Question 1

A 9-year-old girl sustains an injury (Slide) as a result of a fall. What is her risk of avascular necrosis:

Explanation

This patient has a displaced basicervical fracture of the femur that is classified as Delbet type III. The risk of avascular necrosis is approximately 20% to 25%. She should be monitored closely for the first 12 to 18 months after injury for this complication. Orthopedic Prometric Exam Chapter 3 Image

Orthopedic Prometric Exam Chapter 3 Image

Question 2

A 9-year-old girl sustains an injury (Slide 1) as a result of a fall. What is the recommended treatment:

Explanation

This patient has a basicervical fracture, which is prone to development of varus. Traction, spica cast, and Steinman pin fixation do not provide adequate control of this process. Steinmann pins do not allow compression Orthopedic Prometric Exam Chapter 3 Image

across the fracture site. C losed or open reduction and internal fixation with a compression screw fixation, preferably a hip screw, provide the best control of the fracture. A hip screw provides the best protection against the development of varus. If the fracture is not opened, then aspiration of the hematoma is recommended.

Question 3

A 6-year-old boy presents with a 3-month history of medial midfoot pain. Based on his radiograph (Slide), which of the following is the correct diagnosis:

Explanation

This child has avascular necrosis of the tarsal navicular. This is an idiopathic phenomenon more common in boys of this age than girls. The condition responds to rest and orthotics or cast immobilization. The navicular revascularizes over the ensuing year.

Question 4

Which of the following syndromes has the highest incidence of scoliosis as a percentage of affected patients:

Explanation

Marfan syndrome, due to a mutation in fibrillin-1, causes spinal deformity in two-thirds of patients. Rett syndrome, caused by a mutation in MEC P-2, results in neurological balance disorder and may cause scoliosis in up to half of affected patients. Scoliosis is seen in smaller numbers of patients with Prader-Willi, Down, and Loeys-Dietz syndromes.

Question 5

Acute pain that presents in the lateral arm and shoulder is suggestive of:

Explanation

Acute radiculopathies of the upper extremity are suggestive of soft cervical disk herniations. Three types of soft disk herniations have been described: Intraforaminal is the most common and is often evidenced by radicular symptoms in a dermatomal distribution. Posterolateral herniation results in predominantly motor symptoms. Midline disk herniations may result in myelopathy.

Question 6

A cervical disk herniation that causes weakness in the wrist extensors will likely produce sensory changes in the:

Explanation

The wrist extensors are innervated by C6. Weakness would likely be the result of a C5-C6 cervical disk herniation, thus causing a C 6 radiculopathy. The dermatome of C 6 includes the radial side of the forearm and radial digits.

Question 7

In order to diagnose a disk herniation, the preferred test is:

Explanation

Magnetic resonance imaging (MRI) has become the modality of choice for diagnosis of disk herniation. It is readily available, noninvasive, and has proven as accurate as post-myelogram computerized tomography scans in the evaluation of cervical radiculopathy. An MRI study should include a T1- and T2-weighted image sequence with both sagittal and axial images.

Question 8

Initial management of cervical radiculopathy includes all of the following except:

Explanation

Initial management of cervical radiculopathy is nonoperative. This includes: Nonsteroidal anti-inflammatory drugs Occasional narcotic analgesic medications Immobilization in a soft collar for 10 to 14 days Physical therapy with emphasis on isometric exercises Home traction Surgical intervention is indicated for patients who fail nonoperative treatment. Motor deficits intertractable pain may serve as indication for early surgical therapy. In addition, patients with intertractable pain or motor deficits may be recommended for early surgery.

Question 9

This patient has a wide-based gait and hyper-reflexia in his lower extremities. His magnetic resonance image is presented. Other physical findings in this patient would likely include:

Explanation

This patientâ s clinical presentation is suggestive of cervical spondylotic myelopathy. The T2 sagittal magnetic resonance image shows multiple areas of spinal cord compression due to spondylosis. In this situation, one sees evidence of upper motor neuron dysfunction in the lower extremites such as hyper-reflexia, Hoffman sign, clonus, wide-based gait, and sexual or bladder dysfunction. The upper extremities may demonstrate upper and lower motor neuron findings, hypo-reflexia or hyper-reflexia, crossed radial reflex, Hoffman sign, and hand intrinsic wasting.

Question 10

A useful test to differentiate cervical radiculopathy from diabetic peripheral neuropathy is:

Explanation

An electromyogram detects motor changes as a result of nerve compression. It can be used to differentiate cervical radiculopathy from peripheral neuropathy.

Question 11

With a left-sided anterior cervical spine approach, the structure at increased risk for injury is the:

Explanation

On the left side of the neck, the thoracic duct ascends lateral to the carotid sheath and is at potential risk for laceration with resulting chylothorax. This potential risk must be avoided by remaining medial to the carotid sheath during the left-sided anterior cervical spine approach.

Question 12

With a right-sided anterior cervical spine approach, the structure at increased risk is the:

Explanation

The left recurrent laryngeal nerve enters the thorax within the carotid sheath before looping around the aortic arch and ascending into the neck between the trachea and the esophagus. On the right side, the nerve exits the carotid sheath at a higher level, making the nerve susceptible to injury during the surgical dissection.

Question 13

The structure most at risk during lateral mass screw placement is the:

Explanation

Lateral mass screws placed in the cervical spine for plate fixation are directed 30° lateral and 15° cephalad from a point 1 mm medial to the mid- portion of the particular pillar. The nerve root exits at the anterolateral portion of the facet joint and is at risk of injury. The vertebral artery may be injured in screws placed too medially. The spinal cord is essentially free of danger with accepted techniques.

Question 14

After undergoing an anterior cervical discectomy and fusion through a left- sided neck incision, the patient is noted to have a drooping eyelid and a right pinpoint pupil. This is likely due to:

Explanation

This patient has postoperative Horner syndrome. The sympathetic chain lies lateral to the longus colli muscles. Retractors must be placed deep into these muscles. Retractors placed ventrally to the longus colli muscles can cause injury to the sympathetic chain, esophagus medially, and carotid sheath contents laterally.

Question 15

After an anterior cervical discectomy and fusion with autogenous iliac crest bone graft, the patient reports numbness in the lateral thigh. This is due to:

Explanation

The lateral femoral cutaneous nerve emerges from the lateral border of the psoas major muscle and crosses the ilium as it runs toward the anterior superior iliac spine. The course of the nerve is variable. The nerve is at risk of injury, with resulting meralgia paresthetica, in approximately 10% of patients.

Question 16

One advantage of posterior laminoforaminotomy in the treatment of cervical radiculopathy is:

Explanation

The posterior cervical foraminotomy has a surgical success rate similar to an anterior cervical discectomy and fusion. Proponents argue that the posterior procedure obviates the need for fusion, therefore, postoperative immobilization is unnecessary. The posterior approach cannot address segmental kyphosis or recreate disk space height.

Question 17

The most frequently involved spinal segment in rheumatoid arthritis is:

Explanation

C 1-C2 is the most frequently involved spinal segment in rheumatoid arthritis (RA), and it is also the most clinically significant. These articulations are exclusively synovial and the primary target of RA.

Question 18

The most useful measurement for predicting neurological deficit in rheumatoid arthritis involvement of the cervical spine is:

Explanation

The posterior atlantodens interval (PADI) is the distance between the posterior surface of the dens and the anterior edge of the posterior ring of C 1, as seen on a lateral radiograph. A PADI < 14 mm was 97% sensitive in predicting the presence of neurological deficit. Patients with a PADI >14 mm had a 94% chance of being neurologically intact.

Question 19

A relative contraindication to cervical laminectomy for the treatment of cervical spondylosis is:

Explanation

Cervical laminectomy for spondylosis is performed to allow the spinal cord to migrate posteriorly in order to decompress the spine. This can be accomplished only if the spine is lordotic. If kyphosis exists, then the cord may remain draped over anterior osteophytes and continued compression may exist. In cases of cervical kyphosis, anterior decompression is preferred.

Question 20

The major risk factor for nonunion in a type 2 odontoid fracture is:

Explanation

A posterior displacement >5 mm has the greatest risk of nonunion. However, age >65 years old is a next risk factor. Type 2 odontoid fractures have the highest rate of nonunion of the 3 types and there has been reported to be >60% nonunion when not treated with a halo immobilization. Halo traction is a viable alternative for a patient who has minimal displacement and/or is not a candidate for surgery.

Question 21

A 12-year-old obese boy presents with right hip and knee pain for 3 months. A radiograph is shown

. He is diagnosed with a stable slipped capital femoral epiphysis (SCFE). Which of the following is the most appropriate initial management?

Explanation

The gold standard treatment for a stable SCFE is in situ pinning with a single central cannulated screw. Attempting closed reduction increases the risk of avascular necrosis.

Question 22

An 8-year-old boy presents with a painless limp and restricted hip internal rotation. Radiographs demonstrate fragmentation of the capital femoral epiphysis with 60% involvement of the lateral pillar. According to the Herring Lateral Pillar Classification, which group does this represent?

Explanation

In Herring's Lateral Pillar Classification, Group B involves >50% maintenance of lateral pillar height. Group C has <50% height, and Group A has no lateral pillar involvement.

Question 23

A 4-week-old female infant is diagnosed with a dislocated but reducible left hip. Treatment with a Pavlik harness is initiated. Which of the following is an absolute contraindication to the continued use of a Pavlik harness?

Explanation

Failure to achieve reduction within 3-4 weeks is an absolute contraindication to continued Pavlik harness use. Prolonged use of a harness on a dislocated hip causes "Pavlik harness disease" (posterior lip damage) and risks femoral nerve palsy.

Question 24

A 4-year-old girl is evaluated for severe bowing of the left leg. Radiographs reveal varus deformity at the proximal tibia with a metaphyseal-diaphyseal angle (Drennan's angle) of 18 degrees. What is the most appropriate treatment?

Explanation

For infantile Blount disease in a child over age 3 or with a metaphyseal-diaphyseal angle >16 degrees, surgical realignment (proximal tibial osteotomy) is indicated. Bracing is typically ineffective at this advanced stage and age.

Question 25

A 6-year-old boy sustains a completely displaced, extension-type supracondylar humerus fracture. After closed reduction and percutaneous pinning with two lateral pins, you notice the anterior interosseous nerve (AIN) is non-functional. What is the most common physical finding of AIN palsy?

Explanation

The AIN innervates the flexor pollicis longus (FPL) and flexor digitorum profundus (FDP) to the index finger. Palsy results in the inability to make an "OK" sign (flexion of thumb IP and index DIP joints).

Question 26

A 7-year-old boy presents with an established nonunion of a lateral condyle fracture of the humerus

that occurred 3 years ago. Which of the following nerve palsies is he at greatest risk of developing?

Explanation

Lateral condyle nonunions often lead to progressive cubitus valgus deformities. This valgus stretch pulls the ulnar nerve behind the medial epicondyle, classically causing tardy ulnar nerve palsy.

Question 27

When treating an idiopathic clubfoot using the Ponseti method, what is the correct sequence of deformity correction?

Explanation

The Ponseti method corrects deformities sequentially using the CAVE acronym: Cavus (by supinating forefoot), Adductus, Varus, and finally Equinus (usually requiring a percutaneous Achilles tenotomy).

Question 28

A 12-year-old boy presents with recurrent ankle sprains and rigid flatfeet. A lateral radiograph of the foot reveals an "anteater nose" sign. Which of the following coalitions is most likely present?

Explanation

The "anteater nose" sign on a lateral foot radiograph is characterized by an elongated anterior process of the calcaneus. This finding is pathognomonic for a calcaneonavicular coalition.

Question 29

A 3-year-old boy sustains an isolated midshaft femur fracture

. He is hemodynamically stable and has no other injuries. What is the preferred definitive treatment?

Explanation

In children aged 6 months to 5 years with an isolated femur fracture and <2 cm of shortening, early spica casting is the standard of care. This approach has excellent clinical outcomes and avoids surgery.

Question 30

A 13-year-old girl sustains an ankle injury. Radiographs show a Salter-Harris III fracture of the anterolateral distal tibial epiphysis. What ligament is responsible for the avulsion of this bony fragment?

Explanation

A juvenile Tillaux fracture is an avulsion of the anterolateral distal tibial epiphysis. It is caused by tension on the anterior inferior tibiofibular ligament (AITFL) during an external rotation injury.

Question 31

In a 6-year-old child with spastic quadriplegic cerebral palsy, routine hip surveillance radiographs show a Reimers migration index of 45%. Which of the following is the most appropriate management?

Explanation

A Reimers migration index >40% indicates significant hip subluxation in CP. Bony reconstructive surgery (VDRO and possibly pelvic osteotomy) is required to restore joint congruency and prevent dislocation.

Question 32

An 18-month-old child presents with a painless limp and is found to have an untreated developmental dysplasia of the hip (DDH) on the right side. Which of the following is the most appropriate treatment?

Explanation

In children >18 months of age with DDH, open reduction is generally required due to adaptive soft tissue and bony changes. Concomitant pelvic and/or femoral osteotomies are frequently necessary to maintain reduction.

Question 33

Which of the following pediatric physis injuries has the highest risk of premature physeal closure and subsequent growth arrest?

Explanation

Salter-Harris IV fractures cross the epiphysis, physis, and metaphysis, intrinsically carrying a high risk of physeal bar formation. The distal femur physis is particularly prone to severe growth arrest after injury.

Question 34

A 2-year-old boy presents with anterolateral bowing of the tibia and a radiographic pseudarthrosis

. This condition is most strongly associated with which of the following systemic disorders?

Explanation

Anterolateral bowing of the tibia and congenital pseudarthrosis of the tibia (CPT) are highly associated with Neurofibromatosis type 1 (NF1). Up to 50% of patients with CPT have clinical or genetic findings of NF1.

Question 35

A 5-year-old boy presents with right hip pain, a limp, and a temperature of 38.8°C. He refuses to bear weight. His WBC is 13,000/mm³ and ESR is 45 mm/hr. According to the Kocher criteria, what is the probability that this child has septic arthritis rather than transient synovitis?

Explanation

The Kocher criteria include: non-weight-bearing, temperature >38.5°C, ESR >40 mm/hr, and WBC >12,000/mm³. Having 3 out of 4 criteria gives a 93% predictive probability for septic arthritis.

Question 36

A 10-year-old boy presents after a high-energy fall. Radiographs demonstrate a displaced transcervical femoral neck fracture.

According to the Delbet classification, what is the approximate risk of avascular necrosis (AVN) for this fracture pattern?

Explanation

Delbet Type II (transcervical) fractures are the most common pediatric femoral neck fractures and have an AVN risk of approximately 50%. Type I (transepiphyseal) has the highest rate (up to 90%), but Type II is more frequently encountered.

Question 37

A 6-year-old boy presents with medial midfoot pain and a limp for 2 months. Radiographs reveal sclerosis and flattening of the navicular bone. What is the most appropriate initial management?

Explanation

Kohler disease is an avascular necrosis of the navicular that is typically self-limiting. Treatment consists of observation or, in highly symptomatic cases, a short leg walking cast for 4 to 6 weeks to alleviate pain.

Question 38

Which of the following conditions is the strongest indication for prophylactic pinning of the contralateral asymptomatic hip in a patient presenting with a unilateral slipped capital femoral epiphysis (SCFE)?

Explanation

Endocrine and metabolic disorders (such as renal osteodystrophy and hypothyroidism) significantly increase the risk of bilateral SCFE. Prophylactic pinning of the contralateral hip is highly recommended in these high-risk populations.

Question 39

When correcting an idiopathic clubfoot deformity using the Ponseti method, what is the proper sequence of deformity correction?

Explanation

The acronym CAVE dictates the correct sequence of manipulation and casting: Cavus, Adduction, Varus, then Equinus. Equinus is the final deformity corrected, which typically requires a percutaneous Achilles tenotomy.

Question 40

A 5-year-old boy sustains a completely displaced supracondylar humerus fracture. On examination, the hand is pink and well-perfused but the radial pulse is absent. What is the next best step in management?

Explanation

For a pulseless, pink, and well-perfused hand associated with a supracondylar fracture, the initial step is urgent closed reduction and pinning. If the hand remains pink and perfused post-reduction despite an absent pulse, close observation without immediate exploration is standard practice.

Question 41

A 4-year-old child presents with an elbow injury. Radiographs reveal a displaced lateral condyle fracture.

If this fracture goes on to nonunion, which of the following long-term complications is most likely to develop?

Explanation

Nonunion of a lateral condyle fracture typically results in a progressive cubitus valgus deformity due to loss of the lateral column support. Over years, this stretching of the ulnar nerve behind the medial epicondyle can lead to tardy ulnar nerve palsy.

Question 42

An infant with developmental dysplasia of the hip (DDH) is being treated with a Pavlik harness. During a follow-up visit, the infant is unable to actively extend the knee on the treated side. Which of the following harness adjustments was most likely flawed?

Explanation

Excessive flexion in a Pavlik harness can compress the femoral nerve against the inguinal ligament, leading to a temporary femoral nerve palsy (manifesting as loss of active knee extension). Excessive abduction, conversely, increases the risk of avascular necrosis.

Question 43

A 13-year-old girl sustains an ankle injury.

Radiographs reveal an avulsion fracture of the anterolateral distal tibial epiphysis. What is the typical pathomechanics of this fracture?

Explanation

A juvenile Tillaux fracture is a Salter-Harris III injury of the anterolateral distal tibial epiphysis. It is caused by external rotation of the foot, which places tension on the anterior inferior tibiofibular ligament (AITFL), avulsing the bony attachment.

Question 44

In Legg-Calve-Perthes disease, the Herring Lateral Pillar classification is most useful for predicting outcome. In a Group C classification, what percentage of the lateral pillar height is maintained?

Explanation

In the Herring Lateral Pillar classification, Group C is defined by the lateral pillar retaining less than 50% of its original height. This group carries the poorest prognosis for hip remodeling.

Question 45

A 2-year-old child presents with bilateral genu varum. A standing AP radiograph is obtained. Which radiographic parameter most strongly predicts the progression of infantile Blount disease rather than physiologic bowing?

Explanation

A metaphyseal-diaphyseal angle (Drennan angle) greater than 16 degrees on an AP radiograph strongly suggests progression to infantile Blount disease. Angles less than 10 degrees are typically associated with physiologic bowing.

Question 46

A 10-year-old active boy complains of posterior heel pain that worsens with soccer practice. Examination reveals point tenderness at the insertion of the Achilles tendon on the calcaneal apophysis. Radiographs are unremarkable. What is the most appropriate initial treatment?

Explanation

Calcaneal apophysitis (Sever disease) is a common overuse injury in growing children caused by traction on the apophysis. Standard conservative management includes Achilles stretching, heel lifts/cups to relieve tension, and temporary activity modification.

Question 47

A 6-year-old child presents with a Bado Type I Monteggia fracture-dislocation. After closed reduction and casting, follow-up radiographs show re-dislocation of the radial head. What is the most common cause of failure to maintain radial head reduction in this scenario?

Explanation

In pediatric Monteggia injuries, failure to fully correct the plastic deformation or angulation of the ulna is the leading cause of persistent or recurrent radial head dislocation. The ulnar bow must be anatomically reduced to stabilize the radiocapitellar joint.

Question 48

Osteogenesis imperfecta (OI) is primarily caused by mutations affecting which of the following structural proteins?

Explanation

Osteogenesis imperfecta is most commonly caused by autosomal dominant mutations in the COL1A1 or COL1A2 genes. This results in qualitative or quantitative defects in Type I collagen, the predominant structural protein in bone.

Question 49

An infant with achondroplasia presents with hypotonia, sleep apnea, and hyperreflexia. Which of the following is the most likely underlying etiology?

Explanation

Infants with achondroplasia have abnormal endochondral ossification at the skull base, placing them at high risk for foramen magnum stenosis. This can cause severe cervicomedullary compression, presenting with sleep apnea, hypotonia, and hyperreflexia.

Question 50

A 14-year-old boy presents with a painful, rigid flatfoot and a history of recurrent ankle sprains.

Radiographs demonstrate a "C-sign" on the lateral view. Which of the following is the most likely diagnosis?

Explanation

The continuous "C-sign" on a lateral radiograph is highly specific for a talocalcaneal coalition, typically involving the middle facet. Calcaneonavicular coalitions usually present earlier (8-12 years) and demonstrate an "anteater nose" sign on oblique views.

Question 51

Congenital pseudarthrosis of the tibia (CPT) is most strongly associated with which of the following systemic conditions?

Explanation

Congenital pseudarthrosis of the tibia is heavily associated with Neurofibromatosis type 1 (NF1), occurring in about 50% of CPT cases. It presents as an anterolateral bow of the tibia that is highly prone to fracture and nonunion.

Question 52

A 13-year-old obese boy presents with 3 weeks of vague left knee pain and a limp. Examination reveals an obligate external rotation of the hip during active flexion.

What is the most devastating potential complication of the underlying condition?

Explanation

Avascular necrosis (AVN) is the most devastating complication of Slipped Capital Femoral Epiphysis (SCFE), often secondary to unstable slips or overly aggressive reduction attempts. Chondrolysis is another severe complication but generally has a more predictable, albeit stiff, long-term outcome compared to segmental collapse from AVN.

Question 53

In a 7-year-old boy diagnosed with Legg-Calve-Perthes disease, which of the following radiographic findings is considered a 'head at risk' sign according to Catterall?

Explanation

Catterall's 'head at risk' signs include the Gage sign (a V-shaped radiolucency in the lateral portion of the epiphysis/metaphysis), lateral calcification, lateral subluxation, horizontal growth plate, and metaphyseal cysts. These indicate a poorer prognosis.

Question 54

According to the Ponseti method for the treatment of idiopathic congenital talipes equinovarus (clubfoot), what is the correct sequence of deformity correction?

Explanation

The Ponseti method corrects the deformities in a specific order remembered by the acronym CAVE: Cavus (by elevating the first ray), Adductus, Varus, and finally Equinus (usually requiring a percutaneous Achilles tenotomy).

Question 55

A 6-month-old girl is diagnosed with developmental dysplasia of the hip (DDH) and has failed a proper 3-week trial of a Pavlik harness, with the hip remaining dislocated. What is the most appropriate next step in management?

Explanation

If a Pavlik harness fails to achieve reduction within 3 to 4 weeks, it should be abandoned to prevent 'Pavlik harness disease' (damage to the posterior acetabular wall). The next appropriate step is closed reduction and spica casting under general anesthesia.

Question 56

A 14-year-old boy sustains an ankle injury. Radiographs demonstrate a Salter-Harris III fracture of the anterolateral distal tibia.

Which ligament's avulsion force is responsible for this specific fracture pattern?

Explanation

This describes a juvenile Tillaux fracture, which occurs due to avulsion of the anterolateral tibial epiphysis by the anterior inferior tibiofibular ligament (AITFL) during external rotation injuries in adolescents.

Question 57

A 6-year-old girl sustains a severely displaced extension-type supracondylar humerus fracture. On presentation, her hand is well-perfused and pink, but the radial pulse is absent. What is the most appropriate initial management?

Explanation

In a 'pulseless, pink' hand following a supracondylar fracture, the collateral circulation is intact. The standard of care is urgent closed reduction and percutaneous pinning, which often restores the palpable pulse.

Question 58

A 5-year-old boy sustains a lateral condyle fracture of the humerus.

If left untreated, leading to nonunion and progressive deformity, what late neurological complication is he at highest risk of developing?

Explanation

Untreated or nonunited lateral condyle fractures often lead to progressive cubitus valgus deformity. This chronic stretching of the ulnar nerve over the medial epicondyle results in tardy ulnar nerve palsy years later.

Question 59

A 7-year-old child with spastic quadriplegic cerebral palsy is undergoing routine hip surveillance.

What radiographic measurement is most critical for monitoring lateral hip subluxation in this patient?

Explanation

The Reimers migration percentage (or index) measures the proportion of the ossified femoral head outside the lateral margin of the acetabulum (Perkin's line). It is the standard metric used in cerebral palsy hip surveillance.

Question 60

A 3-year-old boy presents with a temperature of 38.8 C, refusal to bear weight on his right leg, an ESR of 55 mm/hr, and a serum WBC of 14,000/mm3 with suspected hip pathology. According to Kocher criteria, what is the statistical probability of septic arthritis?

Explanation

The Kocher criteria for septic arthritis of the hip include non-weight-bearing, temperature >38.5 C, ESR >40 mm/hr, and WBC >12,000/mm3. Having all 4 predictors yields a 99% probability of septic arthritis.

Question 61

A 2-year-old girl presents with bilateral genu varum. Radiographs reveal a metaphyseal-diaphyseal angle (Drennan's angle) of 18 degrees. What is the most likely diagnosis?

Explanation

A metaphyseal-diaphyseal angle (Drennan's angle) greater than 16 degrees on standing AP radiographs is highly predictive of infantile Blount's disease (tibia vara) rather than physiologic bowing.

Question 62

A 14-year-old boy presents with frequent ankle sprains and a rigid, painful flatfoot. Radiographs reveal a 'C sign' on the lateral view of the ankle. What is the most likely underlying diagnosis?

Explanation

The 'C sign' on a lateral foot/ankle radiograph represents a continuous bony bridge between the talar dome and the sustentaculum tali, which is highly indicative of a talocalcaneal (subtalar) coalition.

Question 63

In which of the following patients presenting with a unilateral slipped capital femoral epiphysis (SCFE) is prophylactic pinning of the contralateral hip most strongly indicated?

Explanation

Prophylactic pinning of the contralateral hip is strongly recommended in patients with endocrine or metabolic disorders (e.g., renal osteodystrophy, hypothyroidism) due to a very high rate of subsequent contralateral slips.

Question 64

A 13-year-old boy presents with vague anterior knee pain. Radiographs demonstrate an osteochondritis dissecans (OCD) lesion. What is the most common anatomic location for this lesion in the knee?

Explanation

The classic and most common location for an osteochondritis dissecans (OCD) lesion of the knee is the lateral aspect of the medial femoral condyle (LAME acronym).

Question 65

An 11-year-old gymnast sustains an elbow dislocation that is reduced in the emergency department. Subsequent radiographs show a medial epicondyle fracture. Which of the following is an absolute indication for operative fixation?

Explanation

Absolute indications for open reduction and internal fixation of a medial epicondyle fracture include incarceration of the fragment in the joint, open fracture, and associated ulnar nerve entrapment/injury that occurs during reduction.

Question 66

A 3-year-old boy weighing 14 kg sustains an isolated, closed, spiral midshaft femur fracture after a ground-level fall. Which of the following is the most appropriate definitive treatment?

Explanation

For young children aged 6 months to 4-5 years with an isolated, length-stable or minimally shortened femur fracture, early spica casting is the gold standard treatment with excellent remodeling potential and outcomes.

Question 67

Proximal focal femoral deficiency (PFFD) in a newborn is most frequently associated with which of the following concurrent congenital anomalies?

Explanation

Fibular hemimelia is the most common concurrent congenital anomaly associated with proximal focal femoral deficiency (PFFD), occurring in up to 70-80% of these patients.

Question 68

A 13-year-old girl sustains a twisting injury to her ankle. A CT scan confirms a classic triplane fracture. In which planes do the fracture lines of a typical triplane fracture occur?

Explanation

A classic triplane fracture consists of three planes: a sagittal fracture through the epiphysis, a transverse fracture through the physis, and a coronal fracture through the posterior metaphysis.

Question 69

A 2-year-old boy with anterolateral bowing of the tibia develops a spontaneous fracture. This condition (congenital pseudoarthrosis of the tibia) is most strongly associated with which of the following genetic disorders?

Explanation

Anterolateral bowing of the tibia progressing to congenital pseudoarthrosis is highly associated with Neurofibromatosis type 1 (NF1). Over 50% of patients with this pseudoarthrosis have NF1.

Question 70

A 12-year-old elite baseball pitcher presents with insidious onset of proximal shoulder pain while throwing. Radiographs show widening and irregularity of the proximal humeral physis. What is the most appropriate initial treatment?

Explanation

Little Leaguer's shoulder is a stress injury (Salter-Harris I) of the proximal humeral physis caused by repetitive torsional forces. The mainstay of treatment is absolute rest from throwing, typically for 3 months, followed by a gradual return-to-throw program.

Question 71

A 6-year-old girl is noted by her parents to have a painless, clunking sensation in her lateral knee with active flexion and extension. MRI confirms a complete, asymptomatic discoid lateral meniscus. What is the recommended management?

Explanation

An asymptomatic discoid meniscus in a child should be managed with observation alone. Surgical intervention (such as partial meniscectomy or stabilization) is reserved for symptomatic patients (e.g., pain, catching, locking).

Question 72

A 7-year-old boy is diagnosed with Legg-Calvé-Perthes disease. Which of the following describes the most critical prognostic factors for long-term hip deformity?

Explanation

The most important prognostic factors in Legg-Calvé-Perthes disease are the age at clinical presentation (worse outcomes if >8 years) and the Herring lateral pillar classification. Preservation of the lateral pillar height corresponds to better long-term sphericity of the femoral head.

Orthopedic Prometric MCQs - Chapter 3 Part 1

Orthopedic Prometric MCQs - Chapter 3 Part 20

Orthopedic Prometric MCQs - Chapter 3 Part 20

Chapter Index