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4. Pediatrics MCQs

Practice Set 91 of 334

This practice set contains high-yield board review questions covering key concepts in 4. Pediatrics. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 1801

Topic: 4. Pediatrics

An 8-year-old girl sustained a displaced fracture at the base of the femoral neck in a motor vehicle accident. Management should consist of

. closed reduction and spica cast immobilization.
. closed reduction and fixation of the femoral fracture with smooth pins across the physis.
. open reduction and fixation with screws across the fracture and short of the growth plate, and a spica cast.
. skeletal traction in a 90 - 90 position.
. temporary traction until fixation with a specially ordered pediatric hip screw is possible.

Correct Answer & Explanation

. open reduction and fixation with screws across the fracture and short of the growth plate, and a spica cast.

Explanation

Pediatric intracapsular hip fractures are challenging because of the high rates of complications, including osteonecrosis and varus malunion. These patients should be treated as emergencies. Principles of treatment include anatomic reduction with internal fixation. Screw fixation short of the physis is preferred and may need to be supplemented with spica cast immobilization. Fixation may be achieved with smooth pins across the physis when little metaphyseal bone is available. Fixation across the physis with threaded screws is acceptable only when the patient is close to skeletal maturity. Pediatric hip screws are appropriate if immediately available. Emergent open reduction, capsulotomy, or joint aspiration may decrease the rate of osteonecrosis. Cheng JC, Tang N: Decompression and stable internal fixation of femoral neck fractures in children can affect the outcome. J Pediatr Orthop 1999;19:338-343. Azouz EM, Karamitsos C, Reed MH, et al: Types and complications of femoral neck fractures in children. Pediatr Radiol 1993;23:415-420. Song KS, Kim YS, Sohn SW, et al: Arthrotomy and open reduction of the displaced fracture of the femoral neck in children. J Pediatr Orthop B 2001;10:205-210.

Question 1802

Topic: 4. Pediatrics

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?

. Teratologic hip dislocation
. Septic right hip
. Congenital coxa vara
. Transphyseal fracture of the proximal femur
. Postpartum ligamentous laxity

Correct Answer & Explanation

. Transphyseal fracture of the proximal femur

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 1803

Topic: 4. Pediatrics

A nonambulatory verbal 6-year-old child with spastic quadriplegic cerebral palsy has progressive bilateral hip subluxation of more than 50%. There is no pain with range of motion, but abduction is limited to 20 degrees maximum. An AP radiograph is seen in Figure 34. Management should consist of

Pediatrics Board Review 2007: High-Yield MCQs (Set 4) - Figure 2

. percutaneous bilateral adductor tenotomy.
. oral baclofen.
. phenol injection into the obturator nerve.
. open adductor tenotomy with neurectomy of the anterior branch of the obturator nerve.
. open adductor tenotomy with release of the iliopsoas and bilateral proximal femoral varus derotation osteotomy.

Correct Answer & Explanation

. open adductor tenotomy with release of the iliopsoas and bilateral proximal femoral varus derotation osteotomy.

Explanation

The natural history of the patient's hips, if left untreated, is gradual progression to dislocation. To prevent future pain, prevention of dislocation is often helpful. The patient is too old for soft-tissue releases alone. Therefore, the treatment of choice is medial release of both hips to obtain 45 degrees or better of hip abduction in conjunction with psoas tenotomy and bilateral femoral varus osteotomies. Presedo A, Oh CW, Dabney KY, et al: Soft-tissue releases to treat spastic hip subluxation in children with cerebral palsy. J Bone Joint Surg Am 2005;87:832-841.

Question 1804

Topic: 4. Pediatrics

A 6-year-old child has a fixed flexion deformity of the interphalangeal (IP) joint of the right thumb. The thumb is morphologically normal, with a nontender palpable nodule at the base of the metacarpophalangeal joint. Clinical photographs are shown in Figures 42a and 42b. Based on these findings, what is the treatment of choice?

. Complete release of the proximal annular pulley of the flexor sheath
. Removal of the nodule in the flexor pollicis longus
. Fractional lengthening of the flexor pollicis longus tendon at the musculotendinous junction
. Steroid injection into the palpable nodule
. No treatment because this condition normally spontaneously resolves

Correct Answer & Explanation

. Complete release of the proximal annular pulley of the flexor sheath

Explanation

The child has a trigger thumb deformity. A trigger thumb is a developmental mechanical problem rather than a congenital deformity. The anomaly generally is not noted at birth. A fixed flexion deformity of the IP joint of the thumb most commonly occurs in children in the first 2 years of life. A stretching and splinting program may correct the deformity in the first year of life, but nonsurgical management after age 3 years results in a success rate of only 50%. Release of the proximal annular pulley of the flexor sheath is recommended at this age. Tan AH, Lam KS, Lee EH: The treatment outcome of trigger thumb in children. J Pediatric Orthop B 2002;11:256-259. Slakey JB, Hennrikus WL: Acquired thumb flexion contracture in children: Congenital trigger thumb. J Bone Joint Surg Br 1996;78:481-483.

Question 1805

Topic: 4. Pediatrics

An 18-month-old infant with myelomeningocele and rigid clubfeet has grade 5 quadriceps and hamstring strength, but no muscles are functioning below the knee. What is the best treatment option for the rigid clubfeet?

. Triple arthrodesis
. Soft-tissue releases as necessary
. Tendon transfers to balance the feet in a neutral plantigrade position
. Physical therapy for range of motion and stretching
. Botulinum injections followed by serial casting

Correct Answer & Explanation

. Soft-tissue releases as necessary

Explanation

This child has the potential to walk and therefore should have all the contracted structures in the feet released as necessary to place the feet in a plantigrade position for fitting of ankle-foot orthoses. Physical therapy, manipulation, and casting may provide some benefit in a newborn with flexible feet but are not effective in an older infant with rigid clubfeet. Botulinum injections and tendon transfers are of no use because there are no muscles functioning below the knee. Tendon releases are more effective than tendon transfers in children with myelomeningocele. Mazur JM: Management of foot and ankle deformities in the ambulatory child with myelomeningocele, in Sarwark JR, Lubicky JP (eds): Caring for the Child with Spina Bifida. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2001, pp 155-160.

Question 1806

Topic: 4. Pediatrics

Figure 11a shows the clinical photograph of a 46-year old woman who reports a 3-week history of pain and a "lump" at the base of her neck. She is otherwise in good health and denies any trauma. A 3-D reconstruction CT is shown in Figure 11b. What is the most likely diagnosis?

. Unreduced posterior sternoclavicular dislocation
. Congenital hypoplasia of the medial clavicle
. Postmenopausal arthritis of the sternoclavicular joint
. Sternoclavicular hyperostosis
. Spontaneous subluxation of the right sternoclavicular joint

Correct Answer & Explanation

. Spontaneous subluxation of the right sternoclavicular joint

Explanation

Spontaneous subluxation of the sternoclavicular joint occurs without any significant trauma. It is usually accentuated by placing the extremity in an overhead position. Discomfort usually resolves within 4 to 6 weeks with nonsurgical management. Rockwood CA, Wirth MA: Disorders of the sternoclavicular joint, in Rockwood CA, Matsen FA, Wirth MA, et al (eds): The Shoulder. Philadelphia, PA, WB Saunders, 2004, vol 2, pp 1078-1079.

Question 1807

Topic: 4. Pediatrics

A 6-month-old child is seen in the emergency department with a spiral fracture of the tibia. The parents are vague about the etiology of the injury. There is no family history of a bone disease. In addition to casting of the fracture, initial management should include

. a skeletal survey to rule out other fractures.
. a punch biopsy of the skin for collagen analysis to rule out osteogenesis imperfecta.
. DNA testing for osteogenesis imperfecta.
. blood studies for calcium, phosphorus, and alkaline phosphate levels.
. blood studies for parathyroid hormone levels.

Correct Answer & Explanation

. a skeletal survey to rule out other fractures.

Explanation

Unwitnessed spiral fractures should raise the possibility of child abuse, especially prior to walking age. With nonaccidental trauma being considered in the differential diagnosis, a skeletal survey is indicated to determine if there are other fractures in various stages of healing. Kempe CH, Silverman FN, Steele BF, et al: The battered-child syndrome. JAMA 1962;181:17-24.

Question 1808

Topic: Pediatric Lower Extremity

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

Pediatrics 2001 Practice Questions: Set 1 (Solved) - Figure 19

. phonophoresis treatment and a program of quadriceps stretching.
. application of a hinge, post, and shell design functional knee brace.
. application of a hinge, post, and strap design functional knee brace.
. an MRI scan of the knee, a CT scan of the chest, a technetium Tc 99m bone scan, liver function tests, and a biopsy of the proximal tibia.
. excision of the ossicle and prominence of the tibial tuberosity.

Correct Answer & Explanation

. excision of the ossicle and prominence of the tibial tuberosity.

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 1809

Topic: 4. Pediatrics

A 22-month-old girl has cerebral palsy. Which of the following findings is a good prognostic indicator of the child's ability to walk in the future?

. Asymmetric tonic neck reflex
. Moro reflex
. Extensor thrust
. Positive parachute reaction
. Absent foot placement

Correct Answer & Explanation

. Positive parachute reaction

Explanation

For the parachute test, the examiner holds the child prone and then lowers the child rapidly toward the floor. The parachute reaction is normal or positive if the child reaches toward the floor. The Moro or startle reflex should not be present beyond age 6 months. Asymmetric tonic neck reflex, extensor thrust, and absent foot placement are abnormal findings at any age. Bleck EE: Orthopaedic Management in Cerebral Palsy. Lavenham, Suffolk, The Lavenham Press, 1987, pp 121-139.

Question 1810

Topic: 4. Pediatrics

A 12-year-old girl has bilateral developmentally dislocated hips. History reveals no previous treatment, and she reports no discomfort. Good long-term clinical results are most likely to occur with

. surgical reduction of both hips and stabilization with a pelvic procedure.
. no development of false acetabula.
. performance of surface replacements.
. abductor strengthening exercises.
. Chiari osteotomy.

Correct Answer & Explanation

. no development of false acetabula.

Explanation

The natural history of complete developmental dislocation of the hip is dependent on two factors: bilaterality and the presence or absence of a false acetabulum. Patients with bilateral dislocations may have low back pain because of hyperlordosis, but they tend to have less disability than patients with unilateral dislocations who have secondary problems related to limb-length inequality. Degenerative joint disease and clinical disability are most likely to develop in patients with completely dislocated hips and well-developed false acetabula. In a 12-year-old child who has bilateral developmental hip dislocations, it would be difficult to obtain surgical treatment results that are better than the natural history of the disorder. Abductor strengthening exercises are unlikely to influence the long-term outcome in this disorder. Surface replacements are not indicated in young asymptomatic patients. Weinstein SL: Natural history of congenital hip dislocation (CDH) and hip dysplasia. Clin Orthop 1987;225:62-76.

Question 1811

Topic: 4. Pediatrics
What is the mechanism of action of an intramuscular injection of botulinum type A toxin in reducing spasticity?
. Blocks the release of presynaptic acetylcholine release at the neuromuscular junction and end plate
. Acts as a gamma-aminobutyric acid (GABA) agonist
. Inhibits afferent fibers in the dorsal root of the spinal nerve
. Competitively blocks the acetylcholine receptor
. Destroys the neuromuscular junction

Correct Answer & Explanation

. Blocks the release of presynaptic acetylcholine release at the neuromuscular junction and end plate

Explanation

The use of intramuscular botulinum type A toxin has been shown to be a useful adjuvant in the management of dynamic deformity in patients with cerebral palsy. Botulinum type A toxin is a neurotoxin produced by Clostridium botulinum that works by interfering with presynaptic acetylcholine release at cholinergic nerve terminals. At the cellular level, the mechanism involves endocytosis of the intact botulinum toxin molecule by cells in the end plate, followed by disulfide cleavage and translocation of the light chain into the cytosol where it disrupts the normal binding of the synaptosomal vesicles to the axon terminal membrane. Neither the nerve terminal nor the neuromuscular junction is damaged. The muscle paralysis is reversible and dose-dependent. Baclofen is a neuropharmacologic agent that functions as a GABA agonist. Dorsal rhizotomy is a neurosurgical procedure that reduces spasticity by dividing afferent (excitatory) fibers in the posterior rootlet of the spinal nerves.

Question 1812

Topic: Pediatric Upper Extremity & Spine
A 7-year-old girl who sustained a type III posteromedial extension supracondylar fracture underwent a closed reduction at the time of injury. Figure 27a shows the position of the fracture fragments prior to percutaneous medial and lateral pin fixation. Following surgery, healing was uneventful and the patient regained a full painless range of motion. Fifteen months after the injury, she now reports loss of elbow motion and moderate pain with activity. A current AP radiograph is shown in Figure 27b. What is the most likely cause of her symptoms?
. Latent osteomyelitis from the percutaneous pins
. Muscle weakness because of a lack of postinjury rehabilitation
. Tardy ulnar nerve paralysis from injury by the medial pin
. Osteonecrosis of the trochlea, producing joint incongruity
. A new acute process

Correct Answer & Explanation

. Osteonecrosis of the trochlea, producing joint incongruity

Explanation

The patient sustained a very distal supracondylar fracture of the humerus. Fractures in this area can disrupt the blood vessels supplying the lateral ossification center of the trochlea. With disturbance of the blood supply in this area, local osteonecrosis occurs and disrupts the support for the overlying articular surface, producing joint incongruity and localized degenerative arthritis.

Question 1813

Topic: Pediatric Upper Extremity & Spine

Examination of a 5-year-old boy with amyoplasia shows a flexion contracture of 70 degrees of the right knee. The active arc of motion is from 70 degrees to 90 degrees, and the opposite knee has a flexion contracture of 10 degrees. Both hips are dislocated with flexion contractures of 10 degrees, passive hip motion is from 10 degrees to 90 degrees of flexion, and the feet are plantigrade and easily braceable. Despite a daily stretching program, the parents and physical therapists note that it is increasingly difficult for him to walk because of the flexion contracture of the right knee. Management of the knee flexion contracture should now include

. intense physical therapy.
. an intramuscular injection of botulinum toxin A.
. radical posterior soft-tissue release.
. supracondylar femoral extension osteotomy.
. gradual correction with a circular ring external fixator.

Correct Answer & Explanation

. radical posterior soft-tissue release.

Explanation

Most children with amyoplasia are ambulatory and when a decrease in function occurs because of a severe contracture, it must be addressed. A radical posterior soft-tissue release, including the posterior knee capsule and often the collateral ligaments and the posterior cruciate ligament, is needed to obtain extension. After the age of 1 year, aggressive physical therapy will do little to correct a contracture. Botulinum toxin A is indicated for spasticity and is contraindicated with severe contractures. Supracondylar femoral extension osteotomy works well, but will remodel at an average rate of 1 degree per month, which is not considered ideal in a young patient. Gradual correction with a circular ring external fixator is an option, but a soft-tissue release will also most likely be needed for a contracture of this severity. Sarwark JF, MacEwen GD, Scott CI Jr: Amyoplasia (a common form of arthrogryposis). J Bone Joint Surg Am 1990;72:465-469. DelBello DA, Watts HG: Distal femoral extension osteotomy for knee flexion contracture in patients with arthrogryposis. J Pediatr Orthop 1996;16:122-126.

Question 1814

Topic: 4. Pediatrics
A 14-year-old boy sustains a twisting injury to his right shoulder and recalls feeling a snap during a wrestling match. Examination shows hesitancy to raise the arm away from the side, diffuse tenderness and swelling of the upper arm, and no evidence of neurovascular compromise. Figures 6a and 6b show an AP radiograph and MRI scan. What is the most likely diagnosis?
. Anterior dislocation of the shoulder
. Salter-Harris type I fracture of the proximal humeral physis
. Rupture of the subscapularis tendon
. Sprain of the acromioclavicular joint
. Fracture of the glenoid neck

Correct Answer & Explanation

. Salter-Harris type I fracture of the proximal humeral physis

Explanation

While difficult to appreciate on the AP radiograph of the shoulder, the increased physeal signal demonstrated on the axial MRI scan is consistent with a nondisplaced growth plate fracture. A comparison radiograph of the left shoulder also could be considered and the injured shoulder evaluated for physeal widening. Proximal humeral fractures in children are somewhat unusual, representing less than 1% of all fractures seen in children and only 3% to 6% of all epiphyseal fractures. Physeal injuries are classified according to the Salter-Harris classification scheme. Salter-Harris type I fractures represent approximately 25% of physeal injuries to the proximal humerus in adolescents. The proximal humeral physis is responsible for 80% of the longitudinal growth of the humerus; therefore, there is tremendous potential for remodeling of fractures in this region. Management for nondisplaced Salter-Harris type I fractures is limited to a short period of immobilization followed by a gradual return to activities as clinical symptoms resolve.

Question 1815

Topic: 4. Pediatrics

An 8-year-old girl was treated for a Salter-Harris type I fracture of the right distal femur 2 years ago. Examination reveals symmetric knee flexion, extension, and frontal alignment compared to the contralateral knee. She has 1-cm of shortening of the right femur. History reveals that she has always been in the 50th percentile for height, and her skeletal age matches her chronologic age. Radiographs are shown in Figure 9. What is the expected consequence at maturity?

Pediatrics 2007 Practice Questions: Set 1 (Solved) - Figure 23

. 6-cm limb-length discrepancy with the right femur longer
. 6-cm limb-length discrepancy with the left femur longer
. 12-degree varus deformity
. 18-degree valgus deformity
. 20-degree recurvatum deformity

Correct Answer & Explanation

. 6-cm limb-length discrepancy with the left femur longer

Explanation

The child has a near complete central physeal arrest of the distal femur and worsening limb-length discrepancy will develop. She is growing at the average rate for the population. The distal femoral physis grows at a rate of roughly 9 mm per year. Girls finish their growth at approximately age 14 years. Thus, at maturity the left leg will be 6.4 cm longer than the right. An angular deformity has not developed at this point and her arrest is central; therefore, angular deformity is unlikely to develop in any plane. Little DG, Nigo L, Aiona MD: Deficiencies of current methods for the timing of epiphysiodesis. J Pediatr Orthop 1996;16:173-179.

Question 1816

Topic: 4. Pediatrics

Examination of a 6-year-old boy who sustained a displaced Salter-Harris type II fracture of the distal radius reveals 35 degrees of volar angulation. A satisfactory reduction is obtained with the aid of a hematoma block. At the 10-day follow-up examination, radiographs show loss of reduction and 35 degrees of volar angulation. Management should now consist of

Orthopedic Surgery Board Review 2026 | High-Yield MCQs - Set 9 - Figure 62

. acceptance of the malalignment and continued cast immobilization.
. repeat closed reduction with the aid of IV morphine and midazolam.
. repeat closed reduction with the aid of IV ketamine.
. repeat closed reduction with the patient under general anesthesia.
. gentle open reduction with smooth cross-pin fixation.

Correct Answer & Explanation

. acceptance of the malalignment and continued cast immobilization.

Explanation

In a 6-year-old child with a physeal fracture, the healing response 10 days after injury is so advanced that manipulation would have to be very forceful to be successful. A forceful manipulation in a patient this age increases the risk of early growth arrest and a significant disability because 80% of the growth of the radius comes from the distal physis. Because of the large contribution of growth from the distal radial physis and the angulation being in the plane of wrist motion, the potential for remodeling of this fracture is great. It is highly probable that this fracture will completely remodel in 1 to 2 years of growth. In this patient, even a "gentle" open reduction would probably require enough force that the physis would be damaged. Dimeglio A: Growth in pediatric orthopaedics, in Morrissy RT, Weinstein SL (eds): Lovell and Winter's Pediatric Orthopaedics, ed 5. Philadelphia, PA, Lippincott Williams and Wilkins, 2001, pp 33-62.

Question 1817

Topic: 4. Pediatrics

A well-developed college football player reports swelling and a heaviness in the arm after lifting weights. Examination reveals that distal pulses are normal and equal in both arms. A venogram is shown in Figure 13. What is the most likely cause of this condition?

Upper Extremity Board Review 2005: High-Yield MCQs (Set 2) - Figure 4

. Intimal tearing of the subclavian artery
. Compression of the subclavian vein by scalene muscle hypertrophy
. Postural compression of the neurovascular bundle between the clavicle and the first rib
. A congenital cervical rib
. Arterial thrombosis induced by repeated overhead activities

Correct Answer & Explanation

. Compression of the subclavian vein by scalene muscle hypertrophy

Explanation

The clinical findings indicate venous obstruction without arterial compression, and the venogram reveals occlusion of the subclavian vein, which is most likely the result of thoracic outlet compression. In the developed athlete, scalene muscle hypertrophy (Paget-Schroetter syndrome) causes compression of the subclavian vein. Treatment should consist of thrombolysis followed by decompressive surgery. Angle N, Gelabert HA, Farooq MM, et al: Safety and efficacy of early surgical decompression of the thoracic outlet for Paget-Schroetter syndrome. Ann Vasc Surg 2001;15:37-42.

Question 1818

Topic: 4. Pediatrics
Figure 38 shows the radiograph of a 5-year-old child who sustained a type III supracondylar fracture. Examination reveals the absence of a radial pulse, but an otherwise well-perfused hand. Following closed reduction and percutaneous pinning, the radial pulse remains absent; however, the hand is pink and well perfused. Management should now include
. close observation with frequent neurovascular checks.
. emergency angiography.
. emergency exploration of the brachial artery.
. removal of pin fixation and exploration of the brachial artery.
. thrombectomy.

Correct Answer & Explanation

. close observation with frequent neurovascular checks.

Explanation

In a study of over 400 patients with displaced supracondylar fractures, 3.2% of the fractures were associated with the absence of the radial pulse with an otherwise well-perfused hand. Based on this study, a period of close observation with frequent neurovascular checks should be completed before attempting invasive correction of the problem. Because of the satisfactory results with expectant management, angiography, exploration, removal of fixation and exploration, and thrombectomy are contraindicated.

Question 1819

Topic: Pediatric Hip

Figure 36 shows the radiograph of a 14-year-old boy who has been treated in the past for Perthes' disease with an abduction brace. He now has hip pain that limits his activity, and nonsteroidal anti-inflammatory drugs have failed to provide relief. What is the most appropriate treatment?

Pediatrics Board Review 2007: High-Yield MCQs (Set 4) - Figure 6

. Proximal femoral varus osteotomy
. Salter innominate osteotomy
. Distal transfer of the greater trochanter
. Shelf acetabuloplasty
. Hip arthrodesis

Correct Answer & Explanation

. Shelf acetabuloplasty

Explanation

Several authors have reported good success in relieving pain with shelf acetabuloplasty. This patient's Perthes' disease is in the healed phase; therefore, proximal femoral varus and Salter innominate osteotomies aimed at improving containment are not indicated. The medial one half of the patient's femoral head is markedly deformed, and rotating it into a weight-bearing position with proximal femoral valgus osteotomy is unlikely to relieve pain. Hip arthrodesis can always be performed as a salvage procedure if the shelf acetabuloplasty fails. Daly K, Bruce C, Catterall A: Lateral shelf acetabuloplasty in Perthes' disease: A review of the end of growth. J Bone Joint Surg Br 1999;81:380-384.

Question 1820

Topic: Pediatric Upper Extremity & Spine

A 5-year-old boy sustained an elbow injury. Examination in the emergency department reveals that he is unable to flex the interphalangeal joint of his thumb and the distal interphalangeal joint of his index finger. The radial pulse is palpable at the wrist, and sensation is normal throughout the hand. Radiographs are shown in Figures 6a and 6b. In addition to reduction and pinning of the fracture, initial treatment should include

. repair of the posterior interosseous nerve.
. repair of the median nerve at the elbow.
. neurolysis of the anterior interosseous nerve.
. observation of the nerve palsy.
. immediate electromyography and nerve conduction velocity studies.

Correct Answer & Explanation

. observation of the nerve palsy.

Explanation

The findings are consistent with a neurapraxia of the anterior interosseous branch of the median nerve. This is the most common nerve palsy seen with supracondylar humerus fractures, followed closely by radial nerve palsy. Nearly all cases of neurapraxia following supracondylar humerus fractures resolve spontaneously, and therefore, further diagnostic studies and surgery are not indicated. Cramer KE, Green NE, Devito DP: Incidence of anterior interosseous nerve palsy in supracondylar humerus fractures in children. J Pediatr Orthop 1993;13:502-505.

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