter RE: Paralytic spinal deformity following traumatic spinal cord injury in children and adolescents. J Bone Joint Surg Am 1981;63:47-53.

Dearolf WW III, Betz RR, Vogel LC, Levin J, Clancy M, Steel HH: Scoliosis in pediatric spinal cord injured patients.  J Pediatr Orthop 1990;10:214-218. 

5.         A 12-year-old girl has progressive development of cavus feet.  Examination reveals slightly diminished vibratory sensation on the bottom of the foot.  Reflexes are 1+ at the knees and ankles.  Motor examination shows that all muscles are 5/5 in the foot, except the peroneal and anterior tibial muscles are rated as 4+/5.  Which of the following studies is considered most diagnostic?

 

1-         Nerve conduction velocity studies

2-         Biopsy of the quadriceps femoris muscle

3-         Biopsy of the sural nerve

4-         DNA testing 

5-         Chromosomal analysis 

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The patient most likely has a form of Charcot-Marie-Tooth disease, or hereditary motor sensory neuropathy (HMSN).  The most common varieties can now be diagnosed by DNA testing.  Mutations have been detected in the peripheral myelin protein-22 (PMP-22) gene in HMSN type IA and in the connexin gene in the x-linked HMSN.  Specific DNA diagnosis is useful in genetic counseling.  Routine chromosomal testing most likely would not detect these mutations.  Nerve conduction velocity study results are normal in some types of HMSN, and delayed nerve conduction, when found, indicates a peripheral neuropathy but does not specify the type or inheritance pattern.  Biopsy of the sural nerve or of the quadriceps can be informative in some patients, but is not as specific as DNA testing.  These procedures are most often reserved for patients with negative DNA test results.

 

REFERENCES: Chance PF:  Molecular genetics of hereditary neuropathies.  J Child Neurol 1999;14:43-52.

Bell C, Haites N:  Genetic aspects of Charcot-Marie-Tooth disease.  Arch Dis Child 1998;78:296-300.

6.         A 2-year-old girl was born with the toe deformity shown in Figure 2.  She has difficulty wearing shoes despite having adequate room in the toe box.  Management at this time should consist of

 

1-         stretching exercises, followed by taping of the toes in a derotational maneuver.

2-         lengthening of the extensor digitorum longus tendon of the second toe and release of the metatarsophalangeal joint dorsal capsule. 

3-         resection arthroplasty of the proximal interphalangeal joint of the third toe, with release of the volar plate.

4-         tenotomy of the flexor digitorum longus and brevis of the third toe.

5-         a Girdlestone-Taylor transfer of the flexor digitorum longus to the extensor digitorum longus of the third toe.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The patient has a congenital curly toe deformity of the third toe, and tenotomy of the toe flexors is highly effective for this problem.  Stretching and taping are ineffective for this deformity.  The position of the second toe is secondary; therefore, procedures on that toe are unnecessary and ineffective.  The flexor to extensor transfer is a more complicated procedure that produces negligible results, or may even worsen the deformity.  Resection arthroplasty is contraindicated because it causes abnormal growth of the toes.

 

REFERENCES: Hamer AJ, Stanley D, Smith TW: Surgery for curly toe deformity:  A double-blind, randomized, prospective trial.  J Bone Joint Surg Br 1993;75:662-663.

Ross ER, Menelaus MB: Open flexor tenotomy for hammer toes and curly toes in childhood.  J Bone Joint Surg Br 1984;66:770-771.

Sullivan JA: The child’s foot, in Morrissy RT, Weinstein SL (eds):  Lovell & Winter’s Pediatric Orthopaedics, ed 4.  Philadelphia, Pa, Lippincott-Raven, 1996, pp 1077-1135.

7.         Figure 3 shows the radiograph of an asymptomatic 10-year-old boy.  Management should consist of

 

1-         physical therapy.

2-         restriction from contact sports.

3-         periodic observation, but no activity restriction.

4-         immobilization with a thoracolumbosacral orthosis (TLSO).

5-         direct surgical repair.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Asymptomatic spondylolysis in a child or adolescent should be observed for the possible development of spondylolisthesis, but no other active intervention is needed.  The initial treatment of choice for symptomatic spondylolysis includes rest and activity modifications, nonsteroidal anti-inflammatory drugs, physical therapy, bracing, and casting.  Immobilization with a TLSO or pantaloon spica cast may permit healing of an acute pars fracture.  Rarely, surgical treatment may be necessary.  Surgical options include posterolateral L5-S1 fusion or direct repair of the pars defect.

 

REFERENCES: Pizzutillo PD, Hummer CD III: Nonoperative treatment for painful adolescent spondylolysis or spondylolisthesis.  J Pediatr Orthop 1989;9:538-540.

Richards BS (ed): Orthopaedic Knowledge Update: Pediatrics.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1996, pp 129-137.

8.         A 12-year-old girl has had lower back pain for the past 6 months that interferes with her ability to participate in sports.  She denies any history of radicular symptoms, sensory changes, or bowel or bladder dysfunction.  Examination reveals a shuffling gait, restriction of forward bending, and tight hamstrings.  Radiographs show a grade III spondylolisthesis of L5 on S1, with a slip angle of 20°.  Management should consist of

 

1-         brace treatment.

2-         laminectomy, nerve root decompression, and in situ fusion of L4 to the sacrum.

3-         in situ fusion of L4 to the sacrum.

4-         excision of the L5 lamina.

5-         physical therapy.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Indications for surgical treatment of spondylolisthesis include pain and/or progression of deformity.  Specifically, surgery is necessary when there is persistent pain or a neurologic deficit that fails to respond to nonsurgical therapy, there is significant slip progression, or the slip is greater than 50%.  For patients with mild spondylolisthesis, in situ posterolateral L5-S1 fusion is adequate.  In patients with more severe slips (greater than 50%), extension of the fusion to L4 offers better mechanical advantage.  Postoperative immobilization may be achieved with instrumentation, casting, or both.  In patients with a slip angle of greater than 45°, reduction of the lumbosacral kyphosis with instrumentation or casting is desirable to prevent slip progression.  Laminectomy alone is contraindicated in a child.  Nerve root decompression is indicated if radiculopathy is present clinically. 

 

REFERENCES: Seitsalo S, Osterman K, Hyvarinen H, Tallroth K, Schlenzka D, Poussa M: Progression of spondylolisthesis in children and adolescents: A long-term follow-up of 272 patients.  Spine 1991;16:417-421.

Newton PO, Johnston CE II: Analysis and treatment of poor outcomes following in situ arthrodesis in adolescent spondylolisthesis.  J Pediatr Orthop 1997;17:754-761.

9.         Figures 4a through 4c show the clinical photographs and radiographs of a 12-month-old boy who has progressive difficulty wearing shoes because of the length of the second toe, as well as width of the forefoot.  Management should consist of

 

1-         form-fitted shoes.

2-         amputation of the second toe at the metatarsophalangeal joint.

3-         amputation of the first ray and amputation of the second toe.

4-         amputation of the second ray.

5-         an MRI scan of the foot, a CT scan of the chest, and a biopsy of the foot with the possibility of ankle disarticulation amputation.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The patient has macrodactyly involving the second ray, with significant enlargement of the width and height of the foot.  The radiographs show widening of the interval between the first and second metatarsal and between the second and third metatarsal.  With this degree of involvement, amputation of the second ray with excision of the overgrowth of affected soft tissue provides the most consistent desired reduction in foot size.  A threaded Steinmann pin should be inserted across the remaining metatarsals until healing has occurred.  Patients with macrodactyly should be examined to exclude neurofibromatosis type 1 and Klippel-Trenaunay-Weber syndrome.

 

REFERENCE: Sullivan JA: The child’s foot, in Morrissy RT, Weinstein SL (eds):  Lovell & Winter’s Pediatric Orthopaedics, ed 4.  Philadelphia, Pa, Lippincott-Raven, 1996, pp 1077-1135.

 

10.        Figures 5a and 5b show the radiographs of an 11-year-old boy who felt a pop and immediate pain in his right knee as he was driving off his right leg to jam a basketball.  Examination reveals that the knee is flexed, and the patient is unable to actively extend it or bear weight on that side.  There is also a large effusion.  Management should include

 

1-         ice and elevation, followed by graduated range-of-motion exercises.

2-         a long leg cast.

3-         excision of the fragment.

4-         open reduction and internal fixation.

5-         observation until maturity, followed by anterior cruciate ligament repair.   

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Fractures through the cartilage on the inferior pole of the patella, the so-called sleeve fracture, are often difficult to diagnose because of the paucity of ossified bone visible on the radiographs.  If the fracture is missed and the fragments are widely displaced, the patella may heal in an elongated configuration that may result in compromise of the extensor mechanism function.  The treatment of choice is open reduction and internal fixation using a tension band wire technique to achieve close approximation of the fragments and restore full active knee extension.  

 

REFERENCES: Heckman JD, Alkire CC: Distal patellar pole fractures: A proposed common mechanism of injury.  Am J Sports Med 1984;12:424-428.

Tolo VT: Fractures and dislocations around the knee, in Green NE, Swiontkowski MF (eds): Skeletal Trauma in Children.  Philadelphia, Pa, WB Saunders, 1994, vol 3, pp 380-382.

11.         A 2-year-old child has been referred for management of congenital kyphosis.  Neurologic examination is normal, and radiographs show a type I congenital kyphosis.  Which of the following anomalies is seen in the MRI scan shown in Figure 6?

 

1-         Chiari II malformation

2-         Syrinx

3-         Diastematomyelia

4-         Meningocele

5-         Tethered cord

 

PREFERRED RESPONSE: 5

 

DISCUSSION: There is a high incidence of intraspinal anomalies in patients with congenital scoliosis and kyphosis.  Bradford and associates reported an incidence rate of 38% in 42 patients.  The MRI scan shows that the filum terminale is thickened and adherent distally in the spinal canal.  Although the conus is at L1, which may be normal, neurologic dysfunction may occur with further growth.  There are no signals of high intensity within the cord that would suggest a syrinx.  A Chiari II malformation would be found in the upper cervical region, not shown in this MRI scan.  Meningocele and diastematomyelia are not present.

 

REFERENCES: Bradford DS, Heithoff KB, Cohen M: Intraspinal abnormalities and congenital spine deformities: A radiographic and MRI study.  J Pediatr Orthop 1991;11:36-41.

Mimaston MJ: Occult intraspinal anomalies and congenital scoliosis.  J Bone Joint Surg Am 1984;66:588-601.

 

12.        A 15-year-old boy with a type I hereditary sensory motor neuropathy (Charcot-Marie-Tooth disease) reports recurrent ankle sprains and significant pain in the hindfoot and midfoot despite orthotic management.  Examination reveals that he walks with a drop foot and has dynamic clawing of the toes.  Clinical photographs of the left foot are shown in Figure 7.  Management should consist of

 

1-         revision of the current orthotics.

2-         metatarsal osteotomies to correct cavus.

3-         a sliding calcaneal osteotomy to correct hindfoot varus.

4-         triple arthrodesis, with anterior transfer of the posterior tibialis.

5-         extensor transfer to the metatarsal necks, soft-tissue releases, and anterior transfer of the posterior tibialis tendon.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The clinical photographs show a patient with a type I hereditary sensory motor neuropathy who has cavus feet with a flexible hindfoot.  The Coleman block test shows that the hindfoot corrects into valgus.  To prevent progressive cavus, patients with this condition may benefit from soft-tissue releases at a younger age while the foot is flexible.  Once there is fixed deformity, combined soft-tissue and bone procedures usually are necessary.  Metatarsal osteotomies will correct the cavus, but will do nothing for the drop foot.  Transfer of the extensor hallucis longus to the neck of the first metatarsal and modified transfer of the extensor digitorum longus to the dorsum of the foot will prevent further claw toes and improve foot dorsiflexion.  Anterior transfer of the posterior tibialis tendon will also aid in dorsiflexion.  Calcaneal osteotomy should be reserved for fixed hindfoot varus that does not correct with block testing, and triple arthrodesis should be avoided as long as possible because the long-term outcome is poor.

 

REFERENCES: Beaty JH (ed): Orthopaedic Knowledge Update 6.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1999, pp 235-245.

Coleman SS: Complex Foot Deformities in Children.  Philadelphia, Pa, Lea & Febiger, 1983, pp 147-165.

Thometz JG, Gould JS: Cavus deformity, in Drennan JC (ed): The Child’s Foot and Ankle.  New York, NY, Raven Press, 1992, pp 343-353.

 

13.        Figures 8a through 8d show the radiographs and CT scans of a 14-year-old girl who has a painful, rigid planovalgus foot.  Management consisting of arch supports and anti-inflammatory drugs failed to provide relief.  A below-knee walking cast resulted in pain resolution, but she now reports that the pain has recurred.  Management should now consist of

 

1-         custom orthotics.

2-         a below-knee non-weight-bearing cast.

3-         exploration and resection of the calcaneocuboid joint.

4-         exploration and resection of the talocalcaneal joint.

5-         triple arthrodesis.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Tarsal coalitions commonly present in the preadolescent age group as a rigid, planovalgus foot.  Small coalitions of the calcaneonavicular joint or the middle facet of the talocalcaneal joint can be excised with interposition of fat or muscle tissue.  Isolated calcaneocuboid joint coalitions are very rare.  This patient has an associated large talocalcaneal coalition; therefore, resection is contraindicated.  Surgery is warranted after failure of nonsurgical management, and because of the involvement of two joints, the only viable option for the severely symptomatic foot is triple arthrodesis.  

 

REFERENCES: Vincent KA: Tarsal coalition and painful flatfoot.  J Am Acad Orthop Surg 1998;6:274-281.

Olney BW: Tarsal coalition, in Drennan JC (ed): The Child’s Foot and Ankle.  New York, NY, Raven Press, 1992, pp 169-181.

14.        Figures 9a and 9b show the spinal radiographs of a 3-year-old child with short limb dwarfism.  The lateral radiograph is obtained with maximal lumbar extension.  Management should consist of

 

1-         close clinical follow-up.

2-         a thoracolumbosacral orthosis.

3-         anterior spinal fusion.

4-         posterior spinal fusion.

5-         fibroblast growth factor replacement.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The patient has kyphosis in association with achondroplasia.  The AP radiograph shows decreased interpedicular distance at the lower lumbar vertebrae, a feature considered to be a distinctive sign of achondroplasia.  Most patients with achondroplasia have kyphosis, and this usually resolves spontaneously.  When the fixed component is greater than 30°, however, brace treatment is recommended.  Spinal fusion is seldom required.

 

REFERENCE: Pauli RM, Breed A, Horton VK, Glinski LP, Reiser CA: Prevention of fixed angular kyphosis in achondroplasia. J Pediatr Orthop 1997;17:726-733.

15.        A 10-year-old boy with severe hemophilia A (factor VIII) sustained an injury to his right forearm 2 hours ago when a classmate fell on his arm during a scuffle.  Examination reveals moderate swelling in the forearm, decreased sensation in the distribution of the median and ulnar nerves, and pain on passive extension of the fingers.  What is the most appropriate sequence of treatment?

 

1-         Measurement of volar compartment pressures and, if elevated, a bolus transfusion of 4 unit/kg of factor VIII concentrate, followed by continuous transfusion of factor VIII

2-         Splinting of the extremity with the elbow flexed and the wrist in extension, elevation of the extremity, observation, and if no improvement, continuous transfusion of factor VIII (4 unit/kg)

3-         A bolus transfusion of 4 unit/kg of factor VIII concentrate, followed by continuous transfusion of factor VIII, measurement of forearm compartment pressures, splinting of the extremity with the elbow and wrist flexed, and surgical release of the volar forearm compartments if pressures are elevated

4-         A bolus transfusion of 4 unit/kg of factor VIII concentrate, followed by continuous transfusion of factor VIII and an emergency fasciotomy

5-         A bolus transfusion of 4 unit/kg of factor VIII concentrate, laboratory studies consisting of serum electrolytes and creatine phosphokinase levels, IV injections of bicarbonate to alkalize the urine, and renal dialysis

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The patient has severe hemophilia with a volar forearm hemorrhage and an emerging compartment syndrome.  Therefore, it is critical to normalize the clotting deficiency as the first step in treatment.  In a patient who has a factor VIII level of less than 1% and no inhibitors to factor VIII, transfusion with 4 unit/kg will typically raise the factor VIII level to 100%.  Continuous transfusion can then be used to maintain this level.  Compartment pressures can be safely measured after infusion of factor VIII.  Because the hemorrhage is of limited duration and any surgery is considered serious in a patient with hemophilia, the compartment pressure should be measured before making a decision regarding a fasciotomy.  However, it is important to note that the use of factor VIII concentrates allows both emergency and elective surgery provided that adequate hematology backup is available.  Splinting the elbow and wrist in flexion reduces the pressure in the volar compartments, protects the forearm from further trauma, and makes the patient more comfortable.

 

REFERENCES: Greene WB: Diseases related to the hematopoietic system, in Morrissy RT, Weinstein SL (eds):  Lovell & Winter’s Pediatric Orthopaedics, ed 4.  Philadelphia, Pa, Lippincott-Raven, 1996, pp 345-391.

Greene WB, McMillan CW: Nonsurgical management of hemophilic arthropathy, in Barr JS (ed): Instructional Course Lectures 38.  Park Ridge, Ill, American Academy of Orthopaedic Surgeons, 1989, pp 367-381.

Naranja RJ Jr, Chan PS, High K, Esterhai JL Jr, Heppenstall RB: Treatment considerations in patients with compartment syndrome and an inherited bleeding disorder. Orthopedics 1997;20:706-711.

16.        Figures 10a and 10b show the radiographs of an athletic 9-year-old boy who has activity-related anterior knee pain with intact active knee extension.  Examination reveals tenderness to palpation over the inferior pole of the patella.  There is no effusion or ligamentous instability.  Initial management should consist of

 

1-         long leg cast immobilization for 6 weeks.

2-         open reduction and internal fixation.

3-         activity restrictions and nonsteroidal anti-inflammatory drugs.

4-         cessation of sports for 6 to 18 months.

5-         diagnostic arthroscopy.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The radiographs show fragmentation of the inferior pole of the patella.  This finding, along with the clinical presentation, is most consistent with Sindig-Larsen-Johansson disease.  This is an overuse syndrome commonly seen in boys ages 9 to 11 years.  The differential diagnosis includes bipartite patella and patellar sleeve fracture.  Like most overuse syndromes, Sindig-Larsen-Johansson disease responds to activity modification and nonsteroidal anti-inflammatory drugs.  While symptoms usually resolve with short periods of activity restriction, radiographic findings may persist.

 

REFERENCES: Stanitski CL: Anterior knee pain syndromes in the adolescent.  J Bone Joint Surg Am 1993;75:1407-1416.

Stanitski CL: Anterior knee pain syndromes in the adolescent, in Schafer M (ed): Instructional Course Lectures 43.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1994, pp 211-220.

17.        A 2-week-old infant has been referred for evaluation of nonmovement of the left hip.  History reveals that the patient was delivered 6 weeks premature by cesarean section.  Examination reveals no fever, and there is mild swelling of the thigh.  Passive movement of the hip appears to elicit tenderness and very limited hip motion.  A radiograph of the pelvis shows mild subluxation of the left hip.  The next step in evaluation should consist of

 

1-         aspiration of the left hip.

2-         application of a Pavlik harness.

3-         a gallium scan.

4-         an MRI scan of the spine.

5-         modified Bryant traction.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The diagnosis of bone and joint sepsis in a newborn is difficult because of the relative lack of obvious signs and symptoms.  Fever is usually absent.  A study of 34 newborns with osteomyelitis identified prematurity and delivery by cesarean section as predisposing factors.  In that study, the most common clinical findings were pseudoparalysis, local swelling, and pain on passive movement.  Because early diagnosis is so important, any infant who exhibits these findings should be suspected as having bone or joint sepsis.  Once the area of involvement is identified, aspiration is mandatory.  In newborns who have an infection about the hip, radiographs may reveal subluxation.  In this patient, septic arthritis must be ruled out by aspiration of the hip.  Developmental dysplasia of the hip is not painful and is not accompanied by localized swelling.  If no purulent material is obtained at the time of hip aspiration, an arthrogram should be obtained to rule out epiphysiolysis of the proximal femur.  Because the area of involvement has been identified by clinical examination, a gallium scan or MRI scan of the spine is not indicated.

 

REFERENCES: Knudsen CJ, Hoffman EB:  Neonatal osteomyelitis.  J Bone Joint Surg Br 1990;72:846-851.  

Morrissy RT:  Bone and joint sepsis, in Morrissy RT, Weinstein SL (eds): Lovell and Winter’s Pediatric Orthopaedics, ed 4.  Philadelphia, Pa, Lippincott-Raven, 1996, pp 579-624.

18.        Figure 11 shows the lateral radiograph of a 16-year-old boy who has been unable to participate in sports activities because of pain in the anterior aspect of the knee.  He states that the pain is aching in nature and is located in the region of the tibial tuberosity.  He denies having joint effusion or symptoms of instability.  Management should consist of

 

1-         phonophoresis treatment and a program of quadriceps stretching.

2-         application of a hinge, post, and shell design functional knee brace.

3-         application of a hinge, post, and strap design functional knee brace.

4-         an MRI scan of the knee, a CT scan of the chest, a technetium Tc 99m bone scan, liver function tests, and a biopsy of the proximal tibia.

5-         excision of the ossicle and prominence of the tibial tuberosity.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The prognosis for most patients with Osgood-Schlatter disease is good.  When the secondary ossification center unites with the main body of the tibial tubercle, the patellar tendon has a more rigid anchor, and heterotopic ossification and its associated reaction often become quiescent.  However, even after closure of the growth plates, some patients have persistent symptoms.  Excision of the ossicle and prominence of the tibial tuberosity decompresses the patellar tendon and allows most patients to resume sports activities.  Nonsurgical modalities are ineffective.  Better results have been reported after excision than after drilling of the tubercle.  Excision of the ossicle is not indicated prior to skeletal maturity because symptoms will resolve in most patients when the secondary ossification center unites.

 

REFERENCES: Flowers MJ, Bhadreshwar DR: Tibial tuberosity excision for symptomatic Osgood-Schlatter disease.  J Pediatr Orthop 1995;15:292-297.

Greene WB: Osteochondrosis and tibia vara, in Canale ST, Beaty JH (eds): Operative Pediatric Orthopaedics, ed 2.  Philadelphia, Pa, Mosby, 1995, pp 804-854.

19.        A 10-lb, 2-oz infant who was born via a difficult breech delivery 12 hours ago is now being evaluated for hip pain.  Although the infant is resting comfortably, examination reveals that the patient is not moving the right lower extremity and manipulation of the right hip causes the infant to cry.  The Galeazzi sign is positive.  An AP radiograph of the pelvis shows proximal and superior migration of the right proximal femoral metaphysis.  What is the most likely diagnosis?

 

1-         Teratologic hip dislocation

2-         Septic right hip

3-         Congenital coxa vara

4-         Transphyseal fracture of the proximal femur

5-         Postpartum ligamentous laxity

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Transphyseal fractures of the proximal femur at birth are more likely to occur in large newborns after a difficult delivery.  At rest, the patients are comfortable and show a pseudoparalysis; however, passive motion of the lower extremity results in discomfort.  Teratologic hip dislocations will have a positive Galeazzi sign, but are not painful.  Development of a septic hip would be unlikely within 12 hours postpartum.  Congenital coxa vara is typically painless.  Postpartum ligamentous laxity might account for a positive Ortolani sign, but is painless.

 

REFERENCES: Weinstein JN, Kuo KN, Millar EA: Congenital coxa vara:  A retrospective review.  J Pediatr Orthop 1984;4:70-77.

Beaty JH: Orthopaedic Knowledge Update 6.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1999, pp 409-425.

 

20.       A 10-year-old girl has been referred for evaluation of a prominence at the lower cervical spine.  The patient is asymptomatic, and the examination reveals no evidence of neurologic abnormality.  A radiograph and CT scans are shown in Figures 12a through 12c.  What is the most likely diagnosis?

 

1-         Tuberculosis

2-         Congenital kyphosis

3-         Blastomycosis

4-         Aneurysmal bone cyst

5-         Osteoblastoma

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Tuberculosis is uncommon in the cervical spine but has a relatively greater incidence in young children.  In a review of 40 patients with lower cervical spine involvement (C2 to C7), 24 were younger than age 10 years at presentation.  In children, the disease is characterized by more extensive involvement with the formation of large abscesses.  In older patients with lower cervical tuberculosis, the disease is more localized but is more likely to cause paraplegia.  Four-drug antituberculosis therapy should be used.  For patients with pain or neurologic dysfunction, anterior excision of diseased bone and grafting are indicated.  Whether vertebral body excision and grafting should be done in an asymptomatic 10-year-old child is debatable.  The CT scan shows a large “cold” abscess that is partially calcified.  

 

REFERENCES: Hsu LC, Leong JC: Tuberculosis of the lower cervical spine (C2 to C7): A report on 40 cases.  J Bone Joint Surg Br 1984;66:1-5.

Loder RT: The cervical spine, in Morrissy RT, Weinstein SL (eds):  Lovell & Winter’s Pediatric Orthopaedics, ed 4.  Philadelphia, Pa, Lippincott-Raven, 1996, pp 739-789.

21.        Which of the following types of iliac osteotomy provides the greatest potential for increased coverage?

 

1-         Ganz periacetabular

2-         Pemberton innominate

3-         Salter innominate

4-         Sutherland double innominate

5-         Steele triple innominate

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The degree of acetabular dysplasia and the age of the child are important considerations when choosing what type of osteotomy to perform.  The ability to obtain concentric reduction is a prerequisite of all osteotomies that redirect the acetabulum.  Procedures that cut all three pelvic bones allow more displacement and, therefore, correction of acetabular dysplasia.  The closer the osteotomy is to the acetabulum, the greater the coverage of the femoral head.  Compared with the other acetabular osteotomies, the Ganz periacetabular osteotomy provides the greatest potential for correcting acetabular deficiency because there are no bone or ligamentous restraints to limit correction, but it has the disadvantage of being a technically demanding procedure.  The amount of coverage provided by the Salter osteotomy is limited.

 

REFERENCES: Millis MB, Poss R, Murphy SB: Osteotomies of the hip in the prevention and treatment of osteoarthritis, in Eilert RE (ed): Instructional Course Lectures XLI. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1992, pp 145-154.

Weinstein SL: Developmental hip dysplasia and dislocation, in Morrissy RT, Weinstein SL (eds):  Lovell & Winter’s Pediatric Orthopaedics, ed 4.  Philadelphia, Pa, Lippincott-Raven, 1996, pp 903-950.

 

 

 

22.       The mother of a 26-month-old boy reports that he has been unwilling to bear weight on his left lower extremity since he awoke this morning.  She denies any history of trauma.  He has a temperature of 99.4°F (37.4°C), and examination reveals that abduction of the left hip is limited to 30°.  Laboratory studies show a WBC of 11,000/mm³ and an erythrocyte sedimentation rate of 22 mm/h.  A radiograph of the pelvis is shown in Figure 13.  Management should consist of

 

1-         aspiration of the hip.

2-         a bone scan.

3-         an MRI scan.

4-         bed rest, frequent temperature checks, and reevaluation in 24 to 48 hours.

5-         hospital admission and placement in traction.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The most likely diagnosis is transient synovitis.  Initial management should consist of bed rest and serial observation to rule out atypical septic arthritis of the hip.  In an unreliable family situation, hospitalization for bed rest and observation may be indicated.  Other disorders such as proximal femoral osteomyelitis, leukemia, juvenile rheumatoid arthritis, pelvic osteomyelitis, diskitis, and arthralgia secondary to other inflammatory disorders should be considered.  However, these disorders are unlikely because of the paucity of abnormal clinical signs exhibited by the patient.  On the other hand, transient synovitis of the hip in children is a diagnosis of exclusion; other possibilities should be explored if the patient’s symptoms do not follow a typical course and resolve in 4 to 21 days.

 

REFERENCE: Frymoyer JW (ed): Orthopaedic Knowledge Update 4.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1993, pp 505-513.

 

23.       A 10-year-old girl with a monoarticular pattern of juvenile rheumatoid arthritis (JRA) has had a 3-cm limb-length discrepancy since age 8 years when inflammation in the right knee came under good medical control.  Because her right leg is longer, the patient states that she would like her legs to be close to equal in length in the future.  A growth-remaining chart is shown in Figure 14.  Management should consist of

 

1-         immediate proximal right tibial physeal arrest.

2-         immediate distal right femoral physeal arrest.

3-         a shoe lift and follow-up in 2 years.

4-         observation with the expectation that the discrepancy may correct itself and not require surgery.

5-         limb lengthening of the shorter left limb.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: In a subgroup of patients with monoarticular JRA and a limb-length discrepancy that developed before the age of 9 years, Simon and associates showed that a subsequent growth deceleration on the affected side may correct a large part of the difference in length.  This possibility would make surgery unnecessary and should prompt further observation.

 

REFERENCES: Simon S, Whiffen J, Shapiro F: Leg-length discrepancies in monoarticular and pauciarticular juvenile rheumatoid arthritis.  J Bone Joint Surg Am 1981;63:209-215.

Ansell BM, Bywaters EGL: Growth in Still’s disease.  Ann Rheum Dis 1956;15:295-319.

24.       A 14-year-old girl with polyarticular juvenile rheumatoid arthritis (JRA) has severe neck pain and reports the onset of urinary incontinence.  A lateral radiograph and lateral tomogram of the cervical spine are shown in Figures 15a and 15b.  An MRI scan of the upper cervical spine is shown in Figure 15c.  Management should consist of

 

1-         a rigid cervical orthosis.

2-         a soft cervical collar.

3-         posterior C1-2 fusion with halo immobilization.

4-         administration of methotrexate.

5-         activity restrictions.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The plain radiograph and tomogram show an abnormality of the upper cervical spine, with erosion of the dens.  The MRI scan shows evidence of cord impingement.  The cervical spine is frequently involved in polyarticular JRA.  Stiffness and autofusion are commonly seen, but C1-2 instability can also occur secondary to synovitis and bony erosion.  Basilar invagination is rare in JRA.  There is no consensus regarding fusion in the asymptomatic patient.  In patients with symptoms and neurologic signs, C1-2 posterior fusion is indicated.

 

REFERENCES: Fried JA, Athreya B, Gregg JR, Das M, Doughty R: The cervical spine in juvenile rheumatoid arthritis.  Clin Orthop 1983;179:102-106.

Hensinger RN, DeVito PD, Ragsdale CG: Changes in the cervical spine in juvenile rheumatoid arthritis.  J Bone Joint Surg Am 1986;68:189-198.

 

25.       Figures 16a and 16b show the radiographs of an otherwise healthy 3 1/2-year-old boy who has an isolated deformity of the left leg.  Definitive primary treatment of this condition should consist of 

 

1-         distraction osteogenesis.

2-         an intramedullary nail and onlay bone graft.

3-         a short leg cast.

4-         a vascularized free fibular graft.

5-         plate fixation and an autogenous bone graft.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Treatment of congenital pseudarthrosis of the tibia is problematic.  To achieve union, a resection of the pseudarthrosis, stabilization, and bone grafting must be performed.  Simple cast immobilization does not yield union.  There are various options for the resection, immobilization, and grafting.  On the first surgical attempt, retrograde intramedullary nailing offers the best chance for success by transfixing the ankle and subtalar joints with abundant autogenous bone grafting.  Distraction osteogenesis and vascularized free fibular graft are reserved as salvage procedures.

 

REFERENCES: Gilbert A, Brockman R: Congenital pseudarthrosis of the tibia:  Long-term follow-up of 29 cases treated by microvascular bone transfer.  Clin Orthop 1995;314:37-44.

Boero S, Catagni M, Donzelli O, Facchini R, Frediani PV: Congenital pseudarthrosis of the tibia associated with neurofibromatosis - 1: Treatment with Ilizarov’s device.  J Pediatr Orthop 1997;17:675-684.  

Anderson DJ, Schoenecker PL, Sheridan JJ, Rich MM: Use of an intramedullary rod for the treatment of congenital pseudarthrosis of the tibia.  J Bone Joint Surg Am 1992;74:161-168.

 

 

26.       Figure 17 shows the radiograph of a 2-year-old girl who sustained a fracture of the femur in a fall while walking with her parents.  History reveals that this is her third long bone fracture, having sustained a humerus fracture 1 year ago and a fracture of the opposite femur 9 months ago.  There is no family history of any similar problem.  Examination reveals distinctly blue sclerae, normal appearing teeth, and no skin lesions.  What is the most likely cause of this patient’s disorder?

 

1-         A quantitative defect of type I collagen synthesis

2-         A deficiency of vitamin D

3-         Parental abuse

4-         Abnormal osteoclast function

5-         Excess excretion of keratin sulfate in the urine

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Osteogenesis imperfecta (OI) is a genetically determined disorder of type I collagen synthesis that is characterized by bone fragility.  This patient has had three fractures of the long bones by age 2 years, with the last one occurring after relatively minor trauma.  The patient’s history and clinical features are consistent with a diagnosis of Sillence type IA OI.  Type I OI is the mildest and most common form.  Inheritance is autosomal-dominant; however, as in this patient, new mutations are frequent.  Type I is subclassified into the A type (absence of dentinogenesis imperfecta) and B type (presence of dentinogenesis imperfecta).  The sclerae are blue, and the first fractures usually occur in the preschool years after walking has begun.  Cells from individuals with type I OI largely demonstrate a quantitative defect of type I collagen; they synthesize and secrete about half the normal amount of type I procollagen.  Qualitative mutations that lead to an abnormal type I procollagen molecule result in more severe types of the disorder.  There are no indications that this child has been abused.  Radiographs of the femur show no evidence of rickets, pyknodysostosis, or osteopetrosis.  Morquio syndrome, characterized by excess excretion of keratin sulfate in the urine, is not associated with bone fragility.

 

REFERENCES: Kocher MS, Shapiro F: Osteogenesis imperfecta.  J Am Acad Orthop Surg 1998;6:225-236.  

Sillence DO, Senn A, Danks DM: Osteogenesis imperfecta: An expanding panorama of variants.  Clin Orthop 1981;159:11-25.  

Cole WG: Etiology and pathogenesis of heritable connective tissue diseases.  J Pediatr Orthop 1993;13:392-403.

 

27.       An 8-year-old boy with severe hemophilia A (factor VIII) and no inhibitor is averaging eight transfusions per month for bleeding into the right ankle.  Examination shows synovial hypertrophy; range of motion consists of 0° of dorsiflexion and 20° of plantar flexion.  The patient’s knees, elbows, and left ankle have no restriction of motion.  Standing radiographs of the right ankle are shown in Figure 18.  Management should consist of

 

1-         prophylactic transfusions three times per week.

2-         application of ankle-foot orthoses.

3-         ankle synovectomy.

4-         ankle arthrodesis performed with physeal protection.

5-         pantalar arthrodesis.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The patient has bilateral hypertrophic synovitis that is causing repeated hemarthroses and progressive arthropathy.  Ankle synovectomy in patients with hemophilia is effective in significantly reducing the rate of joint bleeding and in slowing the progression of the arthropathy; therefore, bilateral synovectomies is the treatment of choice.  Range of motion can be effectively maintained after ankle synovectomy.  Bracing and prophylactic transfusions would be ineffective at this time.  Ankle arthrodesis should be reserved for patients with severe pain.  Compared with patients who have juvenile rheumatoid arthritis, patients with hemophilia generally do not have involvement of the subtalar joint and rarely require a pantalar arthrodesis.

 

REFERENCES: Greene WB: Synovectomy of the ankle for hemophilic arthropathy.  J Bone Joint Surg Am 1994;76:812-819.

Greene WB: Chronic inflammatory arthridities and diseases related to the hematopoietic system, in Drennan JC (ed): The Child’s Foot and Ankle, New York, NY, Raven Press, 1992, pp 461-482.

 

 

 

 

28.       Figures 19a through 19c show radiographs of the cervical spine of an asymptomatic patient with Down syndrome who wants to participate in a Special Olympics running event.  The neurologic examination is normal.  Management should consist of

 

1-         an MRI scan.

2-         fusion from the occiput to C2.

3-         fusion of C1-C2.

4-         application of a cervical collar and no participation in any sports.

5-         periodic follow-up examinations and no contact sports.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: An atlanto-dens interval (ADI) of up to 4 mm in children is considered normal.  Children with Down syndrome have increased ligamentous laxity, with atlantoaxial instability occurring in as many as 15% to 20% of patients.  These patients are at risk for catastrophic injury following minor trauma and should be routinely screened for instability, generally beginning when the patient starts to walk.  Patients with an ADI of greater than 5 mm should avoid contact sports and high-risk activities such as gymnastics, diving, the high jump, and the butterfly stroke.  The American Academy of Pediatrics Committee of Sports Medicine and Fitness guidelines recommend that lateral views of the cervical spine in neutral, flexion, and extension should be obtained in all children with Down syndrome who wish to participate in sports.  Patients with normal radiographs and examinations do not need repeat radiographs, although some authors suggest that instability increases with age, and therefore recommend repeat radiographs every 5 years.  Cervical spine fusion in patients with Down syndrome has a high rate of complications and should be performed only on patients with symptoms and evidence of myelopathy.

 

REFERENCES: American Academy of Pediatrics Committee of Sports Medicine and Fitness: Atlantoaxial instability in Down syndrome.  Pediatrics 1995;96:151-154.

Copley LA, Dormans JP: Cervical spine disorders in infants and children.  J Am Acad Orthop Surg 1998;6:204-214.

Tredwell SJ, Newman DE, Lockitch G:  Instability of the upper cervical spine in Down syndrome.  J Pediatr Orthop 1990;10:602-606.

 

 

29.       Compared with amputation, limb salvage for osteosarcoma of the distal end of the femur will result in

 

1-         an improved chance for long-term survival.

2-         an improved quality of life.

3-         a lessened need for chemotherapy.

4-         a better functional outcome.

5-         a reduced need for reoperation.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Major advances in diagnostic imaging, neoadjuvant chemotherapy, and surgical techniques have allowed limb salvage to be performed as an alternative to amputation in children with osteosarcoma.  The outcome of treatment of nonmetastatic, high-grade osteosarcoma of the distal femur was studied in 227 patients from 26 institutions.  The authors found no difference in the long-term survival or quality of life between patients treated with limb salvage and those treated with amputation.  Patients treated with limb salvage had a higher rate of reoperation, but a better functional outcome.

 

REFERENCES: Rougraff BT, Simon MA, Kneisl JS, Greenberg DB, Mankin HJ: Limb salvage compared with amputation for osteosarcoma of the distal end of the femur: A long-term oncological, functional, and quality-of-life study.  J Bone Joint Surg Am 1994;76:649-656.  

Simon MA: Limb salvage for osteosarcoma.  J Bone Joint Surg Am 1988;70:307-310. 

 

 

30.       Examination of a 7-year-old boy reveals 20° of valgus following a lawn mower injury to the lateral femoral epiphysis.  Treatment consists of total distal femoral epiphyseodesis and varus osteotomy.  Following surgery, he has a limb-length discrepancy of 3 cm and 5° of genu valgum.  Assuming that he undergoes no further treatment, the patient’s predicted limb-length discrepancy at maturity would be how many centimeters?

 

1-         Less than 7

2-         7 to 10

3-         11 to 13

4-         14 to 17

5-         Greater than 17

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The distal femoral epiphysis grows approximately 1 cm per year and in boys, growth ceases at approximately age 16 years.  Therefore, the patient’s limb-length discrepancy at maturity would be 12 cm (9 cm plus the 3-cm discrepancy he has from the previous surgery).

 

REFERENCES: Little DG, Nigo L, Aiona MD:  Deficiencies of current methods for the timing of epiphyseodesis.  J Pediatr Orthop 1996;16:173-179.

Westh RN, Menelaus MB:  A simple calculation for the timing of epiphyseal arrest: A further report.  J Bone Joint Surg Br 1981;63:117-119.

 

 

31.        When the iliac apophysis starts ossifying in the normal adolescent, growth of the sitting height or trunk height is characterized by 

 

1-         no appreciable change during the remainder of growth for either boys or girls.

2-         an increase of 3 to 5 cm in girls and an increase of 5 to 8 cm in boys.

3-         an increase of 5 to 8 cm in girls and an increase of 3 to 5 cm in boys.

4-         an increase of 8 to 11 cm in girls and an increase of 11 to 13 cm in boys.

5-         an increase of 11 to 13 cm in girls and an increase of 8 to 11 cm in boys.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Studies by Anderson and associates have resulted in a growth-remaining chart for sitting height that shows an increase of 3 to 5 cm in girls and an increase of 5 to 8 cm in boys.  Future growth of the spine may impact brace longevity and fit.

 

REFERENCES: Anderson M, Hwang SC, Green WT: Growth of the normal trunk in boys and girls during the second decade of life: Related to age, maturity, and ossification of the iliac epiphyses.  J Bone Joint Surg Am 1965;47:1554-1564.

Zaoussis AL, James JIP: The iliac apophysis and the evolution of curves in scoliosis.  J Bone Joint Surg Br 1958;40:442-453.

 

 

 

32.       A 10-year-old girl was thrown over the handlebars of her bicycle and landed directly on her left shoulder.  She was treated with a figure-of-8 strap and analgesics.  Follow-up examination 2 weeks later reveals that the lateral end of the clavicle is superiorly dislocated relative to the acromion.  A radiograph of the shoulder shows calcification lateral to the coracoid process at the level of the acromion, and the clavicle is superiorly displaced.  Management should consist of

 

1-         supportive immobilization until the patient is pain-free.

2-         coracoclavicular ligament repair.

3-         open reduction and internal fixation of the acromioclavicular dislocation.

4-         resection of the distal clavicle and Weaver and Dunn reconstruction.

5-         open biopsy of the calcific mass.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: In adults, a direct blow on the acromion usually results in an acromioclavicular dislocation.  In children, however, the usual injury from this mechanism is a physeal fracture of the lateral clavicle.  The clavicular shaft fragment, analogous to the metaphyseal portion of a physeal fracture, herniates through the periosteum, leaving the distal periosteal sleeve in contact with the lateral (distal) physeal fragment.  The treatment of choice is immobilization until the patient is pain-free.

 

REFERENCES: Falstie-Jensen S, Mikkelsen P: Pseudodislocation of the acromioclavicular joint.  J Bone Joint Surg Br 1982;64:368-369.

Havranek P: Injuries of the distal clavicular physis in children.  J Pediatr Orthop 1989;9:213-215.

 

 

 

33.        Figures 20a and 20b show the radiographs of an obese 15-year-old boy who has severe left groin pain and is unable to bear weight following a minor injury.  Treatment should consist of

 

1-         fixation with one or two screws.

2-         cast immobilization.

3-         manipulative reduction with single screw fixation.

4-         in situ fixation with multiple screws.

5-         open epiphyseodesis.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The radiographs and history are consistent with an acute unstable slipped capital femoral epiphysis.  Aronson and Loder documented an increased rate of osteonecrosis associated with manipulative reduction.  They recommended bed rest with skin traction to allow the synovitis to resolve, followed by in situ pinning.  They noted, however, that many of these slips reduced with anesthesia and positioning on a fracture table.  Biomechanic studies have shown a slight increased resistance to shear stress when two screws are used, but it is unknown if this is significant in the clinical setting.  Open epiphyseodesis does not provide postoperative stability; therefore, adjunctive fixation or immobilization is required.  Numerous studies have noted the inadvisability of using multiple screws.  Casting has a high rate of complications, including chondrolysis and progression of the slip.

 

REFERENCES: Aronson DD, Loder RT: Treatment of the unstable (acute) slipped capital femoral epiphysis.  Clin Orthop 1996;322:99-110.

Karol LA, Doane RM, Cornicelli SF, Zak PA, Haut RC, Manoli A II: Single versus double screw fixation for treatment of slipped capital femoral epiphysis: A biomechanical analysis.  J Pediatr Orthop 1992;12:741-745.

Stanitski CL: Acute slipped capital femoral epiphysis: Treatment alternatives.  J Am Acad Orthop Surg 1994;2:96-106.

 

 

 

34.       What is the recommended treatment of a skeletally immature 12-year-old boy who has an anterior cruciate ligament-deficient knee?

 

1-         Reduced activity, rehabilitation exercises, and functional bracing until the patient is near skeletal maturity

2-         Bone-patellar tendon-bone autograft reconstruction

3-         Allograft reconstruction

4-         Hamstring tendon intra-articular repair using a centrally placed tibial tunnel and an over-the-top femoral attachment

5-         Extra-articular repair

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Traditional surgeries for anterior cruciate ligament-deficient knees carry the potential risk of premature physeal closure in young athletes.  Therefore, most surgeons are reluctant to recommend intra-articular reconstruction using bone tunnels with bone-patellar tendon-bone autografts or hamstring tendons.  The current recommendation for young athletes is activity modification, rehabilitation, and functional bracing until the patient is near skeletal maturity.  At that time, for the very symptomatic patient, the treatment of choice is intra-articular repair of the anterior cruciate ligament.  If a skeletally immature patient continues to have instability despite rehabilitation and bracing, a modification of the femoral tunnel to the over-the-top position will not place the lateral femoral physis at risk for premature closure and deformity.  A centrally placed tibial tunnel will minimize the risk of angular deformity and minimize limb-length discrepancy if physeal arrest occurs.

 

REFERENCES: Barry P: Anterior cruciate ligament injuries, in Andrews JR, Timmerman LA (eds): Diagnostic and Operative Arthroscopy.  Philadelphia, Pa, WB Saunders, 1997, p 358.

McCarroll JR, Shelbourne KD, Porter DA, Rettig AC, Murray S: Patellar tendon graft reconstruction for midsubstance anterior cruciate ligament rupture in junior high school athletes: An algorithm for management.  Am J Sports Med 1994;22:478-484.

Nottage WM, Matsuura PA: Management of complete traumatic anterior cruciate ligament tears in the skeletally immature patient: Current concepts and review of the literature.  Arthroscopy 1994;10:569-573.

Stanitski CL: Anterior cruciate ligament injury in the skeletally immature patient: Diagnosis and treatment.  J Am Acad Orthop Surg 1995;3:146-158.

 

 

35.       Figures 21a and 21b show the radiographs of a 12-year-old patient with an L4-level myelomeningocele who has scoliosis that has been slowly progressing for the past several years.  There has been no loss of motor function.  An MRI scan shows no syringomyelia or increased hydrocephalus.  Management should consist of

 

1-         follow-up with repeat radiographs in 6 months.

2-         brace treatment.

3-         posterior spinal fusion with instrumentation.

4-         anterior and posterior spinal fusion with instrumentation.

5-         anterior spinal fusion with instrumentation.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Scoliosis is a common occurrence in children with myelomeningocele, with the incidence increasing as the neurologic level moves cephalad.  The rate of pseudarthrosis for isolated anterior or posterior fusions has been reported as high as 75%.  The combination of anterior and posterior fusions with some type of instrumentation has been shown to decrease the rate of pseudarthrosis to 20%.  Brace treatment in smaller curves can be used as a temporizing measure to delay surgery, but as with idiopathic scoliosis, the brace is ineffective for larger curves.  Observation is not indicated with a curve of this magnitude.  

 

REFERENCES: Ward WT, Wenger DR, Roach JW: Surgical correction of myelomeningocele scoliosis: A critical appraisal of various spinal instrumentation systems.  J Pediatr Orthop 1989;9:262-268.

Muller EB, Nordwall A: Brace treatment of scoliosis in children with myelomeningocele.  Spine 1994;19:151-155.

 

 

36.       A 3-year-old child is referred for evaluation of bowed legs.  History reveals no dietary deficiencies; however, family history is significant for several members with bowed legs.  Examination reveals genu varum, and the child is in the 5th percentile for height and weight.  Laboratory studies show normal renal function, a normal calcium level, a decreased phosphate level, and an elevated alkaline phosphatase level.  A plain radiograph of the lower extremities is shown in Figure 22.  What is the most likely diagnosis?

 

1-         Blount’s disease

2-         Chondrometaphyseal dysplasia

3-         Renal osteodystrophy

4-         Vitamin D-deficient rickets

5-         Vitamin D-resistant rickets

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The differential diagnosis of genu varum includes physiologic genu varum, Blount's disease, skeletal dysplasia, and metabolic bone disease.  Children with Blount's disease are generally in the 95th percentile for height and weight, and usually multiple family members are not affected.  The radiographs show widening of the physis and metaphyseal flaring.  In Blount's disease, the characteristic radiographic changes involve only the tibia, and at this age, most commonly show beaking of the medial metaphysis.  Skeletal dysplasias, such as chondrometaphyseal dysplasia, are associated with short stature, and the radiographic changes are similar to those seen here.  However, laboratory studies in these children will be within normal limits.  Children with chronic renal disease will often be of short stature, and the radiographic findings are again similar to those shown here.  However, BUN and creatinine levels are elevated and phosphate levels are elevated rather than decreased in children with renal disease.  The absence of dietary deficiencies and positive family history rules out vitamin D-deficient rickets.  There are four types of vitamin D-resistant rickets: failure of production of 1,25-dihydroxy vitamin D, phosphate diabetes (hypophosphatemic rickets), end organ insensitivity to vitamin D, and renal tubular acidosis.  All types of vitamin D-resistant rickets are resistant to treatment with physiologic doses of vitamin D.  The patient’s clinical picture, family history, laboratory studies, and radiographs are most consistent with hypophosphatemic rickets.  This entity is inherited as a sex-linked dominant trait.

 

REFERENCES: Evans GA, Arulanantham K, Gage JR: Primary hypophosphatemic rickets: Effect of oral phosphate and vitamin D on growth and surgical treatment.  J Bone Joint Surg Am 1980;62:1130-1138.

Loeffler RD Jr, Sherman FC: The effect of treatment on growth and deformity in hypophosphatemic vitamin D-resistant rickets.  Clin Orthop 1982;162:4-10.

Loder RT, Johnston CE II: Infantile tibia vara.  J Pediatr Orthop 1987;7:639-646.

Bassett GS, Scott CI: The osteochondrodysplasias, in Morrissy RT (ed): Pediatric Orthopaedics, ed 3.  Philadelphia, Pa, JB Lippincott, 1990, vol 1, pp 91-142.

 

 

 

37.       A 14-year-old boy sustained a femoral neck fracture in a fall from a tree and underwent open reduction and internal fixation 6 months ago.  Follow-up examination now reveals an antalgic Trendelenburg gait and painful range of motion.  A radiograph is shown in Figure 23, and a CT scan shows a nonunion.  Treatment should consist of

 

1-         revision in situ pinning and application of a cast.

2-         hip fusion.

3-         curettage of the nonunion, intertrochanteric valgus osteotomy, and revision internal fixation.

4-         non-weight-bearing on the affected side and electrical stimulation of the fracture site.

5-         vascularized fibula grafting and application of a cast.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The coxa vara deformity and fracture nonunion should be treated simultaneously; therefore, the treatment of choice is curettage of the nonunion, intertrochanteric valgus osteotomy, and revision internal fixation.  In addition, valgus osteotomy will convert the shear forces across the nonunion to compression, aiding in healing of the nonunion.  None of the other procedures addresses both issues, and hip fusion is inappropriate under these conditions.

 

REFERENCES: Lam SF: Fractures of the neck of the femur in children.  J Bone Joint Surg Am 1971;53:1165-1179.  

Canale ST, Beaty JH: Pelvic and hip fractures, in Rockwood CA Jr, Wilkins KE, Beaty JH (eds): Fractures in Children.  Philadelphia, Pa, Lippincott-Raven, 1996, pp 1109-1193. 

 

 

38.        A 22-month-old child has scrapes and bruises on his head and a severe deformity of the forearm after being thrown from a car as an unrestrained passenger in a motor vehicle accident.  Examination reveals a Glasgow Coma Scale score of 12.  Prior to treatment of the forearm, management should include

 

1-         a mannitol infusion of 0.25 to 1 g/kg.

2-         high-dose IV methylprednisolone, consisting of a 30 mg/kg bolus, followed by 5.4 mg/kg/h for 23 hours.

3-         an immediate CT scan.

4-         an electroencephalogram.

5-         radiographs of the skull.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: As CT scanning has become available, the use of radiographs of the skull has decreased in importance for evaluation of head trauma.  The indications for CT scanning for suspected head trauma include any degree of obtundation, focal neurologic deficit, history of a high-velocity injury, amnesia for the injury, progressive headache, persistent vomiting, children younger than age 2 years, serious facial injury, posttraumatic seizure, skull penetration, or a Glasgow Coma Scale score of 13 or less.  Evidence of improved outcome with use of steroids in head trauma is lacking.  Steroids are useful for increased intracranial pressure caused by brain tumors or abscesses.  High-dose IV methylprednisolone is indicated for spinal cord trauma and improves the ultimate degree of recovery of function.  When herniation is suspected in a patient with asymmetric neurologic findings or the patient’s condition is deteriorating rapidly, a mannitol infusion may be used.  

 

REFERENCES: Hall DE: Head injuries, in Hoekelman RA (ed): Primary Pediatric Care.  St Louis, Mo, Mosby, 1997, pp 1709-1712.

Nelson WE, Behrman RE, Kliegman RM (eds): Nelson Essentials of Pediatrics.  Philadelphia, Pa, WB Saunders, 1998, p 712.  

Beaty JH (ed): Orthopaedic Knowledge Update 6.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1999, pp 123-130.

 

 

39.       Examination of a 5-year-old boy with amyoplasia shows a flexion contracture of 70° of the right knee.  The active arc of motion is from 70° to 90°, and the opposite knee has a flexion contracture of 10°.  Both hips are dislocated with flexion contractures of 10°, passive hip motion is from 10° to 90° of flexion, and the feet are plantigrade and easily braceable.  Despite a daily stretching program, the parents and physical therapists note that it is increasingly difficult for him to walk because of the flexion contracture of the right knee.  Management of the knee flexion contracture should now include

 

1-         intense physical therapy.

2-         an intramuscular injection of botulinum toxin A. 

3-         radical posterior soft-tissue release.

4-         supracondylar femoral extension osteotomy.

5-         gradual correction with a circular ring external fixator.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Most children with amyoplasia are ambulatory and when a decrease in function occurs because of a severe contracture, it must be addressed.  A radical posterior soft-tissue release, including the posterior knee capsule and often the collateral ligaments and the posterior cruciate ligament, is needed to obtain extension. After the age of 1 year, aggressive physical therapy will do little to correct a contracture.  Botulinum toxin A is indicated for spasticity and is contraindicated with severe contractures.  Supracondylar femoral extension osteotomy works well, but will remodel at an average rate of 1° per month, which is not considered ideal in a young patient.  Gradual correction with a circular ring external fixator is an option, but a soft-tissue release will also most likely be needed for a contracture of this severity.  

 

REFERENCES: Sarwark JF, MacEwen GD, Scott CI Jr: Amyoplasia (a common form of arthrogryposis).  J Bone Joint Surg Am 1990;72:465-469.

DelBello DA, Watts HG: Distal femoral extension osteotomy for knee flexion contracture in patients with arthrogryposis.  J Pediatr Orthop 1996;16:122-126.

Sells JM, Jaffe KM, Hall JG: Amyoplasia, the most common type of arthrogryposis: The potential for good outcome.  Pediatrics 1996;97:225-231.

 

 

 

40.       A 13-year-old girl who is 2 years postmenarche has been referred for management of scoliosis.  She denies any history of back pain.  Radiographs show a right thoracic curve of 35°.  She has a Risser sign of 4 and a bone age of 15.5 years.  Management should consist of

 

1-         a low-profile spinal orthosis.

2-         observation and follow-up radiographs in 6 months.

3-         anterior spinal fusion with instrumentation.

4-         posterior spinal fusion with instrumentation.

5-         in situ posterior spinal fusion.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Because the patient is skeletally mature with a curve of less than 40°, there is no benefit to bracing and surgery is not indicated.  Management should consist of observation and follow-up radiographs in 6 months.

 

REFERENCES: Lonstein JE, Carlson JM: The prediction of curve progression in untreated idiopathic scoliosis during growth.  J Bone Joint Surg Am 1984;66:1061-1071.

Frymoyer JW (ed): Orthopaedic Knowledge Update 4.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1993, pp 447-459.

 

 

 

41.        In children with isolated zone II lacerations of the flexor tendon, poor digital motion is best correlated with

 

1-         a patient age of less than 5 years.

2-         a patient age of greater than 15 years.

3-         early passive motion.

4-         immobilization for 3 weeks.

5-         immobilization for 6 weeks.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: In a recent study on restoration of motion following zone I and zone II flexor tendon repairs in children, age was found to have no effect on the results of zone II tendon repairs.  Early passive motion offered no better results than immobilization for 3 weeks.  Immobilization for more than 4 weeks correlated with poorer results.

 

REFERENCE: O’Connell SJ, Moore MM, Strickland JW, Frazier GT, Dell PC: Results of zone I and zone II flexor tendon repairs in children.  J Hand Surg Am 1994;19:48-52.

 

 

42.       In a longitudinal study of children with spastic diplegia, analysis of long-term function will most likely reveal

 

1-         a deterioration of gait stability and an increase in double support time.

2-         a deterioration of gait stability and a decrease in double support time.

3-         improved excursion about the knee, ankle, and pelvis.

4-         improvement in the popliteal angle.

5-         increases in single support time.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: In a longitudinal study of 18 patients with spastic diplegia over a period of 32 months, three-dimensional gait analysis revealed a deterioration of gait stability with increases in double support time and decreases in single support time.  Kinematic data also identified a loss of excursion about the knee, ankle, and pelvis.  Interestingly, the static examination of the children showed a decrease in the popliteal angle over time.  The authors concluded that ambulatory ability tends to worsen over time in children with spastic diplegia.

 

REFERENCE: Johnson DC, Damiano DL, Abel MF: The evolution of gait in childhood and adolescent cerebral palsy.  J Pediatr Orthop 1997;17:392-396.

 

 

43.       Examination of a 7-year-old girl with myelomeningocele reveals calcaneal deformities of both feet.  She ambulates on both extremities wearing ankle-foot orthoses and has no upper extremity aids.  She has grade 5/5 motor strength to the tibialis anterior muscles and absent motor strength to the triceps surae.  There is no varus or valgus deformity of the hindfoot, and the skin over the heels is intact; however, mild callosities are present.  Management should consist of

 

1-         bilateral calcaneal osteotomies.

2-         modification of the ankle-foot orthoses.

3-         extra-articular subtalar arthrodesis.

4-         transfer of the anterior tibial tendon to the calcaneus.

5-         Achilles tendon tenodesis to the fibula.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: A calcaneal deformity of the foot may occur in children who have low lumbar myelomeningocele.  Strong dorsiflexors overcome a weak or absent gastrocnemius-soleus complex, leading to downward growth of the calcaneal apophysis.  The deformity is usually progressive and does not respond to nonsurgical management.  Most authorities recommend transfer of the tibialis anterior muscle through the interosseous membrane to the posterior aspect of the calcaneus.  This procedure has been reported to be effective in limiting progression of the deformity.  An extra-articular subtalar arthodesis, a treatment option for valgus deformity of the hindfoot, is not indicated.  Similarly, Achilles tendon tenodesis to the fibula, an option for managing valgus of the ankle, is not indicated.  Calcaneal osteotomy may be used in older children with severe calcaneal deformity.

 

REFERENCES: Stott NS, Zionts LE, Gronley JK, Perry J: Tibialis anterior transfer for calcaneal deformity: A postoperative gait analysis.  J Pediatr Orthop 1996;16:792-798.  

Georgiadis GM, Aronson DD: Posterior transfer of the anterior tibial tendon in children who have a myelomeningocele.  J Bone Joint Surg Am 1990;72:392-398.

 

 

 

44.       Figure 24 shows the radiograph of a 4-year-old girl with spina bifida.  Examination reveals an L3 motor level, excellent sitting and standing balance, and satisfactory range of motion at the hips.  Management should consist of

 

1-         observation.

2-         closed reduction and cast immobilization.

3-         bilateral medial open reduction of the hips.

4-         anterior open reduction with femoral shortening.

5-         valgus osteotomy.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Children with spina bifida and bilateral symmetrical dislocation of the hips usually do not require treatment.  A level pelvis and good range of motion of the hips are more important for ambulation than reduction of bilateral hip dislocations.  Because the patient has good sitting and standing balance and good range of motion, maintenance of that range of motion and symmetry is more important than reduction.  Surgery is not recommended.

 

REFERENCE: Heeg M, Broughton NS, Menelaus MB: Bilateral dislocation of the hip in spina bifida: A long-term follow-up study.  J Pediatr Orthop 1998;18:434-436.

 

 

 

45.       Posterior spinal fusion for scoliosis should be performed on a patient with Duchenne muscular dystrophy when

 

1-         the patient is still ambulatory.

2-         lordotic posture is present.

3-         the forced vital capacity (FVC) is less than 30% of the predicted value.

4-         curve magnitude measures 25° or greater. 

5-         orthotic management fails.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Progressive scoliosis develops in most patients with Duchenne muscular dystrophy.  The onset of spinal deformity typically follows the cessation of walking, and curves can be expected to progress about 10° per year.  Posterior spinal fusion with instrumentation should be performed as soon as a curve of 25° or greater is documented and before deterioration of pulmonary function (a FVC of less than 30%) precludes surgery.  Patients with kyphotic posture tend to progress more rapidly than those with lordotic posture.  Brace treatment is contraindicated because it is not definitive and it may mask curve progression while pulmonary function is concomitantly worsening.

 

REFERENCES: Beaty JH (ed): Orthopaedic Knowledge Update 6.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1999, pp 635-651.

Mubarak SJ, Morin WD, Leach J: Spinal fusion in Duchenne muscular dystrophy: Fixation and fusion to the sacropelvis?  J Pediatr Orthop 1993;13:752-757.

 

 

46.       Figures 25a and 25b show the radiograph and MRI scan of a 7 1/2-year-old boy who has been limping for 1 year.  His pain has worsened over the past 2 weeks, and his parents note swelling over the dorsum of the foot for the past 4 days.  Examination reveals no fever, and laboratory studies show a WBC of 6,700/mm³, an erythrocyte sedimentation rate of 26 mm/h, and a normal C-reactive protein level.  What is the most likely diagnosis? 

 

1-         Acute hematogenous osteomyelitis

2-         Kohler’s disease

3-         Tarsal coalition

4-         Tuberculosis

5-         Lisfranc fracture-dislocation

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The diagnosis of tuberculous osteomyelitis in children is often delayed.  In one series of 23 children, the average interval between the onset of symptoms and definite diagnosis was 4.3 months.  In these patients, the presenting signs and symptoms were found to be mild, with the most common signs being localized swelling (69.6%) and a painful disability of the involved limbs (65.2%).  A mild elevation of the erythrocyte sedimentation rate may be present, but the C-reactive protein level is usually normal.  In patients who have osteoarticular tuberculosis, an MRI scan generally shows large intra-articular effusions, periarticular osteoporosis, and gross thickening of the synovial membrane.  Differential diagnosis between tuberculosis and pyogenic arthritis is difficult, and an accurate diagnosis usually requires biopsy of synovial tissue.  Aspiration of synovial fluid often results in insufficient information to make a diagnosis.  Treatment generally consists of surgical debridement and combined antituberculous chemotherapy with isoniazid, ethambutol, and rifampin.

 

REFERENCES: Wang MN, Chen WM, Lee KS, Chin LS, Lo WH: Tuberculous osteomyelitis in young children.  J Pediatr Orthop 1999;19:151-155.  

Watts HG, Lifeso RM: Tuberculosis of the bones and joints.  J Bone Joint Surg Am 1996;78:288-298.

 

 

47.       A 10-year-old boy who plays baseball reports acute pain after throwing a softball from the outfield to second base.  A radiograph is shown in Figure 26.  Management should consist of

 

1-         observation during healing of the fracture, followed by bone marrow or corticosteroid injection.

2-         biopsy and appropriate chemotherapy.

3-         curettage and bone grafting.

4-         high-dose systemic corticosteroids.

5-         pulsed electromagnetic fields.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The patient has a fracture through a unicameral bone cyst, as evidenced by the “falling leaf” sign on the radiograph.  Following healing of the fracture, treatment should consist of corticosteroid injection or bone marrow injection.  Some cysts heal with the fracture and do not require injections.  Biopsy is unnecessary because the radiograph shows that the cyst is benign.  Curettage and bone grafting are seldom necessary because these cysts regularly heal with injections.  Corticosteroids are useful when injected into the cyst, but are not used systemically.  Pulsed electromagnetic fields have not been used therapeutically in this condition.

 

REFERENCE: Yandow SM, Lundeen GA, Scott SM, Coffin C: Autogenic bone marrow injections as a treatment for simple bone cyst.  J Pediatr Orthop 1998;18:616-620.

 

 

 

48.       The mother of an otherwise healthy 1-month-old infant reports that he is not moving his left leg after falling from his high chair 2 days ago.  He has a temperature of 99.5°F (37.5°C).  Examination reveals that the left thigh is moderately tender to palpation.  Because the infant is apprehensive, range of motion is difficult to quantify, but appears to be normal at the hips and ankles.  Range of motion of the left knee is approximately 25° to 90°.  A radiograph of the leg is shown in Figure 27.  Management should consist of

 

1-         application of a long leg splint and admission to the hospital for further evaluation and consultation.

2-         application of a long leg cast, with follow-up radiographs in 3 days.

3-         immediate application of a spica cast under general anesthesia.

4-         a CBC, an erythrocyte sedimentation rate, blood cultures, aspiration of the distal femur for culture, and hospital admission with administration of IV antibiotics if required.

5-         a CBC, an erythrocyte sedimentation rate, a technetium bone scan, and consultation for bone marrow aspiration.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The patient has a bucket-handle fracture of the distal femur with bilateral corner fractures of the distal femur and a transverse fracture of the proximal tibia.  These fractures are virtually pathognomonic of child abuse.  The infant should be admitted to the hospital, and child protection services should be notified for investigation of possible abuse.  A skeletal survey should be obtained, along with laboratory studies that include a CBC, a platelet count, a prothrombin time, a partial thromboplastin time, and a bleeding time.

 

REFERENCES: Akbarnia BA: The role of the orthopaedic surgeon in child abuse, in Morrissy RT, Weinstein SL (eds): Lovell & Winter’s Pediatric Orthopaedics, ed 4.  Philadelphia, Pa, Lippincott-Raven, 1996, pp 1315-1334.

Black GB: Child abuse fractures, in Letts RM (ed): Management of Pediatric Fractures.  New York, NY, Churchill Livingstone, 1994, pp 931-944.

 

 

49.       A 12-year-old girl with juvenile rheumatoid arthritis (JRA) has had chronic pain and synovitis about the knee that is now well-controlled medically.  Examination reveals 20° of valgus at the knee.  Knee range of motion shows 10° to 90° of flexion.  Treatment should consist of

 

1-         arthroscopic synovectomy.

2-         open synovectomy.

3-         staple hemiepiphyseodesis.

4-         knee arthrodesis.

5-         varus osteotomy.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Children with JRA frequently have valgus in association with hypervascularity because of chronic inflammation.  This is normally caused by overgrowth of the medial femoral epiphysis.  Staple hemiepiphyseodesis, if done early, can reverse the deformity.  Osteotomy is usually unnecessary at this age, and there is a risk of stiffness of the knee following the procedure.  Synovectomy may be helpful but will not prevent or correct a deformity.

 

REFERENCE: Rydholm U, Brattstrom H, Bylander B, Lidgren L: Stapling of the knee in juvenile chronic arthritis.  J Pediatr Orthop 1987;7:63-68.

 

 

50.       Figure 28 shows the radiograph of a 6-year-old girl who has a right thoracic scoliosis that measures 60°.  Examination shows multiple cafe-au-lait spots, and family history reveals that the child’s mother has the same disorder.  The gene responsible for this disorder codes for

 

1-         dystrophin.

2-         frataxin.

3-         neurofibromin.

4-         peripheral myelin protein.

5-         sulfate transport protein.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The patient has the dystrophic type of scoliosis seen in patients with neurofibromatosis type I (NF-1).  The NF-1 gene is located on chromosome 17 and codes for neurofibromin, believed to be a tumor-suppresser gene.  Abnormalities in the dystrophin gene are seen in Duchenne muscular dystrophy and Becker muscular dystrophy.  A mutation in the frataxin gene is responsible for Friedreich ataxia.  The most common type of hereditary motor and sensory neuropathy (Charcot-Marie-Tooth), HMSN type IA is caused by a complete duplication of the peripheral myelin protein gene.  A defect in the cellular sulfate transport protein results in undersulfation of proteoglycans seen in diastrophic dysplasia.  

 

REFERENCE: Beaty JH: Orthopaedic Knowledge Update 6.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1999, pp 225-234.

 

 

51.        Figures 29a and 29b show the radiographs of a 13-year-old competitive gymnast who has had elbow pain for the past 2 weeks.  The pain is worse with tumbling activities.  Examination reveals a mild effusion and slight limitation of extension and forearm rotation with no locking.  Initial management should consist of

 

1-         elbow arthroscopy.

2-         arthrotomy and internal fixation of the lesion.

3-         cessation of gymnastic activities.

4-         use of an elbow brace and continued gymnastic activities.

5-         open drilling of the lesion.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The radiographs show a lesion in the capitellum that is consistent with osteochondritis dissecans.  There is no evidence of a loose body at this time.  Initial management should consist of cessation of gymnastic activities.  Nonsteroidal anti-inflammatory drugs and ice may help to alleviate acute symptoms; most symptoms usually resolve in 6 to 12 weeks.  The patient may then begin range-of-motion and strengthening exercises, with a slow return to activities once full range of motion and good strength have been achieved.  However, the prognosis for a return to high-level competitive gymnastics is guarded.  Surgery is indicated for intra-articular loose bodies, a locked elbow, or failure of nonsurgical management.  Surgery may be done either open or arthroscopically.  Loose bodies should be removed, and cartilage flaps should be debrided.  The results of bone grafting and internal fixation generally have been poor.  Drilling the base of the defect may stimulate replacement with fibrocartilage, but the benefits of this procedure are not well documented.

 

REFERENCES: Maffulli N, Chan D, Aldridge MJ: Derangement of the articular surfaces of the elbow in young gymnasts.  J Pediatr Orthop 1992;12:344-350.

Bauer M, Jonsson K, Josefsson PO, Linden B: Osteochondritis dissecans of the elbow: A long-term follow-up study.  Clin Orthop 1992;284:156-160.

Tivnon MC, Anzel SH, Waugh TR: Surgical management of osteochondritis dissecans of the capitellum.  Am J Sports Med 1976;4:121-128.

 

 

52.       A 12-year-old boy who has had a 1-month history of right thigh pain and a limp reports worsening of the pain after a fall, and he can no longer walk or bear weight on the involved extremity.  Radiographs of the pelvis reveal a slipped capital femoral epiphysis with moderate to severe displacement.  While positioning the patient on the fracture table for screw fixation, partial reduction of the slip is achieved.  No further reduction maneuvers are attempted, and the epiphysis is stabilized with a single cannulated screw.  What complication is most likely to develop following this procedure?

 

1-         Infection

2-         Chondrolysis

3-         Nonunion

4-         Osteonecrosis

5-         Epiphyseal arrest

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Traditional classification of slipped capital femoral epiphyses is based on the following temporal criteria: acute (symptoms that persist for less than 3 weeks); chronic (symptoms that persist for more than 3 weeks); or acute on chronic (acute exacerbation of long-standing symptoms).  A newer classification differentiates between a stable slip where weight bearing is possible, and an unstable slip if it is not.  Reduction of an unstable slip often occurs unintentionally with induction of anesthesia and positioning of the patient for surgery.  The rate of satisfactory results is lower primarily because of a much higher incidence of osteonecrosis following internal fixation of an unstable slip. 

 

REFERENCES: Loder RT, Richards BS, Shapiro PS, Reznick LR, Aronson DD: Acute slipped capital femoral epiphysis: The importance of physeal stability.  J Bone Joint Surg Am 1993;75:1134-1140.

Richards BS (ed): Orthopaedic Knowledge Update: Pediatrics.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1996, pp 151-159.

 

 

 

53.       Figure 30 shows the AP radiograph of a 9-month-old girl who has been referred for evaluation of unequal leg lengths.  Examination reveals symmetrical abduction of the hips.  When the hips are flexed 90°, the right knee height is greater than the left knee.  The girth of the right thigh and calf is larger than the contralateral side.  There are no cutaneous lesions, and examination of the spine is normal.  The infant is moving all extremities equally and spontaneously.  Management should consist of

 

1-         assessment of the bone age in the left wrist and hand.

2-         an MRI scan of the spine.

3-         an ultrasound of the hips.

4-         a renal ultrasound.

5-         a Pavlik harness.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Hemihypertrophy or hemihypotrophy is usually idiopathic, and either the leg or the entire side of the body may be involved.  In the infant or young child, it is often difficult to determine which side is abnormal if the condition is mild.  Because of the association of Wilms’ tumor with hemihypertrophy, these patients should undergo a yearly renal ultrasound until at least age 5 years.  Other conditions that may exhibit hemihypertrophy include Klippel-Trenaunay-Weber syndrome, Proteus syndrome, and neurofibromatosis.  In this patient, the mild hemihypertrophy is idiopathic.  Because of the normal spinal examination and absence of neurologic findings, an MRI scan is unnecessary.  The absence of clinical and radiographic evidence of hip dysplasia makes both an ultrasound of the hips and application of a Pavlik harness unnecessary.

 

REFERENCES: Richards BS (ed): Orthopaedic Knowledge Update: Pediatrics.  Rosemont Ill, American Academy of Orthopaedic Surgeons, 1996, pp 185-193.  

Sponseller PD: Localized disorders of bone and soft tissue, in Morrissy RT, Weinstein SL (eds):  Lovell and Winter’s Pediatric Orthopaedics, ed 4.  Philadelphia, Pa, Lippincott-Raven, 1996, pp 305-344.  

Beals RK: Hemihypertrophy and hemihypotrophy.  Clin Orthop 1982;166:199-203.

 

 

 

 

54.       What is the mechanism of action of an intramuscular injection of botulinum type A toxin in reducing spasticitiy?

 

1-         Blocks the release of presynaptic acetylcholine release at the neuromuscular junction and end plate

2-         Acts as a g-aminobutyric acid (GABA) agonist

3-         Inhibits afferent fibers in the dorsal root of the spinal nerve

4-         Competitively blocks the acetylcholine receptor

5-         Destroys the neuromuscular junction

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The use of intramuscular botulinum type A toxin has been shown to be a useful adjuvant in the management of dynamic deformity in patients with cerebral palsy. Botulinum type A toxin is a neurotoxin produced by Clostridium botulinum that works by interfering with presynaptic acetylcholine release at cholinergic nerve terminals.  At the cellular level, the mechanism involves endocytosis of the intact botulinum toxin molecule by cells in the end plate, followed by disulfide cleavage and translocation of the light chain into the cytosol where it disrupts the normal binding of the synaptosomal vesicles to the axon terminal membrane.  Neither the nerve terminal nor the neuromuscular junction is damaged.  The muscle paralysis is reversible and dose-dependent.  Baclofen is a neuropharmacologic agent that functions as a GABA agonist.  Dorsal rhizotomy is a neurosurgical procedure that reduces spasticity by dividing afferent (excitatory) fibers in the posterior rootlet of the spinal nerves.

 

REFERENCES: Koman LA, Mooney JF III, Smith B, Goodman A, Mulvaney T: Management of cerebral palsy with botulinum-A toxin: Preliminary investigation.  J Pediatr Orthop 1993;13:489-495.

Brin MF: Botulinum toxin: Chemistry, pharmacology, toxicity, and immunology.  Muscle Nerve Suppl 1997;6:S146-168.

 

55.       A 5-year-old boy has had right hip pain and a limp for the past 3 months.  Examination of the right hip reveals irritability and restricted abduction and internal rotation.  AP and lateral radiographs of the hips are shown in Figures 31a and 31b.  Initial management should consist of

 

1-         a Salter innominate osteotomy.

2-         a shelf acetabuloplasty.

3-         a varus femoral osteotomy.

4-         symptomatic treatment, including traction, activity modification, and nonsteroidal anti-inflammatory drugs.

5-         abduction bracing.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: A favorable prognosis can be expected in up to 70% of children with Legg-Calve-Perthes disease who are younger than age 6 years.  Containment treatment has not been shown to alter the outcome in this age group.  The goals of treatment in this patient are to reduce pain (synovitis), restore motion, and improve function.  Symptomatic treatment modalities include bed rest, traction, crutches, activity modification, and nonsteroidal anti-inflammatory drugs.  

 

REFERENCES: Herring JA: The treatment of Legg-Calve-Perthes disease: A critical review of the literature.  J Bone Joint Surg Am 1994;76:448-458.

Richards BS (ed): Orthopaedic Knowledge Update: Pediatrics.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1996, pp 161-166.

 

 

 

56.       Hamstring lengthening and posterior transfer of the rectus femoris will be most successful in a patient with cerebral palsy who has which of the following gait abnormalities?

 

1-         Excessive knee flexion through stance, stiff knee during swing, and rectus femoris activity in swing

2-         Excessive knee flexion through stance and continuous quadricep activity in stance and swing

3-         Excessive knee flexion through stance, short stride length, and continuous hamstring activity in swing

4-         Knee hyperextension in stance, knee extension during swing, and rectus femoris activity in swing

5-         Knee hyperextension in stance, continuous rectus femoris activity in stance and swing, and drop foot

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Children with cerebral palsy typically ambulate with a crouched gait characterized by excessive flexion of the hips and knees during stance.  Many patients exhibit co-contracture of the quadriceps and hamstrings, causing a stiff-knee gait.  Normally, the rectus femoris fires at the initiation of swing and in terminal swing through initial contact.  Prolonged activity of the rectus femoris throughout the swing phase interferes with normal knee flexion.  This contributes to a stiff knee during swing phase and prevents clearance of the foot.  Lengthening of the hamstrings alone will not improve foot clearance.  Hamstring lengthening is contraindicated when there is hyperextension during stance.  Transfer of the rectus femoris to one of the knee flexors has been shown to improve knee flexion during swing by an average of 15°.  This allows improved foot clearance.

 

REFERENCES: Gage JR, Perry J, Hicks RR, Koop S, Werntz JR: Rectus femoris transfer to improve knee function of children with cerebral palsy.  Dev Med Child Neurol 1987;29:159-166.

Sutherland DH, Santi M, Abel MF: Treatment of stiff-knee gait in cerebral palsy: A comparison by gait analysis of distal rectus femoris transfer versus proximal rectus release.  J Pediatr Orthop 1990;10:433-441.

 

57.       Figures 32a and 32b show the radiographs of a 13-year-old boy who sustained a fracture while playing football 1 week ago.  Management at the time of injury included application of a cast and the use of crutches.  A follow-up office visit reveals a normal neurologic examination, and the patient reports no discomfort with the cast and crutches.  Management should now include

 

1-         cast wedging in the outpatient clinic.

2-         closed reduction under anesthesia and application of a new long leg cast.

3-         reduction and placement of an intramedullary rod.

4-         anatomic open reduction and compression plating with interfragmentary screws.

5-         pins and plaster to maintain the reduction.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Stable fractures and minimally displaced fractures in children can and should be treated by closed methods.  Because loss of reduction is common, alignment of tibia fractures must be monitored closely for the first 3 weeks after cast application.  This is most easily handled in a cooperative patient by cast wedging.  Some children require application of a second cast under general anesthesia 2 to 3 weeks after injury, particularly if the subsidence of swelling has caused the cast to loosen.  Surgical indications include the presence of soft-tissue injuries, unstable fracture patterns, fractures associated with compartment syndrome, and the child with multiple injuries.  Surgical options in children include percutaneous pins, external fixation, plates and screws, and intramedullary nails. 

 

REFERENCES: Heinrich SD: Fractures of the shaft of the tibia and fibula, in Rockwood CA, Wilkins KE, Beaty JH (eds): Fractures in Children, ed 4.  Philadelphia, Pa, Lippincott-Raven, 1996, pp 1340-1346.

Beaty JH (ed): Orthopaedic Knowledge Update 6.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1999, pp 583-595.

 

 

58.       A 14-year-old patient with an L3 myelomeningocele underwent anterior and posterior spinal fusion for a curve of 50°.  Follow-up examination 1 week after the procedure now reveals persistent drainage from the posterior wound.  Results of laboratory cultures show Streptococcus viridans, Staphylococcus aureus, and Enterococcus.  In addition to IV antibiotics, surgical irrigation, and debridement, management should include

 

1-         removal of all hardware.

2-         temporary placement of antibiotic beads.

3-         wound closure over drains.

4-         bedside dressing changes.

5-         a RAST test for latex allergy.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The rate of wound infections has dramatically decreased with the routine use of prophylactic antibiotics.  Factors known to increase the risk of infection include instrumentation, prolonged surgical time, excessive blood loss, poor perioperative nutritional status, a history of surgery, and a history of infection.  The use of allograft does not result in an increased rate of infection.  Adequate treatment requires early diagnosis and intervention.  Temperature elevation and persistent wound drainage are highly suspicious for infection.  An erythrocyte sedimentation rate and a WBC are not useful in diagnosis unless serial examinations show rising levels.  Patients should be taken to the operating room where the entire wound can be reopened, irrigated, and debrided.  Bone graft can be washed and replaced.  Hardware should not be removed.  The wound should be closed over suction drains.  IV antibiotics should be given for a period of at least 10 days, followed by 6 weeks orally.  Leaving the wound open to granulate with dressing changes results in prolonged hospitalization, inadequate treatment of the infection, and a poor cosmetic result.

 

REFERENCES: Lonstein JE:  Complications of treatment, in Bradford DS, Lonstein JE, Moe JH, et al (eds): Moe’s Textbook of Scoliosis and Other Spinal Deformities, ed 2.  Philadelphia, Pa, WB Saunders, 1987, p 476.

Beaty JH (ed): Orthopaedic Knowledge Update 6.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1999, pp 713-721.

 

 

59.       What is the primary mechanism of injury for the fracture shown in Figures 33a and 33b?

 

1-         Hyperdorsiflexion

2-         External rotation of the foot

3-         Internal rotation of the foot

4-         Adduction of the foot and ankle

5-         Excessive eversion of the foot and ankle

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The radiographs show a triplane fracture of the ankle.  In adolescence, closure of the distal tibial physis starts peripherally at the anteromedial aspect of the medial malleolus and extends posteriorly and laterally.  The anterolateral quadrant of the physis is the last to close, making this region the most susceptible to separation.  When the foot is twisted into external rotation, the anterolateral portion of the epiphysis is avulsed by the pull of the anterior tibiofibular ligament.  When this fragment alone is avulsed, the result is a juvenile Tillaux fracture.  When the fracture extends to involve the remainder of the physis and posterior metaphysis, as in this patient, the result is a triplane fracture.

 

REFERENCES: Richards BS (ed): Orthopaedic Knowledge Update: Pediatrics.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1996, pp 267-272.  

Dias LS, Giegerich CR: Fractures of the distal tibial epiphysis in adolescence.  J Bone Joint Surg Am 1983;65:438-444.  

Kling TF Jr: Operative treatment of ankle fractures in children.  Orthop Clin North Am 1990;21:381-392.

 

60.       Figure 34 shows the standing AP radiograph of a 2-year-old girl who has a left bowleg deformity.  Her mother states that she first noticed the problem when the child began walking at age 10 months, and the deformity has worsened over the past 6 months.  Examination reveals a definite lateral thrust of the knee during the stance phase of gait.  Management should consist of

 

1-         observation.

2-         a proximal tibial and fibular osteotomy.

3-         daytime ambulatory bracing.

4-         elevation of the medial tibial plateau.

5-         an MRI scan of the knee.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Infantile tibia vara is a developmental condition characterized by a varus angulation of the proximal end of the tibia that is caused by a growth disturbance of the proximal medial physis.  In a study of 42 affected extremities in 24 children younger than age 3 years, it was found that daytime ambulatory brace treatment favorably altered the natural history of tibia vara.  Another study of 27 patients with stage II Langenskiöld disease found a success rate of 70% (improved alignment without the need for osteotomy) using brace treatment.  These authors also noted that children with unilateral disease were more likely to obtain correction of the deformity compared with those with bilateral disease.  In this patient, observation is not warranted because untreated tibia vara has a significant risk for progressive worsening.  Osteotomy is best reserved for those patients who, despite bracing, do not show satisfactory clinical and radiographic improvement by age 4 years.  Elevation of the medial tibial plateau is a treatment option for older patients who have more advanced disease.  An MRI scan would not provide any useful clinical information at this time.

 

REFERENCES: Zionts LE, Shean CJ: Brace treatment of early infantile tibia vara.  J Pediatr Orthop 1998;18:102-109.  

Richards BS, Katz DE, Sims JB: Effectiveness of brace treatment in early infantile Blount’s disease.  J Pediatr Orthop 1998;18:374-380.

Raney EM, Topoleski TA, Yaghoubian R, Guidera KJ, Marshall JG: Orthotic treatment of infantile tibia vara.  J Pediatr Orthop 1998;18:670-674.

 

 

61.        Figures 35a and 35b show the radiographs of a 7-year-old patient who has progressive deformity of the right thigh accompanied by a dull persistent pain radiating to the knee.  Examination reveals an obvious bulge in the right thigh, with flexion of the hip beyond 50° only if the hip is allowed to externally rotate.  Management should consist of

 

1-         multiple osteotomies and femoral rodding.

2-         pharmocologic doses of vitamin D and phosphate.

3-         biopsy, followed by appropriate chemotherapy.

4-         pamidronate therapy.

5-         radiation therapy and a bone marrow transplant.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The patient has radiographic signs of osteogenesis imperfecta, including osteopenia, mild acetabular protrusio, cortical thinning, and bowing associated with anterior stress fracturing.  The treatment of choice is correction of the bow with osteotomies, followed by intramedullary fixation to prevent further deformity.  Biphosphonates, such as pamidronate, may be useful in increasing bone density and preventing fractures.  Large multicenter studies on biphosphonate efficacy are currently in progress.

 

REFERENCES: Zionts LE, Ebramzadeh E, Stott NS: Complications in the use of the Bailey-Dubow extensible nail.  Clin Orthop 1998;348:186-195. 

Luhmann SJ, Sheridan JJ, Capelli AM, Schoenecker PL: Management of lower-extremity deformities in osteogenesis imperfecta with extensible intramedullary rod technique: A 20-year experience.  J Pediatr Orthop 1998;18:88-94. 

Glorieux FH, Bishop NJ, Plotkin H, Chabot G, Lanoue G, Travers R: Cyclic administration of pamidronate in children with severe osteogenesis imperfecta.  N Engl J Med 1988;339:947-952.

 

 

62.       Figures 36a and 36b show the MRI scans of a 15-year-old girl who has had pain and recurrent hemarthrosis in the knee for the past year.  Plain radiographs are normal.  What is the most likely diagnosis?

 

1-         Hemangioma of the knee

2-         Hemophilia

3-         Discoid lateral meniscus

4-         Torn medial meniscus

5-         Pauciarticular-type juvenile rheumatoid arthritis (JRA)

 

PREFERRED RESPONSE: 1

 

DISCUSSION: In pediatric patients who have pain and recurrent hemarthrosis in the knee, hemangioma is often seen as an internal derangement of the knee, and long delays in diagnosis are common.  An MRI scan is noninvasive and will best aid in diagnosis.  In this patient, the MRI scan shows a hemangioma with no evidence of meniscal injury or discoid meniscus.  Hemophilia is unlikely because the patient is female.  The presence of hemarthrosis makes JRA an unlikely diagnosis.  

 

REFERENCE: Price NJ, Cundy PJ: Synovial hemangioma of the knee.  J Pediatr Orthop 1997;17:74-77.

 

 

 

63.       A 2-year-old child has marked hypotonia and depressed reflexes.  History reveals that the child was normal at birth and developed normally for the first year.  The child also began to ambulate, but lost this ability during the next 6 months.  Laboratory studies show a creatine phosphokinase level that is within the normal range.  DNA testing confirms a deletion in the survival motor neuron (SMN) gene.  What is the most likely diagnosis?

 

1-         Rett syndrome

2-         Spinal muscular atrophy, type 2

3-         Congenital muscular dystrophy

4-         Duchenne muscular dystrophy

5-         Congenital myotonic dystrophy

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The patient has spinal muscular atrophy, type 2.  This type is intermediate in severity between the Werdnig-Hoffmann type (type 1) and the Kugelberg-Welander type
(type 3).  It normally manifests itself between the ages of 3 and 15 months.  Survival until adolescence is common.  All three types of spinal muscular atrophy have been linked to the SMN gene at the 5q12.2-13.3 locus.  DNA testing is available and is preferred to muscle biopsy because it is less invasive and more definitive.

 

REFERENCES: Biros I, Forrest S: Spinal muscular atrophy: Untangling the knot?  J Med Genet 1999;36:1-8.

Zerres K, Wirth B, Rudnik-Schoneborn S: Spinal muscular atrophy: Clinical and genetic correlations.  Neuromuscul Disord 1997;7:202-207.

 

64.       A 13-year-old boy sustains a valgus stress injury to the knee while playing football, and he is unable to bear weight after the injury.  Examination reveals tenderness medially superior to the joint line.  The knee is held in flexion, and he has a large effusion and localized medial swelling.  Plain radiographs show no obvious fracture.  What is the next diagnostic step?

 

1-         Arthroscopy

2-         MRI scan

3-         Stress radiographs

4-         Tomogram

5-         Arthrogram

 

PREFERRED RESPONSE: 3

 

DISCUSSION: In the skeletally mature individual, this mechanism of injury will often result in a sprain of the medial collateral ligament.  In skeletally immature patients, the same mechanism can cause a fracture of the distal femoral physis.  If the fracture is nondisplaced, the plain radiographs may show only soft-tissue swelling or effusion.  While the MRI scan may show edema in the soft tissues on the medial side of the knee and even an abnormality of the physis, stress radiographs provide a quicker and less expensive means of making the diagnosis.  Arthroscopy and arthrography would not be helpful in making the diagnosis.  Arthroscopy may result in further displacement of the injury.

 

REFERENCES: Smith L: Concealed injury to the knee.  J Bone Joint Surg Am 1962;44:1659-1660.

Beaty JH, Kumar A: Fractures about the knee in children.  J Bone Joint Surg Am 1994;76:1870-1880.

 

 

 

65.       Figure 37 shows the clinical photograph of a 1-day-old infant who weighed 10.25 lb at birth.  Examination reveals an absent right Moro reflex and limited active motion of the right shoulder, elbow, and wrist, but flexion of the fingers.  Passive range of motion of the shoulder and elbow is normal.  What is the most likely diagnosis?

 

1-         Pseudoparalysis secondary to fracture of the proximal humerus

2-         Cervical myelomeningocele

3-         Erb palsy

4-         Arthrogryposis

5-         Cerebral palsy and spastic hemiplegia

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The patient’s right upper extremity is held in the “head waiter’s” posture with the shoulder internally rotated, the elbow extended, and the wrist in flexion.  The Erb type of obstetrical brachial plexus palsy involves the C5 and C6 nerve root, and occasionally, as in this child, the C7 nerve root.  Obstetrical palsy is a traction injury, and is associated with a high birth weight, shoulder dystocia, cephalopelvic disproportion, or the use of forceps.  Erb palsy is four times more common than injury to the entire plexus or injury to the C8 and T1 nerve roots.  It results from the shoulder being depressed while the head and neck are laterally rotated, extended, and tilted in the opposite direction.  Most patients recover wrist extension and elbow flexion.  Patients with residual weakness of shoulder external rotation and abduction will benefit from release of the pectoralis major, latissimus dorsi, and teres major, with transfer of the latissimus dorsi and the teres major to the posterosuperior aspect of the rotator cuff.  Recent studies using arthrograms and CT scans have shown a higher incidence of posterior glenoid deficiency and posterior subluxation than that observed with plain radiographs.  The posterior subluxation or dislocation can be effectively reduced by tendon release and transfer procedures.

 

REFERENCES: Hoffer MM, Phipps GJ: Closed reduction and tendon transfer for treatment of dislocation of the glenohumeral joint secondary to brachial plexus birth palsy.  J Bone Joint Surg Am 1998;80:997-1001.

Pearl ML, Edgerton BW: Glenoid deformity secondary to brachial plexus birth palsy.  J Bone Joint Surg Am 1998;80:659-667.

Waters PM, Smith GR, Jaramillo D: Glenohumeral deformity secondary to brachial plexus birth palsy.  J Bone Joint Surg Am 1998;80:668-677.

 

 

66.       Figure 38 shows the radiograph of a 5-year-old child who sustained a type III supracondylar fracture.  Examination reveals the absence of a radial pulse, but an otherwise well-perfused hand.  Following closed reduction and percutaneous pinning, the radial pulse remains absent; however, the hand is pink and well perfused.  Management should now include

 

1-         close observation with frequent neurovascular checks.

2-         emergency angiography.

3-         emergency exploration of the brachial artery.

4-         removal of pin fixation and exploration of the brachial artery.

5-         thrombectomy.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: In a study of over 400 patients with displaced supracondylar fractures, 3.2% of the fractures were associated with the absence of the radial pulse with an otherwise well-perfused hand.  Based on this study, a period of close observation with frequent neurovascular checks should be completed before attempting invasive correction of the problem.  Because of the satisfactory results with expectant management, angiography, exploration, removal of fixation and exploration, and thrombectomy are contraindicated.

 

REFERENCE: Sabharwal S, Tredwell SJ, Beauchamp RD, Mackenzie WG, Jakubec DM, Cairns R: Management of pulseless pink hand in pediatric supracondylar fractures of humerus.  J Pediatr Orthop 1997;17:303-310. 

 

 

67.       Figures 39a and 39b show the radiographs of an otherwise healthy 10-year-old boy who has had thigh pain and a limp for the past 9 months.  Examination reveals that the left lower extremity is 1 cm shorter, with reduced flexion, abduction, and internal rotation on the left side.  The patient is at the 50th percentile for height and the 90th percentile for weight.  Serum studies will most likely show

 

1-         an elevated thyroid-stimulating hormone level.

2-         an elevated estrogen level.

3-         elevated blood urea nitrogen and creatinine levels.

4-         a growth hormone deficiency.

5-         normal laboratory values.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The patient has a slipped capital femoral epiphysis (SCFE) at a younger than average age (average age 13.5 years for boys and 12.0 years for girls); therefore, an etiology that is not idiopathic must be considered.  Hypothyroidism can result in a SCFE, but these children typically fall into the category of less than the 10th percentile for height.  SCFE may develop in children with a growth hormone deficiency who have undergone hormonal replacement.  Osteodystrophy caused by chronic renal failure may result in a SCFE, but the bone quality is markedly osteopenic on radiographs and the children are chronically ill with both low height and weight percentiles.  An elevated estrogen level results in physeal closure and is protective to physeal slippage.  Therefore, this child will most likely have normal laboratory values.

 

REFERENCES: Loder RT, Hensinger RN: Slipped capital femoral epiphysis associated with renal failure osteodystrophy.  J Pediatr Orthop 1997;17:205-211.

Loder RT, Wittenberg B, DeSilva G: Slipped capital femoral epiphysis associated with endocrine disorders.  J Pediatr Orthop 1995;15:349-356.

 

 

68.       A 7-year-old patient has had a painless limp for several months.  Examination reveals pain and spasm with internal rotation, and abduction is limited to 10° on the involved side.  Management consists of 1 week of bed rest and traction, followed by an arthrogram.  A maximum abduction/internal rotation view is shown in Figure 40a, and abduction and adduction views are shown in Figures 40b and 40c.  The studies are most consistent with

 

1-         Catterall II involvement.

2-         tubercular synovitis.

3-         Herring type A involvement.

4-         hinge abduction.

5-         osteochondritis dissecans.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The radiographs show classic hinge abduction.  The diagnostic feature is the failure of the lateral epiphysis to slide under the acetabular edge with abduction, and the abduction view shows medial dye pooling because of distraction of the hip joint.  Persistent hinge abduction has been shown to prevent femoral head remodeling by the acetabulum.  Radiographic changes are characteristic of severe involvement with Legg-Calve-Perthes disease.  The Catterall classification cannot be well applied without a lateral radiograph, but this degree of involvement would likely be considered a grade III or IV.  Because the lateral pillar is involved, this condition would be classified as type C using the Herring lateral pillar classification scheme.

 

REFERENCE: Reinker KA: Early diagnosis and treatment of hinge abduction in Legg-Perthes disease.  J Pediatr Orthop 1996;16:3-9.

 

 

 

69.       A 14-year-old football player has had thigh pain and weakness following a full-contact scrimmage 24 hours ago.  He recalls that he felt a sharp pain in his back after colliding with a much heavier player.  Examination reveals that the spine is minimally tender to palpation in the upper lumbar region.  Motor testing reveals quadriceps weakness bilaterally, and a reverse straight leg raising test is positive.  Plain radiographs of the thoracolumbar spine are normal.  A myelogram, a CT scan with contrast, and an MRI scan are shown in Figures 41a through 41c.  What is the most likely diagnosis?

 

1-         Disk herniation

2-         Congenital spinal stenosis

3-         Intraspinal tumor

4-         Vertebral end plate fracture

5-         Facet subluxation

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Fracture of the vertebral end plate is a relatively uncommon injury that is most often seen in adolescent boys.  The injury is characterized by traumatic displacement of the vertebral ring-apophysis into the spinal canal and associated disk herniation.  Over one third of these injuries are seen in children with lumbar Scheuermann disease.  The injury most frequently involves the midlumbar vertebra, and symptoms are often indistinguishable from those associated with a herniated disk.  The injury is usually not visible on plain radiographs.  The diagnosis is typically made after obtaining MRI or contrast CT scans.  Treatment consists of laminotomy and excision of the osteochondral fragments.

 

REFERENCES: Beaty JH (ed): Orthopaedic Knowledge Update 6.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1999, pp 635-651.

Epstein NE, Epstein JA, Mauri T: Treatment of fractures of the vertebral limbus and spinal stenosis in five adolescents and five adults.  Neurosurgery 1989;24:595-604.

 

 

70.       Figure 42 shows the radiograph of a 12-year-old boy who has a limp and pain in the left hip with athletic activity.  Examination reveals decreased abduction and internal rotation of the left hip, with pain at the extremes of motion and a 1-cm limb-length discrepancy.  Management should consist of

 

1-         total hip arthroplasty.

2-         innominate osteotomy.

3-         varus osteotomy of the proximal femur.

4-         valgus osteotomy of the proximal femur.

5-         a shoe lift.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The radiograph shows changes that are most consistent with Legg-Calve´ Perthes disease.  Valgus extension osteotomy is the salvage procedure of choice in patients with late symptomatic Perthes disease with severe joint incongruity.  Prerequisites for valgus extension osteotomy include an adequate range of hip adduction and proof of improved congruity in the new position.  Total hip arthroplasty is not a good alternative in the young patient.  Varus osteotomy would further shorten the extremity and place a flattened portion of the femoral head in the acetabulum.  A prerequisite of the innominate osteotomy is a congruent reduction.

 

REFERENCES: Skaggs DL, Tolo VT: Legg-Calve-Perthes disease.  J Am Acad Orthop Surg 1996;4:9-16.

Quain S, Catterall A: Hinge abduction of the hip: Diagnosis and treatment.  J Bone Joint Surg Br 1986;68:61-64.

 

 

71.        The mother of a 5-year-old child reports that he has had a fever of 103°F (39.4°C), leg swelling, and has been unwilling to bear weight on his right lower leg for the past 7 days.  Examination reveals point tenderness at the distal femur.  Aspiration at the metaphysis yields 10 mL of purulent fluid, and a Gram stain reveals gram-positive cocci.  In addition to hospital admission, management should include

 

1-         IV antibiotics.

2-         IV antibiotics and immobilization of the lower extremity.

3-         IV antibiotics, surgical incision and drainage of the abscess, and immobilization of the lower extremity.

4-         IV antibiotics and repeated aspirations of the metaphyseal region.

5-         oral antibiotics with careful monitoring of blood levels.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The patient has a subperiosteal abscess.  Because aspiration revealed 10 mL of purulent fluid, the treatment of choice is surgical incision and drainage of the abscess, followed by immobilization to reduce the risk of pathologic fracture.  With an adequate response to IV antibiotics and a susceptible bacteria, the patient may then be switched to oral antibiotics.  

 

REFERENCE: Kasser JR (ed): Orthopaedic Knowledge Update 5.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1996, pp 149-161.

 

 

72.       Figure 43 shows the lateral radiograph of a 12-year-old boy with mild osteogenesis imperfecta who injured his left elbow after pushing his brother.  Treatment should consist of

 

1-         closed reduction and cast immobilization.

2-         closed reduction and percutaneous pinning.

3-         open reduction and fixation using an absorbable suture.

4-         open reduction and fixation using two Kirschner wires and a figure-of-8 tension band of absorbable suture.

5-         open reduction and fixation using an intramedullary screw.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The patient has a displaced fracture of the apophysis of the olecranon for which most authorities recommend surgical treatment.  In older children, stability of the reduction may be achieved by the use of two parallel medullary Kirschner wires and a figure-of-8 tension band loop of either stainless steel wire or absorbable suture.  The use of an absorbable suture does not require removal of the implant.  Absorbable suture alone is best used in very young patients who have this type of injury.  An intramedullary screw would pose an unnecessary risk of future growth disturbance.

 

A displaced, isolated fracture of the apophysis of the olecranon is an unusual injury in a child.  It has been suggested by several authors that children who have osteogenesis imperfecta may be especially prone to this injury.  One study reported seven of these fractures occurring in five children who had the mild form of osteogenesis imperfecta (Sillence type IA).  The authors of this study suggest that the diagnosis of osteogenesis imperfecta be considered in any child who has a displaced fracture of the apophysis of the olecranon, especially when the injury is associated with relatively minor trauma.

 

REFERENCES: Stott NS, Zionts LE: Displaced fractures of the apophysis of the olecranon in children who have osteogenesis imperfecta.  J Bone Joint Surg Am 1993;75:1026-1033.  

Gaddy BC, Strecker WB, Schoenecker PL: Surgical treatment of displaced olecranon fractures in children.  J Pediatr Orthop 1997;17:321-324.

Dormans JP, Rang M: Fractures of the olecranon and radial neck in children.  Orthop Clin North Am 1990;21:257-268.

 

 

 

73.        Figure 44 shows the radiograph of an 11-year-old girl who has hip pain.  Further diagnostic workup should include

 

1-         a renal ultrasound.

2-         an echocardiogram.

3-         an electromyogram.

4-         an MRI scan of the spine.

5-         an iliac crest biopsy.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The patient has severe acetabular protrusio, a condition that is frequently associated with Marfan syndrome.  An echocardiogram is necessary to rule out the most serious consequence of this syndrome, aortic root widening, which can lead to aortic valve dysfunction or fatal aortic rupture.  An electromyogram may be indicated for Charcot-Marie-Tooth disease, which is associated with acetabular dysplasia, but not protrusio.  The renal ultrasound, the MRI scan, and the biopsy would be of no value in this patient.  Protrusio can also be seen in patients with osteogenesis imperfecta and juvenile rheumatoid arthritis.

 

REFERENCES: Steel HH: Protrusio acetabuli: Its occurrence in the completely expressed Marfan syndrome and its musculoskeletal component and a procedure to arrest the course of protrusion in the growing pelvis.  J Pediatr Orthop 1996;16:704-718.

Wenger DR, Ditkoff TJ, Herring JA, Mauldin DM: Protrusio acetabuli in Marfan’s syndrome.  Clin Orthop 1980;147:134-138.

 

74.       Figure 45 shows the radiograph of a 2-year-old patient who has progressive lumbar scoliosis as the result of hemivertebra.  Examination reveals no associated cutaneous lesions, and an MRI scan shows no associated intraspinal anomalies.  Treatment should consist of

 

1-         hemivertebra excision.

2-         anterior and posterior spinal fusion with instrumentation from T4 to L4.

3-         convex anterior hemiepiphyseodesis.

4-         convex posterior hemiarthrodesis.

5-         an orthosis.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: In a retrospective review of 10 patients treated with hemivertebra excision for hemivertebra in the levels of T12 to L3, the procedure was found to be safe and effective.  The procedure provided an average curve correction of 67° and was greatest in patients who were younger than age 4 years at the time of surgery.  Long anterior and posterior fusion with instrumentation is not the treatment of choice at this age.  Either anterior hemiepiphyseodesis or posterior hemiarthrodesis in this isolated hemivertebra setting would be inadequate.  Brace treatment is ineffective in management of the primary curvature.

 

REFERENCE: Callahan BC, Georgopoulos G, Eilert RE: Hemivertebral excision for congenital scoliosis.  J Pediatr Orthop 1997;17:96-99.

 

 

75.       A 10-year-old girl with a history of an obstetrical brachial plexus palsy has been referred for evaluation.  Examination reveals a severe adduction internal rotation contracture of the shoulder and a mild flexion contracture of the elbow.  Hand function is normal.  Radiographs show mild glenohumeral joint incongruity.  To achieve the best functional outcome, management should consist of

 

1-         physical therapy to stretch the tight structures.

2-         a humeral rotational osteotomy.

3-         anterior shoulder release and posterior muscle transfers.

4-         anterior shoulder release.

5-         shoulder fusion.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The patient has an upper plexus palsy (Erb palsy) with severe shoulder contracture.  While physical therapy for stretching is the treatment of choice to prevent contracture in the newborn, it is unlikely to be of benefit in the older child with an established contracture.  Contracture release alone or in combination with muscle transfers can improve the cosmetic appearance, and in the case of a mild deformity, may also improve function.  These procedures are less likely to help when there is deformity of the shoulder joint or when arthritic changes are present.  The procedure of choice for an older child with joint deformity is rotational osteotomy of the proximal humerus because it can improve cosmesis and function, even in the face of joint deformity.

 

REFERENCES: Jahnke AH Jr, Bovill DF, McCarroll HR Jr, James P, Ashley RK: Persistent brachial plexus birth palsies.  J Pediatr Orthop 1991;11:533-537.

Strecker WB, McAllister JW, Manske PR, Schoenecker PL, Dailey LA: Sever-L’Episcopo transfers in obstetrical palsy: A retrospective review of 20 cases.  J Pediatr Orthop 1990;10:442-444.

Goddard NJ, Fixsen JA: Rotation osteotomy of the humerus for birth injuries of the brachial plexus.  J Bone Joint Surg Br 1984;66:257-259.

 

 

76.       A 4-year-old boy sustained a nondisplaced, but complete, fracture of the left proximal tibial metaphysis 1 year ago.  The fracture healed uneventfully in an anatomic position.  Examination of the injured extremity now reveals 18° of valgus compared with 3° of valgus on the opposite side.  Management should now include

 

1-         observation.

2-         a knee-ankle-foot orthosis.

3-         a medial proximal tibial epiphyseodesis.

4-         a proximal tibial osteotomy.

5-         lateral proximal tibial stapling.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The development of a valgus deformity after this type of fracture is a well-known occurrence, and the patient’s parents should be informed about this risk.  In a patient who is age 4 years, the natural history is one of gradual correction by the development of a physiologic varus deformity at the distal tibial physis; therefore, no active intervention is needed at this time.  Bracing has no effect on the deformity, and the child is too young for any procedure on the growth plate.  Proximal tibial osteotomy is reserved until the patient nears skeletal maturity because of the risk of recurrence of the deformity.  Lateral stapling can be done near skeletal maturity if the deformity persists, but this is unlikely to be necessary.

 

REFERENCES: Zionts LE, MacEwen GD: Spontaneous improvement of posttraumatic tibia valga.  J Bone Joint Surg Am 1986;68:680-687.  

Beaty JH, Kumar A: Fractures about the knee in children.  J Bone Joint Surg Am 1994;76:1870-1880.

 

 

77.        A 16-year-old boy with spastic quadriplegic cerebral palsy has been referred for evaluation and management of scoliosis.  His parents report increasing problems with sitting balance, positioning, and hygiene because of the deformity.  The radiograph shown in Figure 46 reveals a lordoscoliosis of 105° with marked pelvic obliquity.  Attempts at correcting the pelvic obliquity on supine bending radiographs show significant rigidity.  Management should consist of

 

1-         a thoracolumbosacral orthosis.

2-         posterior spinal fusion.

3-         anterior and posterior spinal fusion.

4-         electrical stimulation.

5-         wheelchair modifications.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Spinal stabilization is the treatment of choice in patients with severe scoliosis who have progressive positioning, sitting balance, and/or hygiene problems despite maximal nonsurgical management.  Pelvic rigidity and marked frontal plane deformity necessitate anterior and posterior procedures so as to maximize correction and fusion.

 

REFERENCES: Weinstein SL (ed): The Pediatric Spine: Principles and Practice.  New York, NY, Raven Press, 1994, pp 977-997.

Frymoyer JW (ed): Orthopaedic Knowledge Update 4.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1993, pp 447-459.

 

 

78.        A 10-year-old boy reports a gradual onset of weakness; however, he is fully ambulatory.  History reveals that he has a 17-year-old brother who has just stopped walking because of a similar condition.  Laboratory studies show a creatine kinase level of 5,480 IU/L (normal 25 to 232 IU/L), and examination shows a slightly positive Gower sign.  What is the most likely diagnosis?

 

1-         Spinal muscular atrophy, type II

2-         Myotonic dystrophy

3-         Duchenne muscular dystrophy

4-         Becker muscular dystrophy

5-         Hereditary motor sensory neuropathy, type II (HMSN)

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The patient has Becker muscular dystrophy.  Patients with this condition have a slower rate of progression of disease compared with patients who have Duchenne muscular dystrophy, and walking may continue into the late teens.  The creatine kinase level is not as high as in Duchenne muscular dystrophy, which can range from 20,000 to 30,000 IU/L.  Becker muscular dystrophy is allelic to Duchenne muscular dystrophy, resulting in a mutation in the dystrophin gene.  Myotonic dystrophy is characterized by a progressive inability to relax the muscles after contracture.  The Gower sign is not helpful in this disease.  Patients with Charcot-Marie-Tooth disease, one type of which is also known as HMSN type II, do not have elevated creatine kinase levels and usually present with a foot deformity.  Spinal muscular atrophy, type II, usually presents with severe weakness in the second year of life.

 

REFERENCES: Matsuo M:  From molecular diagnosis to gene therapy.  Brain Dev  1996;18:167-172.

Darras BT: Molecular genetics of Duchenne and Becker muscular dystrophy.  J Pediatr 1990;117:1-15.

Gutmann DH, Fischbeck KH: Molecular biology of Duchenne and Becker’s muscular dystrophy: Clinical applications.  Ann Neurol 1989;26:189-194.

 

 

79.       Figure 47 shows the radiograph of a 2-day-old girl who has been referred for swelling and limited use of the right upper extremity.  The second of twins, the infant was breech and delivered with forceps at age 38 weeks, weighing 5.37 lb.  Difficulty in moving the arm was noted shortly after birth.  Examination shows no active motion of the shoulder, elbow, or wrist.  Active finger flexion and extension are present.  The elbow is mildly swollen, and passive motion shows lack of full extension of 20°, lack of full flexion of 15°, and no restriction of pronation or supination.  What is the most likely diagnosis?

 

1-         Obstetrical brachial plexus palsy

2-         Congenital dislocation of the elbow

3-         Congenital dislocation of the radial head

4-         Arthrogryposis

5-         Transphyseal fracture of the distal humerus

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Fractures involving the entire distal humeral physis may be a complication of a difficult delivery.  Basing the diagnosis on radiographs can be difficult at this age because the secondary ossification center of the lateral condyle has not developed.  The key to the diagnosis is the constant relationship of the radius and ulna, with medial and posterior displacement of the forearm relative to the humerus.  An ultrasound can be obtained to confirm the diagnosis in newborns.  Because the fracture is through cartilage, examination may reveal only mild swelling, and crepitation may be muffled or not apparent.  The lack of apparent active motion of the shoulder, elbow, and wrist is secondary to pseudoparalysis.  Child abuse is a common mechanism of this injury in a child who is age 1 month to age 3 years.

 

REFERENCES: Beaty JH, Wilkins KE: Fractures involving the entire distal humeral physis, in Rockwood CA, Wilkins KE, Beaty JH (eds): Fractures in Children, ed 4.  Philadelphia, Pa, Lippincott-Raven, 1996, vol 3, pp 790-801. 

Dias JJ, Lamont AC, Jones JM: Ultrasonic diagnosis of neonatal separation of the distal humeral epiphysis.  J Bone Joint Surg Br 1988;70:825-828.

Gruel CR, Sullivan JA: Transcondylar fractures of the distal humerus, in Letts RM (ed): Management of Pediatric Fractures.  New York, NY, Churchill Livingstone, 1994, pp 199-209.

 

 

80.       Examination of a 12-year-old girl with a painful flatfoot deformity reveals tenderness in the region of the sinus tarsi and no appreciable subtalar motion.  Radiographs are shown in Figures 48a through 48c.  Two attempts to relieve her symptoms by cast immobilization fail to relieve the pain.  Management should now consist of

 

1-         triple arthrodesis.

2-         manipulation of the foot under general anesthesia.

3-         continued nonsurgical management until the synchondrosis ossifies.

4-         resection of the coalition and interposition with the extensor digitorum brevis.

5-         a medial closing wedge osteotomy of the calcaneus.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Surgical treatment is indicated for a symptomatic tarsal coalition that has failed to respond to nonsurgical management.  In this patient, the radiographs reveal a calcaneonavicular coalition and no degenerative changes.  The patient is symptomatic, and two attempts at use of a short leg walking cast have failed to provide relief.  For calcaneonavicular coalitions, good results have been reported following resection and interposition of the extensor digitorum brevis.  A retrospective study of this procedure achieved good to excellent results in 58 of 75 feet (77%).  Degenerative arthritis or persistent pain following resection of a coalition is a reasonable indication for a triple arthodesis.  A medial closing wedge osteotomy of the calcaneus may be indicated for a rigid flatfoot with severe valgus deformity.  There are no studies documenting the long-term effectiveness of a manipulation under general anesthesia for this condition.

 

REFERENCES: Gonzalez P, Kumar SJ: Calcaneonavicular coalition treated by resection and interpostion of the extensor digitorum brevis muscle.  J Bone Joint Surg Am 1990;72:71-77.  

Richards BS (ed): Orthopaedic Knowledge Update: Pediatrics.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1996, pp 211-218.

81.        When counseling a patient with hypophosphatemic rickets, which of the following scenarios will always result in a child with the same disorder?

 

1-         Female patient who has a female child

2-         Female patient who has a male child

3-         Male patient who has a female child

4-         Male patient who has a male child

5-         Disorder not inherited

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Hypophosphatemic rickets is an inherited disorder that is transmitted by a unique sex-linked dominant gene.  Therefore, if a male patient has a female offspring, his affected X chromosome will be transmitted and all of his female children will have hypophosphatemic rickets.  All male offspring of a male patient will be unaffected.  All offspring of a female patient have a 50% chance of having the disorder.  Understanding the inheritance of hypophosphatemic rickets facilitates early diagnosis and early treatment.  Medical treatment with phosphorus and some types of vitamin D (most authors recommend calcitriol) improves, but does not fully correct, the mineralization defect in hypophosphatemic rickets.  However, if medical treatment is begun before the child begins walking, the growth plate is then adequately protected and a bowleg deformity will most likely be prevented.

 

REFERENCES: Evans GA, Arulanantham K, Gage JR: Primary hypophosphatemic rickets: Effect of oral phosphate and vitamin D on growth and surgical treatment.  J Bone Joint Surg Am 1980;62:1130-1138.

Greene WB, Kahler SG: Hypophosphatemic rickets: Still misdiagnosed and inadequately treated.  South Med J 1985;78:1179-1184.

 

 

82.       A 15-year-old boy with Duchenne muscular dystrophy has a progressive scoliosis that now measures 55°.  He is in foster care and is no longer ambulatory.  Because posterior spinal fusion with instrumentation is the recommended treatment, the patient participates in a thorough discussion of the risks and benefits of the procedure.  However, he refuses the surgery.  The physician should now

 

1-         obtain a court order to perform the surgery.

2-         follow the patient clinically.

3-         place the patient in a brace.

4-         perform the surgery with permission from the legal guardians.

5-         perform the surgery with the consent of two surgeons.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Traditionally, patients have been viewed as ignorant about medical matters and ill-equipped to determine what is in their best interest.  This has been especially true for minors.  However, recent informed consent policies are now based on the patient’s right to self-determination.  While most spinal surgeons would agree that spinal fusion improves pulmonary function, sitting balance, and comfort, they would also agree that this comes at considerable risk in a patient with compromised pulmonary function and ultimately, a terminal condition.  With increasing frequency, young people older than age 14 years are gaining greater autonomy in decision making about their health care matters.  This includes do not resuscitate orders when young patients are terminally ill, as well as in less serious situations.  Surgery could be performed with the permission of the legal guardians; however, in this situation it is preferable to follow the patient clinically until he consents to surgery along with the legal guardians.  Bracing is contraindicated.

 

REFERENCES: Reich WT (ed): Encyclopedia of Bioethics.  New York, NY, Simon and Schuster, 1995, pp 1256-1265.

Confidential health services for adolescents.  Council on Scientific Affairs, American Medical Association.  JAMA 1993;269:1420-1424.

Holder AR: Minors’ rights to consent to medical care.  JAMA 1987;257:3400-3402.

 

 

 

83.        Figure 49 shows the radiograph of a 3-year-old child with progressive bowlegs.  Laboratory studies show a calcium level of 9.5 mg/dL (normal 9.0 to 11.0 mg/dL), a phosphorus level of 4.2 mg/dL (normal 3 to 5.7 mg/dL), and an alkaline phosphatase level of 305 IU/L (normal 104 to 345 IU/L).  What is the most likely diagnosis?

 

1-         Blount’s disease

2-         Hypophosphatemic rickets

3-         Nutritional rickets

4-         Schmid metaphyseal dysostosis

5-         Jansen metaphyseal dysostosis

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The patient has bowlegs associated with very wide physes, particularly noted at the hips.  The widening of the growth plates is a classic sign of rickets; however, the normal levels of calcium, phosphorus, and alkaline phosphatase rule out both nutritional and hypophosphatemic rickets.  Patients with nutritional rickets or hypophosphatemic rickets have hypophosphatemia and increased alkaline phosphatase levels.  Jansen metaphyseal dysostosis has very severe radiographic findings that are not found in this patient; however, these radiographic findings are classic for Schmid metaphyseal dysostosis.  This disorder is caused by a mutation in the gene for type X collagen, which is found only in the growth plates of growing children.

 

REFERENCES: Lachman RS, Rimoin DL, Spranger J: Metaphyseal chondrodysplasia - Schmid type: Clinical and radiographic delineation with a review of the literature.  Pediatr Radiol 1988;18:93-102.

Warman ML, Abbot M, Apte SS, et al: A type X collagen mutation causes Schmid metaphyseal chondrodysplasia.  Nat Genet 1993;5:79-82.

 

84.       Figures 50a and 50b show the standing clinical photographs of a 12-year-old boy who has had increasing pain in the left foot for the past 9 months.  He reports that the pain is activity related, aching in nature, and localized to the medial aspect of the midfoot and hindfoot.  History reveals that he sustained a puncture wound located superior and posterior to the medial malleolus from a plate glass window 18 months ago.  Examination reveals no restriction of ankle or subtalar motion, normal neurovascular status, no masses, and a well-healed 1.5-cm laceration posterior to the superior aspect of the medial malleolus.  Inversion strength of the foot is decreased to grade 3/5.  Radiographs of the foot show no bony abnormalities.  Treatment should consist of

 

1-         application of a UCBL orthoses.

2-         application of an ankle-foot orthosis.

3-         transfer of the flexor digitorum longus to the posterior tibialis tendon.

4-         a lengthening osteotomy of the calcaneus.

5-         talocalcaneal arthrodesis.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The photographs show a planovalgus posture of the foot.  The foot deformity and decreased inversion strength are secondary to laceration of the posterior tibial tendon 18 months ago.  If the injury had been recognized acutely, optimal treatment would have consisted of repair of the tendon; however, contracture now precludes that possibility.  Therefore, transfer of the flexor digitorum longus or flexor hallucis longus is the preferred treatment.  In adults with posterior tibial dysfunction, the entire tendon is typically degenerated and the transfer must be anchored through a drill hole in the navicular.  In this patient, the distal end of the posterior tibial tendon is a satisfactory insertion site.  Lengthening osteotomy of the calcaneus could be combined with the tendon transfer if the patient had a fixed deformity of the foot.  UCBL orthoses and an ankle-foot orthosis are not considered good long-term solutions for a 12-year-old patient.

 

REFERENCES: Mosca VS: Flexible flatfoot and skewfoot, in Drennan JC (ed): The Child’s Foot and Ankle.  New York, NY, Raven Press, 1992, pp 355-376.

Myerson MS: Adult acquired flatfoot deformity: Treatment of dysfunction of the posterior tibial tendon, in Springfield DS (ed): Instructional Course Lectures 46.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1997, pp 393-405.

 

 

 

85.       Which of the following clinical scenarios represents an appropriate indication for convex hemiepiphysiodesis/hemiarthrodesis in the treatment of a child with a congenital spinal deformity?

 

1-         A 3-year-old child with a hemivertebra opposite a contralateral bar and thoracic scoliosis that measures 53°

2-         A 4-year-old child with a fully segmented L1 hemivertebra and scoliosis that measures 80°

3-         A 4-year-old child with a fully segmented T10 hemivertebra and scoliosis that measures 50°

4-         A 4-year-old child with a posterolateral hemivertebra at the thoracolumbar junction and a kyphoscoliotic deformity that measures 45°

5-         A 10-year-old child with a hemivertebra and scoliosis that measures 50°

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Convex hemiarthrodesis and hemiepiphysiodesis are procedures designed to gradually reduce curve magnitude in congenital scoliosis because of hemivertebrae.  They are used to surgically create an anterior and posterior bar to arrest growth on the convexity of the existing deformity.  Success of the technique is predicated on continued growth on the concave side of the deformity.  Prerequisites for this procedure include curves of limited length (less than or equal to five vertebrae), curves of reasonable magnitude (less than 70°), absence of kyphosis, concave growth potential, and appropriate age (younger than age 5 years).

 

REFERENCE: Winter RB, Lonstein JE, Denis F, Sta-Ana de la Rosa H: Convex growth arrest for progressive congenital scoliosis due to hemivertebrae.  J Pediatr Orthop 1988;8:633-638.  

 

 

 

86.       Figures 51a through 51c show the radiographs of a 7-year-old soccer player who reports a gradual onset of midfoot pain that began shortly after the start of soccer season.  He states that the pain is worse with activity and is partially alleviated by rest.  Examination reveals soft-tissue swelling, and tenderness and warmth in the region of the talonavicular and navicular cunieform joints.  Management should consist of

 

1-         biopsy.

2-         curettage and bone grafting.

3-         open reduction and fixation.

4-         immobilization with a long leg cast and no weight bearing.

5-         immobilization with a short leg walking cast or fracture boot.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Osteochondrosis of the tarsal navicular (Kohler disease) is an infrequent cause of midfoot pain in children, and the etiology is unknown.  The typical radiographic findings include flattening and irregular ossification of the tarsal navicular.  The medial cunieform and talus maintain their normal articular contours.  The acute process is best treated with rest and immobilization.  A short leg walking cast results in relief of pain and a quicker return to activity compared with orthotics, although long-term success is similar with either method of treatment.  Children may return to activities when the symptoms subside.  The radiographic appearance of the talus begins to normalize by about 8 to 10 months following the onset of symptoms.

 

REFERENCE: Lutter LD: Sports-related injuries, in Drennan JC (ed): The Child’s Foot and Ankle.  New York, NY, Raven Press, 1992.

 

 

87.        A 10-year-old child with cerebral palsy undergoes bilateral hamstring lengthening for severe knee flexion contractures, and knee immobilizers are applied postoperatively.  Examination at the initial postoperative check 2 hours after surgery reveals that she can dorsiflex her toes on the right foot, but not on the left foot.  The physician should now

 

1-         repeat the examination in a few hours.

2-         remove the left knee immobilizer and flex the knee.

3-         apply long leg casts that include the feet.

4-         obtain an electromyogram and nerve conduction velocity studies.

5-         perform peroneal nerve exploration.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Children with cerebral palsy are often difficult to examine.  However, this patient clearly has a peroneal nerve deficit, most likely from the acute stretch after the hamstring lengthening.  The nerve has the best chance of recovery if it is relaxed by flexing the knee.  Once the nerve has recovered, gradual knee extension can be accomplished.  

 

REFERENCES: Aspden RM, Porter RW: Nerve traction during correction of knee flexion deformity: A case report and calculation.  J Bone Joint Surg Br 1994;76:471-473.

Heydarian K, Akbarnia BA, Jabalameli M, Tabador K: Posterior capsulotomy for the treatment of severe flexion contractures of the knee.  J Pediatr Orthop 1984;4:700-704.

 

 

88.        Figures 52a and 52b show the plain radiographs of a 12-year-old girl who has right distal leg pain.  She reports that symptoms are present with weight-bearing activities and improve with rest.  Examination reveals diffuse tenderness over the distal tibial metaphysis and mild swelling.  A photomicrograph of the biopsy specimen is shown in Figure 52c.  What is the most likely diagnosis?

 

1-         Giant cell tumor

2-         Aneurysmal bone cyst

3-         Unicameral bone cyst

4-         Eosinophilic granuloma

5-         Ewing’s sarcoma

 

PREFERRED RESPONSE: 1

 

DISCUSSION: This lytic lesion is in the epiphyseal-metaphyseal region of the distal tibia.  The most common lesion in this area is a giant cell tumor.  Although these lesions are most commonly seen in adults, they can also occur in the skeletally immature patient.  The photomicrograph shows a lesion with multiple giant cells, the nuclei of which are similar to those in the background stroma; this finding is characteristic of giant cell tumors.  Giant cells can be seen in many benign lesions, including aneurysmal bone cysts, Brown tumors, and eosinophilic granuloma.  These lesions usually have fewer giant cells with less nuclei.  The location of this lesion in the epiphyseal-metaphyseal area is not seen in aneurysmal bone cysts, unicameral bone cysts, Ewing’s sarcoma, or eosinophilic granuloma.

 

REFERENCE: Picci P, Manfrini M, Zucchi Z, et al: Giant cell tumor of bone in skeletally immature patients.  J Bone Joint Surg Am 1983;65:486-490.

 

89.       A 15-year-old boy with epilepsy who is treated with phenytoin sustains a vertebral compression fracture during a breakthrough seizure.  Radiographs of the spine reveal generalized osteopenia.  What is the most likely cause of the osteopenia?

 

1-         Induced osteoporosis

2-         Acquired osteomalacia

3-         Calcitonin effect

4-         Hyperparathyroidism

5-         Disuse osteoporosis

 

PREFERRED RESPONSE: 2

 

DISCUSSION: As a side effect of treatment, phenytoin induces osteomalacia, or rickets, in growing children, through interference with metabolism of vitamin D.  Oral supplementation of vitamin D can minimize this effect in patients who are undergoing prolonged treatment with phenytoin.

 

REFERENCE: Chung S, Ahn C: Effects of anti-epileptic drug therapy on bone mineral density in ambulatory epileptic children.  Brain Dev 1994;16:382-385.

 

 

90.       Figure 53 shows the pedigree of a family with an unusual type of muscular dystrophy.  This pedigree is most consistent with what type of inheritance pattern?

 

1-         Autosomal-dominant

2-         Autosomal-recessive

3-         X-linked dominant

4-         X-linked recessive

5-         Mitochondrial inheritance

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The pedigree documents involvement of male offspring only, and it also shows transmission through an uninvolved female carrier.  This inheritance pattern is most consistent with a x-linked recessive inheritance.  It would be inconsistent with a dominant inheritance pattern unless there was incomplete penetrance.  Autosomal-recessive inheritance would be possible only if the family member labeled II.F was also a carrier of the same gene; however, this is unlikely.  Mitochondrial inheritance is possible, but as with autosomal patterns, mitochondrial inheritance normally affects both male and female offspring.  It is transmitted only through the maternal line.  

 

REFERENCE: Gelehrter TD, Collins FS: Principles of Medical Genetics.  Baltimore, Md, Williams & Wilkins, 1990, pp 27-45.

 

 

91.        Which of the following is considered the most accurate test to determine the amount of limb-length discrepancy in a patient with a knee flexion contracture of 35°?

 

1-         Standing block test

2-         Standing AP radiograph of the pelvis with blocks under the foot of the short leg 

3-         CT scanogram

4-         Scanogram

5-         Measurement from the anterior superior iliac spine to the medial malleolus

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Flexion contractures and angular deformities of a limb cause inaccurate limb-length measurement results with most clinical methods.  A CT scanogram is more accurate than standard scanograms for determining limb length in patients with knee flexion contractures of 30° or more.  The cost and time necessary to complete the examinations are comparable, but the CT scanogram delivers only 20% of the radiation needed for standard scanograms.

 

REFERENCES: Aaron A, Weinstein D, Thickman D, Eilert R: Comparison of orthoroentgenography and computed tomography in the measurement of limb-length discrepancy.  J Bone Joint Surg Am 1992;74:897-902.

Tachdjian MO: Pediatric Orthopedics.  Philadelphia, Pa, WB Saunders, 1990, pp 2867-2870.

92.       Figures 54a and 54b show the radiograph and MRI scan of a 7-year-old boy who has a painful right thoracic scoliosis that measures 35°.  Neurologic examination is normal.  Management should consist of

 

1-         repeat radiographs in 6 months.

2-         a technetium Tc 99m bone scan.

3-         posterior spinal fusion.

4-         anterior and posterior spinal fusion.

5-         a neurosurgical consultation.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Because hydrosyringomyelia, with or without an Arnold-Chiari malformation, is now being recognized as the etiology of many infantile and juvenile idiopathic scolioses, management should consist of a neurosurgical consultation.  Observation with follow-up radiographs is not an option in curves of this magnitude.  A technitium Tc 99m bone scan is unnecessary because the etiology of the curve has been identified.  Although spinal fusion may be needed in the future, it should not be undertaken before the neurosurgical problem has been addressed.

 

REFERENCES: Zadeh HG, Sakka SA, Powell MP, Mehta MH: Absent superficial abdominal reflexes in children with scoliosis: An early indicator of syringomyelia.  J Bone Joint Surg Br 1995;77:762-767.

Schwend RM, Hennrikus W, Hall JE, Emans JB: Childhood scoliosis: Clinical indications for magnetic resonance imaging.  J Bone Joint Surg Am 1995;77:46-53.

Farley FA, Song KM, Birch JG, Browne R: Syringomyelia and scoliosis in children.  J Pediatr Orthop 1995;15:187-192.

 

 

93.       A 10-month-old girl has the spinal deformity shown in Figures 55a and 55b with no apparent neurologic finding.  The next step in evaluation should be to obtain

 

1-         a genitourinary ultrasound.

2-         an MRI scan of the spine.

3-         an AP radiograph of the pelvis.

4-         an electromyogram and nerve conduction velocity studies.

5-         an echocardiogram.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Approximately 60% of patients with a congenital spine abnormality have associated malformations outside the spinal column.  Genitourinary abnormalities are probably the most common, occurring in up to 37% of patients.  These are usually anatomic anomalies, such as renal agenesis, duplication, fusion, and ectopia.  A genitourinary ultrasound is the least invasive screening tool.  Other associated anomalies include cervical vertebral abnormalities, VATER syndrome, and intraspinal abnormalities such as diastematomyelia.  An MRI scan is not recommended as part of the screening examination; however, if the patient had neurologic signs or symptoms, an MRI scan would be indicated.

 

REFERENCES: Beals RK, Robbins JR, Rolfe B: Anomalies associated with vertebral malformations.  Spine 1993;18:1329-1332.

Bradford DS, Heithoff KB, Cohen M: Intraspinal abnormalities and congenital spine deformities: A radiographic and MRI study.  J Pediatr Orthop 1991;11:36-41.

 

 

94.       A 12-year-old girl has scoliosis at T5-T10 that measures 62°.  A clinical photograph of the axilla is shown in Figure 56.  Management should consist of

 

1-         a thoracolumbosacral orthosis.

2-         in situ posterior spinal fusion.

3-         posterior spinal fusion with segmental instrumentation.

4-         anterior spinal fusion with instrumentation.

5-         anterior and posterior spinal fusion with posterior segmental instrumentation.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Neurofibromatosis type 1 (NF-1) is an autosomal-dominant disorder affecting about 1 in 4,000 people.  NF-1 causes tumors to grow along various types of nerves and affects the development of non-nervous tissues, such as bone and skin.  The gene for NF-1 is located on the long arm of chromosome 17 and codes the protein neurofibromin.  Research indicates that NF-1 acts as a tumor-suppressor gene and, as such, plays an important role in the control of cell growth and differentiation.  Axillary and inguinal freckling is considered a good diagnostic marker for NF-1.  The hyperpigmented spots that measure from 2 mm to 4 mm may be congenital, but these typically appear and increase later in life.  Scoliosis is the most common musculoskeletal disorder of NF-1.  The curves are frequently dystrophic, kyphotic, and have a high risk of pseudarthrosis following spinal fusion.  Anterior and posterior spinal fusion with rigid posterior segmental instrumentation is the treatment of choice.

 

REFERENCES: Goldberg Y, Dibbern K, Klein J, Riccardi VM, Graham JM Jr: Neurofibromatosis type 1: An update and review for the primary pediatrician.  Clin Pediatr 1996;35:545-561.

Kim HW, Weinstein SL: Spine update: The management of scoliosis in neurofibromatosis.  Spine 1997;22:2770-2776.

 

 

95.       A 12-year-old girl has bilateral developmentally dislocated hips.  History reveals no previous treatment, and she reports no discomfort.  Good long-term clinical results are most likely to occur with

 

1-         surgical reduction of both hips and stabilization with a pelvic procedure.

2-         no development of false acetabula.

3-         performance of surface replacements.

4-         abductor strengthening exercises.

5-         Chiari osteotomy.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The natural history of complete developmental dislocation of the hip is dependent on two factors: bilaterality and the presence or absence of a false acetabulum.  Patients with bilateral dislocations may have low back pain because of hyperlordosis, but they tend to have less disability than patients with unilateral dislocations who have secondary problems related to limb-length inequality.  Degenerative joint disease and clinical disability are most likely to develop in patients with completely dislocated hips and well-developed false acetabula.  In a 12-year-old child who has bilateral developmental hip dislocations, it would be difficult to obtain surgical treatment results that are better than the natural history of the disorder.  Abductor strengthening exercises are unlikely to influence the long-term outcome in this disorder.  Surface replacements are not indicated in young asymptomatic patients.

 

REFERENCES: Weinstein SL: Natural history of congenital hip dislocation (CDH) and hip dysplasia.  Clin Orthop 1987;225:62-76.  

Wedge JH, Wasylenko MJ: The natural history of congenital dislocation of the hip: A critical review.  Clin Orthop 1978;137:154-162.

 

 

96.       Thyroid hormone regulates skeletal growth at the physis by stimulation of

 

1-         proteoglycan and aggrecan synthesis in the zone of proliferation.

2-         fibroblast growth factor (FGF) activity.

3-         transforming growth factor type beta (TGF-b=) and parathyroid hormone-related protein (PTHrP) activity.

4-         chondrocyte proliferation.

5-         chondrocyte hypertrophy, type X collagen synthesis, and alkaline phosphatase activity.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Children with hypothyroidism have delayed bone age, reduced thickness of the physis, disorganization of the cartilage columns of the physis, and impaired differentiation of proliferating chondrocytes into hypertrophic cells.  As a result, these children have severe growth retardation, and slipped capital femoral epiphysis may develop because of mechanical weakening of the physis.  Thyroid hormone regulates terminal differentiation of the growth plate chondrocytes, with a resultant increase in type X collagen and alkaline phosphatase.  These substances are important factors in matrix mineralization.  Insulin-like growth factors and FGF-2 appear to act synergistically to stimulate mitotic activity of the growth plate chondrocytes.  TGF-b= and PTHrP stimulate proteoglycan synthesis and mitotic activity of the chondrocytes and inhibit type X collagen and alkaline phosphatase activity.

 

REFERENCES: Ballock RT: Regulation of skeletal growth and maturation by thyroid hormone, in Buckwalter JA, Ehrlich MG, Sandell LJ, Trippel SB (eds): Skeletal Growth and Development:  Clinical Issues and Basic Science Advances.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1998, pp 301-317.

Rosier RN, O’Keefe RJ, Reynolds PR, Hicks DG, Puzas JE: Expression and function of TGF-b= and PTHrP in the growth plate, in Buckwalter JA, Ehrlich MG, Sandell LJ, Trippel SB (eds): Skeletal Growth and Development: Clinical Issues and Basic Science Advances.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1998, pp 285-299.

Trippel SB: IGF-I and FGF-2 in growth plate regulation, in Buckwalter JA, Ehrlich MG, Sandell LJ, Trippel SB (eds): Skeletal Growth and Development: Clinical Issues and Basic Science Advances.  Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1998, pp 263-283.

 

 

 

97.       A newborn has an anterolateral bow of the tibia and a duplication of the great toe.  Which of the following conditions will develop as the infant grows?

 

1-         Lisch nodules and axillary freckling

2-         Fracture of the tibia with pseudarthrosis

3-         Increased tibial bowing and varus deformity

4-         Decreased tibial bowing and limb-length discrepancy

5-         Progressive valgus of the ankle

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Anterolateral bowing of the tibia is normally associated with congenital pseudarthrosis of the tibia.  This, in turn, is associated with neurofibromatosis.  Posterior bowing is more benign and usually corrects spontaneously.  However, anterolateral bowing also corrects spontaneously, and the limb-length discrepancy may be the only remaining sequela when associated with duplication of the great toe.  Lisch nodules and axillary freckling are pathognomonic findings in neurofibromatosis but would not be expected in this patient because this type of tibial deformity is not associated with neurofibromatosis.

 

REFERENCE: Weaver KM, Henry GW, Reinker KA: Unilateral duplication of the great toe with anterolateral tibial bowing.  J Pediatr Orthop 1996;16:73-77.

 

 

98.       During stabilization of a slipped capital femoral epiphysis, the screw penetrates into the joint.  The screw is repositioned so that it is within the femoral head.  This transient penetration of the hip joint will most likely lead to

 

1-         an increased risk of chondrolysis.

2-         an increased risk of osteonecrosis.

3-         an increased risk of stiffness.

4-         an increased time to closure of the physis.

5-         no deleterious effect.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Chondrolysis may be associated with unrecognized permanent penetration of the joint space by a pin or screw.  However, transient penetration by the guide wire or screw is not associated with this problem.  One study described 11 hips in which there was transient intraoperative penetration of the joint space by a guide wire or screw.  These patients were followed for at least 2 years, with none showing any clinical or radiographic evidence of chondrolysis.  Another retrospective study of 55 slipped epiphyses described 11 hips with transient intraoperative pin penetration, with none showing development of chondrolysis.  There are no studies to suggest that transient pin penetration leads to osteonecrosis, stiffness, or premature physeal closure.

 

REFERENCES: Zionts LE, Simonian PT, Harvey JP Jr: Transient penetration of the hip joint during in situ cannulated-screw fixation of slipped capital femoral epiphysis.  J Bone Joint Surg Am 1991;73:1054-1060.  

Vrettos BC, Hoffman EB: Chondrolysis in slipped upper femoral epiphysis: Long-term study of the etiology and natural history.  J Bone Joint Surg Br 1993;75:956-961.

 

 

99.       The mother of a 3-month-old infant states that she has difficulty positioning the infant’s legs during diaper changes.  Examination reveals limited abduction of both hips and a negative Ortolani sign.  A radiograph reveals bilaterally dislocated hips.  Initial management consists of guided reduction in a Pavlik harness, with weekly follow-up.  Figures 57a and 57b show the radiograph and CT scan obtained after 6 weeks in the harness.  Management should now consist of

 

1-         placement of the hips in wider abduction and continued use of the harness.

2-         increased flexion of the hips and continued use of the harness.

3-         removal of the harness and application of an Ilfeld splint.

4-         removal of the harness and application of a von Rosen splint.

5-         removal of the harness, followed by closed or open reduction.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: In an infant younger than age 6 months with a complete dislocation of the hip that is not initially reducible, the Pavlik harness may be used for a trial of guided reduction.  When the harness is used in these patients, the infant should be followed at weekly intervals to see if reduction has been achieved.  If the hip does not reduce after 3 to 4 weeks of harness wear, the harness should be discontinued, and closed or open reduction should be considered to avoid secondary deformation of the posterolateral acetabulum, also known as Pavlik harness pathology.  Changing to other abduction braces is not indicated.

 

REFERENCES: Jones GT, Schoenecker PL, Dias LS: Developmental hip dysplasia potentiated by inappropriate use of the Pavlik harness.  J Pediatr Orthop 1992;12:722-726.  

Atar D, Lehman WB, Grant AD: Pavlik harness pathology.  Isr J Med Sci 1991;27:325-330.  

Weinstein SL: Developmental hip dysplasia and dislocation, in Morrissy RT, Weinstein SL (eds): Lovell and Winter’s Pediatric Orthopaedics, ed 4.  Philadelphia, Pa, Lippincott-Raven, 1996, pp 903-950.

 

 

100.     A 6-year-old boy with severe spastic quadriplegic cerebral palsy is nonambulatory.  Examination reveals 10° of hip abduction on the left and 30° on the right with the hips and knees extended.  The Thomas test shows 20° of flexion bilaterally, and Ely test results are 3+/4 bilaterally.  Radiographs show a center edge angle of 0° on the left and
-10° on the right.  The neck shaft angles are 170° bilaterally.  Which of the following procedures would offer the best results?

 

1-         Proximal femoral resections

2-         Bilateral adducter, iliopsoas, and hamstring lengthenings

3-         Bilateral varus derotation shortening osteotomies

4-         Injection of botulinum toxin into the adducters bilaterally

5-         Posterior branch obturator neurectomies bilaterally

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The patient has bilateral subluxated hips, with nearly vertical neck shaft angles; therefore, the treatment of choice is varus derotation osteotomy.  Shortening of the bone on one or both sides may be necessary to allow adequate range of motion postoperatively.  In patients this age and with this degree of bony deformity, soft-tissue releases are not likely to lead to hip stability.  Botulinum toxin has been shown to be effective in the treatment of ankle equinus, but its efficacy in other areas has not been demonstrated as yet.  The indications for obturator neurectomy are unclear at present.  Proximal femoral resection is a salvage procedure for long-standing hip dislocations that are symptomatic and not reconstructable.

 

REFERENCES: Tylkowski CM, Rosenthal RK, Simon SR: Proximal femoral osteotomy in cerebral palsy.  Clin Orthop 1980;151:183-192.

Brunner R, Baumann JU: Long-term effects of intertrochanteric varus-derotation osteotomy on femur and acetabulum in spastic cerebral palsy: An 11- to 18-year follow-up study.  J Pediatr Orthop 1997;17:585-591.

 

 

 

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