Question 1

Which of the following aspects of reconstruction of chronic posttraumatic dislocation of the radial head has not been shown to improve the success rate:

Explanation

Reconstruction with an ulnar osteotomy with apex-posterior angulation and slight lengthening with rigid fixation to allow early range of motion have been shown to improve results. Radiocapitellar pin fixation may cause arthrosis, breakage, and infection so it is not routinely recommended.

Question 2

In patients with idiopathic adolescent scoliosis, clinically noticeable shortness of breath from restrictive lung disease begins to occur at a mean curve of:

Explanation

Clinically noticeable pulmonary compromise begins to occur at a mean curve of 75° thoracic, although a decrease can be measured by pulmonary function testing with curves as little as 50°. C or pulmonale does not occur until a curve is larger then 100°.

Question 3

Which of the following statements is true of patients with idiopathic scoliosis not treated surgically (long-term follow-up data) when compared to nonscoliotic controls:

Explanation

Patients with idiopathic scoliosis have a mortality rate that is not statistically different from the general population. They do not have a significant risk of neuropathy or spine fracture. Their curves worsen in maturity if they are greater than approximately 40°. They also have an increased prevalence of back pain.

Question 4

The cause of Ehlers-Danlos syndrome types I (gravis) and II (mitis) is a mutation in which of the following:

Explanation

Ehlers-Danlos syndrome is subclassified into at least nine types. Types I and II result from defects in type V collagen.

Question 5

The most common neural injury after a supracondylar fracture of the distal humerus is:

Explanation

The most commonly injured nerve after a supracondylar fracture of the distal humerus is the anterior interosseous nerve. An injury to this nerve results in the inability to flex the interphalangeal joint of the thumb and the distal interphalangeal joint of the index finger.

Question 6

Which of the following conditions does not have a risk of cervical deformity greater than the general population:

Explanation

Achondroplasia is associated with frequent stenosis of the foramen magnum in infancy, as well as lower cervical stenosis. However, it is not associated with an actual deformity of the cervical spine. By contrast, neurofibromatosis, Larsen syndrome, and diastrophic dysplasia are associated with infantile cervical kyphosis. Down syndrome is associated with the risk of upper cervical instability.

Question 7

Which of the following iliac osteotomies provides the greatest freedom of mobilization of the acetabular segment:

Explanation

Osteotomies that are made closest to the acetabulum provide the greatest freedom of mobilization. Of the choices provided, the Ganz or Bernese osteotomy is made closest to the acetabulum.

Question 8

Displaced tibial eminence fractures contain the attachment of which of the following structures in addition to the anterior cruciate ligament:

Explanation

Displaced tibial eminence fractures have been shown by arthroscopy to routinely contain the anterior attachment of the lateral meniscus. In addition, the anterior tibial attachment of the meniscus is torn. The cruciate and the meniscus pull the fragment in different directions.

Question 9

A 10-year-old boy sustains a type III avulsion of the anterior tibial eminence. When his knee is placed in extension, the fragment does not reduce. Which of the following factors is likely preventing its reduction:

Explanation

Type III tibial eminence fractures usually contain attachments of both the anterior cruciate ligament and the lateral meniscus. The opposing pull of both of these structures often prevents reduction during extension of the knee.

Question 10

A 13-year-old boy who underwent in situ fixation of slipped capital femoral epiphysis 1 year ago calls your office to complain of knee pain on the other side. He is able to bear his weight on the leg. You recommend:

Explanation

This patient most likely has a contralateral slipped capital femoral epiphysis. It may even be in the â preslipâ category. Acute progression to an unstable slip is possible at any time and may lead to avascular necrosis and permanent loss of motion. Therefore, urgent examination with physical examination and plain radiographs is necessary.

Question 11

An 8-year-old boy suffers a hip dislocation while playing tackle football. His hip is reduced by closed means, and he is immobilized in abduction for a month. Radiographs at that time demonstrate a normal appearance of the hip. You recommend:

Explanation

This patient may suffer avascular necrosis as a result of the dislocation. Avascular necrosis may not become evident until 1 year after the accident, so continued surveillance and protection are recommended.

Question 12

Which population of patients with cerebral palsy is at greatest risk of neuromuscular hip subluxation:

Explanation

Patients with total-involvement cerebral palsy are at the greatest risk of hip subluxation. The rate is documented to be between 25% and 60%.

Question 13

Which group of children with cerebral palsy are at greatest risk of hip subluxation after selective dorsal rhizotomy:

Explanation

Nonambulators with some degree of pre-existing hip migration are at highest risk of hip subluxation after selective dorsal rhizotomy. Patients over the age of 10 and those with hemiplegia are not typically offered selective rhizotomy.

Question 14

Which of the following muscles is most often preserved during adductor tenotomy for patients with cerebral palsy:

Explanation

Adductor tenotomy performed on patients with cerebral palsy typically involves multiple releases until abduction of more than 60° is obtained. This usually begins with release of the longus, brevis, and gracilis (with the pectineus if necessary). The adductor magnus is almost never released because of its important extensor function.

Question 15

The parameter most often recommended to follow the reciprocal relationship of the femoral head to the acetabulum in patients with cerebral palsy is known as the:

Explanation

The migration index (of Reimer) is most commonly used to track the femoral-acetabular relationship in patients with cerebral palsy because it most accurately portrays the progressive migration of the femoral head that may occur. The acetabular index only measures the acetabular response. The epiphyseal extrusion index is used for patients with Perthes disease (where the epiphysis deforms). The Stulberg index is for late outcome of Perthes, and the Tonnis index is for developmental dysplasia of the hip.

Question 16

The upper limit for a normal migration index in young children is less than:

Explanation

The migration index (of Reimer) is the percentage of the femoral head lateral to the Perkins line. The index is used to quantify hip migration in patients with cerebral palsy. It is more useful than the center-edge angle because it is a linear variable angle and because the center of the aspherical, immature femoral head may be hard to accurately identify. The upper limit of a normal migration in young children is listed as 25%.

Question 17

The acetabular sourcil is best described as:

Explanation

The acetabular sourcil is a lateral articular border, which normally should be downsloping and below the dome of the acetabulum. In dysplastic hips, the femoral head pushes the acetabular sourcil up and gives it an upsloping shape.

Question 18

In patients with single thoracic idiopathic scoliosis treated with posterior pedicle screw constructs, the distal extent of the fusion may be stopped at which of the following levels with respect to the neutral vertebra and still routinely maintain balance:

Explanation

In single thoracic idiopathic scoliosis, the distal extent of the fusion may be stopped at one level above the neutrally rotated vertebra and still maintain trunk balance.

Question 19

The greatest number of malpractice suits in pediatric orthopedics relates to which diagnosis:

Explanation

The largest number of malpractice claims in pediatric orthopedics relates to fractures. This diagnosis accounts for 77% of all claims, in contrast to 57% for adults. However, the mean amount paid for each claim is lower than other diagnostic groups. Orthopedic surgeons should be aware of the issue when taking care of children with fractures.

Question 20

For a given femur fracture pattern and age, which method of treatment causes the longest time to union in children ages 6 to 12 years:

Explanation

External fixation produces the longest times to healing, presumably because of load-shielding. The fracture ends may also be distracted.

Question 21

A 12-year-old premenarchal female presents with right thoracic idiopathic scoliosis. Radiographs demonstrate a Cobb angle of 30 degrees and a Risser stage of 0. What is the most appropriate management?

Explanation

Bracing is indicated for skeletally immature patients (Risser 0-2) with idiopathic scoliosis curves between 25 and 45 degrees. A TLSO worn for at least 18 hours daily has been shown to significantly decrease the risk of curve progression to the surgical threshold.

Question 22

A 3-year-old child is diagnosed with congenital scoliosis secondary to a fully segmented hemivertebra. Which of the following is the most appropriate routine screening test required in this patient?

Explanation

Congenital scoliosis is highly associated with genitourinary anomalies (up to 30%), most commonly unilateral kidney. A renal ultrasound is a mandatory screening test in these patients to evaluate for associated defects.

Question 23

Which of the following radiographic criteria is required for the classic diagnosis of Scheuermann's disease?

Explanation

Sorensen's criteria for classic Scheuermann's kyphosis require anterior wedging of at least 5 degrees in three or more consecutive vertebrae. Endplate irregularities and Schmorl nodes are supportive but not strictly required for the formal definition.

Question 24

Which of the following best describes the primary vascular supply to the proximal pole of the scaphoid?

Explanation

The primary blood supply to the scaphoid is retrograde, originating from the dorsal carpal branch of the radial artery, which enters the dorsal ridge at the waist and supplies the proximal pole. This retrograde flow is why proximal pole fractures have a high risk of avascular necrosis and nonunion.

Question 25

In the surgical management of a 'terrible triad' injury of the elbow, which of the following sequences of repair is generally recommended to best restore stability?

Explanation

Standard protocol for terrible triad reconstruction proceeds from deep to superficial and typically from anterior to posterior. The sequence is fixing the coronoid, then repairing or replacing the radial head, and finally repairing the lateral collateral ligament (LCL).

Question 26

In infantile idiopathic scoliosis, a rib-vertebra angle difference (RVAD) of Mehta greater than what value is highly predictive of curve progression?

Explanation

Mehta's rib-vertebra angle difference (RVAD) is used to predict progression in infantile idiopathic scoliosis. An RVAD greater than 20 degrees strongly predicts curve progression, whereas an RVAD less than 20 degrees typically resolves spontaneously.

Question 27

A 14-year-old gymnast presents with back pain and L5 radiculopathy. Radiographs show a Grade III isthmic spondylolisthesis at L5-S1 with a high pelvic incidence. Which of the following is the most appropriate surgical strategy if conservative management fails?

Explanation

For high-grade (Grade III or IV) isthmic spondylolisthesis in adolescents, L4 to S1 posterior instrumented fusion is often recommended due to the severe slip angle and high pelvic incidence. A single-level L5-S1 fusion in high-grade slips carries a high rate of hardware failure and pseudarthrosis.

Question 28

During a lateral approach to the elbow (Kocher approach), the surgical interval is developed between which two muscles?

Explanation

The Kocher approach utilizes the internervous plane between the anconeus (radial nerve) and the extensor carpi ulnaris (posterior interosseous nerve). This provides excellent access to the radial head and capitellum.

Question 29

Failure to stabilize the volar lunate facet fragment in a distal radius fracture most commonly leads to subluxation of the carpus in which direction?

Explanation

The volar lunate facet is critical for the stability of the radiocarpal joint due to the attachment of the short radiolunate ligament. Failure to capture this fragment often results in volar subluxation of the carpus and catastrophic joint failure.

Question 30

A 35-year-old female sustains a Dubberley Type 3B capitellum fracture. What specific anatomical feature distinguishes a Type B from a Type A in the Dubberley classification?

Explanation

The Dubberley classification divides capitellum fractures based on the presence (Type B) or absence (Type A) of posterior condylar comminution. This is critical because Type B fractures lack posterior cortical support and often require specific fixation strategies.

Question 31

A 6-year-old boy presents with a completely displaced, extension-type supracondylar humerus fracture. He is unable to flex his interphalangeal joint of the thumb or the distal interphalangeal joint of the index finger. Which nerve is most likely injured?

Explanation

The anterior interosseous nerve (AIN) is the most commonly injured nerve in extension-type pediatric supracondylar humerus fractures. Injury presents with the inability to make an 'OK' sign, indicating weakness of the flexor pollicis longus and flexor digitorum profundus.

Question 32

A 28-year-old manual laborer presents with Lichtman Stage IIIA Kienbock's disease and ulnar minus variance. Which of the following is the most appropriate surgical intervention?

Explanation

In Kienbock's disease with ulnar minus variance and no carpal collapse (Stage IIIA), joint leveling procedures such as a radial shortening osteotomy are indicated. This unloads the lunate and can arrest disease progression.

Question 33

Which of the following is the most proximal potential site of ulnar nerve compression in cubital tunnel syndrome?

Explanation

The Arcade of Struthers is a fascial band located about 8 cm proximal to the medial epicondyle and represents the most proximal potential site for ulnar nerve compression. Other sites include the medial intermuscular septum, Osborne's ligament, and the FCU aponeurosis.

Question 34

According to the Lenke classification for adolescent idiopathic scoliosis, what criteria define a structural proximal thoracic curve?

Explanation

In the Lenke classification, minor curves are considered structural if they do not bend out to less than 25 degrees on side-bending films, or if there is regional kyphosis of at least +20 degrees. For the proximal thoracic curve, the kyphosis is measured between T2 and T5.

Question 35

According to the Bado classification, a Monteggia lesion consisting of a diaphyseal fracture of the ulna with posterior dislocation of the radial head is classified as:

Explanation

Bado Type II Monteggia fractures are characterized by posterior or posterolateral dislocation of the radial head with an associated ulnar diaphyseal fracture. They are most commonly seen in adults.

Question 36

To prevent the 'crankshaft phenomenon' in a skeletally immature patient with adolescent idiopathic scoliosis (Risser 0, open triradiate cartilages) undergoing posterior spinal fusion, what surgical strategy has historically been indicated?

Explanation

The crankshaft phenomenon occurs due to continued anterior vertebral growth after a solid posterior fusion in very immature patients. Historically, a combined anterior (to arrest growth) and posterior fusion was required to prevent this progressive deformity.

Question 37

A 5-year-old sustains a lateral condyle fracture of the humerus. Which of the following complications is most highly associated with nonunion of this specific fracture?

Explanation

Nonunion of a lateral condyle fracture leads to progressive cubitus valgus deformity. This increasing valgus stretches the ulnar nerve over time, leading to tardy ulnar nerve palsy years after the initial injury.

Question 38

In radial tunnel syndrome, compression of the posterior interosseous nerve most frequently occurs at which of the following structures?

Explanation

While compression can occur at multiple sites within the radial tunnel, the most common site of compression for the posterior interosseous nerve is the Arcade of Frohse. This is the thickened proximal aponeurotic edge of the superficial supinator muscle.

Question 39

In the management of a Galeazzi fracture, which of the following radiographic signs most strongly indicates gross instability of the distal radioulnar joint (DRUJ) requiring operative stabilization?

Explanation

A basilar ulnar styloid fracture in the setting of a Galeazzi fracture frequently signifies complete detachment of the triangular fibrocartilage complex (TFCC) from its foveal insertion. This indicates severe DRUJ instability that often requires pinning or direct repair.

Question 40

A 12-year-old male with Duchenne muscular dystrophy presents with a 45-degree sweeping thoracolumbar scoliosis and progressive loss of sitting balance. What is the primary indication to extend the spinal fusion down to the pelvis in this neuromuscular patient?

Explanation

In nonambulatory patients with neuromuscular scoliosis, extending the fusion to the pelvis is primarily indicated to correct pelvic obliquity. This provides a level pelvis, which is essential for maintaining sitting balance and preventing skin breakdown.

Question 41

In a patient with idiopathic adolescent scoliosis, at what thoracic curve magnitude does right-sided heart failure (cor pulmonale) typically begin to occur?

Explanation

In idiopathic scoliosis, restrictive lung disease becomes clinically significant at curves >80 degrees. However, right-sided heart failure (cor pulmonale) typically occurs when the thoracic curve exceeds 110 degrees.

Question 42

When surgically reconstructing a terrible triad injury of the elbow, which of the following represents the most accepted and standard sequence of repair?

Explanation

The standard inside-out sequence for repairing a terrible triad injury is coronoid fixation first, followed by radial head replacement or fixation, and finally LCL repair. This restores the deep skeletal stabilizers before reconstructing the lateral ligamentous constraints.

Question 43

Among the following patterns of congenital spinal deformity, which carries the highest risk of rapid curve progression?

Explanation

Unilateral unsegmented bar with a contralateral hemivertebra has the highest risk of progression in congenital scoliosis. This is due to tethered growth on the concave side coupled with active growth on the convex side.

Question 44

A patient presents with a Dubberley Type 3B fracture of the capitellum. In this classification system, what does the suffix "B" specifically denote?

Explanation

In the Dubberley classification of capitellum fractures, Type 3 denotes comminution. The addition of the suffix "B" indicates posterior articular comminution, which implies a lack of a bony buttress and often necessitates bone grafting or excision.

Question 45

When evaluating an AP radiograph of an infant with idiopathic scoliosis, a Rib Vertebral Angle Difference (RVAD) of Mehta greater than what value is considered highly predictive of curve progression?

Explanation

The Rib Vertebral Angle Difference (RVAD) of Mehta evaluates the risk of progression in infantile idiopathic scoliosis. An RVAD greater than 20 degrees strongly predicts an aggressive, progressing curve rather than a resolving one.

Question 46

Which of the following ligamentous structures is the primary restraint to valgus stress at the elbow during the throwing motion (between 30 and 120 degrees of flexion)?

Explanation

The anterior bundle of the ulnar collateral ligament (UCL) is the primary restraint to valgus instability at the elbow. It is most taut from 30 to 120 degrees of flexion, making it a critical stabilizer for throwing athletes.

Question 47

A 16-year-old non-ambulatory patient with spastic quadriplegic cerebral palsy presents with a 75-degree neuromuscular scoliosis and marked pelvic obliquity. To maximize sitting balance, the distal extent of the spinal fusion should be:

Explanation

In non-ambulatory neuromuscular patients with scoliosis and pelvic obliquity, spinal fusion must be extended to the pelvis. This securely corrects the obliquity, prevents ischial decubitus ulcers, and establishes a level platform for sitting.

Question 48

An Essex-Lopresti fracture-dislocation is characterized by a radial head fracture, distal radioulnar joint (DRUJ) dislocation, and disruption of which of the following structures?

Explanation

An Essex-Lopresti injury is defined by a radial head fracture accompanied by disruption of the DRUJ and the interosseous membrane. This longitudinal instability requires radial head restoration to prevent proximal radial migration and chronic wrist pain.

Question 49

According to the Sorensen criteria, a definitive radiographic diagnosis of Scheuermann's kyphosis requires which of the following findings?

Explanation

Sorensen criteria for Scheuermann's kyphosis require anterior wedging of greater than 5 degrees in at least three consecutive vertebrae. This structural deformity is distinct from flexible postural roundback, which lacks these bony wedging changes.

Question 50

In a pediatric patient with an extension-type supracondylar humerus fracture that is displaced posteromedially, which nerve is at the highest risk of injury due to tethering over the proximal fragment?

Explanation

In an extension-type supracondylar humerus fracture with posteromedial displacement of the distal fragment, the proximal fragment is directed anterolaterally. This anteriorly displaced bony spike places the radial nerve at the highest risk of injury.

Question 51

Which of the following spinopelvic parameters is an anatomical constant for a given individual and, when elevated, strongly correlates with a higher risk of spondylolisthesis progression?

Explanation

Pelvic incidence (PI) is a fixed anatomical parameter that defines the shape of the pelvis. A high PI creates a steeper lumbosacral angle, resulting in increased shear forces across the L5-S1 junction and a higher risk of spondylolisthesis progression.

Question 52

A pediatric patient sustains a Bado Type III Monteggia fracture-dislocation. What is the direction of the radial head dislocation in this specific injury pattern?

Explanation

The Bado classification describes Monteggia fracture-dislocations based on the direction of radial head dislocation. A Type III injury features a lateral or anterolateral dislocation of the radial head along with a proximal ulnar metaphyseal fracture.

Question 53

A 14-year-old pre-menarchal female (Risser 0) presents with a 35-degree right thoracic idiopathic scoliosis curve. What is the most appropriate initial management?

Explanation

In a skeletally immature patient (e.g., Risser 0, pre-menarchal) with a progressing idiopathic curve between 25 and 45 degrees, bracing is the standard of care. A TLSO has been shown to be highly effective in preventing curve progression to surgical thresholds.

Question 54

The lateral ulnar collateral ligament (LUCL) is the primary stabilizing structure preventing posterolateral rotatory instability (PLRI) of the elbow. Where does this ligament distally insert?

Explanation

The lateral ulnar collateral ligament (LUCL) acts as a sling supporting the radial head and prevents PLRI. It originates on the lateral epicondyle and inserts on the supinator crest of the proximal ulna.

Question 55

In the evaluation of adult spinal deformity, which of the following radiographic parameters has been shown to most closely correlate with decreased health-related quality of life (HRQOL) scores?

Explanation

Sagittal vertical axis (SVA) measures global sagittal alignment and is the single most important radiographic parameter correlating with poor HRQOL. Positive sagittal imbalance results in significantly increased energy expenditure to maintain an upright posture.

Question 56

During a single-incision anterior approach for repairing an acute distal biceps tendon rupture, which nerve is most frequently injured or irritated due to its superficial location and proximity to the cephalic vein?

Explanation

The lateral antebrachial cutaneous nerve (LABCN) runs closely with the cephalic vein and the distal biceps tendon, making it the most commonly injured nerve during a single-incision anterior approach. Injury results in lateral forearm paresthesias.

Question 57

When grading a patient with cervical spondylotic myelopathy, the Nurick classification system primarily evaluates which functional aspect?

Explanation

The Nurick classification grades the severity of cervical spondylotic myelopathy based solely on gait disturbance and ambulatory status. Grade 0 denotes root symptoms only, while Grade 5 indicates a wheelchair-bound or bedridden patient.

Question 58

Following severe elbow trauma or an open surgical contracture release, what is the most effective and widely accepted prophylactic regimen to prevent heterotopic ossification (HO)?

Explanation

Heterotopic ossification is a severe complication following elbow trauma or capsular release. Prophylaxis with oral indomethacin or a single dose of low-dose radiation (typically 700 cGy) is highly effective at preventing ectopic bone formation.

Question 59

A 65-year-old male with pre-existing cervical spondylosis sustains a hyperextension injury to his neck in a motor vehicle accident. He presents with Central Cord Syndrome. Which of the following best describes his expected pattern of motor deficit?

Explanation

Central Cord Syndrome typically results from hyperextension injuries compressing the spinal cord in a narrowed canal. Because the cervical motor tracts controlling the upper extremities are located more centrally, patients present with profound upper extremity weakness (especially hands) while retaining better lower extremity function.

Question 60

A 12-year-old girl with adolescent idiopathic scoliosis presents with a right thoracic curve of 32 degrees. She is premenarcheal and has a Risser stage of 0. What is the most appropriate management?

Explanation

Bracing is indicated for growing children (Risser 0-2, premenarcheal) with curves between 25 and 45 degrees. A TLSO worn 16-23 hours a day significantly decreases the risk of curve progression to the surgical threshold.

Question 61

A 2-year-old boy is diagnosed with congenital scoliosis secondary to a fully segmented hemivertebra at T8. Which of the following screening tests is most critical for this patient?

Explanation

Congenital scoliosis is frequently associated with VACTERL anomalies, with genitourinary anomalies occurring in up to 30% of patients. A renal ultrasound is mandatory to rule out unilateral renal agenesis or obstructive uropathy.

Question 62

Which of the following radiographic findings is a required criterion for the classic diagnosis of Scheuermann's kyphosis (Sorensen criteria)?

Explanation

The Sorensen criteria for Scheuermann's kyphosis require anterior wedging of at least 5 degrees in three or more consecutive vertebrae. Associated findings often include Schmorl's nodes and endplate irregularities, but the sequential wedging is diagnostic.

Question 63

In the surgical management of a "terrible triad" injury of the elbow, which of the following sequences of reconstruction provides the most biomechanically stable construct?

Explanation

Standard protocol for terrible triad reconstruction generally proceeds from deep to superficial. This involves fixing or replacing the coronoid first, followed by the radial head, and finally repairing the lateral collateral ligament (LCL) complex.

Question 64

According to the Lonstein and Carlson formula, which combination of factors carries the highest risk for curve progression in a patient with idiopathic scoliosis?

Explanation

Risk of curve progression in idiopathic scoliosis is highest in young, skeletally immature patients (low Risser sign, premenarcheal) with larger curve magnitudes at the time of presentation.

Question 65

A 1-year-old child presents with a left thoracic infantile idiopathic scoliosis measuring 25 degrees. The rib-vertebra angle difference (RVAD) of Mehta is calculated at 25 degrees. What is the most likely clinical course?

Explanation

A Mehta's rib-vertebra angle difference (RVAD) greater than 20 degrees is highly predictive of curve progression in infantile idiopathic scoliosis. These progressive curves typically require intervention such as serial elongation-derotation-flexion (EDF) casting.

Question 66

A 14-year-old gymnast has a Grade II isthmic spondylolisthesis at L5-S1. She complains of radicular pain and hamstring tightness. Which of the following best explains the mechanism of her hamstring tightness?

Explanation

Hamstring tightness in pediatric isthmic spondylolisthesis (the "Phalen-Dickson sign") is a reflexive spasm meant to vertically orient the pelvis (retroversion) to decrease lumbar lordosis and prevent further anterior translation.

Question 67

A 35-year-old patient presents with recurrent clicking and giving way of the elbow when pushing up from a chair. The lateral ulnar collateral ligament (LUCL) is suspected to be deficient. Which physical exam test is most specific for this condition?

Explanation

The lateral pivot shift test of the elbow specifically evaluates for posterolateral rotatory instability (PLRI) caused by LUCL insufficiency. It involves applying an axial load, valgus stress, and supination while flexing the elbow.

Question 68

A 14-year-old non-ambulatory male with Duchenne muscular dystrophy presents with a progressing 50-degree thoracolumbar scoliosis and pelvic obliquity. What is the most appropriate surgical strategy?

Explanation

In non-ambulatory patients with Duchenne muscular dystrophy and significant pelvic obliquity, posterior spinal fusion must typically extend to the pelvis to provide a stable, level sitting base and prevent further deformity.

Question 69

A 6-year-old boy sustains a Bado Type I Monteggia fracture-dislocation. Closed reduction of the ulna is achieved, but the radial head remains anteriorly dislocated. What is the most common anatomical block to reduction of the radial head in this scenario?

Explanation

The annular ligament is the most common structure that becomes interposed and blocks closed reduction of the radial head in a pediatric Monteggia fracture-dislocation. Open reduction is frequently required to extricate the ligament.

Question 70

During a single-incision anterior approach for distal biceps tendon repair, excessive radial retraction is applied. Postoperatively, the patient is unable to extend their fingers or thumb at the MCP joints, but wrist extension is preserved with radial deviation. Which nerve was most likely injured?

Explanation

The posterior interosseous nerve (PIN) is highly susceptible to traction injury from radial retractors during the anterior approach to the elbow. PIN palsy presents with loss of digit extension and radial-deviated wrist extension, as ECRL innervation is proximal to the PIN.

Question 71

A 45-year-old female falls on an outstretched hand and sustains a Hahn-Steinthal (Type I) capitellum fracture. Which of the following accurately describes this fracture pattern?

Explanation

A Hahn-Steinthal (Type I) fracture involves a large osseous piece of the capitellum and often includes a portion of the lateral trochlea. In contrast, a Kocher-Lorenz (Type II) fracture is an articular cartilage shear with minimal subchondral bone.

Question 72

A 30-year-old man falls from a height, sustaining a comminuted radial head fracture and distal radioulnar joint (DRUJ) dislocation. Which of the following management steps is strictly contraindicated?

Explanation

In an Essex-Lopresti injury, the interosseous membrane is disrupted. Excision of the radial head without replacement removes the proximal stabilizing column, leading to severe proximal radial migration and chronic wrist dysfunction.

Question 73

A 10-year-old boy with Klippel-Feil syndrome wishes to play contact sports. He has a fusion of C2-C3 but normal neurologic exam. According to current guidelines, what is the most appropriate recommendation?

Explanation

Patients with Klippel-Feil syndrome typically have congenital cervical fusions leading to compensatory hypermobility at adjacent unfused segments. They are generally restricted from contact or collision sports to prevent catastrophic neurologic injury.

Question 74

A 5-year-old girl sustains an extension-type Gartland III supracondylar humerus fracture with posteromedial displacement. Which nerve is most commonly injured in this specific displacement pattern?

Explanation

In posteromedial displacement of extension-type supracondylar humerus fractures, the distal fragment goes medially, leaving the proximal fragment protruding laterally. This lateral spike puts the radial nerve at the highest risk of injury.

Question 75

Which of the following conditions is the primary indication for the use of a Vertical Expandable Prosthetic Titanium Rib (VEPTR) device?

Explanation

VEPTR is specifically designed to manage thoracic insufficiency syndrome by expanding the constrained thorax. This allows for lung growth and treats early-onset complex spinal deformities without permanently fusing the spine.

Question 76

A 13-year-old girl with adolescent idiopathic scoliosis presents with a 25-degree right thoracic curve. Her Risser stage is 0, and she is premenarcheal. What is the most appropriate initial management?

Explanation

For a growing child (Risser 0-2) with an idiopathic curve between 25 and 45 degrees, TLSO bracing for a minimum of 18 hours per day is the standard of care to prevent curve progression. The BRAIST trial demonstrated a dose-dependent success rate with brace wear.

Question 77

In adult spinal deformity surgery, achieving optimal sagittal balance requires matching the postoperative lumbar lordosis (LL) to the patient's pelvic incidence (PI). The postoperative LL should ideally fall within how many degrees of the PI?

Explanation

Sagittal plane correction in adult spinal deformity aims for a lumbar lordosis (LL) within 10 degrees of the pelvic incidence (PI). A PI-LL mismatch greater than 10 degrees correlates with residual pain and adjacent segment disease.

Question 78

What is the recommended sequence for the surgical reconstruction of a 'terrible triad' injury of the elbow (radial head fracture, coronoid fracture, and elbow dislocation)?

Explanation

The standard surgical sequence for a terrible triad injury begins deep-to-superficial: repairing the coronoid first, followed by the radial head, and finally repairing the lateral collateral ligament (LCL) complex. MCL repair is only considered if the elbow remains unstable after these steps.

Question 79

Which of the following morphological patterns of congenital scoliosis carries the highest risk of rapid curve progression and requires the most urgent surgical intervention?

Explanation

A unilateral unsegmented bar with a contralateral fully segmented hemivertebra causes asymmetric growth that almost always leads to rapid, severe progression. Early surgical intervention, typically via in situ fusion or hemivertebra excision, is strictly indicated.

Question 80

A 35-year-old male presents with lateral elbow pain and mechanical clicking when pushing out of a chair. Examination reveals a positive lateral pivot-shift test. Deficiency of which of the following structures is the primary cause of his symptoms?

Explanation

The patient describes symptoms of posterolateral rotatory instability (PLRI) of the elbow. PLRI is primarily caused by an injury or deficiency of the lateral ulnar collateral ligament (LUCL).

Question 81

According to the Sorensen criteria, a definitive radiographic diagnosis of Scheuermann's kyphosis requires anterior wedging of at least 5 degrees in a minimum of how many consecutive vertebrae?

Explanation

The classic Sorensen criteria define Scheuermann's disease as hyperkyphosis with anterior wedging of at least 5 degrees in three or more adjacent vertebral bodies. Endplate irregularities and Schmorl's nodes are also typical findings.

Question 82

In the evaluation of infantile idiopathic scoliosis, a rib-vertebra angle difference (RVAD) of Mehta greater than what threshold is considered highly predictive of curve progression?

Explanation

An RVAD (Mehta's angle) greater than 20 degrees in infantile idiopathic scoliosis strongly suggests that the curve will be progressive rather than spontaneously resolving. These patients typically require early cast or brace treatment.

Question 83

Compared to a single anterior incision, a two-incision approach for distal biceps tendon repair is associated with a higher risk of which of the following complications?

Explanation

The two-incision (Boyd-Anderson) approach historically carries a higher risk of heterotopic ossification and radioulnar synostosis compared to a single-incision anterior approach. Single-incision approaches carry a higher risk of lateral antebrachial cutaneous neuropraxia.

Question 84

A 40-year-old sustains an Essex-Lopresti injury with an unreconstructible comminuted radial head fracture, tear of the interosseous membrane, and distal radioulnar joint (DRUJ) dislocation. What is the most appropriate management of the radial head?

Explanation

In an Essex-Lopresti injury, longitudinal forearm stability is compromised due to the interosseous membrane tear. Radial head arthroplasty is mandatory if the radial head cannot be fixed, to prevent proximal migration of the radius and chronic DRUJ instability.

Question 85

In a non-ambulatory patient with severe spastic cerebral palsy, neuromuscular scoliosis, and severe pelvic obliquity, surgical correction typically requires which of the following approaches?

Explanation

To adequately correct and maintain the correction of pelvic obliquity in non-ambulatory neuromuscular patients, instrumentation and fusion must typically extend down to the pelvis. Stopping short at L5 often leads to progressive pelvic obliquity and sitting imbalance.

Question 86

According to the O'Driscoll classification, an anteromedial facet fracture of the coronoid is most commonly associated with which mechanism of injury?

Explanation

Anteromedial facet fractures of the coronoid occur due to a varus posteromedial rotatory instability mechanism. This typically injures the LCL and causes the anteromedial coronoid facet to impact the medial trochlea.

Question 87

In the Lenke classification for adolescent idiopathic scoliosis, a lumbar curve modifier of 'C' indicates that the center sacral vertical line (CSVL) falls in which relation to the apical lumbar vertebra?

Explanation

A Lenke 'C' modifier indicates a substantial lumbar curve where the CSVL falls completely medial to the medial border of the apical lumbar pedicle. A 'B' modifier touches the pedicle, and an 'A' modifier falls between the pedicles.

Question 88

During a posterior spinal fusion for scoliosis, somatosensory evoked potentials (SSEPs) are utilized. SSEPs primarily monitor which spinal cord tract, and are supplied by which vascular territory?

Explanation

SSEPs monitor the sensory pathways of the dorsal columns, which are supplied by the posterior spinal arteries. Motor evoked potentials (MEPs) are used to monitor the anterior cord and corticospinal tracts supplied by the anterior spinal artery.

Question 89

What is the most common complication following an intra-articular chevron olecranon osteotomy utilized for exposure in distal humerus fracture fixation?

Explanation

The most frequent complication of an olecranon osteotomy is symptomatic hardware (typically tension band wire or prominent screws) at the proximal ulna, which often necessitates hardware removal once the osteotomy has healed.

Question 90

Which of the following clinical or radiographic findings in a patient with presumed adolescent idiopathic scoliosis is an absolute indication for a preoperative MRI of the total spine to rule out neural axis abnormalities?

Explanation

A left-sided thoracic curve is atypical for adolescent idiopathic scoliosis and carries a significantly higher association with intraspinal anomalies, such as a syrinx or Chiari malformation. It warrants a full-spine MRI.

Question 91

A coronal shear fracture of the distal humerus that extends medially to include the trochlea is classified as which type in the McKee modification of the Bryan and Morrey classification?

Explanation

McKee modified the Bryan and Morrey classification of capitellar fractures by adding Type IV, which is a coronal shear fracture that involves both the capitellum and the trochlea. It often requires extensile surgical exposure for anatomical fixation.

Question 92

In a non-ambulatory patient with Duchenne muscular dystrophy, at what scoliotic curve magnitude is posterior spinal fusion generally recommended to prevent severe respiratory decline and preserve seating balance?

Explanation

Scoliosis in Duchenne muscular dystrophy is relentlessly progressive once the patient becomes wheelchair-bound. Early surgical stabilization is recommended when the curve exceeds 20 to 30 degrees to prevent severe respiratory compromise.

Question 93

A 6-year-old sustains a Bado Type I Monteggia fracture. Closed reduction of the ulnar shaft is achieved perfectly, but the radial head remains dislocated. What is the most common cause of failure to achieve closed reduction of the radiocapitellar joint in this scenario?

Explanation

While inadequate ulnar reduction is the most common overall reason for persistent radial head subluxation, if the ulna is anatomically reduced and the radial head remains out, the most common block to reduction is interposition of the torn annular ligament or joint capsule.

Question 94

Which of the following factors most significantly increases the risk of developing heterotopic ossification (HO) following surgical management of severe traumatic elbow injuries?

Explanation

Patients with severe elbow trauma coupled with central nervous system injuries, particularly severe traumatic brain injury, have a markedly increased risk of developing clinically significant heterotopic ossification.

Question 95

A 14-year-old competitive gymnast presents with persistent lower back pain. Radiographs reveal a Grade 2 isthmic spondylolisthesis at L5-S1. After 6 months of dedicated conservative management including bracing and physical therapy, she remains highly symptomatic. What is the most appropriate surgical treatment?

Explanation

For a symptomatic Grade 2 isthmic spondylolisthesis at L5-S1 failing conservative management, a single-level instrumented posterior spinal fusion is the standard of care. Direct pars repair is generally reserved for L4 or higher with grade 1 or less slip.

Orthopedic Prometric MCQs - Chapter 3 Part 1

Orthopedic Prometric MCQs - Chapter 3 Part 7

Orthopedic Prometric MCQs - Chapter 3 Part 7

Chapter Index