FREE Orthopedics MCQS 2022 1751-1800..

1751. (585) Q5-821:

A 15-year-old basketball player has mild scoliosis, pes planus, pectus carinatum, and long slender fingers. In order to help determine if he has Marfan syndrome and should be allowed to continue playing basketball, it is most useful to order a:

1) C ardiac echo

3) Slit lamp examination

2) Magnetic resonance image of the lumbosacral spine

5) Dermal fibroblast assay

4) C hest radiograph

A cardiac echo will give information about enlargement of the ascending aorta, as well as the valves. This is the most important information for activity recommendations and patient prognosis.

A magnetic resonance image (MRI) of the lumbosacral spine will either rule in or out dural ectasia, but a MRI has no clinical importance for activity recommendations.

A slit lamp examination is not as important as a cardiac echo in making sport recommendations. A chest radiograph may be helpful, if the patient is suspected of having a pneumothorax.

A dermal fibroblast assay is useful in assessing collagen, such as in osteogenesis imperfecta, but it is not helpful in diagnosing Marfan syndrome.

 

■Correct Answer:C ardiac echo

1752. (586) Q5-823:

The following skeletal feature helps to establish a diagnostic level of major skeletal involvement in Marfan syndrome:

1) Hyperextensible knees

3) Standing height over 2 m

2) Atlantoaxial subluxation

5) Pectus carinatum

4) Increased thoracic kyphosis

Pectus carinatum has a high diagnostic value for Marfan syndrome.

Hyperextension of the knees is not common in patients with Marfan syndrome. This skeletal feature is seen in many other conditions; therefore, it has low diagnostic specificity.

Atlantoaxial subluxation is rare in Marfan syndrome, but is common in some of the skeletal dysplasias.

Although patients with Marfan syndrome are generally tall, height is too nonspecific to be a helpful diagnostic criterion. Kyphosis is not a skeletal diagnostic criterion.

 

■Correct Answer:Pectus carinatum

1753. (587) Q5-824:

A 12-year-old girl has a scoliosis of 36° from T2-T7 and 15° from T7-L1. She is premenarchal. The following treatment is recommended:

1) C harleston bending brace

3) Milwaukee brace

2) Boston overlap brace

5) Posterior spinal fusion

4) Lateral electrical spinal stimulation

The Milwaukee brace offers the best chance of controlling this curve.

C harleston bending braces are not effective for curves larger than 35°. Boston overlap braces are not effective for curves with an apex above T8. Lateral electrical spinal stimulation has been proven ineffective for scoliosis. This curve is not large enough to pose a recommend fusion.

 

■Correct Answer:Milwaukee brace

1754. (588) Q5-825:

All of these findings are features of patients with Scheuermann kyphosis, except:

1) Vertebral wedging

3) Schmorl nodes

2) Endplate irregularity

5) Back pain

4) Truncal obesity

Obesity is not any more common in patients with Scheuermann kyphosis than in the general population.

Vertebral wedging is a common feature of Scheuermann kyphosis. Endplate irregularity is a common feature of Scheuermann kyphosis.

Schmorl nodes are a manifestation of the disordered behavior of the vertebral endplates under load. Back pain is common in Scheuermann kyphosis.

 

■Correct Answer:Truncal obesity

1755. (589) Q5-826:

An 18-year-old man is seen in the office because of back pain in the thoracic region. He has a kyphosis of 65°, a slight wedging in the midthoracic spine, and a Risser sign of 4. Recommended treatment includes:

1) A program of strengthening and stretching exercises

3) A Boston brace

2) A Milwaukee brace

5) An anterior and posterior spinal fusion

4) A posterior spinal fusion

Exercises must be the first treatment for this patient because he is too mature for brace treatment.

Brace treatment is not indicated for someone of this skeletal maturity. Surgery is not indicated unless the patient fails conservative treatment.

 

■Correct Answer:A program of strengthening and stretching exercises

1756. (590) Q5-827:

Prior to treatment, this pathologic finding characterizes clubfoot:

1) The talar head and neck are deviated medially.

3) The navicular is positioned more laterally than normal.

2) The dome of the talus is flattened.

5) The tendoachilles inserts in a more lateral position than normal.

4) The foot has a rocker deformity.

The talar head and neck are deviated medially. This deformity cannot be corrected surgically but may improve with growth.

The dome of the talus is not originally flattened, but it may become this way after repeated manipulation. The navicular is positioned more medially than normal and may touch the medial malleolus.

The foot has either a normal arch or a cavus deformity (the opposite of a rocker bottom). The rocker bottom foot may develop as a result of over-vigorous manipulation of a clubfoot against a tight heelcord.

The tendoachilles inserts are more medially positioned than normal on the calcaneus. 

■Correct Answer:The talar head and neck are deviated medially.

1757. (591) Q5-828:

In the surgical correction of a clubfoot, the following clinical or radiographic finding indicates that a child should have a plantar release:

1) Anterior extrusion of the talus

3) Medial subluxation of the calcaneocuboid joint

2) Inferior subluxation of the calcaneocuboid joint

5) Lack of ability to dorsiflex the ankle

4) Plantarflexion of the first ray

Plantarflexion of the first ray, especially if the first ray is not colinear with the talus on the lateral radiograph, should serve as an indication for a plantar release.

Anterior extrusion of the talus is common because of the tightness of the Achilles tendon and the posterior capsule. Inferior subluxation of the calcaneocuboid joint is not a feature of clubfoot.

Medial subluxation of the calcaneocuboid joint, in combination with the clinical appearance of a curved lateral border of the foot, should serve as an indication for a lateral release, not a plantar release.

Inability to dorsiflex the ankle is an indication for a posterior release. 

■Correct Answer:Plantarflexion of the first ray

1758. (592) Q5-830:

Hip subluxation is most likely to occur in patients with this type of cerebral palsy:

1) Athetoid

3) Hemiplegic

2) Diplegic

5) Monoplegic

4) Total involvement

Patients with total involvement have the highest degree of axial muscle imbalance; therefore, they have the highest risk of hip subluxation (greater than 50%).

Hip dysplasia is uncommon in athetoid cerebral palsy (C P).

Diplegic C P has the second highest incidence of neuromuscular hip dysplasia, but total involvement has the highest rate. Hip subluxation is not common in hemiplegic C P.

Monoplegia is a rare form of C P with a low rate of subluxation. 

■Correct Answer:Total involvement

1759. (593) Q5-831:

A 13-year-old boy sustains a Salter II fracture of the proximal humeral epiphysis. On radiograph, there is a 40° varus angulation and a 30° apex anterior angulation. Recommended treatment includes:

1) C losed reduction and abduction cast

3) C losed reduction and percutaneous pin fixation

2) C losed reduction and sling

5) Application of a sling and swathe

4) Open reduction and percutaneous pin fixation

Spontaneous partial reduction will occur when the patient becomes upright, and there is good remodeling potential due to growth.

C losed reduction and abduction cast is not necessary because of the patientâs age, remodeling potential, and range of motion available in the joint.

A formal attempt at closed reduction is not necessary because there is no way of holding it without internal fixation. This process will occur naturally to a large degree when the patient becomes upright.

Open reduction and percutaneous pin fixation poses a risk of pin tract infection because of the large amount of muscle traversed. This procedure is not necessary because of the good results with conservative treatment.

 

■Correct Answer:Application of a sling and swathe

1760. (594) Q5-832:

A 12-year-old girl sustains a closed type III Monteggia fracture. One week after closed reduction, the radial head resubluxates and the ulna bows. The next step of treatment is:

1) Repeat closed reduction and a long arm cast

3) Reduce and internally fix the ulna and close-reduce the radial head

2) Reconstruct the annular ligament using a strip of triceps fascia

5) Reduce and pin the radial head

4) Reduce and internally fix the ulna and open-reduce the radial head

Once the ulna is predictably reduced, the radial head has a good chance of staying reduced.

Repeat closed reduction and a long arm cast has a significant chance of redisplacement. If further time passes, radial head reduction will be difficult.

Annular ligament reconstruction is only indicated if there is late subluxation (after several weeks) that does not reduce with closed means.

Once the ulna is realigned and fixed, closed reduction of the radius must be tried next.

Pinning of the radial head should be a last resort because of the risk of breakage and stiffness. 

■Correct Answer:Reduce and internally fix the ulna and close-reduce the radial head

1761. (595) Q5-833:

The following parameter is the most useful in predicting the need for surgical correction of developmental coxa vara:

1) The range of active abduction

3) The acetabular index

2) The epiphyseal extrusion index

5) Presence of a Trendelenburg gait

4) The Hilgenreiner-epiphyseal  angle

The Hilgenreiner-epiphyseal  angle is a measure of the shear stress on the femoral neck. A value greater than 60° is an indication for surgery.

The range of abduction does not directly reflect the mechanical stresses on the femoral neck that may need correction. The epiphyseal extrusion index is a parameter used in Perthes disease.

The acetabular index is used in developmental hip dysplasia. It is usually essentially within normal limits, even in severe coxa vara.

 

■Correct Answer:The Hilgenreiner-epiphyseal  angle

1762. (596) Q5-834:

A 7-month-old girl is newly seen for a dislocation of the left hip. The newborn exam was unremarkable; there was no history of trauma or evidence of spasticity. Recommended treatment includes:

1) Exam, arthrogram and attempted closed reduction under anesthesia to guide treatment

3) Open reduction through a medial approach

2) Pavlik harness

5) A Salter osteotomy

4) Open reduction through a lateral approach

An exam under anesthesia and arthrogram should be performed. C losed reduction must be performed if the hip reduces with a medial dye pool less than 4 mm and a safe zone greater than 20°.

The Pavlik harness is not strong enough to hold an infant older than 4 to 6 months. Open reduction is reserved for hips that do not reduce by closed means.

A Salter osteotomy is only indicated if the hip is still unstable after an open reduction.

 

■Correct Answer:Exam, arthrogram and attempted closed reduction under anesthesia to guide treatment

1763. (597) Q5-835:

A 4-year-old girl has unilateral idiopathic avascular necrosis involving the entire femoral head. Sixty percent of the height of the lateral column is resorbed. There is no lateral subluxation or physeal disturbance. The range of abduction is 30°. Recommended treatment consists of:

1) Observation

3) Femoral osteotomy

2) Atlanta Scottish Rite orthosis

5) Petrie cast

4) Iliac osteotomy

The young age is the overwhelmingly positive factor in this patient. None of the findings mandate a more vigorous approach than observation.

The Atlanta Scottish Rite orthosis has not been proven to have any effect on the disorder. Femoral osteotomy would only be possibly indicated, if there were subluxation greater than 25%.

Iliac osteotomy would only be indicated in this age group, if there were subluxation and/or other poor prognostic factors. Petrie cast is indicated only if the patient has subluxation.

 

■Correct Answer:Observation

1764. (598) Q5-836:

A 13-year-old girl has hip pain and the inability to bear weight. On anteroposterior and lateral hip radiographs the femoral head is displaced inferiorly and posteriorly by 50% of its diameter. Recommended treatment includes:

1) C losed reduction and immobilization in a spica cast

3) Open reduction and pin fixation

2) Traction followed by internal fixation

5) In situ fixation with screw(s)

4) Metaphyseal osteotomy and internal fixation

In situ fixation has results superior to any of the other methods.

Besides being extremely cumbersome, spica cast treatment carries significant risk of redisplacement and chondrolysis. There is no indication for traction in this situation.

The amount of displacement can be accepted as long as it is stabilized.

Metaphyseal osteotomy carries a risk of avascular necrosis. It should only be undertaken in grade III slips. 

■Correct Answer:In situ fixation with screw(s)

1765. (599) Q5-837:

A 12-year-old boy is brought to the emergency department with posterior left pelvic pain, a limp, a temperature of 101° F, and a white blood count of 15,000. C -reactive protein is 55. Magnetic resonance imaging shows increased signal within the posterior ilium on T2 weighted images, but no fluid is outside the bone. Recommended treatment includes:

1) Obtaining a percutaneous bone biopsy

3) Oral dicloxacillin

2) Irrigation and debridement

5) Intravenous oxacillin and gentamicin

4) Intravenous oxacillin

Staphylococcal osteomyelitis is the presumptive diagnosis; therefore, intravenous oxacillin should be administered.

Infection is much more likely than tumor. The predicted organisms should be sensitive to oxacillin. A bone biopsy is not mandatory unless the patient fails to respond to intravenous antibiotics.

Debridement is not likely to be necessary given no evidence of a sequestrum.

Although acute hematogenous osteomyelitis is the likely diagnosis, it is standard practice to begin treatment with intravenous antibiotics and then switch to oral antibiotics when a clinical response is evident.

Gentamicin is not needed in this setting. 

■Correct Answer:Intravenous oxacillin

1766. (600) Q5-838:

A newborn infant in the nursery must be seen because of his foot. The dorsum of the foot rests against the tibia. The heel moves up when the forefoot moves down. Power is present in all muscles. The foot has an arch and the leg lengths are equal. The diagnosis is:

1) Fibular hemimelia

3) C alcaneovalgus foot

2) Vertical talus

5) Lipomeningocele

4) Tethered cord

C alcaneovalgus foot has all of these findings and resolves spontaneously.

Fibular hemimelia typically has less calcaneus attitude and more valgus and shortening. Vertical talus entails loss of an arch and loss of cohesive movement of the foot as a whole. There is no evidence of muscle weakness.

There is no evidence of a neuropathic component. 

■Correct Answer:C alcaneovalgus foot

1767. (601) Q5-839:

A newborn girl is noted to have decreased movement in the right upper extremity. She was large (10 lbs) at birth and was delivered vaginally with shoulder dystocia. She does not have elbow flexion, external shoulder rotation, or abduction. She has had weak finger flexion for 3 months. At 4-months-old, she regains the ability to flex her elbow. Recommended treatment includes:

1) Magnetic resonance imaging of the shoulder

3) Physical therapy

2) Tendon transfers of the teres major and latissimus

5) Open reduction of the glenohumeral joint

4) Microvascular repair of the brachial plexus

C onservative therapy is predicted to bring a good result because biceps are returning at four months of age. However, stretching of the shoulder is indicated to maintain a range of external rotation and abduction.

Magnetic resonance imaging is only indicated if there is a need to consider microvascular repair.

Tendon transfers are performed later (at several years of age), if shoulder abduction and external rotation are significantly limited.

Microvascular repair is mainly considered in patients who do not have return of biceps function by five months.

Open reduction is indicated later (if the shoulder joint is subluxated or severely contracted) after motor recovery has reached a plateau.

 

■Correct Answer:Physical therapy

1768. (602) Q5-840:

A 7-year-old boy with diplegic cerebral palsy has had lengthening of his hamstrings and heelcords. He is examined 2 years later. He walks with the knees nearly straight throughout the gait cycle and circumducts each extremity during swing. This pattern is most likely due to:

1) Recurrent hamstring tightness

3) Spasticity of the rectus femoris

2) Overlengthening of the heelcords

5) Spasticity of the psoas muscle

4) C ontracture of the tensor fascia lata

The straight legs and circumduction suggest spasticity of the rectus femoris as the most likely cause.

Recurrent hamstring tightness (by itself) would cause the opposite combination of problems.

Overlengthening of the heelcords usually causes increased dorsiflexion at the ankles and would help to increase the flexion moment rather than the extension.

C ontracture of the tensor fascia lata is extremely rare in cerebral palsy. Spasticity in the psoas muscle would not lead to a stiff knee gait.

 

■Correct Answer:Spasticity of the rectus femoris

1769. (603) Q5-841:

A 3-year-old girl is brought in for evaluation of leg alignment. She has bilateral foot progression angles of 35° internal. Her thigh-foot angles are 40° internal. Her hip rotation in the prone position is 50° external and 30° internal. The metaphyseal- diaphyseal angle is 2° on each side. Recommended treatment includes:

1) Denis Browne bar with feet 45° outward

3) Femoral derotation osteotomy

2) Bilateral double-upright knee-ankle-foot orthoses

5) Observation

4) Tibial osteotomy

The tibial torsion described has an excellent chance of resolution over time. Observation is indicated.

This child has tibial torsion. The Denis Browne bar has not been proven to affect the natural history of tibial torsion. The knee-ankle-foot orthoses are used for genu varum, which is not the primary problem in this case.

A femoral osteotomy is rarely used to correct femoral anteversion in older children. A tibial osteotomy is rarely used to correct tibial torsion in older children.

 

■Correct Answer:Observation

1770. (604) Q5-842:

A newborn baby has a foot that is dorsiflexed and in valgus. The differential diagnosis includes all of the following conditions except:

1) C alcaneovalgus foot

3) Muscle imbalance from an L5 myelomeningocele

2) Vertical talus

5) Tibial hemimelia

4) Posteromedial bow of the tibia

The foot in a patient with tibial hemimelia does not resemble the other four conditions described; the foot is in equinus and varus.

C alcaneovalgus foot is dorsiflexed and everted through the axis of the ankle joint. A vertical talus has excessive forefoot dorsiflexion and valgus.

A patient with an L5 myelomeningocele may have this appearance due to activity of the dorsiflexors and evertors, with absent power in the plantarflexors and invertors.

Due to the posteromedial bow in the tibia, the foot may appear dorsiflexed and in valgus. 

■Correct Answer:Tibial hemimelia

1771. (605) Q5-843:

A 6-year-old girl with osteogenesis imperfecta has severe bowing of both femurs. The family is interested in surgery to correct the condition. This method will give her the longest interval between procedures in the future:

1) C losed osteoclasis and cast application

3) Multiple osteotomies and realignment over parallel rods

2) Multiple osteotomies and realignment over a single smooth rod

5) Excision of the abnormal bone and replacement with allograft

4) Multiple osteotomies and realignment over telescoping rods

Telescoping or Bailey-Dubow rods are able to grow with the patient and maintain stabilization for a mean of 4 years between operations in growing children.

Without the addition of internal fixation, bowing is likely to resume.

Although a single rod is likely to provide current stability, bowing is likely to occur as the patient grows and the bone becomes longer than the rod.

Parallel rods do not interlock and are likely to splay and lose fixation.

There are no reports of large segment allograft replacement for diaphyses in osteogenesis imperfecta. In the absence of internal fixation, bowing is likely to resume as growth occurs.

 

■Correct Answer:Multiple osteotomies and realignment over telescoping rods

1772. (606) Q5-844:

An infant is seen in the office for the first time. She has slender, stiff fingers with few creases, elbow range of motion 20° to

45°, and internally rotated arms. Her legs are flexed and externally rotated at the hip. Knee range of motion is 15° to 40° of flexion, and she has bilateral clubfeet that are stiff. The most likely diagnosis is:

1) Larsen syndrome

3) Ehlers-Danlos syndrome

2) C erebral palsy

5) Arthrogryposis

4) Down syndrome

The patient has enough joint contractures to make arthrogryposis a likely diagnosis.

Larsen syndrome is characterized by dislocation of multiple joints.

C erebral palsy is characterized by spasticity and flexors overpowering extensors. Ehlers-Danlos is characterized by hyperlaxity of the large joints.

Down syndrome does not present with stiffness. 

■Correct Answer:Arthrogryposis

1773. (607) Q5-845:

Which of the following statements best characterizes the natural history of metatarsus adductus in a newborn:

1) Metatarsus adductus is likely to become fixed if not treated with casts.

3) Metatarsus adductus is likely to become fixed if not surgically corrected.

2) Metatarsus adductus is likely to become fixed if not treated by 6 months.

5) Most infants will improve spontaneously.

4) Metatarsus adductus is likely to later develop hindfoot equinus.

Virtually all patients with metatarsus adductus will improve with time in the absence of active treatment.

C asts are not needed for the majority of cases because spontaneous improvement is by far the most common outcome. Reverse last shoes are not needed in the majority of patients with metatarsus adductus.

Most patients will not need surgery.

Equinus of the hindfoot is not part of the pathology in metatarsus adductus. 

■Correct Answer:Most infants will improve spontaneously.

1774. (608) Q5-846:

A 2½-year-old boy has severe spastic diplegia and hips that are subluxating. His abduction is 20° on each side. The migration index is 35% on each side. Recommended treatment includes:

1) Traction followed by bilateral Salter osteotomy

3) Nighttime abduction splinting

2) Trochanteric transfer

5) Physical therapy each day to stretch abductors along with night

4) Bilateral adductor lengthening and abduction bracing

If followed by postoperative bracing, lengthening of the adductors is usually successful in children younger than 4 to 6 years of age.

Traction would not be appropriate because the muscles are spastic. The surgical plan does not include the most important component â weakening the overactive adductors.

Trochanteric transfer is not advisable in patients younger than 8 years old. Trochanteric transfer would not help decrease the overpull of the adductors which is the cause of the subluxation.

Nighttime abduction splinting should be a component of the care after surgery. Bracing alone would not be an adequate treatment.

Physical therapy in the absence of surgery does not seem to be enough to overcome the pull of the adductors. 

■Correct Answer:Bilateral adductor lengthening and abduction bracing

1775. (609) Q5-847:

A 15-year-old boy has a Salter type-2 fracture of the distal tibia. His foot is in valgus and external rotation. Recommended treatment is:

1) Obtaining computed tomograms of the fracture

3) C losed reduction and immobilization in a long leg cast

2) Obtaining a magnetic resonance imaging study of the ankle

5) Open reduction and internal fixation

4) C losed reduction and percutaneous fixation of the fracture

There is a good chance that a satisfactory closed reduction may be achieved by correcting the valgus and external rotation.

The fracture should first be reduced. There is a good chance of a satisfactory reduction. The patient is old enough that a significant physeal growth disorder is not likely.

Magnetic resonance imaging is not indicated unless there is a question of physeal disorder after healing or an entrapped fragment.

 

■Correct Answer:C losed reduction and immobilization in a long leg cast

1776. (610) Q5-848:

Adolescent girls with multiple radiographs for idiopathic scoliosis are statistically at increased risk for which of the following problems later in life:

1) Lung cancer

3) Lymphoma

2) Breast cancer

5) Squamous carcinoma

4) Leukemia

In a historical cohort study, the risk was increased to 1.7 times the expected rate of breast cancer. The radiation dose is currently lower. The exposure to the breast may be lowered by taking posteroanterior rather than anteroposterior films, and eliminating lateral films in routine situations.

 

■Correct Answer:Breast cancer

1777. (611) Q5-849:

The mean amount of growth height occurring in each vertbra per year during later childhood and early adolescence is:

1) 0.7 mm

3) 2.9 mm

2) 2 mm

5) 6 mm

4) 4 mm

The mean growth is 0.7 mm per vertebra per year. This measurement is averaged across all of the thoracic and lumbar vertebrae.

 

■Correct Answer:0.7 mm

1778. (612) Q5-850:

Which of the following features is true of congenital scoliosis but not infantile idiopathic scoliosis:

1) Bracing has been shown to decrease progression.

3) The thoracic curve may be convex to either the left side or the right in either curve type.

2) The age of onset is before 3 years old.

5) Vertebrae are abnormally formed from birth.

4) The rib-vertebral angle difference predicts the risk of worsening.

In congenital scoliosis, the vertebrae are abnormally formed from birth. The vertebrae are normal at birth in infantile idiopathic scoliosis.

Age of onset is before age 3 in both types of scoliosis.

The thoracic curve may be convex to the left slide or the right side in either curve type. In infantile idiopathic scoliosis, it is most commonly convex to the left.

The rib-vertebral angle difference (angle between the apical vertebral endplate and the rib on the convexity minus the rib on the concavity) greater than 20° predicts an increased risk of worsening in infantile idiopathic scoliosis but not in congenital scoliosis.

Bracing has not been shown to affect infantile idiopathic scoliosis. 

■Correct Answer:Vertebrae are abnormally formed from birth.

1779. (613) Q5-851:

A 12-year-old child with sickle cell anemia has had pain in the distal femur for 1 day, a temperature of 101.5° F, and a white blood count of 14,000/mm3 . Plain films are unremarkable. Recommended treatment includes:

1) Magnetic resonance imaging of the area

3) Needle biopsy of the distal femur

2) Bone scan

5) Intravenous hydration and analgesia

4) Indium labeled white cell scan

Because the odds are greatly in favor of a noninfectious process, it is appropriate to treat empirically with rehydration and analgesia.

Magnetic resonance imaging would not distinguish between infection and vaso-occlusive crisis. Bone scan would not distinguish between infection and vaso-occlusive crisis.

Needle biopsy is not necessary at this stage since the odds are high (greater than 95%) that the process is not infection. White blood cell scan is not able to distinguish between infection and vaso-occlusive crisis.

 

■Correct Answer:Intravenous hydration and analgesia

1780. (614) Q5-852:

A 6-year-old girl is wearing a seatbelt but no shoulder harness when the car she is occupying strikes another car. She suffers an abdominal contusion as well as a spine injury. The facets of L1 and L2 are spread apart as is the disk between them. The angle between the two vertebrae is 35°. The neurologic exam is within normal limits. Recommended treatment includes:

1) Reduction and immobilization in a hyperextension cast

3) Traction for 3 weeks followed by an orthosis

2) Reduction and immobilization in a plastic orthosis

5) Open reduction, in situ fusion, and cast immobilization

4) Open reduction, instrumentation, and fusion L1-L2

Open reduction and 2-level fusion is the simplest way of handling this injury.

Immobilization in a hyperextension cast is likely to exacerbate the abdominal injury. An orthosis is not likely to reduce the deformity.

Traction would not be a good mechanism to reduce the deformity. In situ fusion would be insufficient without instrumentation.

 

■Correct Answer:Open reduction, instrumentation, and fusion L1-L2

1781. (650) Q5-893:

Secondary ossification of the elbow

1) Occurs over a two-year period

3) Proceeds in a predictable fashion through skeletal maturity

2) Occurs more rapidly in males

5) Is complete by age 10

4) Is not important for the orthopedist to understand

Secondary ossification is very imprtant in managing fractures. It begins at age 1-2 and is complete by 14 years girls and 16 years in boys.

■Correct Answer:Proceeds in a predictable fashion through skeletal maturity

1782. (651) Q5-894:

Definitive diagnosis of septic arthritis is made by:

1) Magnetic resonance imaging

3) Needle aspiration

2) Plain radiographs

5) Serologic testing

4) Open biopsy

Definitive diagnoisis of septic arthritis is made by needle asperation.

■Correct Answer:Needle aspiration

1783. (652) Q5-895: Osteomyelitis in the child

1) requires operative debridement in the majority of cases.

3) never causes growth disturbance of the involved bone.

2) requires antibiotic therapy for 3 to 6 weeks.

5) Always crosses the physis in children

4) occurs in the diaphysis in most cases.

Osteomyelitis in the child requires 3-6 weeks of antiobiotics which may be administered parenterally or internally.C orrect Answer:

requires antibiotic therapy for 3 to 6 weeks.

1784. (4039) Q5-896:

All of the following characterize lateral patellar compression syndrome except:

1) Anterior knee pain localized to the patellofemoral joint

3) Subluxation of the patella

2) A tight lateral retinaculum

5) May be unilateral or bilateral

4) A lateral patella tilt with narrowing of the lateral patella and femoral articular surfaces on the sunrise radiograph

By definition, patients with a lateral patellar compression syndrome do not have a subluxation or dislocation of the patella.C orrect

Answer: Subluxation of the patella

1785. (653) Q5-898:

Osteochondral defects occur bilaterally in the distal femur in approximately:

1) 10% to 20% of patients.

3) 30% to 40% of patients.

2) 20% to 30% of patients.

5) 80% to 90% of patients

4) 60% to 70% of patients.

Osteochondral defects occur bilaterally in the distal femur for approximately 20% to 30% of patients. The fact that 20% to 30% of patients with an osteochondral lesion in the distal femur have bilateral involvement suggests that there is a predisposition to the development of a lesion at this location, either genetic or secondary to repetitive microtrauma.

■Correct Answer:20% to 30% of patients.

1786. (654) Q5-899:

The magnetic resonance imaging signs that suggest instability of an osteochondral dissecans lesion include all the following except:

1) The presence of a low signal intensity line at the interface between the lesion and the underlying bone.

3) Focal cartilaginous defects.

2) C artilaginous fractures.

5) Fluid signal between lesion and bone

4) C ysts underlying the osteochondritis dissecans lesion.

The presence of a high signal intensity line at the interface between the lesion and the underlying bone suggests instability of an osteochondritis dissecans lesion.

■Correct Answer:The presence of a low signal intensity line at the interface between the lesion and the underlying bone.

1787. (655) Q5-903: The neonatal hand:

1) Has no primary ossification centers visible at birth.

3) Ossifies the carpus from the margins, centrally.

2) Demonstrates secondary ossification centers from proximal to distal.

4) Is proportionately different from the mature hand.

The neonatal hand is proportionally different from the mature hand.

■Correct Answer:Is proportionately different from the mature hand.

1788. (656) Q5-904: Pediatric bone:

1) Has a higher modulus of elasticity than adult bone.

3) Has a short plastic phase on the load-deformation curve.

2) Has lower bending strength than adult bone.

5) Is more mineralized than adult bone

4) Has periosteum, which is more prone to tear than adult periosteum.

Pediatric bone has less mineral and more vascular channels than adult bone. This gives it a lower bending strength and lower modules of elasticity than adult bone.

■Correct Answer:Has lower bending strength than adult bone.

1789. (657) Q5-905:

In congenital lesions characterized by failure of formation of parts, the most functional, without treatment, is/are:

1) Transverse arrest at the wrist.

3) VATER syndrome.

2) C entral deficiencies.

5) Radial deficiencies

4) Ulnar deficiencies.

C entral deficiencies allow a wide grasp, good release and pinch. These are also termed "cleft hand". The other conditions produce greater impairment.

■Correct Answer:C entral deficiencies.

1790. (658) Q5-906:

Which category of failure of formation anomalies is most often associated with systemic anomalies?

1) Radial deficiencies.

3) C entral deficiencies.

2) Ulnar deficiencies.

5) Tibial deficiencies

4) Transverse deficiencies.

Radial deficiencies are often seen in the later association. which may include cardiac,renal,anorectal and tracheoesphogeal abnormalities.

■Correct Answer:Radial deficiencies.

1791. (659) Q5-910:

Arthrogryposis multiplex congenita:

1) Primarily affects joints, and secondarily the muscles which move them.

3) Is typically asymmetrical.

2) Is more often neuropathic than myopathic.

5) Has a natural history of increasing joint range of motion with time

4) Does not respond to passive joint mobilization.

Arthrogryposis multiplex congenita is an idiopathic disorder that may be due to a primary deficiency of anterior horn cells. Arthrogryposis multiplex congenita results in lack of muscle development; the joint stiffness is secondary to this. It is usually reasonably symmetrical.

■Correct Answer:Is more often neuropathic than myopathic.

1792. (677) Q5-936:

What percentage of the human genome represents the actual genes:

1) 80%

3) 50%

2) 66%

5) 5%

4) 20%

The percentage of the genome that represents the sequence of our genes is approximately 5%. The rest of the genome codes are for initiator and termination sequences, maintenance functions, and unknown functions.

 

■Correct Answer:5%

1793. (678) Q5-937:

In studying a newly recognized disorder using a large population of affected individuals, geneticists discover that although the disorder often affects siblings, it was rarely, if ever, detected in their ancestors. This disorder most closely follows which pattern of inheritance:

1) Autosomal dominant

3) Sex-linked

2) Autosomal recessive

5) Anticipation

4) Multifactorial

Autosomal recessive conditions classically show âhorizontalâ inheritance. Ancestors do not display the gene because they would likely have only one copy of the mutant allele. Only when two carriers reproduce is the phenotype manifest in approximately one- fourth of their offspring.

Autosomal dominant inheritance is characterized by vertical transmission. Many generations manifest the trait because it takes only a single copy of a mutant allele to display the phenotype.

Sex-linked conditions are often traced back in a family. Normally the males are affected and the females are carriers. Multifactorial conditions are thought to result from the combination of different genes. Although the risk of recurrence in kindred is somewhat greater than the population as a whole, it is still quite low (only a few percent). It is rare for siblings to be affected.

Anticipation refers to the phenomenon in which successive generations are likely to display more severe forms of a given disorder. Myotonic dystrophy is a classic example of this phenomenon.

 

■Correct Answer:Autosomal recessive

1794. (679) Q5-938:

Diseases caused by enzyme deficiency are commonly inherited by which of the following patterns:

1) Autosomal dominant

3) X-linked dominant

2) Autosomal recessive

5) Non-mendelian

4) Multifactorial

Two copies of a mutant allele are required to reduce enzyme function to levels that cause clinical impairment.

Enzyme defects are rarely inherited by an autosomal dominant pattern because even half of the normal activity of most enzymes is adequate to maintain normal function.

Enzyme defects are rarely inherited in an X-linked dominant pattern because one copy of a mutant allele is usually sufficient.

Multifactorial inheritance refers to the interaction of multiple, or different genes, to produce a disorder. Enzyme deficiencies are typically the result of a defect in a single gene.

Because enzymes are typically coded by a single gene, they follow mendelian patterns. 

■Correct Answer:Autosomal recessive

1795. (680) Q5-939:

Morquio syndrome is caused by a deficiency in:

1) Alpha-L-iduronidase

3) Beta-glucuronidase

2) Galactose-6-sulfatase

5) Sulfate transport protein

4) Fibroblast growth factor receptor protein

Morquio syndrome is a member of the family of mucopolysaccharidoses.  Morquio syndrome is a deficiency in the enzyme galactose-6-sulfatase. A deficiency in galactose-6-sulfatase  results in increased urinary excretion of keratosulfate.

Alpha-L-iduronidase is deficient in Hurler syndrome.

Beta-glucuronidase is deficient in some rare mucopolysaccharidoses. Fibroblast growth factor receptor protein is deficient in achondroplasia. Sulfate transport protein is deficient in diastrophic dysplasia.

 

■Correct Answer:Galactose-6-sulfatase

1796. (681) Q5-940:

Polymerase chain reaction (PC R) is best characterized by which of the following descriptions:

1) Use of enzymes to link chains of deoxyribonucleic acid (DNA) together

3) Denaturing and reannealing DNA multiple times with known primers

2) Use of viral vectors to insert new DNA into a cell

5) The process by which a cell-surface receptor turns on the transcription process

4) Use of high temperatures to create ultra-high molecular weight polyethylene

Polymerase chain reaction refers to denaturing DNA, isolating a segment of interest with known primers, and reannealing the strands multiple times to produce exponential copies of a segment.

 

■Correct Answer:Denaturing and reannealing DNA multiple times with known primers

1797. (682) Q5-941:

Pleiotropy is demonstrated by which of the following examples:

1) Patients with osteogenesis imperfecta differ in the number of fractures they have received.

3) Hurler syndrome is usually not present in prior generations of an affected patient.

2) Patients with hemophilia A have different target joints.

5) Patients with Ollier disease often have more involvement on one side of the body.

4) Some patients with Marfan syndrome have scoliosis or pectus carinatum, while other patients with Marfan syndrome do not.

The term pleiotropy refers to a disease taking different shapes in various patients.

Variation in the severity of a given problem is better termed "variable expressivity." Target joints are not genetically determined.

Hurler syndrome usually not being present in prior generations of an affected patient is an example of autosomal recessive inheritance.

The term pleiotropy refers to a disease taking different shapes in different subjects, whereas the cause of patients with

Ollier disease having more involvement on one side of the body is unknown.

 

■Correct Answer:Some patients with Marfan syndrome have scoliosis or pectus carinatum, while other patients with Marfan syndrome do not.

1798. (683) Q5-942:

Which of the following is the most common concern regarding anesthesia for a patient with juvenile rheumatoid arthritis:

1) Basilar invagination

3) Subaxial subluxation

2) Rotatory subluxation of C 1-C 2

5) C ervical stenosis

4) Small, stiff jaw

Stiffness and mandibular hypoplasia are fairly common in juvenile rheumatoid arthritis (JRA) due to inflammation of the temporomandibular joint that affects the growth plates of the mandibles.

Basilar invagination is rare in JRA.

Rotatory subluxation of C 1-C 2 is rare in JRA. Subaxial subluxation is rare in JRA.

C ervical stenosis is not a clinical problem in JRA. 

■Correct Answer:Small, stiff jaw

1799. (684) Q5-943:

A 4-year-old boy is brought to a clinic because he has been fussy, febrile, and unable to bend over for the past 4 days. In the office, his temperature is 38.2° C and his neurologic examination is normal. His lumbar lordosis is flattened and he resists flexion or extension. He has normal range of hip motion. Plain films of the lumbar spine are normal. The next imaging study should be:

1) Magnetic resonance imaging of the spine

3) Spinal ultrasound

2) Hip arthrogram

5) Indium labeled white blood cell scan

4) C omputed tomograms of the lumbar spine

Magnetic resonance imaging should be the next step to rule out pyogenic spondylitis.

Ultrasound has not been proven effective in evaluation of anterior spinal pathology.

C omputed tomograms do not have a greater sensitivity than plain films in early diagnosis of infection.

An indium labeled scan may yield diagnostic information but would not be the preferred test because of the time needed and inability to provide other diagnostic information.

Hip arthrogram would not be the next step because the hip range of motion is normal. Even if hip pathology were suspected, the next step would be a plain film and an ultrasound.

 

■Correct Answer:Magnetic resonance imaging of the spine

1800. (685) Q5-944:

A 6-year-old child suffers a displaced fracture of the distal humerus in the supracondylar region. Neurologic and vascular exams are normal. The surgeon decides to reduce and pin the fracture. Which of the following risks increases if the procedure is delayed more than 8 hours?

1) Brachial artery damage

3) Radial nerve palsy

2) Median nerve palsy

5) No risks increase

4) Need for an open reduction

A retrospective comparison study has shown no increase of risks in delayed treatment of supracondylar fractures. 

■Correct Answer:No risks increase