Question 1

The radiographs (Slide) of a 13-year-old-boy are presented. The radiographs demonstrate characteristics of which of the following conditions:

Explanation

The radiographs show characteristics of a growth arrest from a medial distal tibial physeal fracture, either a Salter III or Salter IV. The fracture was not internally fixed, and the residual vertical fracture line and step-off are still visible. A growth plate bar developed and Park-Harris growth lines are seen on the lateral side of the bar. Some of the physis is open medially and, especially, laterally. The fibula has continued to grow.

Question 2

An 11½ -year-old boy sustained a Salter IV fracture of the distal tibial physis. The fracture was treated in a cast. Two years later, his radiographs (Slide) are presented. The patient is starting to notice a deformity. Which of the following treatment plans is recommended:

Explanation

This patient has an unacceptable deformity, 2 cm of current shortening, and significant growth remaining. Only right distal tibial and fibular osteotomy, and bilateral distal tibial and fibular epiphyseodesis addresses all of the complications. Bar resection is not uniformly successful and would not correct existing deformity and length inequality, since there is minimal physis medial to the bar that could produce correction. Orthopedic Prometric Exam Chapter 3 Image

Orthopedic Prometric Exam Chapter 3 Image

Question 3

The radiographs (Slide) indicate which of the following diagnoses:

Explanation

The radiographs indicate a supracondylar fracture of the distal humerus. The anterior humeral line should bisect the capitellum on the lateral view. The anterior and posterior fat pads are elevated. The fracture line may be seen on the anteroposterior and the lateral radiographs, although it is subtle. The cortical break of the coronoid fossa is evident. Surgeons must recognize Orthopedic Prometric Exam Chapter 3 Image

these fractures so that the patient and family may be given proper activity restrictions and expectations for improvement.

Question 4

A 5-year-old boy was imaged after being struck by a car. His radiographs (Slide) indicate which of the following diagnoses:

Explanation

The proximal humeral physis has two planes and two ossification centers (in this way, it is analogous to the proximal femur). Orthopedic Prometric Exam Chapter 3 Image

When seen in some projections, the more distal extent of the physis may produce a lucent line. The smooth nature and characteristic location of the line should allow surgeons to make the correct interpretation. The two ossification centers of the humeral head may be misinterpreted as a fracture. This patient had a greenstick fracture of the clavicle (not included on this field), which was not noticed, and a humeral fracture was incorrectly diagnosised.

Question 5

The largest available free muscle flap comes from which of the following muscles:

Explanation

The latissimus dorsi provides the largest available free muscle flap. The gracilis provides a long muscle slip and can be innervated and used for certain innervated muscle transfers. The serratus anterior muscle is thin and can be used when bulk is undesirable.

Question 6

A 12-year-old boy presents for evaluation of a spinal curvature (Slide 1). Which of the following is the most likely cause of the spinal curve:

Explanation

This patient has a 2.5 cm shortening of the left lower extremity, which can be seen from the uneven pelvic height on the radiograph. The shortening produces a compensatory curve. No rotation is present within the curve. Scanogam (Slide 2) documents the inequality. When the patient stands on a 2.5-cm lift, the curve is eliminated (Slide 3). Orthopedic Prometric Exam Chapter 3 Image

Question 7

In the embryo, cells from the ectodermal layer give rise to which elements of the spine:

Explanation

The spine is formed from all three elements of the embryonic plate (Slide). The ectoderm develops into a groove, folding into a tube that becomes the spinal cord. The endoderm gives rise to the notochord, which serves as the organizing structure for the spinal column. The notochord persists as the Orthopedic Prometric Exam Chapter 3 Image

nucleus pulposus. The mesoderm gives rise to muscles and bony elements of the spinal column.

Question 8

How many somites are involved in formation of each vertebral body of the thoracolumbar spine:

Explanation

The somites are repeating groups of axial mesodermal cells that give rise to the osseous and musculoligamentous elements of the spine during embryonic formation. Each somite divides and contributes to two adjacent vertebral bodies.

Question 9

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. Baumannâ s angle measures 85°. The alignment on the lateral film shows no significant translation, but approximately 15° of increased extension. The recommended treatment is:

Explanation

Closed 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.

Question 10

The 7-year-old patient shown in this image (Slide 1) is most likely presenting with:

Explanation

This patient has a spondylolisthesis of the axis, which is also known as a Hangmanâ s fracture. Additionally, a subluxation of the C 2-C 3 facet is present on the right side. Such a subluxation often accompanies a Hangmans fracture. The comparison image (Slide 2) of the opposite facet is shown as a reference to demonstrate the normal alignment. Orthopedic Prometric Exam Chapter 3 Image

Question 11

Which of the following treatment options is recommended for the patient shown in the image (Slide 1, Slide 2):

Explanation

Treatment must address the fracture of the C 2 pars interarticularis and the C 2-C 3 facet subluxation. Options include traction to reduce the subluxation followed by external immobilization, or open reduction of the facet subluxation, which includes the opportunity to internally fix the fracture. Traction failed in this patient because the fracture eliminates a means to pull Orthopedic Prometric Exam Chapter 3 Image

on the arch of C 2. If facet subluxation is not present, then a cervicothoracic orthosis such as a Philadelphia collar is adequate for healing of the C 2 spondylolysis.

Question 12

Flexion-type supracondylar fractures of the distal humerus in children are characterized by which of the following when compared to extension-type injuries:

Explanation

Flexion-type supracondylar fractures of the distal humerus in children include the following characteristics: Frequency is less than one-tenth as that of extension-type supracondylar fractures Tend to occur in older children Lower risk of anterior interosseous nerve injury Higher risk of ulnar nerve injury More often require open reduction

Question 13

The 12-year-old boy shown in the radiographs (Slide 1, Slide 2) sustained his injury during a motor vehicle accident. Which of the following most accurately describes the injury:

Explanation

This patient has a proximal ulna fracture and an anterior dislocation of the radial head. The ulna-trochlea relationship is intact. On the lateral film, the Orthopedic Prometric Exam Chapter 3 Image

radial head does not articulate with the capitellum. On the anteroposterior film, the radial head points to the capitellum, but the joint space is absent in contrast to that of the ulna-trochlear joint, which is normal. This injury is a type 1 (anterior) Monteggia fracture. The dislocation is clearly visible on Slide 3. A Galeazzi fracture refers to a distal radioulnar dislocation with a radial fracture. A Maisonneuve fracture is a related concept in the lower extremity: a proximal fibular fracture with an ankle mortise injury.

Question 14

A 12-year-old boy sustained the injury shown (Slide 1, Slide 2, and Slide 3). A postreduction film is also presented (Slide 4). Which of the following treatments is the most likely to produce satisfactory results:

Orthopedic Prometric Exam Chapter 3 Image

Explanation

This patient has a type 1 (anterior) Monteggia fracture. The radial head is not reduced in the splint. Although supination and flexion may stabilize the radius, the radius remained unstable in this patient because it was dislocated with only a slight offset of the ulna. Plate fixation of the ulna is more likely to stabilize the radius in a patient with this injury. After the ulna is fixed with a plate (Slide 5), the radial head cannot be dislocated. Radiocapitellar pinning should be used only as a final option because of the associated risks of stiffness and breakage.

Question 15

A 7-year-old boy is intubated after being involved in a motor vehicle accident. His lateral cervical film (Slide 1) reveals a:

Explanation

Extensive prevertebral soft tissue swelling is present. This patient received an injury that disrupted the ligaments of the atlantooccipital and atlantoaxial joint. Additionally, he has a congenital synchondrosis of the C1 ring. The dens-basion distance (dens to the anterior rim of the foramen magnum) is 13 mm; the normal distance is less than 10 mm to 12 mm. The patient is pentaplegic. Three-dimensional computed tomography scans (Slide 2, Slide 3) are presented.

Question 16

The images presented (Slide 1, Slide 2) depict which process:

Explanation

The images presented depict a pars interarticularis fracture of the third lumbar vertebra.

Question 17

Patients who have had a unilateral slipped capital femoral epiphysis (SC FE) are at what odds of a contralateral slip compared to the general population:

Explanation

Patients who have presented with a unilateral SC FE are at approximately 2,000 times the risk of a contralateral slip compared to the general population. The risk of a contralateral slip in a juvenile is approximately 1/10,000, which provides justification for prophylactic pinning of a second side if a surgeon thinks it is warranted.

Question 18

Which of the following conditions is represented in the clinical photographs (Slide 1, Slide 2):

Explanation

This patient has ectrodactyly, which is a condition characterized by the central absence of rays. Ectrodactyly, also known as cleft foot or lobster- claw, may affect the upper or lower extremities. The incidence is rare (approximately 1/90,000 live births). The condition may result from a defect in the apical ectodermal ridge. Associated anomalies are not always present but may include cleft hand, deafness, tibial hemimelia, or urinary tract anomalies. Patients with ectrodactyly have nearly normal function, as long as the foot is not so wide as to prohibit normal shoe wear. If shoe wear is difficult, then the foot can be reconstructed using flaps to close the cleft and metatarsal osteotomies as indicated.

Question 19

A 6-year-old child is involved in a motor vehicle accident. What injury is demonstrated by the computed tomography (C T) (Slide

Explanation

This patient has an avulsion injury of the transverse ligament of the atlas. The bony avulsion is visible from its attachment to the left lateral mass and allows the atlas to move forward in relation to the axis. Hematoma and occiptocervical flexion is visible on the MRI. If it were an Orthopedic Prometric Exam Chapter 3 Image

odontoid injury, the odontoid would still have a normal relationship to the ring of C 1 on the C T. Treatment involves reduction and fusion of C 1-C 2.

Question 20

The radiograph (Slide 1) of an 11-year-old boy with significant leg pain is presented. No other abnormalities are found during the patientâ s history or physical examination. The most likely diagnosis is:

Explanation

Fibrous dysplasia is chronically expansile with vague transition to normal bone and a â ground-glassâ appearance. These characteristics differentiate fibrous dysplasia from aneurysmal and unicameral bone cysts. Additionally, the lack of periosteal reaction differentiates fibrous dysplasia from malignancy or osteomyelitis. The patients magnetic resonance image (Slide 2) is also provided.

Question 21

A 4-week-old infant is treated with a Pavlik harness for developmental dysplasia of the hip. At a follow-up visit, the infant is noted to have decreased spontaneous movement of the knee and absent knee extension against gravity. What is the most likely iatrogenic cause?

Explanation

Femoral nerve palsy is a known complication of the Pavlik harness if the hips are hyperflexed. It typically resolves with adjustment of the harness to reduce flexion.

Question 22

An obese 12-year-old boy presents with a 3-week history of knee pain and a limp. He sits with his affected leg externally rotated. Radiographs reveal a widened and irregular proximal femoral physis. What is the most appropriate initial management?

Explanation

Stable Slipped Capital Femoral Epiphysis (SCFE) is best treated with in situ pinning using a single, centrally placed cannulated screw to prevent further slippage. Closed reduction increases the risk of avascular necrosis.

Question 23

A 9-year-old boy sustained a distal femoral physeal fracture 1 year ago. He now presents with a valgus deformity.

Based on the likelihood of a localized physeal bar, what percentage of physeal involvement is generally considered the upper limit for successful bar resection?

Explanation

Physeal bar resection is generally indicated if the bar involves less than 50% of the cross-sectional area of the physis. Additionally, the patient should have at least 2 years of remaining growth.

Question 24

A 6-year-old boy presents with a painless limp. Radiographs demonstrate sclerosis and fragmentation of the proximal femoral epiphysis. Which of the following factors carries the worst prognosis for this condition?

Explanation

In Legg-Calve-Perthes disease, the Lateral Pillar classification is strongly prognostic. Lateral Pillar C (greater than 50% loss of lateral pillar height) has the worst prognosis.

Question 25

A 5-year-old child sustains a displaced extension-type supracondylar humerus fracture. Examination reveals weakness in flexing the interphalangeal joint of the thumb and the distal interphalangeal joint of the index finger. Which nerve is most likely injured?

Explanation

The anterior interosseous nerve (AIN), a branch of the median nerve, is the most commonly injured nerve in extension-type supracondylar humerus fractures. It innervates the flexor pollicis longus and flexor digitorum profundus to the index finger.

Question 26

A 13-year-old boy presents with recurrent ankle sprains and rigid flat feet. CT scan confirms a calcaneonavicular coalition. If conservative management fails, what is the surgical treatment of choice for a coalition comprising less than 50% of the joint space with no degenerative changes?

Explanation

Symptomatic calcaneonavicular coalitions failing nonoperative treatment are treated with resection and interposition (e.g., EDB muscle or fat) to prevent recurrence. This is preferred over arthrodesis if there is no advanced arthritis.

Question 27

A 3-year-old girl presents with progressive bilateral genu varum. Radiographs show a prominent metaphyseal beak and a metaphyseal-diaphyseal angle of 18 degrees. What is the recommended treatment?

Explanation

Infantile Blount disease with a metaphyseal-diaphyseal angle greater than 16 degrees is unlikely to resolve spontaneously. In a 3-year-old, proximal tibial valgus osteotomy is the surgical treatment of choice.

Question 28

A newborn is noted to have a foreshortened right forearm with the hand deviated radially and an absent thumb. Which of the following systemic conditions is NOT typically associated with this deformity?

Explanation

Radial clubhand (radial longitudinal deficiency) is associated with TAR, Holt-Oram, VACTERL, and Fanconi anemia. Neurofibromatosis type 1 is classically associated with anterolateral tibial bowing, not radial clubhand.

Question 29

When correcting a congenital idiopathic clubfoot using the Ponseti method, what is the correct sequence of deformity correction?

Explanation

The Ponseti method corrects deformities in the mnemonic CAVE sequence. Cavus is corrected first by elevating the first ray, followed by Adduction, Varus, and finally Equinus.

Question 30

A 10-year-old boy falls from a tree. Radiographs reveal a fracture extending through the physis and exiting through the metaphysis of the distal radius.

What is the Salter-Harris classification of this fracture?

Explanation

A Salter-Harris Type II fracture involves the physis and exits through the metaphysis. It is the most common type of physeal fracture and typically carries a good prognosis.

Question 31

A 12-year-old premenarchal female (Risser 0) is diagnosed with adolescent idiopathic scoliosis. Her right thoracic curve measures 32 degrees. What is the most appropriate management?

Explanation

Bracing is indicated for growing children (Risser 0-2, premenarchal) with curves between 25 and 40 degrees. It is also indicated for documented progression of >5 degrees in curves of 20-25 degrees.

Question 32

A 4-year-old child sustains an isolated spiral fracture of the femoral shaft after a low-energy fall. Length is preserved with 1 cm of shortening. What is the standard of care for this injury?

Explanation

Early spica casting is the standard of care for isolated femoral shaft fractures in children aged 6 months to 5 years with acceptable shortening (< 2 cm). Flexible nails are typically reserved for children older than 5 years.

Question 33

A 2-year-old boy with blue sclerae presents with his third long bone fracture. Genetic testing reveals a defect in Type I collagen. Which medical treatment has been shown to reduce fracture rates and improve bone density in this condition?

Explanation

Intravenous bisphosphonates (such as pamidronate) are the mainstay of medical treatment for moderate to severe Osteogenesis Imperfecta. They inhibit osteoclast resorption, leading to increased cortical thickness.

Question 34

A 14-year-old boy sustains an ankle injury. Radiographs and CT demonstrate a Salter-Harris III fracture of the anterolateral distal tibial epiphysis. What is the anatomic reason for this specific fracture pattern?

Explanation

A juvenile Tillaux fracture occurs due to avulsion by the anterior inferior tibiofibular ligament (AITFL). It happens because the distal tibial physis closes from central to medial to lateral, leaving the anterolateral physis vulnerable.

Question 35

A 15-year-old gymnast presents with chronic lower back pain. Radiographs demonstrate a grade II isthmic spondylolisthesis at L5-S1. She has failed 6 months of conservative management. What is the most appropriate surgical intervention?

Explanation

For symptomatic low-grade isthmic spondylolisthesis in adolescents failing conservative care, an in situ posterolateral fusion of L5-S1 is the standard surgical treatment. Decompression alone is contraindicated due to instability.

Question 36

A 6-year-old boy sustains a diaphyseal fracture of the proximal third of the ulna.

Which associated injury must be specifically evaluated for and excluded?

Explanation

A Monteggia fracture-dislocation consists of a fracture of the ulnar shaft with an associated dislocation of the radial head. The radiocapitellar line must be carefully evaluated on all views.

Question 37

A 10-year-old girl is predicted to have a 3.5 cm leg length discrepancy at skeletal maturity, with the right leg being shorter. She and her parents desire a minimal surgical intervention. What is the most appropriate management?

Explanation

For a predicted leg length discrepancy of 2-5 cm at maturity, an epiphysiodesis of the longer limb is the standard and least invasive surgical treatment. Discrepancies >5 cm generally require lengthening procedures.

Question 38

A 5-year-old child with spastic quadriplegic cerebral palsy is undergoing routine hip surveillance. Radiographs show a migration percentage of 45% with a break in Shenton's line. What is the most appropriate management?

Explanation

In cerebral palsy, a migration percentage >40% indicates progressive hip subluxation. Bony reconstructive surgery, typically a VDRO with or without pelvic osteotomy, is indicated to prevent painful dislocation.

Question 39

A 2-year-old boy is brought to the clinic because he refuses to bear weight on his left leg. Examination reveals minimal swelling and tenderness over the distal tibia. Initial radiographs are completely normal. What is the most appropriate next step?

Explanation

A Toddler's fracture is a nondisplaced spiral fracture of the distal tibia where initial radiographs are often normal. The standard of care is empiric immobilization and repeat imaging in 1-2 weeks.

Question 40

A 9-year-old boy sustains a pathologic fracture through a centrally located, purely lytic lesion in the proximal humerus metaphysis.

A "fallen leaf" sign is noted. What is the definitive treatment after the fracture has healed if the lesion persists?

Explanation

The "fallen leaf" sign is pathognomonic for a Unicameral Bone Cyst (UBC). If the cyst does not heal after fracture, treatment involves aspiration/injection or curettage and bone grafting to prevent recurrence.

Question 41

A 12-year-old obese boy presents with a 3-week history of left groin pain and a limp. On examination, as the left hip is flexed, it obligatorily externally rotates. Radiographs are shown.

What is the most appropriate definitive management?

Explanation

The presentation is classic for a Slipped Capital Femoral Epiphysis (SCFE). The gold standard treatment for a stable SCFE is in situ pinning with a single cannulated screw to prevent further slippage.

Question 42

A 6-year-old boy presents with a painless limp of 2 months' duration. His hip range of motion reveals decreased abduction and internal rotation. A radiograph reveals sclerosis and fragmentation of the proximal femoral epiphysis. What is the most likely diagnosis?

Explanation

Legg-Calve-Perthes disease typically presents in children aged 4-8 with a painless or mildly painful limp. Radiographs show avascular necrosis of the capital femoral epiphysis.

Question 43

A 14-year-old boy presents with anterior knee pain exacerbating with jumping. Examination reveals tenderness over the tibial tubercle. Radiographs demonstrate fragmentation of the tibial apophysis.

Which of the following is the most appropriate initial management?

Explanation

Osgood-Schlatter disease is a traction apophysitis of the tibial tubercle. It is self-limiting and best managed conservatively with activity modification, stretching, and NSAIDs.

Question 44

A 4-week-old female infant is brought to the clinic for a routine check-up. Barlow and Ortolani maneuvers are positive on the left side. Ultrasound confirms developmental dysplasia of the hip (DDH). What is the initial treatment of choice?

Explanation

The Pavlik harness is the gold standard initial treatment for DDH in infants under 6 months of age, maintaining the hip in flexion and abduction.

Question 45

A 3-year-old child presents with a severe bowleg deformity (varus) that has progressed over the past year. Radiographs show medial beaking and fragmentation of the proximal tibial metaphysis.

What is the most likely diagnosis?

Explanation

Infantile Blount's disease is characterized by a pathologic varus deformity due to disordered growth of the medial proximal tibial physis, displaying a classic metaphyseal beak.

Question 46

A 7-year-old boy falls on an outstretched hand and sustains a widely displaced extension-type supracondylar fracture of the humerus. During assessment, he is unable to flex the interphalangeal joint of his thumb. Which nerve is most likely injured?

Explanation

The anterior interosseous nerve (AIN), a branch of the median nerve, is the most commonly injured nerve in extension-type supracondylar humerus fractures.

Question 47

An infant is born with a rigid equinovarus deformity of the right foot. When applying the Ponseti method of serial casting, which component of the deformity is corrected first?

Explanation

The Ponseti method corrects the clubfoot deformity in the sequence of CAVE: Cavus, Adductus, Varus, and Equinus. The cavus is corrected first by elevating the first metatarsal.

Question 48

A 14-year-old gymnast presents with chronic low back pain exacerbated by extension. Radiographs and an MRI confirm a bilateral pars interarticularis defect at L5 without spondylolisthesis. What is the most appropriate initial management?

Explanation

Spondylolysis in a young athlete is initially managed conservatively with a period of rest, bracing (optional), and core strengthening physical therapy.

Question 49

A 13-year-old boy sustains an ankle injury. Radiographs show a Salter-Harris III fracture of the anterolateral aspect of the distal tibial epiphysis.

What ligament is responsible for the avulsion of this fracture fragment?

Explanation

A Tillaux fracture is a Salter-Harris III fracture of the anterolateral distal tibial epiphysis, avulsed by the anterior inferior tibiofibular ligament (AITFL) due to external rotation.

Question 50

A 15-year-old male complains of a painful, stiff flatfoot. Symptoms are worse when walking on uneven ground. Radiographs reveal a "C sign" on the lateral view. What is the most likely diagnosis?

Explanation

The "C sign" on a lateral radiograph is formed by the medial outline of the talar dome and the posterior outline of the sustentaculum tali, pathognomonic for a talocalcaneal coalition.

Question 51

A 10-year-old boy presents with thigh pain that is worse at night and relieved dramatically by ibuprofen. Radiographs demonstrate a small radiolucent nidus surrounded by dense reactive sclerosis in the proximal femur.

What is the preferred definitive treatment if symptoms are refractory to medical management?

Explanation

The presentation is classic for an osteoid osteoma. Radiofrequency ablation (RFA) is the minimally invasive treatment of choice for symptomatic lesions failing conservative management.

Question 52

A 9-year-old boy sustains a minor fall and presents with arm pain. Radiographs reveal a mildly displaced pathologic fracture through a central, radiolucent, well-circumscribed lesion in the proximal humerus with a "fallen leaf" sign. What is the most likely diagnosis?

Explanation

A unicameral (simple) bone cyst is centrally located in the metaphysis of long bones in children. The "fallen leaf" or "fallen fragment" sign is pathognomonic for a pathologic fracture through the cyst.

Question 53

A 2-year-old child presents with a sudden onset of refusal to use the right arm after being pulled by the wrist. The arm is held in extension and pronation. Radiographs are normal. What is the most appropriate management?

Explanation

Nursemaid's elbow (radial head subluxation) is treated with a closed reduction maneuver involving supination and flexion, or hyperpronation, yielding immediate relief.

Question 54

A 16-year-old boy presents with intermittent knee catching and pain. MRI reveals an unstable osteochondral fragment in the knee joint.

What is the most common location for osteochondritis dissecans in the knee?

Explanation

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

Question 55

A 5-year-old boy presents with anterior bowing of his tibia and a leg length discrepancy. Radiographs reveal a pseudarthrosis of the middle third of the tibia.

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

Explanation

Congenital pseudarthrosis of the tibia (CPT) has a very strong association with Neurofibromatosis type 1 (NF1). Up to 50% of patients with CPT have NF1.

Question 56

A 6-month-old infant is diagnosed with an atypical presentation of multiple fractures in various stages of healing, blue sclerae, and dentinogenesis imperfecta. A genetic defect in which of the following is most likely responsible?

Explanation

Osteogenesis imperfecta is primarily caused by autosomal dominant mutations in the COL1A1 or COL1A2 genes, which encode Type I collagen, leading to brittle bones and blue sclerae.

Question 57

A 14-year-old pitcher presents with progressive shoulder pain during throwing. Radiographs reveal widening of the proximal humeral physis compared to the contralateral side.

What is the best initial treatment?

Explanation

Little League shoulder (proximal humeral epiphysiolysis) is a stress injury to the proximal humeral physis. The primary treatment is complete cessation of throwing to allow the physis to heal.

Question 58

A 12-year-old girl is diagnosed with adolescent idiopathic scoliosis (AIS). She is premenarchal, Risser stage 0, and has a right thoracic curve of 35 degrees. What is the most appropriate management?

Explanation

In a skeletally immature patient (Risser 0, premenarchal) with an AIS curve between 25 and 45 degrees, bracing is indicated to prevent curve progression.

Question 59

A 10-year-old child presents with a spiral fracture of the distal third of the tibia and an intact fibula. Over the next few weeks, what complication should be closely monitored regarding the varus/valgus alignment?

Explanation

An isolated fracture of the distal tibia with an intact fibula in a child often leads to a varus deformity. The intact fibula acts as a strut, causing asymmetric growth or settling.

Question 60

An 8-year-old boy presents with a persistent limp. Radiographs demonstrate a fragmented proximal femoral epiphysis.

Which of the following factors is most predictive of the final radiographic outcome in Legg-Calvé-Perthes disease?

Explanation

Age at clinical onset is the most significant prognostic factor in Legg-Calvé-Perthes disease. Patients presenting before the age of 6 to 8 years generally have a much higher potential for remodeling and a better final radiographic outcome.

Question 61

A 14-year-old boy sustains a twisting ankle injury. Radiographs show a classic triplane fracture.

Which of the following accurately describes the typical fracture pattern seen on standard anteroposterior (AP) and lateral radiographic views?

Explanation

A triplane fracture is a Salter-Harris IV equivalent injury. Radiographically, it appears as a Salter-Harris III fracture on the AP view (sagittal fracture line) and a Salter-Harris II on the lateral view (coronal fracture line).

Question 62

A 13-year-old boy presents with an isolated juvenile Tillaux fracture of the ankle. Which of the following best explains the specific anatomical pathogenesis of this fracture pattern?

Explanation

The distal tibial physis closes asymmetrically, beginning centrally, progressing medially, and closing laterally last. The still-open lateral physis is vulnerable to avulsion by the anterior inferior tibiofibular ligament during an external rotation injury.

Question 63

An 8-month-old girl presents with developmental dysplasia of the hip (DDH) that has failed Pavlik harness treatment. A closed reduction and spica casting is planned. Which of the following is considered the most significant extra-articular block to closed reduction in this age group?

Explanation

The iliopsoas tendon is typically the most significant extra-articular block to reduction in DDH, often causing an hourglass constriction of the hip capsule. The other listed options are intra-articular blocks.

Question 64

A 6-year-old boy presents with a displaced extension-type supracondylar humerus fracture. After anatomic closed reduction and percutaneous pinning, the radial pulse is absent, but the hand remains warm and pink with brisk capillary refill. What is the most appropriate next step in management?

Explanation

A 'pulseless, pink' hand following an adequate reduction and pinning of a supracondylar fracture indicates sufficient collateral circulation. Standard management is close observation and monitoring, as the pulse often returns over several days.

Question 65

When correcting a severe congenital idiopathic clubfoot using the Ponseti method, what is the correct physiological sequence of deformity correction during serial casting?

Explanation

The Ponseti method dictates correcting the deformities in the CAVE sequence: Cavus first (by supinating the forefoot), followed simultaneously by Adductus and Varus, and finally Equinus (which frequently requires a percutaneous Achilles tenotomy).

Question 66

A 12-year-old obese boy presents with right knee pain and an antalgic gait. Hip radiographs

show a stable slipped capital femoral epiphysis (SCFE). He is treated with a single in-situ screw. What is the most common long-term complication of his underlying condition?

Explanation

Even after successful in-situ fixation, the residual metaphyseal prominence of the proximal femur often leads to cam-type femoroacetabular impingement (FAI). Avascular necrosis is a higher risk in unstable SCFE.

Question 67

A radiograph

of a 10-year-old girl who sustained a lateral condyle fracture of the humerus 5 years ago shows an established nonunion. She now complains of clumsiness in her hand and numbness in her little finger. This complication is most directly related to:

Explanation

Nonunion of a lateral condyle fracture typically results in a progressive cubitus valgus deformity. Over time, this valgus angulation stretches the ulnar nerve, leading to tardy ulnar nerve palsy.

Question 68

A 4-year-old boy with spastic diplegic cerebral palsy undergoes routine radiographic screening of his hips. The Reimers migration percentage is calculated to be 45%. What does this value indicate, and what is the generally recommended orthopedic management?

Explanation

A Reimers migration index greater than 33% indicates significant hip subluxation in a child with cerebral palsy. A migration percentage of 45% typically mandates surgical intervention, such as VDRO, to prevent complete dislocation.

Question 69

A 9-year-old boy sustained a fracture to his distal radius physis. One year later, radiographs

reveal a central physeal bar occupying 25% of the cross-sectional area. He has an estimated 3 cm of growth remaining. What is the most appropriate surgical treatment?

Explanation

For a physeal bar occupying less than 50% of the cross-sectional area in a patient with more than 2 years (or 2 cm) of growth remaining, bar resection with interposition material (fat, wax, or cranioplast) is indicated to restore growth potential.

Question 70

A 15-year-old boy complains of vague, chronic ankle pain and a history of frequent sprains. Clinical examination reveals a rigid flatfoot. Lateral radiographs demonstrate a positive 'C-sign'. Which of the following is the most likely diagnosis?

Explanation

The 'C-sign' on a lateral foot radiograph is formed by the continuous bony outline of the talar dome and the sustentaculum tali. It is a classic radiographic indicator of a talocalcaneal coalition.

Question 71

An 18-month-old boy is brought to the clinic with severe bowing of the legs. Radiographs

show an abrupt varus angulation at the proximal medial tibia with a distinct metaphyseal beak. He is diagnosed with infantile Blount's disease. Which of the following Langenskiöld stages denotes the formation of a bony bar across the physis, making spontaneous resolution highly unlikely?

Explanation

Langenskiöld Stage IV is characterized by the development of a bony bar across the medial physis, creating an irreversible tether. At this stage, surgical intervention with corrective osteotomy is mandated.

Question 72

A 13-year-old gymnast presents with acute medial elbow pain after a fall. Radiographs demonstrate a displaced medial epicondyle fracture. Which of the following is universally considered an absolute indication for open reduction and internal fixation?

Explanation

Incarceration of the medial epicondyle fragment within the joint mechanically blocks reduction and articulation, making it an absolute indication for operative extraction and internal fixation.

Question 73

A 12-year-old boy presents with right ankle pain after a severe inversion and external rotation injury. Radiographs show a Salter-Harris III fracture of the anterolateral distal tibial epiphysis.

What is the most likely diagnosis?

Explanation

The juvenile Tillaux fracture is a Salter-Harris III fracture of the anterolateral distal tibia. It occurs due to avulsion by the anterior inferior tibiofibular ligament during external rotation, as this is the last portion of the physis to close.

Question 74

A 14-year-old boy sustains a distal femur Salter-Harris II fracture following a football tackle. Which of the following is the most common significant complication associated with this specific injury pattern at this location?

Explanation

Distal femur physeal fractures have a high risk of growth arrest (up to 50%), even in Salter-Harris I and II patterns. This is due to the undulating nature of the distal femoral physis, which leads to severe crushing of the germinal layer during displacement.

Question 75

A 6-year-old boy presents with a painless limp of 3 months' duration. Radiographs demonstrate sclerosis and fragmentation of the femoral head.

Measurement reveals the lateral pillar height is 60% of normal. What is the appropriate Herring classification?

Explanation

The Herring (lateral pillar) classification for Legg-Calvé-Perthes disease is based on the height of the lateral pillar of the femoral head on the AP radiograph. A height of >50% but <100% indicates Herring B, whereas less than 50% indicates Herring C.

Question 76

An 18-month-old presents with unilateral in-toeing. Physical examination reveals a rigid medial deviation of the forefoot with a completely normal, flexible hindfoot. What is the most likely diagnosis?

Explanation

Metatarsus adductus presents with medial deviation of the forefoot with a normal, flexible hindfoot. While most resolve spontaneously, rigid cases in older toddlers may require serial casting.

Question 77

A 13-year-old obese boy presents with right knee pain and a limp. On examination, obligate external rotation of the right hip is noted during passive flexion.

What is the most appropriate initial treatment?

Explanation

The clinical presentation is classic for a slipped capital femoral epiphysis (SCFE). The gold standard treatment for a stable SCFE is in situ fixation with a single cannulated screw to prevent further slippage.

Question 78

A newborn is diagnosed with severe idiopathic clubfoot. The pediatric orthopedic surgeon begins treatment using the Ponseti method. According to this protocol, which deformity must be corrected first?

Explanation

In the Ponseti method, the sequence of correction follows the mnemonic CAVE (Cavus, Adductus, Varus, Equinus). Cavus is corrected first by supinating the forefoot and elevating the first ray to align it with the hindfoot.

Question 79

A 5-year-old child presents with a 'pink, pulseless' hand after a severely displaced extension-type supracondylar humerus fracture. After prompt closed reduction and percutaneous pinning, the hand remains well-perfused (pink) but the radial pulse is still non-palpable. What is the next best step in management?

Explanation

A pink, pulseless hand after adequate closed reduction and pinning indicates sufficient collateral perfusion. The standard of care is close observation, as the pulse often returns spontaneously within a few days.

Question 80

A 4-year-old girl is evaluated for a persistent limp. Radiographs demonstrate late-presenting developmental dysplasia of the hip (DDH) with a fully dislocated femoral head.

What is the most appropriate definitive management?

Explanation

In a child older than 2-3 years, conservative measures and closed reduction are highly likely to fail. Open reduction combined with pelvic (to correct acetabular dysplasia) and femoral (to correct excessive anteversion) osteotomies is typically required.

Question 81

A pediatric patient presents with anterolateral bowing of the tibia that progresses to a spontaneous fracture. Which of the following systemic conditions is most strongly associated with this finding?

Explanation

Congenital pseudarthrosis of the tibia (CPT) typically presents as anterolateral bowing that eventually fractures and fails to heal. It is strongly associated with Neurofibromatosis type 1 (NF1) in up to 50% of cases.

Question 82

A 9-year-old boy presents with shoulder pain after a minor fall. Radiographs reveal a centrally located, radiolucent metaphyseal lesion in the proximal humerus with a cortical fragment resting at the bottom of the cyst. What is the most likely diagnosis?

Explanation

The 'fallen leaf' or 'fallen fragment' sign is pathognomonic for a unicameral bone cyst (UBC). It occurs when a fractured cortical fragment drops into the fluid-filled cavity of the cyst.

Question 83

A 12-year-old competitive gymnast complains of chronic, bilateral dorsal wrist pain. Radiographs reveal widening of the distal radial physis and cystic changes.

What is the most appropriate initial management?

Explanation

'Gymnast wrist' is a stress injury to the distal radial physis caused by repetitive compressive loading. The primary treatment is complete rest and cessation of upper extremity weight-bearing activities until symptoms and radiographic abnormalities resolve.

Question 84

A 2-year-old presents with a fever of 39.0°C, inability to bear weight on the right leg, an ESR of 50 mm/hr, and a serum WBC of 13,000/mm3. According to Kocher's criteria, what is the probability that this child has septic arthritis of the hip?

Explanation

Kocher's criteria for pediatric septic arthritis include: non-weight-bearing, ESR >40 mm/hr, fever >38.5°C, and WBC >12,000/mm3. The presence of all four criteria carries a 99% probability of septic arthritis.

Question 85

A 5-year-old boy sustains a lateral condyle fracture of the distal humerus. Initial radiographs show 3 mm of displacement.

What is the most appropriate management?

Explanation

Lateral condyle fractures of the humerus with >2 mm of displacement require open reduction and internal fixation. This is essential to ensure anatomic reduction of the articular surface and to minimize risks of nonunion or tardy ulnar nerve palsy.

Question 86

A 13-year-old baseball pitcher presents with acute medial elbow pain after throwing a pitch. Radiographs show an avulsion fracture of the medial epicondyle. What is the primary mechanism of injury?

Explanation

The medial epicondyle is the origin of the flexor-pronator mass and the ulnar collateral ligament. Avulsion fractures typically occur from sudden or repetitive valgus stress combined with intense traction from the flexor-pronator musculature.

Question 87

A 7-year-old is undergoing evaluation for a suspected physeal bar across the distal femur following a previous fracture.

Which imaging modality is considered the gold standard to accurately map the size, geometry, and location of the bar?

Explanation

MRI, particularly using fat-suppressed or gradient-echo sequences, is the best modality for evaluating the physis. It allows for accurate 3D mapping of the uncalcified cartilage and the exact extent of the bony bridge.

Question 88

When considering the surgical resection of a post-traumatic physeal bar, what is the generally accepted maximum percentage of cross-sectional physeal area involvement that still permits successful resection?

Explanation

Resection of a physeal bar (epiphysiodesis takedown) is generally indicated only if it involves less than 50% of the cross-sectional area of the physis. The patient must also have at least 2 years or 2 cm of remaining growth.

Question 89

A 14-year-old adolescent presents with a rigid flatfoot, hindfoot valgus, and frequent ankle sprains. CT scan shows a solid bony bridge between the middle facet of the talus and the calcaneus.

What is the most likely diagnosis?

Explanation

Talocalcaneal coalitions commonly present in adolescence with a rigid, peroneal spastic flatfoot. The coalition most frequently occurs at the middle facet between the talus and calcaneus.

Question 90

A 1-month-old infant is being treated with a Pavlik harness for developmental dysplasia of the hip. The parents report the infant has stopped spontaneously kicking the affected leg. Ultrasound confirms the hip remains reduced. What iatrogenic complication has most likely occurred?

Explanation

Femoral nerve palsy is a known complication of the Pavlik harness, typically caused by excessive hyperflexion of the hip pressing the nerve against the pelvis. Management involves temporary loosening or removal of the anterior straps.

Orthopedic Prometric MCQs - Chapter 3 Part 1

Orthopedic Prometric MCQs - Chapter 3 Part 17

Orthopedic Prometric MCQs - Chapter 3 Part 17

Chapter Index