FREE Orthopedics MCQS 2022 1701-1750.

1701. (438) Q5-576:

A 7-year-old child sustained a type 3 closed supracondylar fracture of the humerus 2 hours ago. Neurologic function is intact, but a pulse cannot be found by palpation or doppler. The hand is slightly cool. Your next step is to perform:

1) Arteriogram of the extremity.

3) An attempt at closed reduction of the fracture

2) Injection of lidocaine into the antecubital region

5) Vascular repair

4) Open reduction of the fracture

C losed reduction should be carefully attempted at first, and often a tethered artery will be freed. If no pulse returns, open exploration is indicated if the hand remains cool.

An arteriogram is rarely indicated because it is unlikely to yield additional information. Lidocaine may be instilled if there is spasm at the time of open reduction.

Open reduction of the fracture is indicated only if closed reduction fails, or if the fracture is open.

Vascular repair is not the first step; exploration and repair should be carried out only if the pulse does not return after an attempt at closed reduction.

 

■Correct Answer:An attempt at closed reduction of the fracture

1702. (439) Q5-577:

The nerve most commonly injured at the time of a supracondylar fracture is:

1) Radial nerve

3) Ulnar nerve

2) Median nerve

5) Posterior interosseous nerve

4) Anterior interosseous nerve

The anterior interosseous nerve is the most commonly injured nerve. The anterior interosseous nerve can be tested by asking the patient to make an "O" with the thumb and index fingers, and watching for active flexion of the distal interphalangeal joints.

The radial nerve is the second most commonly injured, after the anterior interosseous nerve.

The ulnar nerve is not the most commonly injured at time of fracture but is the most commonly injured at time of treatment.

The posterior interosseous nerve is rarely injured.

 

■Correct Answer:Anterior interosseous nerve

1703. (440) Q5-578:

A 9-year-old child presents one year after a supracondylar humerus fracture is healed. The elbow is in 15° more varus than the other side. Which of the following statements to the family is true:

1) This is likely to be due to growth plate damage in the distal humerus.

3) The deformity is probably due to hyperemia and overgrowth of the capitellum.

2) This is likely to correct fully before the end of growth.

5) The varus will likely lead to an increased likelihood of degenerative joint disease.

4) The deformity is likely due to malposition of the fracture during healing.

Fracture malalignment is the most common cause of cubitus varus.

Physeal damage is rare after supracondylar fractures.

Angular malalignment corrects slowly and incompletely in the distal humerus, especially in the coronal plane. There is no reason for selective hyperemia of the capitellum in this fracture.

There is no evidence of predisposition to degenerative joint disease in cubitus varus.

 

■Correct Answer:The deformity is likely due to malposition of the fracture during healing.

1704. (441) Q5-579:

In what region of the United States is Lyme disease most prevalent:

1) Hawaii

3) Northeastern United States

2) Alaska

5) Southern United States

4) Lower Midwestern United States

Lyme disease is most common in the northern United States, Wisconsin, and C alifornia; however, the disease can occur anywhere. Vector ticks identified in Europe transmit several variations of Lyme disease.

Hawaii, Alaska, the lower midwestern states, and southern states do not have an increased incidence of Lyme diseaseC orrect

Answer: Northeastern United States

1705. (442) Q5-580:

Which of the following tests is most specific for the diagnosis of Lyme disease:

1) Elevated erythrocyte sedimentation rate (ESR)

3) Negative antinuclear antibody (ANA)

2) Elevated C -reactive protein (C RP)

5) Elevated antibody titer to Borrelia burgdorferi

4) Negative rheumatoid factor

The most specific laboratory finding is an elevated antibody titer to Borrelia burgdorferi. This test is commonly referred to as a

Lyme titer.

All of the mentioned tests are generally seen in Lyme disease, however, elevated erythrocyte sedimentation rate, elevated C - reactive protein, negative antinuclear antibody, and negative rheumatoid factor are all nonspecific.

■Correct Answer:Elevated antibody titer to Borrelia burgdorferi

1706. (443) Q5-581:

Which of the following statements is true regarding Lyme disease:

1) C ardiac and neurologic symptoms are the most common manifestations of the disease.

3) The characteristic skin rash occurs late in the disease and can be permanently disfiguring.

2) Arthritic symptoms primarily affect large joints and a majority of patients are cured with antibiotic therapy.

5) Lyme disease is easy to diagnose and a majority of cases are picked up after a few weeks.

4) Arthritic symptoms often do not fully resolve with antibiotic treatment, with a majority of patients progressing on to a rheumatoid-like destructive arthritis.

Approximately 60% of patients develop arthritic symptoms that primarily affect large joints. The prognosis for most patients is good after treatment with antibiotics.

C ardiac and neurologic symptoms occur in a minority of patients, however, they can be the most serious symptoms. Erythema chronicum migrans is the characteristic skin rash. The rash tends to remit with antibiotic treatment and permanent disfigurement is not typically a problem.

Only 1%-2% of pediatric patients develop chronic arthritis.

Lyme disease may be difficult to diagnose because of the numerous possible presentations.

 

■Correct Answer:Arthritic symptoms primarily affect large joints and a majority of patients are cured with antibiotic therapy.

1707. (444) Q5-582:

Lyme disease is caused by which of the following organisms or mechanisms:

1) Group A Streptococcus

3) Vibrio vulnificus

2) Borrelia burgdorferi

5) Autoimmune disorder of unknown etiology

4) Group B Streptococcus

Lyme disease was initially thought to be an idiopathic autoimmune disorder; however, in the 1970s, researchers at Yale University identified Borrelia burgdorferi as the cause of the disease. The disease is transmitted by a deer tick known as Ixodes ricinusi.

Group A streptococcal pharyngitis may be followed by rheumatic fever, but not Lyme disease.

Vibrio vulnificus is the organism responsible for severe soft tissue infections in patients who are exposed to fresh-water shellfish. Group B Streptococcus is a common etiologic agent for necrotizing fasciitis.

■Correct Answer:Borrelia burgdorferi

1708. (445) Q5-585:

The most serious long-term sequela of rheumatic fever is:

1) Skin disfiguration from migratory rash

3) Rheumatic valvular heart disease

2) Disabling arthritis in affected joints

5) Decreased lung capacity secondary to fibrosis

4) Need for long-term prophylaxis for the prevention of relapses

The most serious potential long-term sequela of rheumatic fever is rheumatic valvular heart disease.

Patients do not develop any permanent skin lesions or joint disability from the disease.

Some patients require long-term prophylaxis to prevent recurrences, however, this is an inconvenience and not a sequela. The lungs are not affected in the acute fever or subsequent relapses.

 

■Correct Answer:Rheumatic valvular heart disease

1709. (446) Q5-586:

Joint pain in rheumatic fever:

1) Affects 2 to 4 large joints over several months

3) Results in long-term disability with joint destruction

2) Responds to aspirin therapy

5) Is a major criterion for diagnosis

4) Is best treated with penicillin G

Joint pain is common in rheumatic fever. It is an intensely painful arthralgia that migrates from joint to joint within hours. The pain responds to aspirin therapy, as well as rest. Although oral penicillin G is used for treatment of the disease, it will not produce rapid resolution of the joint pain. In untreated cases, it can affect up to 16 joints. Most patients are left with no long-term sequelae or disability of the musculoskeletal system from rheumatic fever. Joint arthralgias are minor criteria for diagnosis.

■Correct Answer:Responds to aspirin therapy

1710. (447) Q5-587:

Patients with homocystinuria phenotypically resemble patients with:

1) Achondroplasia

3) Marfan syndrome

2) Larsen's syndrome

5) Noonan's syndrome

4) Gaucher's disease

Patients with homocystinuria may phenotypically resemble patients with Marfan syndrome. Patients with homocystinuria and

Marfan syndrome are tall with long limbs, arachnodactyly, scoliosis, chest wall deformities, and lens dislocations.

Achondroplasia is characterized by short stature, frontal bossing, and rhizomelic shortening of the limbs. Larsen's syndrome is a disorder characterized by short stature and multiple joint dislocations.

Gaucher's disease is a lysosomal storage disease characterized by accumulation of cerebroside in cells of the reticuloendothelial system. As in patients with homocystinuria, patients with Gaucher's disease have osteoporosis, however, they do not develop any of the other phenotypic features seen in homocystinuria.

Noonan's syndrome effects boys and clinical features include short stature, a webbed neck, and cubitus valgus deformities.

 

■Correct Answer:Marfan syndrome

1711. (448) Q5-589:

A genetic defect found in some types of Ehlers-Danlos syndrome (EDS) is:

1) Fibrillin

3) Fibroblast growth factor (FGF) receptor 3

2) Type I collagen

5) Hypoxanthine-guanine  phosphoribosyl transferase

4) Dystrophin

Ehlers-Danlos syndrome (EDS) was once described as a single gene disorder affecting type I collagen, but it has since been discovered that EDS is a family of heterogeneous disorders with many described mutations. Type I collagen is defective in EDS type VII and collagen type III is defective in EDS type IV and VIII.

Fibrillin and fibroblast growth factor (FGF) receptor 3 are defective in Marfan syndrome and achondroplasia, respectively. Dystrophin is deficient in muscular dystrophy.

Hypoxanthine-guanine  phosphoribosyl transferase is defective in Lesch-Nyhan syndrome.

 

■Correct Answer:Type I collagen

1712. (449) Q5-590:

Which of the following features differentiates Marfan syndrome from Ehlers-Danlos syndrome (EDS):

1) Joint hypermobility

3) Lens dislocation

2) Scoliosis

5) Joint dislocations

4) Vascular problems

Patients with Ehlers-Danlos syndrome (EDS) and Marfan syndrome may have joint hypermobility, scoliosis, vascular problems, and recurrent joint instability. Patients with Marfan syndrome also develop lens dislocations, and while some patients with EDS exhibit eye problems, it is related to ocular globe fragility. Lens dislocation is not a feature of EDS.

■Correct Answer:Lens dislocation

1713. (450) Q5-591:

Which of the following statements concerning Ehlers-Danlos syndrome (EDS) is true:

1) EDS type III is the most severe form of the disease.

3) EDS type VII is characterized by dislocated hips and/or knees at birth.

2) EDS is primarily inherited as an autosomal dominant disorder.

5) Knowing the subtype of the disease does not affect the overall management of the patient.

4) Demonstrating joint hyperlaxity or voluntary dislocation in EDS patients does not damage the joint.

Ehlers-Danlos syndrome (EDS) types I, II, III, and VII are commonly seen by orthopedic surgeons. Type VII is characterized by congenital hip and knee dislocations.

EDS type III is the mildest form of the disease; the main symptom of this type is hyperlaxity. EDS may be inherited via any of the Mendelian patterns.

C hildren with EDS should be encouraged not to use their hyperlaxity as a âtrickâ because of potential long-term joint damage that may occur.

Knowing the subtype of the disease is often helpful in management and perioperative planning because than the surgeon may anticipate operative risks and potential complications.

 

■Correct Answer:EDS type VII is characterized by dislocated hips and/or knees at birth.

1714. (451) Q5-592:

Which subtype of Ehlers-Danlos syndrome (EDS) is caused by lysyl hydroxylase deficiency:

1) EDS type I

3) EDS type III

2) EDS type II

5) EDS type VII

4) EDS type IV

Many of the mutations responsible for the differing subtypes of Ehlers-Danlos syndrome (EDS) have not been identified (EDS types I, II, and III). Lysyl hydroxylase deficiency has been identified as the cause of type IV. A mutation in type I collagen has been identified as the cause of EDS VII.

■Correct Answer:EDS type IV

1715. (452) Q5-593:

The most common type of chronic inflammatory arthritis in childhood is:

1) Pauciarticular juvenile rheumatoid arthritis

3) Systemic juvenile rheumatoid arthritis

2) Polyarticular juvenile rheumatoid arthritis

5) Reactive arthropathy

4) Seronegative spondyloarthropathy

Forty percent to 60% of children afflicted with juvenile rheumatoid arthritis (JRA) have the pauciarticular subtype. Polyarticular JRA is the second most common type occurring in 30%-40%. Systemic onset JRA is the least common form and occurs in approximately 20% of children. Seronegative spondyloarthropathy  is more rare in patients <20 years old.

Polyarticular JRA comprises about 30%-40% of JRA. Systemic onset JRA is the least common form of JRA. Seronegative spondyolarthropathy  is uncommon in childhood. Reactive arthropathy is not a chronic inflammation.

 

■Correct Answer:Pauciarticular juvenile rheumatoid arthritis

1716. (453) Q5-594:

A 14-year-old left-handed boy suffers an avulsion of the medial epicondyle of the distal humerus when landing from a fall. The epicondyle is displaced 7 mm. His physical demands include swimming and lifting boxes. The recommended treatment for this injury is:

1) Open reduction and internal fixation

3) Percutaneous fixation in situ

2) Manipulation and percutaneous fixation

5) Excision of the fragment with reattachment of muscle to bone

4) Splint for 1 week

Unless the fragment is entrapped or significant valgus loading is anticipated, nonoperative treatment is indicated. Range of motion should be started within 1 week.

Open reduction is only indicated, if the epicondyle was entrapped in the joint, or if significant valgus loading was anticipated.

The results of nonoperative treatment are just as good as any invasive treatment.

Excision of the fragment is only indicated, if operative treatment is indicated, and the epicondyle is fragmented.

 

■Correct Answer:Splint for 1 week

1717. (454) Q5-595:

Which of the following statements is true about the medial humeral epicondyle:

1) The medial humeral epicondyle is the first center to ossify in the distal humerus.

3) The medial humeral epicondyle is located anteromedially on the distal humerus.

2) The medial humeral epicondyle usually fuses to the distal humerus at age twelve.

5) The medial humeral epicondyle may ossify from several centers.

4) The medial humeral epicondyle is the origin of the wrist extensor muscles. The medial epicondyle may have several ossification centers.

The medial epicondyle is the third center to ossify, beginning at age 4 to 6 years old.

The medial epicondyle usually fuses near skeletal maturity, at approximately age 15. The medial epicondyle is located posteromedially.

The medial epicondyle is the origin of the flexor-pronator muscles.

 

■Correct Answer:The medial humeral epicondyle may ossify from several centers.

1718. (455) Q5-596:

Which of the following statements is true regarding ankylosing spondylitis:

1) Radiographic changes present early.

3) It is a common inflammatory disorder affecting children < 8 years of age.

2) C haracteristic features make it easy to diagnose.

5) Long-term prognosis is poor.

4) It is an inflammation of ligament insertions associated with HLA-B27.

Ankylosing spondylitis is an inflammatory enthesopathy that rarely affects children. Diagnosis is often difficult because the features may be similar to pauciarticular juvenile rheumatoid arthritis. It typically affects males >8 years of age. It is associated with haplotype HLA-B27. The long-term prognosis in these children is generally good.

■Correct Answer:It is an inflammation of ligament insertions associated with HLA-B27.

1719. (456) Q5-597:

A 4-year-old child injures his elbow and presents with swelling and limitation of voluntary movement. The radiographs show no obvious fracture, but it does show a Baumann angle of 71° and an elevation of the posterior fat pad. You tell the parents that this most likely represents:

1) A congenital anomaly with a valgus deformity of the elbow

3) A Salter I physeal separation

2) A medial epicondyle fracture

5) A variation of normal

4) An occult supracondylar fracture

Occult supracondylar fracture was the most common diagnosis assigned after careful study of a clinical series of elevated pediatric posterior fat pads.

The value for Baumann angle is normally 81° - 64°. Nothing in this description suggests a congenital anomaly. Medial epicondyle fractures are extremely rare before 9 years of age.

Although a Salter I physeal separation is a possibility, it is a rare injury.

With an elevation of the posterior fat pad, there is increasing recognition that a fracture exists. 

■Correct Answer:An occult supracondylar fracture

1720. (457) Q5-598:

A 6-year-old boy sustains a supracondylar fracture of the humerus. The 2 fragments are not completely displaced, but there is some overlap of the medial column and a gap on the lateral column of the distal humerus. Baumannâs angle measures 85Â

°-89º.The alignment on the lateral film shows no significant translation, but approximately 15° of increased extension. The recommended treatment is:

1) Accept this and treat in a long arm cast

3) C losed reduction with the elbow in extension to better monitor the angulation

2) C losed reduction with supination of the forearm and application of long arm cast

5) Open reduction and medial and lateral plate fixation

4) C losed reduction and percutaneous pin fixation

C losed reduction should allow regain of alignment and percutaneous pin fixation will allow it to be maintained.

The elbow is in 10°-15° of varus and this will be an objectionable appearance in the future. Supination will increase the varus.

Extension will exacerbate the deformity seen on the lateral and will cause further loss of contact of the fracture fragments. Medial and lateral plate fixation is needed in adolescents and adults with intercondylar fractures to allow early range of movement but is excessive treatment for this fracture in young children.

 

■Correct Answer:C losed reduction and percutaneous pin fixation

1721. (465) Q5-641:

A 6-year-old girl presents with a fracture of the radial neck that is angulated 25° compared to the other side. No other abnormalities are seen. The recommended treatment is:

1) Sling and early range of motion

3) Reduction using a percutaneously placed K-wire with intraosseous fixation

2) Reduction using an intramedullary K-wire introduced from a retrograde approach (Metaizeau technique)

5) Open reduction and internal fixation

4) Open reduction without internal fixation

Fractures with angulation <30° have an excellent chance of remodeling, and can be left as they are with early range of motion. Reduction using an intramedullary K-wire introduced from a retrograde approach (Metaizeau technique) is indicated mainly for fractures angulated >30°.

Reduction using a percutaneously placed K-wire with intraosseous fixation, while effective, is not needed unless the fracture is angulated >30°.

Open reduction and internal fixation are indicated only if the fracture is angulated >50° and does not reduce by one of the manipulative techniques.

 

■Correct Answer:Sling and early range of motion

1722. (466) Q5-642:

A 7-year-old boy falls and suffers a Salter type IV fracture of the proximal radius. The size of the displaced fragment is 40% of the radial head, and it is translated distally by 2 mm. The optimum treatment is:

1) Immobilization for 2 weeks with early range of motion

3) Percutaneous fixation in situ to prevent further displacement

2) Immobilization for 6 weeks with early range of motion

5) Open reduction, internal fixation

4) Excision of the radial head fragment

Because the displacement is likely to be >2 mm, open reduction may lessen the risk of problems with growth and mobility. This is suggested by clinical series.

The displacement is likely to be greater than the radiograph shows, and growth disturbance is likely. Range of motion at two weeks is too early.

Percutaneous fixation in situ would still carry a risk of growth disturbance, because the displacement is likely to be more than the plain radiographs show due to the largely cartilaginous nature of the radial head.

Excision of a fragment this large is likely to produce incongruity of the radio-capitellar joint.

 

■Correct Answer:Open reduction, internal fixation

1723. (467) Q5-643:

A 12-year-old boy sustains a Salter type II fracture of the proximal humerus during a fall. The fracture has an apex angulation of 40° anteriorly and laterally. The neurovascular examination is normal. The recommended treatment is:

1) Longitudinal traction in abduction followed by slowly bringing the arm into an abduction (airplane) splint

3) Open reduction and plate fixation

2) C losed reduction and percutaneous pin fixation

5) No formal reduction attempt, rather placement of the arm in a sling

4) Skeletal traction in abduction with an olecranon pin

Recommended treatment involves no formal reduction attempt, rather placement of the arm in a sling. This simple treatment is adequate for all patients with at least 2 years of growth remaining. This is due to the tendency to self-align, the remodeling potential, and the ability to tolerate some deformity in the region with no functional consequence.

The abduction splint is cumbersome. It is not necessary because simpler means are effective due to the young age and remodeling potential.

C losed reduction and pin fixation are not needed because adequate remodeling is expected. Any residual deformity is well tolerated in this region. The pins can sometimes cause significant soft tissue irritation in the bulky area of the shoulder. Plate fixation is not feasible because of the open physis. It is also not necessary because simpler means are available. Skeletal traction is not needed because the humerus will align itself better with time in a dependent position.

 

■Correct Answer:No formal reduction attempt, rather placement of the arm in a sling

1724. (468) Q5-644:

The most common cause of a pediatric pathologic fracture of the proximal humerus is:

1) Osteochondroma

3) Unicameral bone cyst

2) Osteogenic sarcoma

5) Fibrous cortical defect

4) C odman tumor (chondroblastoma)

The most common cause of a pathologic fracture of the proximal humerus is unicameral bone cyst. This fluid-filled cyst expands and weakens the humerus, often causing a fracture as its first evidence of existence.

Although the proximal humerus is one of the more common sites of their occurrence, osteochondromas do not significantly weaken the humerus.

Osteogenic sarcoma is a relatively rare bone tumor, and it does not weaken the bone until it is at an advanced stage. C odman tumor (chondroblastoma) is classically described in the proximal humerus, it is rare and typically epiphyseal in location, and does not appreciably weaken the bone.

Although fibrous cortical defects are common tumors, they rarely present in this way. 

■Correct Answer:Unicameral bone cyst

1725. (469) Q5-645:

A 6-year-old boy has a painful elbow, with swelling over the region of the olecranon. Radiographs reveal a thin sliver of bone that is displaced 4 mm from the proximal border of the olecranon. Treatment should consist of:

1) C losed treatment in a cast in 90° of flexion

3) Open excision of the osseous fragment

2) C losed treatment in a cast in extension

5) No immobilization; early range of motion

4) Open reduction and tension band fixation

Open reduction and tension band fixation is the best method to hold the proximal ulnar apophysis.

The patient has a âsleeveâ fracture that should be reduced because it is attached to the olecranon apophysis.

The osseous fragment is attached to the entire olecranon apophysis, which develops a secondary ossification center at age

9.

With early range of motion, further displacement and/or nonunion may develop.

 

■Correct Answer:Open reduction and tension band fixation

1726. (470) Q5-646:

Which of the following statements is true about the radiographic development of the proximal ulna:

1) A small sliver of a secondary ossification center is present at birth.

3) A secondary ossification center appears at 7 years of age.

2) A secondary ossification center appears at 5 years of age.

5) There is no secondary ossification center for this region.

4) A secondary ossification center appears at 9 years of age.

There is a secondary ossification center developing in children approximately 9 years of age. There is no ossification center in the proximal ulna until the child reaches 9 years old.

■Correct Answer:A secondary ossification center appears at 9 years of age.

1727. (471) Q5-647:

A 14-year-old boy sustains an intercondylar fracture of the distal humerus. There is a single fracture line into the joint between the capitellum and the trochlea. The medial column of the distal humerus is comminuted, but the lateral column is not. All fragments are highly displaced. Neurovascular status is normal. The recommended treatment is:

1) Olecranon pin traction overhead for 2 weeks and long arm cast

3) C losed reduction and pin fixation

2) C losed reduction and long arm cast

5) Open reduction and dual plate fixation through a posterior approach

4) Open reduction and dual plate fixation through an anterior incision

A posterior approach (Bryan-Morrey or olecranon osteotomy) will facilitate anatomic reduction and rigid fixation sufficient for early range of motion.

Prolonged traction and cast will result in an incomplete reduction and excessive stiffness. A cast alone will result in an incomplete reduction and excessive stiffness.

Rigid fixation with plates, rather than pins, is required to maintain reduction of these fractures and allow early range of motion.

An anterior approach will not allow adequate exposure of the distal humerus for articular fixation. 

■Correct Answer:Open reduction and dual plate fixation through a posterior approach

1728. (472) Q5-648:

In treating which of the following elbow fractures is it most important to begin early range of motion:

1) Salter I physeal fracture of distal humerus

3) Supracondylar fracture of distal humerus

2) Intercondylar (T-condylar) fracture of distal humerus

5) Lateral epicondyle fracture

4) Lateral condyle fracture

Intercondylar fractures have a significant risk of loss of motion because of the magnitude of injury, intra-articular extension, and older age of patient.

Salter I physeal fractures typically occur in young children. They usually pose no difficulty with regaining motion after 4 to

6 weeks of immobilization.

Supracondylar fractures usually are followed by regaining motion after healing despite immobilization of up to 6 weeks or more.

Patients with this fracture usually regain their motion after healing. Because this is a nonarticular fracture, loss of motion is not a high risk.

 

■Correct Answer:Intercondylar (T-condylar) fracture of distal humerus

1729. (506) Q5-705:

A previously healthy 3-year-old girl presents with 3 weeks of painful torticollis and facial asymmetry. A birth history reveals a normal vaginal delivery with no perinatal complications. The girl has no history of esophagitis or gastrointestinal problems. Her mother reports that approximately 1 month ago, the young girl had an upper respiratory tract infection that has since resolved. The most likely diagnosis is:

1) Muscular torticollis

3) Grisel syndrome

2) Os odontoideum

5) Pseudosubluxation of C 2 on C 3

4) Sandifer syndrome

Grisel syndrome is an abnormal rotation of the atlantoaxial joint that produces painful torticollis and often follows an upper respiratory tract infection.

Muscular torticollis is unlikely in this patient because this condition is usually attributed to a difficult delivery, breech presentation, or some type of in utero positioning problem. Furthermore, muscular torticollis usually presents itself within the first 4-6 weeks and has no association with respiratory infections.

Symptoms associated with os odontoideum consist of neck pain, paresthesia, transient paresis, or myelopathy. Patients with os odontoideum do not have torticollis.

Sandifer syndrome is a painful torticollis and the abnormal trunk rotation is associated with gastroesophageal reflux disease.

Pseudosubluxation does not produce painful torticollis. 

■Correct Answer:Grisel syndrome

1730. (507) Q5-706:

A computerized tomography (C T) scan of the neck reveals an atlantoaxial rotatory displacement with 6 mm of anterior translation. The most likely associated anatomic defect is:

1) Disruption of both the transverse ligament of C 1 and the alar ligaments

3) Disruption of the anterior and posterior longitudinal ligaments

2) Odontoid fracture

5) Ossiculum terminale

4) Disruption of the ligamentum flavum between C 1 and C 2

In order to have anterior displacement of C 1 on C 2 >5 mm, there must be disruption of both the transverse ligament of C 1 and the alar ligaments.

Odontoid fracture does not disrupt the articulation between the dens and the atlas, therefore, there would be no abnormal diastasis between the atlas and the dens.

The anterior and posterior longitudinal ligaments attach to the anterior and posterior aspects of the vertebral bodies respectively. Insufficiency does not affect the atlantoaxial articulation.

Disruption of the ligamentum flavum alone is not thought to result in translation of C 1 on C 2.

An ossiculum terminale is a persistent growth center at the tip of the odontoid, but is not indicative of any pathological condition.

 

■Correct Answer:Disruption of both the transverse ligament of C 1 and the alar ligaments

1731. (508) Q5-707:

A 14-year-old ice hockey player had a jersey pulled over his head in a brawl during a game. He finished the game without incident and denies any other traumatic event. The boy presents the following day with a stiff neck tilted to the right side and an inability to bring his head to a neutral position. On more careful physical examination, the boyâs head is tilted to the right 20°, rotated to the left 20°, and slightly flexed. Attempts at passive rotation to a neutral position produce pain. The exam is otherwise unremarkable. C omputerized tomography scans show atlantoaxial rotatory displacement with no anterior displacement of C 1 on C 2. Treatment should include:

1) Urgent C 1 to C 2 fusion

3) Head halter traction and NSAIDs

2) Use of a soft collar, exercises, and nonsteroidal anti-inflammatory drugs (NSAIDs)

5) Occiput to C 2 fusion

4) Philadelphia collar, Minerva casting, and NSAIDs

A soft collar, exercises, and nonsteroidal anti-inflammatory drugs (NSAIDs) should be tried for 1 week if the diagnosis of atlantoaxial rotatory displacement is made within a week of its onset. The patientâs progress must be followed closely. If NSAIDs and a collar do not work after 1 week, the patient should be hospitalized and head halter traction should be administered along with muscle relaxants. If head halter traction successfully reduces the deformity, the patient should be placed in a Philadelphia collar with Minerva casting for 6 weeks. If the patient has no neurologic findings and no anterior displacement, the condition is likely to resolve with conservative measures alone. If surgery becomes necessary, the occiput should not be included in surgical treatment of atlantoaxial rotatory displacement.

■Correct Answer:Use of a soft collar, exercises, and nonsteroidal anti- inflammatory drugs (NSAIDs)

1732. (509) Q5-709:

C ongenital pseudarthrosis of the clavicle occurs most commonly on which side:

1) Bilateral

3) Left

2) Right

5) The side with the proximal focal femoral dysplasia

4) The side more involved with fibrous dysplasia

Ninety percent of cases are noted on the right side. Ten percent of cases are bilateral and have been associated with bilateral cervical ribs. Only a few cases of left-sided pseudarthrosis have been described and have been associated with dextrocardia.

Only <5% of cases of congenital pseudarthrosis are on the left. C ongenital pseudarthrosis is not related to fibrous dysplasia.

C ongenital pseudarthrosis is not related to proximal focal femoral dysplasia.

 

■Correct Answer:Right

1733. (510) Q5-710:

The most common structure to be injured in conjunction with an elbow dislocation is:

1) The ulnar nerve

3) The radial nerve

2) The median nerve

5) The biceps tendon

4) The brachial artery

With an injury rate of approximately 6%, the ulnar nerve is the most common injured structure in an elbow dislocation.

Median nerve injuries are rare with elbow dislocation. Such injuries may be due to nerve entrapment. If chronic, this may produce the Matev sign of a groove in the distal humerus.

The radial nerve and biceps tendon are not commonly injured with an elbow dislocation. The brachial artery is rarely injured with an elbow dislocation.

 

■Correct Answer:The ulnar nerve

1734. (511) Q5-711:

A 4-year-old girl is brought in for examination by her mother because of a bump on the lateral side of her elbow. The girl is unable to extend her elbow. She falls as much as any child, but no particular injury to the elbow is recalled. Radiographs show a dislocated, enlarged radial head that is convex proximally. There is a proximal radioulnar synostosis. Recommended treatment includes:

1) Radial head excision

3) Open reduction of the radial head and ulnar lengthening osteotomy

2) Open reduction of the radial head and annular ligament reconstruction

5) No treatment

4) Silastic radial head arthroplasty

This child has a congenital dislocation of the radial head, and no treatment is indicated unless the forearm is fixed in a position of extreme malrotation.

Radial head excision should only be performed if there is pain and the child is skeletally mature. Silastic radial head arthroplasty has a significant risk of particulate synovitis.

 

■Correct Answer:No treatment

1735. (512) Q5-712:

A 6-year-old child falls and suffers a fracture of the elbow. The tenderness is mostly lateral. A fracture line may be seen separating a fragment of the humeral metaphysis and physis 3 mm from the lateral portion of the elbow, but the distal extension of the fracture cannot be visualized because of lack of ossification at this age. Treatment should consist of:

1) No immobilization and early range of motion

3) Application of a long arm cast for 8 weeks

2) Application of a long arm cast for 4 weeks followed by early motion

5) Open reduction and plate fixation

4) C losed reduction and percutaneous pin fixation

C losed reduction and pin fixation should be attempted for all lateral condyle fractures that are displaced more than 2 mm. If closed reduction is not successful, open reduction should be performed.

This is a lateral condyle fracture; nonunion may result with no immobilization and early range of motion. With more than 2 mm of displacement, reduction and fixation should be carried out.

Plate fixation is not feasible because of the presence of the physis. Rigid fixation beyond the use of pins is not required.

 

■Correct Answer:C losed reduction and percutaneous pin fixation

1736. (513) Q5-713:

The following is the most common complication of lateral condyle fractures:

1) Radial nerve palsy

3) Heterotopic ossification

2) C ompartment syndrome

5) Posterior interosseous nerve injury

4) Nonunion

Nonunion occurs more commonly after lateral condyle fracture than following most childrenâs fractures because the fracture line is predominantly intra-articular and not always adequately reduced and immobilized.

Radial nerve injury, compartment syndrome, heterotopic ossification, and posterior interosseous nerve injury are uncommon with lateral condyle fractures.

 

■Correct Answer:Nonunion

1737. (514) Q5-714:

The most common nerve injury in a Monteggia fracture and the type of Monteggia fracture with which it is most commonly found is:

1) Ulnar nerve, type I

3) Posterior interosseous nerve, type III

2) Posterior interosseous nerve, type IV

5) Median nerve, type III

4) Median nerve, type I

The posterior interosseous branch of the radial nerve is injured in 10%-20% of Monteggia fractures. Most cases occur at the time of fracture, but some occur later. Spontaneous resolution is the usual outcome.

The ulnar nerve has only been reported injured in one case.

The posterior interosseous nerve is the most commonly injured, at 10-20%, but type I and type III are the most common types affected.

The median nerve is the second most commonly injured, after the radial nerve.

 

■Correct Answer:Posterior interosseous nerve, type III

1738. (515) Q5-715:

A 7-year-old girl is seen because of a persistent anterior dislocation of the radial head that occurred 2 months ago with an ulna fracture. The ulna has healed but has 25° of angulation. Her family would like to have this fixed to remove the prominence in the hope of preventing future joint degeneration. The recommended treatment is:

1) C losed reduction of the radial head

3) Open reduction and annular ligament reconstruction

2) Open reduction and pin fixation of the radial head

5) Open reduction, radial shortening, and annular ligament reconstruction

4) Open reduction, annular ligament reconstruction, and ulnar osteotomy

The combination of open reduction, annular ligament reconstruction, and ulnar osteotomy should correct all of the components of the deformity.

C losed reduction is not successful beyond 1-2 weeks after injury.

Because of the 25° ulnar bow, recurrence is likely, and ulnar osteotomy is indicated. An ulnar osteotomy should be included to prevent recurrence.

 

■Correct Answer:Open reduction, annular ligament reconstruction, and ulnar osteotomy

1739. (516) Q5-716:

A 6-year-old patient has an acute proximal ulnar fracture with an apex posteriorly, as well as a radial head dislocation. Treatment at this stage should consist of:

1) C losed reduction and immobilization in supination and flexion more than 90° in a long arm cast

3) C losed reduction and intramedullary rod fixation of the ulna

2) C losed reduction and immobilization in extension in a long arm cast

5) Open reduction of the radial head and annular ligament reconstruction

4) Open reduction of the radial head and plate fixation of the ulna

Extension will reduce the dislocation and the fracture.

This type II Monteggia proximal fracture is best immobilized in extension. An intramedullary rod is indicated only if closed treatment fails.

Open reduction of the radial head and plate fixation of the ulna are indicated only if closed treatment fails. Annular ligament reconstruction is indicated only if the dislocation is unreduced for more than 1 to 2 weeks.

 

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

1740. (517) Q5-717:

A 5-year-old patient sustains a fracture of the ulna with apex anteriorly, as well as an anterior dislocation of the radial head. The recommended treatment is:

1) C losed reduction with elbow flexed at least 90° and somewhat supinated

3) C losed reduction with the elbow flexed and the forearm in maximal pronation

2) C losed reduction with the elbow in extension

5) Open reduction of the radial head, annular ligament repair, and closed reduction of the ulna

4) C losed reduction of the radial head and intramedullary rod of the ulna

Flexion to at least 90° helps redirect the radial head, as does partial supination.

Extension of the elbow will increase the tendency to dislocate. Pronation of the forearm will increase the tendency to dislocate. An intramedullary rod is needed only if closed treatment fails. Open reduction is required only if closed treatment fails.

 

■Correct Answer:C losed reduction with elbow flexed at least 90° and somewhat supinated

1741. (518) Q5-718:

A 2-year-old boy fell 4 feet from a countertop and landed on his outstretched hand. There is circumferential swelling and tenderness. Radiographs show no fracture, but the posterior fat pad elbow is elevated and the radius and ulna are translated slightly laterally on the anteroposterior view, and posteriorly on the lateral view. The most likely diagnosis is:

1) Undisplaced supracondylar fracture

3) Lateral condyle fracture

2) Transphyseal fracture of the distal humerus

5) C ongenital elbow dislocation

4) Traumatic elbow dislocation

The separation occurs through cartilage, so it is not visible as a fracture on plain films. However, the translation indicates a problem and elbow dislocation does not occur with any frequency at this age.

An undisplaced supracondylar fracture would not produce translation of the radius and ulna. A lateral condyle fracture would not produce translation of the ulna.

Traumatic dislocation is extremely uncommon in this age group.

C ongenital elbow subluxation would not account for the swelling and tenderness. This is an extremely rare condition. 

■Correct Answer:Transphyseal fracture of the distal humerus

1742. (519) Q5-719:

A physeal fracture-separation of the distal humerus is seen in an 18-month-old boy. When the parents ask about the prognosis after this injury, you tell them that the most common complication is:

1) C ubitus varus

3) Ulnar nerve injury

2) Median nerve palsy

5) Undergrowth of the humerus

4) Brachial artery injury

C ubitus varus occurred in seven out of twelve physeal fracture separations of the distal humerus in one series. This most likely occurred due to malalignment or avascular necrosis of the trochlea.

Median nerve injury, ulnar nerve injury, and brachial artery injury are extremely uncommon after this injury because the surfaces of the metaphysis and the physis are relatively smooth in comparison to supracondylar fractures. Also, these injuries are relatively low-energy.

Growth plate damage causing undergrowth is rare after this fracture. 

■Correct Answer:C ubitus varus

1743. (520) Q5-720:

slide 1

A 12-year-old boy presents to the emergency department after being struck by a car (slide 1). His only complaint at the time of presentation is right ankle pain. After obtaining an excellent reduction and casting the leg, the risks of a future growth disturbance through the involved physis must be discussed with the family. What are the chances of a significant growth disturbance of his leg:

1) < 1%

3) 10% to 15%

2) 2% to 3%

5) 80% to 90%

4) 45% to 55%

This is a Salter-Harris type II fracture of the distal tibia. The distal tibia is at moderate risk for growth arrest after physeal injury. The average incidence of growth disturbance is 15% for all physeal injuries in this area. The marked displacement and mechanism of injury in this patient increase the risk of permanent physeal damage. The patientâs age and remaining growth also increase the likelihood of a growth arrest causing a significant deformity or leg length discrepancy.

■Correct Answer:10% to 15%

1744. (521) Q5-721:

Three years after a Salter-Harris type I physeal fracture of the right distal femur, a 12-year-old boy presents with complaints of knee pain and a limp. On examination, the boy has a valgus alignment of his right knee and a 2-cm leg length discrepancy with the right leg shorter than the left. Plain radiographs and a scanogram showed 30% growth plate closure with a femoral-tibial angle of 12° of valgus and 2.5 cm of shortening of the right femur. What is the best treatment:

1) Lengthening procedure on the right leg

3) Physeal bar resection of the right distal femur and opening wedge lateral osteotomy

2) Varus osteotomy of the right femur and bilateral distal femur epiphyseodesis

5) C ompletion of distal femoral epiphyseal closure

4) Right medial hemiepiphyseal stapling

The bar resection has a reasonable chance of success. The angulation can be corrected by the osteotomy and the length would be partially corrected.

C orrection of the length (2 cm) is less important than prevention of future angulation and shortening.

At 12 years old, if varus osteotomy of the right femur and bilateral distal femur epiphyseodesis were performed, the patient would be sacrificing 6 cm of leg length which most patients would consider unacceptable.

Right medial hemiepiphyseal stapling and completion of distal femoral epiphyseal closure would neither produce significant length equalization nor correct the angulation.

 

■Correct Answer:Physeal bar resection of the right distal femur and opening wedge lateral osteotomy

1745. (522) Q5-722:

Two years after a Salter-Harris type II fracture of the right distal femur, a 12-year-old girl presents to the clinic with knee pain. On examination, she is found to have a valgus alignment of the right knee and a 3-cm leg length discrepancy with the right leg shorter than the left leg. The scanogram confirms 3 cm of shortening in the right femur. The next step in the management of this patient is:

1) Obtain a magnetic resonance image of the right distal femoral physis

3) Obtain a bone scan

2) Obtain a computed tomography scan of the right distal femoral physis

5) Patientâs return in 9 months for a repeat scanogram

4) Obtain a single photon emission computed tomography scan

A magnetic resonance image of the right distal femoral physis provides the best detail of the physis if the correct region and sequences are ordered.

A computed tomography scan is not the preferred method to allow visualization of the physis.

A bone scan or photon emission computed tomography scan will not highlight a bar of the physis. Waiting 9 months would allow for worsening of the deformity.

 

■Correct Answer:Obtain a magnetic resonance image of the right distal femoral physis

1746. (523) Q5-725:

The mutations underlying Stickler syndrome have been identified in which of the following molecules:

1) Type I collagen

3) Fibrillin

2) Type II collagen

5) Fibroblast growth factor receptor protein

4) Sulfate transport protein

Type II collagen is abnormal in the classic form of Stickler syndrome, but in a few patients, type XI collagen has been found to be the causative mutation.

Type 1 collagen is predominant in bone and is abnormal in osteogenesis imperfecta, for example. Stickler syndrome is characterized by a defect in type II collagen.

Fibrillin is abnormal in Marfan syndrome, but in Stickler syndrome, the causative abnormalities have been found in type II

collagen.

Sulfate transport protein has been found abnormal in diastrophic dysplasia

Fibroblast growth factor proteins are abnormal in achondroplasia and hypochondroplasia, but the basic defect in Stickler syndrome is type II collagen.

 

■Correct Answer:Type II collagen

1747. (581) Q5-817:

A 15-month-old child has bowing of the legs. Examination reveals a 3 cm distance between the femoral condyles and a thigh- foot angle of 20° internal. Radiographs reveal 10° varus of the mechanical axis, no evidence of skeletal dysplasia, and a metaphyseal-diaphyseal  angle of 9° on each side. Recommended treatment is:

1) Full-time bracing with a knee-ankle-foot orthosis

3) Bilateral hemiepiphyseal stapling of the lateral tibia

2) Bilateral oblique osteotomies of the proximal tibia

5) Reassurance to parents that the legs will develop normally; no further follow-up

4) Re-examination in 6 months

Although a diagnosis of Blount disease cannot be made at this time, the disease cannot be ruled out. The patient should be rechecked in 6 months by an experienced examiner. However, if the parents are reliable, they can be told that they do not need to return if the childâs legs develop a normal shape in 6 months.

The diagnosis of pathologic varus cannot be made; therefore, no treatment is indicated. The findings described are not outside of normal limits; surgery is not necessary.

No pathologic diagnosis has yet been made. In addition, stapling is not an indicated form of treatment for such a young child.

Although a pathologic condition has not been diagnosed, one cannot be ruled out either at this stage. 

■Correct Answer:Re-examination in 6 months

1748. (582) Q5-818:

An 11-year-old girl is observed for legs that have been bowed for the past 5 years. She has a mechanical axis that is in 26° of varus, a medial tibial plateau slope of 8°, a tibial joint angle of 15° varus, and a femoral joint angle of 10° varus. Her physis appears open. Recommended treatment is:

1) Tibial valgus osteotomy

3) Tibial and femoral valgus osteotomy

2) Femoral valgus osteotomy

5) Brace treatment

4) Medial tibial plateau elevation

Both a tibial and a femoral valgus osteotomy are necessary to correct significant deformities in these areas.

A tibial valgus osteotomy is necessary but not sufficient. The femoral joint angle is off by 13° from the normal angle. A femoral valgus osteotomy is necessary but not sufficient. The tibial joint angle is off by 15° of varus.

A tibial plateau elevation is not necessary for this mild degree of plateau depression. Brace treatment is not recommended for patients older than 3 years of age.

 

■Correct Answer:Tibial and femoral valgus osteotomy

1749. (583) Q5-819:

The radiographic feature that is most characteristic of infantile Blount disease is:

1) Widening and irregularity of the entire proximal tibial physis

3) Focal bowing of the distal medial femur

2) Poor bone mineralization

5) External tibial torsion

4) Focal bowing of the proximal medial tibia

Bowing is focally located at the proximal medial tibia in infantile Blount disease.

The physis may be widened medially, but it is normal laterally. Bone mineralization is not impaired in Blount disease.

Bowing is focally located at the proximal tibia, not the distal femur. Blount disease is associated with internal, not external, tibial torsion.

 

■Correct Answer:Focal bowing of the proximal medial tibia

1750. (584) Q5-820:

Marfan syndrome is now recognized as a defect in the following molecule:

1) Fibrillin-1

3) Type II collagen

2) Type I collagen

5) Type IX collagen

4) Sulfate transport protein

Marfan syndrome is due to an abnormality in fibrillin-1, a component of elastic connective tissue.

Type I collagen is most commonly abnormal in osteogenesis imperfecta. Type I collagen is normal in Marfan syndrome. Type II collagen is a homotrimer (encoded by a single gene) and is mainly located in cartilaginous tissues. Type II collagen is abnormal in spondyloepiphyseal dysplasia congenita and Stickler syndrome.

The sulfate transport protein is important for cartilage formation. The sulfate transport protein is impaired in diastrophic dysplasia.

Type IX collagen is also found in cartilage. Type IX collagen is abnormal in some forms of multiple epiphyseal dysplasia. 

■Correct Answer:Fibrillin-1