Orthopedic Pediatrics 2026 MCQs: Board Review Prep

Question 1

The inheritance of the deformity shown in Figure 1 is most commonly

Explanation

Cleft hand and cleft foot malformations are commonly inherited as autosomal-dominant traits and are associated with a number of syndromes. An autosomal-recessive and an x-linked inheritance pattern have also been described, but these are much less common and are usually atypical. In the common autosomal-dominant condition, nearly one third of the known carriers of the gene show no hand or foot abnormalities. This is known as reduced penetrance. The disorder may be variably expressed; affected family members often exhibit a range from mild abnormalities in one limb only to severe anomalies in four limbs. Variable expressivity and reduced penetrance can cause difficulty in counseling families regarding future offspring in an affected family. Many patients have a cleft hand that may be caused by the split-hand, split-foot gene (SHFM1) localized on chromosome 7q21.

Question 2

Examination of a 12-year-old girl with bilateral anterior knee pain reveals excessive femoral anteversion and excessive external tibial torsion. The patient has no patellofemoral instability. Nonsurgical management consisting of muscle strengthening and nonsteroidal medication has failed to relieve the patient's pain. Treatment should now consist of

Explanation

Children with symptomatic severe torsional malalignment of the lower extremity and patellofemoral pathology show excessive femoral anteversion and external tibial torsion on physical examination and analysis of gait. The functional effect of this torsional malalignment is centered about the knee joint. If nonsurgical management fails to alleviate patellofemoral pain, definitive surgical treatment should consist of corrective osteotomies, including internal rotation of the distal part of the tibia or external rotation of the femur, or both. Patients with surgical correction by osteotomy show an improved gait pattern and appearance of the extremity and a marked decrease in knee pain. External rotation of the distal part of the tibia or internal rotation of the distal part of the femur worsens the torsional malalignment. No additional soft-tissue realignment procedures, including retinacular release or patellar realignment, are required.

Question 3

Which of the following patients with cerebral palsy is considered the ideal candidate for a selective dorsal rhizotomy?

Explanation

The enthusiasm with which dorsal rhizotomy was received led to the broadening of selection criteria with poorer results. The ideal candidate is an ambulatory 4- to 8-year-old child with spastic diplegia who does not use assistive devices or have joint contractures. The child must be old enough to actively participate in the rigorous postoperative physical therapy program. The use of the procedure in an ambulatory 16-year-old patient is less desirable because joint contractures will most likely have developed to a varying degree. The hemiplegic child is best treated by orthopaedic interventions. Oppenheim WL: Selective posterior rhizotomy for spastic cerebral palsy: A review. Clin Orthop 1990;253:20-29. Renshaw TS, Green NE, Griffin PP, Root L: Cerebral palsy: Orthopaedic management. J Bone Joint Surg Am 1995;77:1590-1606.

Question 4

A 3-year-old boy sustains a complete paralysis following a high thoracic spinal cord injury consistent with a SCIWORA-type injury (spinal cord injury without radiographic abnormality). Subsequent progressive spinal deformity will develop in what percent of patients with this injury?

Explanation

Spinal cord injury in skeletally immature patients almost always leads to the development of paralytic spinal deformity. The age at injury is the most important factor affecting the development of scoliosis. Spinal cord injury that occurs more than 1 year prior to skeletal maturity is almost always followed by the development of scoliosis. In one study, scoliosis developed in 100% of children who were younger than age 10 years at the time of spinal cord injury. Scoliosis can occur after injury at any level. Spasticity is often a contributing factor. Up to two thirds of patients who have paralytic scoliosis prior to skeletal maturity will eventually require surgery for curve control. Mayfield JK, Erkkila JC, Winter RB: Spine deformity subsequent to acquired childhood spinal cord injury. J Bone Joint Surg Am 1981;63:1401-1411. Lancourt JE, Dickson JH, Carter RE: Paralytic spinal deformity following traumatic spinal cord injury in children and adolescents. J Bone Joint Surg Am 1981;63:47-53.

Question 5

A 12-year-old girl has progressive development of cavus feet. Examination reveals slightly diminished vibratory sensation on the bottom of the foot. Reflexes are 1+ at the knees and ankles. Motor examination shows that all muscles are 5/5 in the foot, except the peroneal and anterior tibial muscles are rated as 4+/5. Which of the following studies is considered most diagnostic?

Explanation

The patient most likely has a form of Charcot-Marie-Tooth disease, or hereditary motor sensory neuropathy (HMSN). The most common varieties can now be diagnosed by DNA testing. Mutations have been detected in the peripheral myelin protein-22 (PMP-22) gene in HMSN type IA and in the connexin gene in the x-linked HMSN. Specific DNA diagnosis is useful in genetic counseling. Routine chromosomal testing most likely would not detect these mutations. Nerve conduction velocity study results are normal in some types of HMSN, and delayed nerve conduction, when found, indicates a peripheral neuropathy but does not specify the type or inheritance pattern. Biopsy of the sural nerve or of the quadriceps can be informative in some patients, but is not as specific as DNA testing. These procedures are most often reserved for patients with negative DNA test results. Chance PF: Molecular genetics of hereditary neuropathies. J Child Neurol 1999;14:43-52.

Question 6

A 2-year-old girl was born with the toe deformity shown in Figure 2. She has difficulty wearing shoes despite having adequate room in the toe box. Management at this time should consist of

Explanation

The patient has a congenital curly toe deformity of the third toe, and tenotomy of the toe flexors is highly effective for this problem. Stretching and taping are ineffective for this deformity. The position of the second toe is secondary; therefore, procedures on that toe are unnecessary and ineffective. The flexor to extensor transfer is a more complicated procedure that produces negligible results, or may even worsen the deformity. Resection arthroplasty is contraindicated because it causes abnormal growth of the toes. Hamer AJ, Stanley D, Smith TW: Surgery for curly toe deformity: A double-blind, randomized, prospective trial. J Bone Joint Surg Br 1993;75:662-663. Ross ER, Menelaus MB: Open flexor tenotomy for hammer toes and curly toes in childhood. J Bone Joint Surg Br 1984;66:770-771.

Question 7

Figure 3 shows the radiograph of an asymptomatic 10-year-old boy. Management should consist of

Explanation

Asymptomatic spondylolysis in a child or adolescent should be observed for the possible development of spondylolisthesis, but no other active intervention is needed. The initial treatment of choice for symptomatic spondylolysis includes rest and activity modifications, nonsteroidal anti-inflammatory drugs, physical therapy, bracing, and casting. Immobilization with a TLSO or pantaloon spica cast may permit healing of an acute pars fracture. Rarely, surgical treatment may be necessary. Surgical options include posterolateral L5-S1 fusion or direct repair of the pars defect. Pizzutillo PD, Hummer CD III: Nonoperative treatment for painful adolescent spondylolysis or spondylolisthesis. J Pediatr Orthop 1989;9:538-540.

Question 8

A 12-year-old girl has had lower back pain for the past 6 months that interferes with her ability to participate in sports. She denies any history of radicular symptoms, sensory changes, or bowel or bladder dysfunction. Examination reveals a shuffling gait, restriction of forward bending, and tight hamstrings. Radiographs show a grade III spondylolisthesis of L5 on S1, with a slip angle of 20 degrees. Management should consist of

Explanation

Indications for surgical treatment of spondylolisthesis include pain and/or progression of deformity. Specifically, surgery is necessary when there is persistent pain or a neurologic deficit that fails to respond to nonsurgical therapy, there is significant slip progression, or the slip is greater than 50%. For patients with mild spondylolisthesis, in situ posterolateral L5-S1 fusion is adequate. In patients with more severe slips (greater than 50%), extension of the fusion to L4 offers better mechanical advantage. Postoperative immobilization may be achieved with instrumentation, casting, or both. In patients with a slip angle of greater than 45 degrees, reduction of the lumbosacral kyphosis with instrumentation or casting is desirable to prevent slip progression. Laminectomy alone is contraindicated in a child. Nerve root decompression is indicated if radiculopathy is present clinically. Seitsalo S, Osterman K, Hyvarinen H, Tallroth K, Schlenzka D, Poussa M: Progression of spondylolisthesis in children and adolescents: A long-term follow-up of 272 patients. Spine 1991;16:417-421.

Question 9

Figures 4a through 4c show the clinical photographs and radiographs of a 12-month-old boy who has progressive difficulty wearing shoes because of the length of the second toe, as well as width of the forefoot. Management should consist of

Explanation

4b 4c The patient has macrodactyly involving the second ray, with significant enlargement of the width and height of the foot. The radiographs show widening of the interval between the first and second metatarsal and between the second and third metatarsal. With this degree of involvement, amputation of the second ray with excision of the overgrowth of affected soft tissue provides the most consistent desired reduction in foot size. A threaded Steinmann pin should be inserted across the remaining metatarsals until healing has occurred. Patients with macrodactyly should be examined to exclude neurofibromatosis type 1 and Klippel-Trenaunay-Weber syndrome.

Question 10

Figures 5a and 5b show the radiographs of an 11-year-old boy who felt a pop and immediate pain in his right knee as he was driving off his right leg to jam a basketball. Examination reveals that the knee is flexed, and the patient is unable to actively extend it or bear weight on that side. There is also a large effusion. Management should include

Explanation

5b Fractures through the cartilage on the inferior pole of the patella, the so-called sleeve fracture, are often difficult to diagnose because of the paucity of ossified bone visible on the radiographs. If the fracture is missed and the fragments are widely displaced, the patella may heal in an elongated configuration that may result in compromise of the extensor mechanism function. The treatment of choice is open reduction and internal fixation using a tension band wire technique to achieve close approximation of the fragments and restore full active knee extension. Heckman JD, Alkire CC: Distal patellar pole fractures: A proposed common mechanism of injury. Am J Sports Med 1984;12:424-428.

Question 11

A 2-year-old child has been referred for management of congenital kyphosis. Neurologic examination is normal, and radiographs show a type I congenital kyphosis. Which of the following anomalies is seen in the MRI scan shown in Figure 6?

Explanation

There is a high incidence of intraspinal anomalies in patients with congenital scoliosis and kyphosis. Bradford and associates reported an incidence rate of 38% in 42 patients. The MRI scan shows that the filum terminale is thickened and adherent distally in the spinal canal. Although the conus is at L1, which may be normal, neurologic dysfunction may occur with further growth. There are no signals of high intensity within the cord that would suggest a syrinx. A Chiari II malformation would be found in the upper cervical region, not shown in this MRI scan. Meningocele and diastematomyelia are not present. Bradford DS, Heithoff KB, Cohen M: Intraspinal abnormalities and congenital spine deformities: A radiographic and MRI study. J Pediatr Orthop 1991;11:36-41.

Question 12

A 15-year-old boy with a type I hereditary sensory motor neuropathy (Charcot-Marie-Tooth disease) reports recurrent ankle sprains and significant pain in the hindfoot and midfoot despite orthotic management. Examination reveals that he walks with a drop foot and has dynamic clawing of the toes. Clinical photographs of the left foot are shown in Figure 7. Management should consist of

Explanation

The clinical photographs show a patient with a type I hereditary sensory motor neuropathy who has cavus feet with a flexible hindfoot. The Coleman block test shows that the hindfoot corrects into valgus. To prevent progressive cavus, patients with this condition may benefit from soft-tissue releases at a younger age while the foot is flexible. Once there is fixed deformity, combined soft-tissue and bone procedures usually are necessary. Metatarsal osteotomies will correct the cavus, but will do nothing for the drop foot. Transfer of the extensor hallucis longus to the neck of the first metatarsal and modified transfer of the extensor digitorum longus to the dorsum of the foot will prevent further claw toes and improve foot dorsiflexion. Anterior transfer of the posterior tibialis tendon will also aid in dorsiflexion. Calcaneal osteotomy should be reserved for fixed hindfoot varus that does not correct with block testing, and triple arthrodesis should be avoided as long as possible because the long-term outcome is poor. Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1999, pp 235-245. Coleman SS: Complex Foot Deformities in Children. Philadelphia, Pa, Lea & Febiger, 1983, pp 147-165.

Question 13

Figures 8a through 8d show the radiographs and CT scans of a 14-year-old girl who has a painful, rigid planovalgus foot. Management consisting of arch supports and anti-inflammatory drugs failed to provide relief. A below-knee walking cast resulted in pain resolution, but she now reports that the pain has recurred. Management should now consist of

Explanation

8b 8c 8d Tarsal coalitions commonly present in the preadolescent age group as a rigid, planovalgus foot. Small coalitions of the calcaneonavicular joint or the middle facet of the talocalcaneal joint can be excised with interposition of fat or muscle tissue. Isolated calcaneocuboid joint coalitions are very rare. This patient has an associated large talocalcaneal coalition; therefore, resection is contraindicated. Surgery is warranted after failure of nonsurgical management, and because of the involvement of two joints, the only viable option for the severely symptomatic foot is triple arthrodesis. Vincent KA: Tarsal coalition and painful flatfoot. J Am Acad Orthop Surg 1998;6:274-281.

Question 14

Figures 9a and 9b show the spinal radiographs of a 3-year-old child with short limb dwarfism. The lateral radiograph is obtained with maximal lumbar extension. Management should consist of

Explanation

9b The patient has kyphosis in association with achondroplasia. The AP radiograph shows decreased interpedicular distance at the lower lumbar vertebrae, a feature considered to be a distinctive sign of achondroplasia. Most patients with achondroplasia have kyphosis, and this usually resolves spontaneously. When the fixed component is greater than 30 degrees, however, brace treatment is recommended. Spinal fusion is seldom required.

Question 15

A 10-year-old boy with severe hemophilia A (factor VIII) sustained an injury to his right forearm 2 hours ago when a classmate fell on his arm during a scuffle. Examination reveals moderate swelling in the forearm, decreased sensation in the distribution of the median and ulnar nerves, and pain on passive extension of the fingers. What is the most appropriate sequence of treatment?

Explanation

The patient has severe hemophilia with a volar forearm hemorrhage and an emerging compartment syndrome. Therefore, it is critical to normalize the clotting deficiency as the first step in treatment. In a patient who has a factor VIII level of less than 1% and no inhibitors to factor VIII, transfusion with 4 unit/kg will typically raise the factor VIII level to 100%. Continuous transfusion can then be used to maintain this level. Compartment pressures can be safely measured after infusion of factor VIII. Because the hemorrhage is of limited duration and any surgery is considered serious in a patient with hemophilia, the compartment pressure should be measured before making a decision regarding a fasciotomy. However, it is important to note that the use of factor VIII concentrates allows both emergency and elective surgery provided that adequate hematology backup is available. Splinting the elbow and wrist in flexion reduces the pressure in the volar compartments, protects the forearm from further trauma, and makes the patient more comfortable. Greene WB: Diseases related to the hematopoietic system, in Morrissy RT, Weinstein SL (eds): Lovell & Winter's Pediatric Orthopaedics, ed 4. Philadelphia, Pa, Lippincott-Raven, 1996, pp 345-391. Greene WB, McMillan CW: Nonsurgical management of hemophilic arthropathy, in Barr JS (ed): Instructional Course Lectures 38. Park Ridge, Ill, American Academy of Orthopaedic Surgeons, 1989, pp 367-381.

Question 16

Figures 10a and 10b show the radiographs of an athletic 9-year-old boy who has activity-related anterior knee pain with intact active knee extension. Examination reveals tenderness to palpation over the inferior pole of the patella. There is no effusion or ligamentous instability. Initial management should consist of

Explanation

10b The radiographs show fragmentation of the inferior pole of the patella. This finding, along with the clinical presentation, is most consistent with Sindig-Larsen-Johansson disease. This is an overuse syndrome commonly seen in boys ages 9 to 11 years. The differential diagnosis includes bipartite patella and patellar sleeve fracture. Like most overuse syndromes, Sindig-Larsen-Johansson disease responds to activity modification and nonsteroidal anti-inflammatory drugs. While symptoms usually resolve with short periods of activity restriction, radiographic findings may persist. Stanitski CL: Anterior knee pain syndromes in the adolescent. J Bone Joint Surg Am 1993;75:1407-1416.

Question 17

A 2-week-old infant has been referred for evaluation of nonmovement of the left hip. History reveals that the patient was delivered 6 weeks premature by cesarean section. Examination reveals no fever, and there is mild swelling of the thigh. Passive movement of the hip appears to elicit tenderness and very limited hip motion. A radiograph of the pelvis shows mild subluxation of the left hip. The next step in evaluation should consist of

Explanation

The diagnosis of bone and joint sepsis in a newborn is difficult because of the relative lack of obvious signs and symptoms. Fever is usually absent. A study of 34 newborns with osteomyelitis identified prematurity and delivery by cesarean section as predisposing factors. In that study, the most common clinical findings were pseudoparalysis, local swelling, and pain on passive movement. Because early diagnosis is so important, any infant who exhibits these findings should be suspected as having bone or joint sepsis. Once the area of involvement is identified, aspiration is mandatory. In newborns who have an infection about the hip, radiographs may reveal subluxation. In this patient, septic arthritis must be ruled out by aspiration of the hip. Developmental dysplasia of the hip is not painful and is not accompanied by localized swelling. If no purulent material is obtained at the time of hip aspiration, an arthrogram should be obtained to rule out epiphysiolysis of the proximal femur. Because the area of involvement has been identified by clinical examination, a gallium scan or MRI scan of the spine is not indicated. Knudsen CJ, Hoffman EB: Neonatal osteomyelitis. J Bone Joint Surg Br 1990;72:846-851.

Question 18

Figure 11 shows the lateral radiograph of a 16-year-old boy who has been unable to participate in sports activities because of pain in the anterior aspect of the knee. He states that the pain is aching in nature and is located in the region of the tibial tuberosity. He denies having joint effusion or symptoms of instability. Management should consist of

Explanation

The prognosis for most patients with Osgood-Schlatter disease is good. When the secondary ossification center unites with the main body of the tibial tubercle, the patellar tendon has a more rigid anchor, and heterotopic ossification and its associated reaction often become quiescent. However, even after closure of the growth plates, some patients have persistent symptoms. Excision of the ossicle and prominence of the tibial tuberosity decompresses the patellar tendon and allows most patients to resume sports activities. Nonsurgical modalities are ineffective. Better results have been reported after excision than after drilling of the tubercle. Excision of the ossicle is not indicated prior to skeletal maturity because symptoms will resolve in most patients when the secondary ossification center unites. Flowers MJ, Bhadreshwar DR: Tibial tuberosity excision for symptomatic Osgood-Schlatter disease. J Pediatr Orthop 1995;15:292-297.

Question 19

A 10-lb, 2-oz infant who was born via a difficult breech delivery 12 hours ago is now being evaluated for hip pain. Although the infant is resting comfortably, examination reveals that the patient is not moving the right lower extremity and manipulation of the right hip causes the infant to cry. The Galeazzi sign is positive. An AP radiograph of the pelvis shows proximal and superior migration of the right proximal femoral metaphysis. What is the most likely diagnosis?

Explanation

Transphyseal fractures of the proximal femur at birth are more likely to occur in large newborns after a difficult delivery. At rest, the patients are comfortable and show a pseudoparalysis; however, passive motion of the lower extremity results in discomfort. Teratologic hip dislocations will have a positive Galeazzi sign, but are not painful. Development of a septic hip would be unlikely within 12 hours postpartum. Congenital coxa vara is typically painless. Postpartum ligamentous laxity might account for a positive Ortolani sign, but is painless. Weinstein JN, Kuo KN, Millar EA: Congenital coxa vara: A retrospective review. J Pediatr Orthop 1984;4:70-77.

Question 20

A 10-year-old girl has been referred for evaluation of a prominence at the lower cervical spine. The patient is asymptomatic, and the examination reveals no evidence of neurologic abnormality. A radiograph and CT scans are shown in Figures 12a through 12c. What is the most likely diagnosis?

Explanation

12b 12c Tuberculosis is uncommon in the cervical spine but has a relatively greater incidence in young children. In a review of 40 patients with lower cervical spine involvement (C2 to C7), 24 were younger than age 10 years at presentation. In children, the disease is characterized by more extensive involvement with the formation of large abscesses. In older patients with lower cervical tuberculosis, the disease is more localized but is more likely to cause paraplegia. Four-drug antituberculosis therapy should be used. For patients with pain or neurologic dysfunction, anterior excision of diseased bone and grafting are indicated. Whether vertebral body excision and grafting should be done in an asymptomatic 10-year-old child is debatable. The CT scan shows a large "cold" abscess that is partially calcified. Hsu LC, Leong JC: Tuberculosis of the lower cervical spine (C2 to C7): A report on 40 cases. J Bone Joint Surg Br 1984;66:1-5.

Question 21

Which of the following types of iliac osteotomy provides the greatest potential for increased coverage?

Explanation

The degree of acetabular dysplasia and the age of the child are important considerations when choosing what type of osteotomy to perform. The ability to obtain concentric reduction is a prerequisite of all osteotomies that redirect the acetabulum. Procedures that cut all three pelvic bones allow more displacement and, therefore, correction of acetabular dysplasia. The closer the osteotomy is to the acetabulum, the greater the coverage of the femoral head. Compared with the other acetabular osteotomies, the Ganz periacetabular osteotomy provides the greatest potential for correcting acetabular deficiency because there are no bone or ligamentous restraints to limit correction, but it has the disadvantage of being a technically demanding procedure. The amount of coverage provided by the Salter osteotomy is limited. Millis MB, Poss R, Murphy SB: Osteotomies of the hip in the prevention and treatment of osteoarthritis, in Eilert RE (ed): Instructional Course Lectures XLI. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1992, pp 145-154.

Question 22

The mother of a 26-month-old boy reports that he has been unwilling to bear weight on his left lower extremity since he awoke this morning. She denies any history of trauma. He has a temperature of 99.4 degrees F (37.4 degrees C), and examination reveals that abduction of the left hip is limited to 30 degrees. Laboratory studies show a WBC of 11,000/mm3 and an erythrocyte sedimentation rate of 22 mm/h. A radiograph of the pelvis is shown in Figure 13. Management should consist of

Explanation

The most likely diagnosis is transient synovitis. Initial management should consist of bed rest and serial observation to rule out atypical septic arthritis of the hip. In an unreliable family situation, hospitalization for bed rest and observation may be indicated. Other disorders such as proximal femoral osteomyelitis, leukemia, juvenile rheumatoid arthritis, pelvic osteomyelitis, diskitis, and arthralgia secondary to other inflammatory disorders should be considered. However, these disorders are unlikely because of the paucity of abnormal clinical signs exhibited by the patient. On the other hand, transient synovitis of the hip in children is a diagnosis of exclusion; other possibilities should be explored if the patient's symptoms do not follow a typical course and resolve in 4 to 21 days.

Question 23

A 10-year-old girl with a monoarticular pattern of juvenile rheumatoid arthritis (JRA) has had a 3-cm limb-length discrepancy since age 8 years when inflammation in the right knee came under good medical control. Because her right leg is longer, the patient states that she would like her legs to be close to equal in length in the future. A growth-remaining chart is shown in Figure 14. Management should consist of

Explanation

In a subgroup of patients with monoarticular JRA and a limb-length discrepancy that developed before the age of 9 years, Simon and associates showed that a subsequent growth deceleration on the affected side may correct a large part of the difference in length. This possibility would make surgery unnecessary and should prompt further observation. Simon S, Whiffen J, Shapiro F: Leg-length discrepancies in monoarticular and pauciarticular juvenile rheumatoid arthritis. J Bone Joint Surg Am 1981;63:209-215.

Question 24

A 14-year-old girl with polyarticular juvenile rheumatoid arthritis (JRA) has severe neck pain and reports the onset of urinary incontinence. A lateral radiograph and lateral tomogram of the cervical spine are shown in Figures 15a and 15b. An MRI scan of the upper cervical spine is shown in Figure 15c. Management should consist of

Explanation

15b 15c The plain radiograph and tomogram show an abnormality of the upper cervical spine, with erosion of the dens. The MRI scan shows evidence of cord impingement. The cervical spine is frequently involved in polyarticular JRA. Stiffness and autofusion are commonly seen, but C1-2 instability can also occur secondary to synovitis and bony erosion. Basilar invagination is rare in JRA. There is no consensus regarding fusion in the asymptomatic patient. In patients with symptoms and neurologic signs, C1-2 posterior fusion is indicated. Fried JA, Athreya B, Gregg JR, Das M, Doughty R: The cervical spine in juvenile rheumatoid arthritis. Clin Orthop 1983;179:102-106.

Question 25

Figures 16a and 16b show the radiographs of an otherwise healthy 3 1/2-year-old boy who has an isolated deformity of the left leg. Definitive primary treatment of this condition should consist of

Explanation

16b Treatment of congenital pseudarthrosis of the tibia is problematic. To achieve union, a resection of the pseudarthrosis, stabilization, and bone grafting must be performed. Simple cast immobilization does not yield union. There are various options for the resection, immobilization, and grafting. On the first surgical attempt, retrograde intramedullary nailing offers the best chance for success by transfixing the ankle and subtalar joints with abundant autogenous bone grafting. Distraction osteogenesis and vascularized free fibular graft are reserved as salvage procedures. Gilbert A, Brockman R: Congenital pseudarthrosis of the tibia: Long-term follow-up of 29 cases treated by microvascular bone transfer. Clin Orthop 1995;314:37-44. Boero S, Catagni M, Donzelli O, Facchini R, Frediani PV: Congenital pseudarthrosis of the tibia associated with neurofibromatosis - 1: Treatment with Ilizarov's device. J Pediatr Orthop 1997;17:675-684.

Question 26

A 6-year-old boy presents with a Gartland type III supracondylar humerus fracture. The hand is pink but pulseless. After closed reduction and percutaneous pinning, the hand remains pink and pulseless. What is the most appropriate next step in management?

Explanation

In a pediatric supracondylar humerus fracture with a pink, pulseless hand after anatomical reduction and pinning, observation for 24-48 hours is indicated. The collateral circulation is adequate to perfuse the hand, and vascular exploration is not immediately required.

Question 27

A 4-year-old child presents with untreated unilateral developmental dysplasia of the hip. Which of the following surgical interventions is most commonly required to achieve and maintain a stable reduction?

Explanation

In children older than 3 years with untreated DDH, open reduction alone is associated with a high risk of avascular necrosis and redislocation. Femoral shortening osteotomy is necessary to decompress the joint, combined with a pelvic osteotomy to provide adequate anterolateral coverage.

Question 28

A 12-year-old obese boy presents with left knee pain and an antalgic gait. Radiographs reveal a severe slipped capital femoral epiphysis (SCFE) with a slip angle of 60 degrees. After in situ pinning of the left hip, which of the following is the most accepted indication for prophylactic pinning of the contralateral asymptomatic hip?

Explanation

Prophylactic pinning of the contralateral hip is highly recommended in patients with endocrine disorders, prior radiation therapy, or those presenting at an atypically young age (girls <10, boys <12). These patients have a significantly higher risk of sequential bilateral involvement.

Question 29

A 7-year-old boy is diagnosed with Legg-Calvé-Perthes disease. Radiographs demonstrate >50% loss of lateral pillar height. According to the Herring lateral pillar classification, what is the expected outcome without surgical intervention?

Explanation

Loss of more than 50% of the lateral pillar height corresponds to Herring Group C. This group has a poor prognosis with a high likelihood of significant residual deformity (coxa magna, severe flattening) and early-onset osteoarthritis.

Question 30

During the initial casting for an infant with a rigid idiopathic clubfoot using the Ponseti method, what is the first deformity that must be corrected?

Explanation

The Ponseti method corrects the deformities of clubfoot in a specific sequence summarized by the acronym CAVE. Cavus is corrected first by elevating the first ray to align the forefoot with the hindfoot.

Question 31

A 6-year-old boy falls from monkey bars and sustains a Gartland Type III supracondylar humerus fracture. On examination, the radial pulse is absent, but the hand is warm, pink, and has a capillary refill of less than 2 seconds. After prompt closed reduction and percutaneous pinning, the pulse remains absent but the hand remains well-perfused. What is the most appropriate next step?

Explanation

A "pulseless but pink" hand following reduction and pinning of a supracondylar fracture indicates adequate collateral circulation. Current guidelines recommend close observation and monitoring rather than immediate surgical exploration.

Question 32

A 2-year-old child presents with bilateral genu varum. Radiographs reveal medial metaphyseal beaking of the proximal tibia. Which of the following radiographic measurements most reliably differentiates infantile Blount disease from physiologic bowing?

Explanation

The metaphyseal-diaphyseal angle of Drennan is used to differentiate infantile Blount disease from physiologic bowing. An angle greater than 16 degrees has a high predictive value for the progression of Blount disease.

Question 33

A 3-year-old boy with multiple recurrent fractures, blue sclerae, and dentinogenesis imperfecta is diagnosed with osteogenesis imperfecta. This condition is most commonly caused by a mutation affecting which of the following?

Explanation

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

Question 34

An infant with achondroplasia presents with central sleep apnea, hyperreflexia, and hypotonia. These clinical findings are most likely secondary to which of the following complications?

Explanation

Infants with achondroplasia are at high risk for foramen magnum stenosis due to abnormal endochondral ossification of the skull base. This can lead to cervicomedullary compression, presenting with central sleep apnea, hypotonia, and sudden death.

Question 35

A 6-year-old child with spastic quadriplegic cerebral palsy has a migration percentage of 45% on an AP pelvis radiograph. He has pain with hip range of motion and limited abduction. What is the most appropriate surgical management?

Explanation

In a child with cerebral palsy and significant hip subluxation (migration percentage >40%), a bony reconstruction consisting of a proximal femoral varus derotational osteotomy (VDRO) and a pelvic osteotomy is the gold standard.

Question 36

A 3-year-old boy treated for idiopathic clubfoot with the Ponseti method presents with a recurrence of the deformity. Examination reveals dynamic supination of the foot during the swing phase of gait. Passive range of motion demonstrates fully correctable deformities. What is the most appropriate next step in management?

Explanation

Dynamic supination in a relapsed Ponseti-treated clubfoot with a flexible deformity is typically managed with a split anterior tibial tendon transfer (SPLATT) to the lateral cuneiform. This is often combined with an Achilles tendon lengthening if equinus is present.

Question 37

A 6-year-old boy sustains a completely displaced posterolateral supracondylar humerus fracture. Upon presentation, he has a pulseless but well-perfused (pink) hand. Closed reduction and percutaneous pinning are performed, achieving an anatomic reduction. Postoperatively, the hand remains pink but the radial pulse is still absent. What is the most appropriate management?

Explanation

In a pulseless, pink hand following anatomic reduction and pinning of a supracondylar fracture, observation is the standard of care. Collateral circulation provides adequate perfusion; open exploration is indicated only for a pulseless, pale (ischemic) hand after reduction.

Question 38

A 6-week-old female is undergoing treatment with a Pavlik harness for developmental dysplasia of the hip (DDH). During the follow-up visit, the parents report that the child has stopped moving her left leg. Examination reveals decreased active knee extension and an absent patellar reflex on the left side. What is the most likely cause of this finding?

Explanation

Femoral nerve palsy is a known complication of Pavlik harness treatment due to excessive hip flexion. The initial management is to temporarily remove or adjust the harness to decrease the flexion, which usually leads to spontaneous recovery.

Question 39

An 11-year-old boy presents with a 4-week history of left groin pain and a limp. Radiographs confirm a mild, stable slipped capital femoral epiphysis (SCFE) of the left hip. The right hip is radiographically normal. Which of the following is the strongest indication for prophylactic pinning of the contralateral (right) hip?

Explanation

Prophylactic pinning of the contralateral hip in SCFE is strongly indicated in patients with underlying endocrinopathies (e.g., hypothyroidism, renal osteodystrophy) or prior radiation therapy. These conditions significantly increase the risk of bilateral involvement.

Question 40

A 10-year-old girl is evaluated for a leg length discrepancy following a distal femoral physeal fracture 2 years ago. A scanogram reveals the injured limb is 3 cm shorter than the normal limb. Based on the multiplier method, her predicted leg length discrepancy at maturity is 4.5 cm. Which of the following is the most appropriate surgical management plan?

Explanation

For a predicted leg length discrepancy of 2 to 5 cm, a contralateral epiphysiodesis appropriately timed near skeletal maturity is the treatment of choice. Lengthening procedures are generally reserved for discrepancies greater than 5 cm.

Question 41

A 7-year-old boy with spastic diplegic cerebral palsy with GMFCS level III presents with a progressive crouch gait. Physical examination reveals fixed knee flexion contractures of 15 degrees bilaterally. Which of the following interventions is most appropriate to address this specific deformity?

Explanation

Fixed knee flexion contractures (>10-15 degrees) in a crouch gait are best treated with bony procedures such as distal femoral extension osteotomies, often combined with patellar tendon advancement. Soft tissue lengthening alone is insufficient for fixed bony/capsular deformities.

Question 42

A 3-year-old girl is diagnosed with congenital scoliosis secondary to a fully segmented hemivertebra at T8. The curve is currently 35 degrees. Renal ultrasound and echocardiogram are normal. An MRI of the entire spine is obtained. What is the most common intraspinal anomaly associated with this condition?

Explanation

Intraspinal anomalies occur in up to 30-40% of patients with congenital scoliosis. The most common of these is a tethered cord, making an MRI of the entire neuraxis mandatory prior to any surgical intervention.

Question 43

A 6-year-old boy with Sillence Type III osteogenesis imperfecta presents with progressive anterolateral bowing of his bilateral femurs, leading to an inability to ambulate. He has been receiving IV pamidronate for 2 years. Which of the following surgical strategies is most appropriate?

Explanation

In a growing child with severe bowing from osteogenesis imperfecta, the standard surgical treatment is multi-level "shish kebab" osteotomies with telescopic (growing) intramedullary nails. This accommodates future growth and prevents recurrent deformities.

Question 44

A newborn male is noted to have unilateral foreshortening of the right lower extremity. Radiographs reveal complete absence of the fibula, a shortened tibia with anterior bowing, and a 3-ray foot. Which of the following knee anomalies is most commonly associated with this presentation?

Explanation

Fibular hemimelia is frequently associated with an absent or deficient anterior cruciate ligament (ACL), leading to anteroposterior instability of the knee. Other common findings include a ball-and-socket ankle, tarsal coalitions, and absent lateral rays.

Question 45

A 10-year-old girl falls while skiing and sustains a Type III (completely displaced) tibial eminence fracture. Closed reduction under anesthesia is attempted but is unsuccessful in achieving an acceptable reduction. What is the most likely anatomic structure blocking the reduction?

Explanation

The anterior horn of the medial meniscus is the most common structure that becomes entrapped under a completely displaced tibial eminence fracture, blocking closed reduction. Arthroscopic or open reduction is required to extricate the meniscus and fix the fracture.

Question 46

A 4-year-old boy presents with right hip pain, a temperature of 38.8°C (101.8°F), inability to bear weight, and a WBC count of 14,000/mm3. ESR is 55 mm/hr. According to the Kocher criteria, what is the approximate probability that this child has septic arthritis rather than transient synovitis?

Explanation

The patient meets all four Kocher criteria (fever >38.5°C, inability to bear weight, WBC >12,000, ESR >40). The probability of septic arthritis with 4 positive predictors is approximately 99%.

Question 47

A 3-year-old boy presents to the emergency department with a spiral fracture of the midshaft femur. He was reportedly running and tripped over a rug. The parents delayed bringing him in for two days. Upon examination, there are multiple bruises in various stages of healing on his back. What is the next most appropriate step in management regarding the mechanism of injury?

Explanation

A femur fracture in a non-ambulatory child or one with a suspicious mechanism/delay in care, combined with bruises in varied stages of healing, is highly indicative of non-accidental trauma. The physician is legally obligated to report suspected abuse immediately.

Question 48

A 7-year-old boy is diagnosed with early-stage Legg-Calvé-Perthes disease. He has a limp and restricted hip abduction. Which of the following factors at the time of presentation is considered the most significant indicator of a poor long-term prognosis?

Explanation

Age at onset is the single most important prognostic factor in Legg-Calvé-Perthes disease. Patients older than 8 years at the onset of symptoms generally have a worse prognosis due to having less remaining growth for femoral head remodeling.

Question 49

A 14-year-old male gymnast presents with persistent lower back pain exacerbated by extension. Radiographs and an MRI confirm a bilateral L5 pars interarticularis defect with a Grade I spondylolisthesis. The pain has not improved after 6 months of rest, bracing, and physical therapy. What is the most appropriate surgical treatment?

Explanation

In a patient with spondylolisthesis (even Grade I) that fails non-operative management, a posterolateral in situ fusion (L5-S1) is the procedure of choice. Direct pars repair is generally reserved for patients with a pars defect (spondylolysis) without any spondylolisthesis (slip).

Question 50

A 12-year-old boy complains of recurrent left ankle sprains and lateral foot pain. On examination, he has a rigid, flat foot and lacks subtalar motion. Radiographs demonstrate a "C-sign" on the lateral view. A CT scan confirms a talocalcaneal coalition involving 25% of the posterior facet. Non-operative management has failed. What is the most appropriate surgical intervention?

Explanation

For symptomatic talocalcaneal coalitions that fail conservative treatment, resection is indicated if the coalition involves less than 50% of the posterior facet and there is no degenerative arthritis. Interposition of material (fat, wax, EDB muscle) prevents recurrence.

Question 51

A 4-year-old child with a history of idiopathic clubfoot treated successfully with the Ponseti method presents with a dynamic supination deformity during the swing phase of gait. Passive range of motion of the ankle and foot is full. What is the most appropriate management?

Explanation

Dynamic supination in a relapsed clubfoot, without fixed deformity, is best managed with a full tibialis anterior tendon transfer to the lateral cuneiform. This converts the deforming supinating force into a corrective dorsiflexion force.

Question 52

A 6-month-old girl with Developmental Dysplasia of the Hip (DDH) undergoes closed reduction and spica casting. Which of the following intraoperative positioning parameters is most strongly associated with an increased risk of avascular necrosis (AVN) of the femoral head?

Explanation

Excessive abduction (greater than 60 degrees) in a spica cast places the medial circumflex femoral artery under tension, significantly increasing the risk of avascular necrosis. The "human position" emphasizes safe limits of abduction to prevent this complication.

Question 53

A 13-year-old obese boy presents with sudden severe right hip pain and inability to bear weight after a minor fall. Radiographs confirm an unstable slipped capital femoral epiphysis (SCFE). What is the primary proposed benefit of performing an urgent capsulotomy and gentle reduction prior to pinning?

Explanation

In unstable SCFE, urgent decompression via capsulotomy and gentle reduction decreases intracapsular pressure and restores capsular blood flow. This intervention is thought to lower the historically high risk of avascular necrosis in unstable slips.

Question 54

A 7-year-old boy is diagnosed with Legg-Calvé-Perthes disease. Radiographs show radiolucency and fragmentation. The lateral pillar of the femoral head maintains 40% of its original height. According to the Herring Lateral Pillar Classification, what is the grade and expected outcome without surgical containment?

Explanation

Herring Group C is defined as less than 50% maintenance of the lateral pillar height. These patients generally have a poor natural history and a higher risk of developing a non-spherical femoral head.

Question 55

A 3-year-old boy presents with progressive bilateral genu varum. Standing radiographs reveal metaphyseal-diaphyseal angles of 18 degrees bilaterally, with prominent medial metaphyseal beaking. What is the most appropriate initial management?

Explanation

A metaphyseal-diaphyseal angle greater than 16 degrees strongly suggests infantile Blount disease. In a child under 3 to 4 years old with early Langenskiöld stages, bracing with KAFOs is the appropriate initial treatment.

Question 56

A 5-year-old girl with spastic quadriplegic cerebral palsy (GMFCS Level V) is evaluated for hip surveillance. Her migration percentage (MP) on an AP pelvis radiograph is 45%. Clinically, she has 20 degrees of hip abduction bilaterally. What is the most appropriate management?

Explanation

In non-ambulatory children with CP, a migration percentage >40% with restricted abduction indicates significant hip subluxation that will not resolve with soft tissue releases alone. Bony reconstruction with VDRO and often a pelvic osteotomy is required.

Question 57

A 6-year-old boy sustains a completely displaced (Gartland Type III) posteromedial supracondylar humerus fracture. On examination, the hand is pink and warm, but the radial pulse is absent. After anatomical closed reduction and percutaneous pinning, the hand remains pink and the pulse remains absent. What is the next best step?

Explanation

A "pulseless, pink" hand after a well-reduced supracondylar fracture usually indicates adequate collateral circulation. Current guidelines recommend close observation over immediate vascular exploration, provided the limb remains well-perfused.

Question 58

A 14-year-old boy complains of recurrent ankle sprains and deep lateral hindfoot pain. On examination, he has rigid pes planus and absent subtalar motion. Radiographs demonstrate a continuous bony C-shaped ring on the lateral view. Which of the following is the most likely diagnosis?

Explanation

The C-sign on a lateral radiograph is characteristic of a talocalcaneal (subtalar) coalition, representing the bony bridge between the talar dome and the sustentaculum tali. Calcaneonavicular coalitions are better visualized on the oblique view.

Question 59

A 14-month-old girl presents with refusal to bear weight on her right leg. She is afebrile with normal inflammatory markers. MRI shows early osteomyelitis in the distal tibial metaphysis. Given her age, what fastidious organism should be highly suspected, and how can its culture yield be optimized?

Explanation

Kingella kingae is a leading cause of pediatric osteoarticular infections in children aged 6 to 36 months, often presenting with mild systemic symptoms. Culturing aspirates directly into aerobic blood culture vials significantly improves detection.

Question 60

A 14-year-old gymnast presents with severe mechanical back pain and L5 radiculopathy. Radiographs reveal a Grade III L5-S1 isthmic spondylolisthesis with a slip angle of 55 degrees. Nonoperative management has failed. What is the most appropriate surgical treatment?

Explanation

Symptomatic high-grade spondylolisthesis (Grade III-V) in adolescents typically requires decompression and instrumented posterior fusion. Fusing from L4 to S1 is often necessary to obtain adequate fixation and counteract severe shear forces.

Question 61

A 12-year-old premenarcheal girl with a Risser stage of 0 presents with a right thoracic adolescent idiopathic scoliosis (AIS). Her curve measures 30 degrees. Which of the following represents the most appropriate management?

Explanation

In an immature patient (Risser 0, premenarcheal) with an AIS curve between 25 and 40 degrees, full-time TLSO bracing is indicated to halt progression. Observation is inappropriate given her high risk for rapid curve worsening.

Question 62

A 5-year-old boy weighing 22 kg sustains a closed, length-stable diaphyseal transverse fracture of the femur. What is the standard of care for definitive management?

Explanation

For children aged 5 to 11 years weighing less than 50 kg with length-stable femoral shaft fractures, flexible intramedullary nailing is the treatment of choice. It provides rapid mobilization and minimizes malunion compared to spica casting.

Question 63

A 6-year-old girl with Osteogenesis Imperfecta Type III presents with a severely bowed femur and a new midshaft fracture. She has a history of multiple fractures. What is the most appropriate surgical management for this fracture?

Explanation

In severely bowing and frequently fracturing long bones of patients with severe OI, the standard surgical treatment is multiple corrective osteotomies to straighten the bone. This is followed by stabilization with a telescoping intramedullary rod that elongates with growth.

Question 64

An 8-month-old boy with achondroplasia presents with hypotonia, sleep apnea, and hyperreflexia. An MRI reveals severe stenosis at the foramen magnum with T2 signal changes in the upper cervical cord. What is the most appropriate next step?

Explanation

Foramen magnum stenosis leading to cervicomedullary compression is a critical complication in infants with achondroplasia. Signs of myelopathy and MRI cord signal changes mandate urgent surgical decompression to prevent sudden death or permanent neurological injury.

Question 65

A 12-year-old boy is diagnosed with a unilateral stable slipped capital femoral epiphysis (SCFE). Which of the following factors most strongly supports the decision for prophylactic pinning of the contralateral hip?

Explanation

An open triradiate cartilage indicates significant remaining skeletal growth, making it one of the strongest predictive risk factors for a subsequent contralateral slip. Prophylactic pinning is highly recommended in these high-risk patients.

Question 66

Which of the following is considered the most common extra-articular block to closed reduction in developmental dysplasia of the hip?

Explanation

The iliopsoas tendon is the most common extra-articular block to closed reduction in DDH, often causing an hourglass constriction of the capsule. The pulvinar, ligamentum teres, inverted limbus, and transverse acetabular ligament are intra-articular blocks.

Question 67

Which of the following factors at presentation is most strongly predictive of developing avascular necrosis following a slipped capital femoral epiphysis (SCFE)?

Explanation

The inability to bear weight (instability) is the strongest predictor of avascular necrosis in SCFE. Unstable SCFE has an AVN rate approaching 50 percent, compared to almost zero for stable SCFE.

Question 68

An infant with idiopathic clubfoot is being treated via the Ponseti casting method. The foot has been successfully abducted to 60 degrees, but dorsiflexion is limited to neutral. What is the most appropriate next step in management?

Explanation

Once abduction reaches 60 degrees and the heel is in valgus, residual equinus should be corrected with a percutaneous Achilles tenotomy. This is required in roughly 80 to 90 percent of idiopathic clubfeet treated with the Ponseti method.

Question 69

An 8-year-old boy presents with lateral pillar B/C border Legg-Calve-Perthes disease. According to current evidence-based guidelines, what is the most appropriate management?

Explanation

Surgical containment, such as a proximal femoral varus osteotomy or pelvic osteotomy, is indicated for children over 8 years of age with lateral pillar B or B/C border Perthes disease. It provides better spherical outcomes than non-operative management in this age group.

Question 70

A 6-year-old girl sustains a displaced Gartland III supracondylar humerus fracture. On examination, the radial pulse is absent, but the hand is warm, pink, and has capillary refill under 2 seconds. What is the most appropriate initial management?

Explanation

A pulseless, pink hand indicates adequate collateral circulation. The most appropriate initial step is urgent closed reduction and percutaneous pinning, which frequently restores the palpable pulse.

Question 71

A 7-year-old non-ambulatory child with spastic quadriplegic cerebral palsy has a Reimers migration index of 45 percent. Radiographs demonstrate significant coxa valga and acetabular dysplasia. What is the most appropriate surgical intervention?

Explanation

In a child with CP and a migration percentage greater than 40 percent combined with bony dysplasia, soft tissue release alone is insufficient. Bony reconstruction with a VDRO and a volume-reducing pelvic osteotomy is required.

Question 72

A 13-year-old boy develops severe hip pain and progressive loss of motion six months after undergoing in situ single screw fixation for a stable SCFE. Radiographs show significant joint space narrowing. What is the most likely etiology of this complication?

Explanation

Chondrolysis in the setting of treated SCFE is most commonly caused by unrecognized penetration of the hardware into the joint space. It presents with pain, stiffness, and radiographic joint space narrowing.

Question 73

Which of the following radiographic findings is recognized as one of Catterall's head-at-risk signs in Legg-Calve-Perthes disease?

Explanation

Catterall's head-at-risk signs include Gage sign (a V-shaped lucency in the lateral epiphysis/metaphysis), lateral subluxation, lateral epiphyseal calcification, horizontal physis, and metaphyseal cysts.

Question 74

A 3-year-old obese girl presents with unilateral genu varum. Radiographs reveal a metaphyseal-diaphyseal (Drennan) angle of 20 degrees. What is the diagnosis and best initial treatment?

Explanation

A Drennan metaphyseal-diaphyseal angle greater than 16 degrees predicts progression to infantile Blount disease. Because the child is 3 years old, early intervention with a Knee-Ankle-Foot Orthosis (KAFO) is indicated.

Question 75

A 2-year-old boy with neurofibromatosis type 1 develops a non-healing fracture of the tibia through an area of anterolateral bowing. Which surgical approach provides the highest union rate for this condition?

Explanation

Congenital pseudarthrosis of the tibia (CPT) is notoriously difficult to heal. The most successful surgical strategy involves radical resection of the hamartoma, robust bone grafting, and mechanical stabilization using intramedullary fixation, often spanning the ankle.

Question 76

A 14-year-old premenarchal girl (Risser 0) presents with adolescent idiopathic scoliosis. Standing radiographs demonstrate a right thoracic curve of 35 degrees. What is the recommended treatment?

Explanation

In a growing child (Risser 0-2) with an adolescent idiopathic scoliosis curve measuring between 25 and 45 degrees, TLSO bracing for a minimum of 16-18 hours daily is the standard of care to prevent progression.

Question 77

A 12-year-old boy presents with a rigid flatfoot and recurrent ankle sprains. CT imaging confirms an isolated calcaneonavicular coalition without arthritic changes. After conservative management fails, what is the most appropriate surgical intervention?

Explanation

For a symptomatic calcaneonavicular coalition without degenerative joint changes, resection of the coalition with interposition of the extensor digitorum brevis muscle or fat graft is the primary surgical treatment of choice.

Question 78

A child presents with short stature, rhizomelic limb shortening, frontal bossing, and a trident hand deformity. What is the most critical and life-threatening cervical spine abnormality associated with this skeletal dysplasia?

Explanation

The clinical picture describes Achondroplasia. The most critical cervical spine issue in these infants is foramen magnum stenosis, which can cause severe cervicomedullary compression, leading to central apnea or sudden death.

Question 79

A healthy 3-year-old boy sustains a closed, length-stable, isolated midshaft femur fracture after a fall from a playground slide. What is the recommended definitive treatment?

Explanation

For children between 6 months and 5 years of age with closed, stable diaphyseal femur fractures, early spica casting is the gold standard treatment with excellent remodeling potential and low complication rates.

Question 80

A 14-year-old gymnast is diagnosed with an L5-S1 isthmic spondylolisthesis with a 60 percent slip (Grade III). She reports persistent mechanical back pain and L5 radiculopathy despite 6 months of rest and therapy. What is the most appropriate surgical management?

Explanation

High-grade spondylolisthesis (greater than 50 percent slip) with refractory symptoms is generally managed with an in situ posterolateral fusion, often with decompression if radicular symptoms are profound. Pars repair is reserved for Grade 0 or I slips.

Question 81

A 3-year-old girl refuses to bear weight on her right leg for 2 days. Her temperature is 38.8 C, ESR is 50 mm/hr, and peripheral WBC is 14,000. Ultrasound confirms a hip effusion. According to the Kocher criteria, what is the probability of septic arthritis?

Explanation

The patient meets all four Kocher criteria: non-weight bearing, temperature >38.5 C, ESR >40, and WBC >12,000. The presence of four criteria is associated with a 93 to 99 percent probability of septic arthritis.

Question 82

When attempting to differentiate transient synovitis from septic arthritis of the pediatric hip, which laboratory value has been shown to be the strongest independent multivariate predictor for septic arthritis?

Explanation

C-reactive protein (CRP) greater than 2.0 mg/dL has been validated as the single strongest independent predictor for septic arthritis, and it is frequently added to modified Kocher criteria to increase diagnostic accuracy.

Question 83

An 11-year-old boy with spastic diplegic cerebral palsy presents with an increasingly severe crouch gait. Examination reveals fixed knee flexion contractures of 20 degrees. What is the most appropriate surgical approach to address the crouch gait?

Explanation

Crouch gait is driven by overactive hamstrings and hip flexors often exacerbated by iatrogenic overly lengthened Achilles tendons. Correcting it requires addressing the knee flexion contractures via hamstring lengthening and a distal femoral extension osteotomy.

Question 84

A 13-year-old boy has an osteochondritis dissecans (OCD) lesion of the medial femoral condyle. MRI shows a 1.5 cm lesion with intact overlying cartilage and no high T2 signal behind the fragment. His distal femoral physis is wide open. What is the best initial management?

Explanation

Stable OCD lesions in skeletally immature patients with open physes have a high rate of spontaneous healing. Initial management should be conservative, prioritizing activity restriction and protected weight bearing.

Question 85

A 15-year-old male basketball player lands forcefully and avulses his tibial tubercle (Ogden Type III fracture) with intra-articular extension. He undergoes surgical fixation. Which complication is most uniquely concerning in the immediate post-injury period for this specific fracture pattern?

Explanation

Tibial tubercle avulsion fractures carry a high risk of anterior compartment syndrome due to bleeding from the anterior tibial recurrent artery, which frequently tears during the injury.

Question 86

A 4-month-old infant with developmental dysplasia of the hip has been treated with a Pavlik harness. At the 4-week follow-up, an ultrasound demonstrates that the hip remains dislocated. What is the primary risk of continuing the Pavlik harness in this patient for an additional 3 weeks?

Explanation

Continuing a Pavlik harness in an unreduced hip beyond 3 to 4 weeks can cause severe pressure on the posterior acetabulum. This leads to "Pavlik harness disease," which degrades the acetabulum and makes subsequent closed reduction much more difficult.

Question 87

An 11-year-old boy with a BMI in the 99th percentile presents with 3 weeks of knee pain and a limp. Examination reveals obligate external rotation of the hip with passive flexion. Radiographs confirm a stable slipped capital femoral epiphysis (SCFE). During in situ pinning, where should the single screw be positioned within the epiphysis?

Explanation

In situ pinning of a SCFE aims to place the screw in the center of the epiphysis to maximize mechanical stability and minimize the risk of joint penetration. The guide wire and screw should be placed centrally in both the anteroposterior and lateral planes.

Question 88

A 6-year-old boy sustains a completely displaced extension-type supracondylar humerus fracture. On presentation, his hand is pale, pulseless, and cold. After rapid closed reduction and percutaneous pinning, his hand becomes warm and pink, with a capillary refill of 2 seconds, but the radial pulse remains absent. What is the most appropriate next step in management?

Explanation

A pulseless but well-perfused (pink) hand after closed reduction of a supracondylar fracture typically results from arterial vasospasm or non-occlusive tethering. Observation is the standard of care, as collateral circulation is adequate and the pulse usually returns within a few days.

Question 89

A 2-week-old infant with idiopathic clubfoot is undergoing serial casting using the Ponseti method. The first casting maneuver should primarily aim to correct the cavus deformity. Which of the following describes the correct technique for this initial step?

Explanation

The initial step in the Ponseti method is correcting the cavus deformity by supinating the forefoot to visually align it with the supinated hindfoot. This is achieved by elevating the first ray while applying counter-pressure to the head of the talus.

Question 90

An 8-year-old boy presents with a painless limp. Radiographs demonstrate sclerosis and fragmentation of the left capital femoral epiphysis with lateral subluxation. According to the Herring lateral pillar classification, he has a Group B/C lesion. Which of the following factors is the strongest predictor of a poor long-term outcome in this patient?

Explanation

Age greater than 8 years at the onset of Legg-Calve-Perthes disease is the most significant predictor of a poor outcome. This is due to the limited remaining growth potential for femoral head remodeling before skeletal maturity.

Question 91

A 4-year-old girl with a history of multiple fractures, blue sclerae, and normal dentition is diagnosed with Osteogenesis Imperfecta (OI) type I. Which of the following genetic mechanisms is most likely responsible for her condition?

Explanation

Osteogenesis imperfecta type I is the mildest and most common form, characterized by a quantitative deficiency (decreased production) of structurally normal type I collagen. Types II, III, and IV typically involve qualitative (structural) mutations in the collagen chains, resulting in more severe phenotypes.

Question 92

A 7-year-old child presents with torticollis and severe neck stiffness one week after undergoing a tonsillectomy. A CT scan confirms atlantoaxial rotatory subluxation. What is the primary pathophysiologic mechanism of this condition (Grisel's syndrome)?

Explanation

Grisel's syndrome is a non-traumatic atlantoaxial rotatory subluxation associated with head and neck infections or recent ENT surgery. Pharyngeal inflammation causes local hyperemia, which leads to laxity of the transverse ligament and subsequent C1-C2 subluxation.

Question 93

A 5-year-old girl falls on an outstretched hand and sustains a lateral condyle fracture of the humerus with 1 mm of displacement. She is treated in a long-arm cast. At her 4-week follow-up, radiographs show delayed union but no change in displacement. What is the most appropriate management?

Explanation

Minimally displaced lateral condyle fractures often exhibit delayed radiographic union. If there is no further displacement, extending cast immobilization for up to 6 to 8 weeks total is appropriate and usually results in successful union.

Question 94

A 6-year-old boy with spastic quadriplegic cerebral palsy (GMFCS level V) has progressive right hip subluxation with a migration percentage of 55%. He has pain during diaper changes and difficulty sitting. Which of the following surgical interventions is most appropriate?

Explanation

In a patient with spastic cerebral palsy and a high migration percentage (>50%), bony reconstruction is required. A combined VDRO and pelvic osteotomy (e.g., Dega or San Diego) is the gold standard to achieve a stable, painless hip.

AAOS Pediatric Orthopedic MCQs (Set 2): DDH, SCFE & Spinal Deformities | Board Review

Orthopedic Pediatrics 2026 MCQs: Board Review Questions & Answers (Part 1)

Key Takeaway

Orthopedic Pediatrics 2026 MCQs: Board Review Questions & Answers (Part 1)

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