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4. Pediatrics MCQs

Practice Set 74 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 1461

Topic: Pediatric Hip

A 13-year-old obese male presents with an unstable slipped capital femoral epiphysis (SCFE). He undergoes in-situ percutaneous pinning. Postoperatively, he develops severe hip pain and restricted range of motion. Radiographs show profound uniform joint space narrowing but no collapse of the femoral head. What is the most likely diagnosis?

. Avascular necrosis of the femoral head
. Chondrolysis
. Iatrogenic femoral neck fracture
. Septic arthritis
. Implant failure with joint penetration

Correct Answer & Explanation

. Avascular necrosis of the femoral head

Explanation

Chondrolysis is a severe complication of SCFE, notably associated with unstable slips and unrecognized hardware penetration into the joint. It is characterized by acute, uniform joint space narrowing, severe stiffness, and pain, differentiating it from the segmental collapse seen in avascular necrosis.

Question 1462

Topic: Pediatric Hip

Which of the following clinical profiles serves as the strongest absolute indication for prophylactic in situ pinning of the contralateral, asymptomatic hip in a child presenting with a unilateral slipped capital femoral epiphysis (SCFE)?

. Age greater than 14 years at initial presentation
. Male sex with a BMI in the 80th percentile
. Presence of an underlying endocrine disorder, such as hypothyroidism
. Acute on chronic symptom presentation
. Presence of a moderate slip angle (30-50 degrees) on the affected side

Correct Answer & Explanation

. Age greater than 14 years at initial presentation

Explanation

Endocrinopathies (such as hypothyroidism or panhypopituitarism) are a strong indication for prophylactic pinning of the contralateral hip due to an extremely high risk of bilateral involvement. Other indications include age under 10 years or inability to follow up reliably.

Question 1463

Topic: 4. Pediatrics
A 5-year-old girl sustained a comminuted Salter-Harris type IV fracture of the left distal tibia 2 years ago. The AP radiograph reveals a growth arrest and a 1.4-cm limb-length discrepancy. The ankle is in approximately 20 degrees of varus. On the sagittal reconstruction image, the bar extends from the 9-mm mark to the 24-mm mark in 3-mm increments. On the coronal image, the bar extends from the 9-mm mark to the 24-mm mark, also in 3-mm increments. Initial treatment should consist of:
. bony bar resection and distal fibula epiphysiodesis.
. bony bar resection and corrective osteotomy.
. bony bar resection and physiodesis of the opposite distal tibial physis.
. corrective osteotomy and a limb-lengthening procedure.
. corrective osteotomy and physiodesis of the opposite distal tibial physis.

Correct Answer & Explanation

. bony bar resection and corrective osteotomy.

Explanation

Mapping of a physeal bar from biplane polytomography or CT helps to identify lesions that should be treated surgically and aids in planning the surgical approach and resection. Criteria for surgical excision are at least 2 years of longitudinal growth remaining and involvement of no more than 50% of the physis. Osteotomy is required if angular deformity is greater than 20 degrees. Although this physeal bar is large, it is slightly less than 50% of the total area of the physis.

Question 1464

Topic: 4. Pediatrics
A teenager is undergoing a correction of deformity and lengthening of the femur. Distractions are proceeding as expected; however, during his 6-week follow-up examination, the patient reports that the distraction motors have become harder to turn over for the past 2 to 3 days. Figures 37a and 37b show current radiographs. What is the most likely complication being encountered?
. Incomplete corticotomy
. Knee subluxation
. Wire breakage
. Poor regenerate bone formation
. Premature consolidation

Correct Answer & Explanation

. Premature consolidation

Explanation

DISCUSSION: Premature consolidation is a complication that is unique to gradual bone lengthening after corticotomy. Causes include excessive latency period, inadequate distraction rate, exuberant bone formation, patient compliance problems, and mechanical failure of the distraction apparatus. The femur and fibula are most commonly involved. This patient did not have an incomplete corticotomy, as initial distraction occurred before the distraction device was noted to seize up. The radiographs show bowing of the Ilizarov wires and mature regenerate bone, both suggestive of premature consolidation. No wire breakage or joint subluxation is seen on the radiographs. Treatment for premature consolidation includes continuing distraction until the consolidation bridge ruptures, or additional surgery may include closed rotational osteoclasis or repeat corticotomy. REFERENCES: Paley D: Problems, obstacles and complications of limb lengthening, in Maiocchi AB, Aronson J (eds): Operative Principles of Ilizarov. Baltimore, MD, Williams & Wilkins, 1991, p 360. Herring JA: Limb length discrepancy, in Herring JA (ed): Tachdjian’s Pediatric Orthopaedics, ed 3. Philadelphia, PA, WB Saunders, 2002, p 1088.

Question 1465

Topic: Pediatric Hip

Figure A is a pelvic radiograph of a healthy 20-month old girl with a limb leg discrepancy. A hip arthrogram under general anesthesia reveals concentric reduction of the left hip ONLY when the hip is positioned in 70 to 80 degrees of abduction. The next best step in treatment would be: Review Topic

. Observation
. Application of Pavlik harness
. Closed reduction and hip spica casting
. Open hip capsulorrhaphy +/- femoral osteotomy +/- pelvic osteotomy
. Open hip capsulorrhaphy, adductor and hamstring tenotomy, gastrocnemius recession +/- pelvic osteotomy

Correct Answer & Explanation

. Observation

Explanation

Figure A shows left hip subluxation consistent with late presenting developmental hip dysplasia (DDH). The most appropriate treatment at this stage would be open hipcapsulorrhaphy, +/- femoral osteotomy +/- pelvic osteotomyIn children older than 18 months, open reduction is the preferred treatment for hip dysplasia. Open reduction is also considered when concentric closed reduction cannot be achieved or when excessive abduction (>60 degrees) is required to maintain reduction (due to increasing risk of avascular necrosis). The goal of open reduction is to remove the blocks to reduction and to increase stability by preforming soft-tissue or bone procedures.Wenger et al. reviewed the surgical treatment of DDH. They say that the impediment to congruent reduction are the iliopsoas muscle, joint capsule, ligamentum teres, pulvinar, labrum, and transverse acetabular ligament. The most commonly used approaches are anterior and medial/anteromedial to the hip.Gholve et al. reviewed DDH and the factors that contribute to secondary procedures. In their study, neither age nor unilateral vs bilateral dislocation had a direct influence on the outcome or the need for secondary procedures. The variable that significantly influenced the need for a secondary procedure was the concomitant use of a femoral osteotomy during initial surgical treatment. Of the 27 patients who did not have concurrent femoral osteotomy at index surgery, 19/27 (73%) required a secondary procedure (P<0.001).Figure A shows an AP pelvic radiograph of an infant. Focusing on the left hip, there is lateral and superior subluxation of the femoral head, with the femoral head lateral to Perkin's line. The medial joint space is increased. The acetabular index is increased>30 degrees. Shenton's line is disrupted. These are all features of DDH.Incorrect Answers:

Question 1466

Topic: 4. Pediatrics

Figures 35a and 35b show the radiographs of a 7-year-old patient who has progressive deformity of the right thigh accompanied by a dull persistent pain radiating to the knee. Examination reveals an obvious bulge in the right thigh, with flexion of the hip beyond 50° only if the hip is allowed to externally rotate. Management should consist of

. multiple osteotomies and femoral rodding.
. pharmocologic doses of vitamin D and phosphate.
. biopsy, followed by appropriate chemotherapy.
. pamidronate therapy.
. radiation therapy and a bone marrow transplant.

Correct Answer & Explanation

. multiple osteotomies and femoral rodding.

Explanation

DISCUSSION: The patient has radiographic signs of osteogenesis imperfecta, including osteopenia, mild acetabular protrusio, cortical thinning, and bowing associated with anterior stress fracturing.  The treatment of choice is correction of the bow with osteotomies, followed by intramedullary fixation to prevent further deformity.  Biphosphonates, such as pamidronate, may be useful in increasing bone density and preventing fractures.  Large multicenter studies on biphosphonate efficacy are currently in progress.REFERENCES: Zionts LE, Ebramzadeh E, Stott NS: Complications in the use of the Bailey-Dubow extensible nail.  Clin Orthop 1998;348:186-195.Luhmann SJ, Sheridan JJ, Capelli AM, Schoenecker PL: Management of lower-extremity deformities in osteogenesis imperfecta with extensible intramedullary rod technique: A 20-year experience.  J Pediatr Orthop 1998;18:88-94.Glorieux FH, Bishop NJ, Plotkin H, Chabot G, Lanoue G, Travers R: Cyclic administration of pamidronate in children with severe osteogenesis imperfecta.  N Engl J Med 1988;339:947-952.

Question 1467

Topic: 4. Pediatrics

A 12-year-old boy with an ankle fracture undergoes closed reduction under sedation in the emergency department. Figure 27 shows a lateral radiograph of the ankle after two attempts at closed reduction. Based on these findings, treatment should now consist of Review Topic

. at least two more attempts at closed reduction in the emergency department before the patient’s sedation wears off.
. at least two attempts at closed reduction in the operating room under general anesthesia with muscle relaxation.
. acceptance of the reduction because the alignment is satisfactory and growth problems are rare with Salter-Harris type I fractures.
. open reduction, extraction of any interposed periosteum, and smooth wire fixation to prevent nonunion.
. open reduction, extraction of any interposed periosteum, and smooth wire fixation to decrease the chance of premature physeal closure.

Correct Answer & Explanation

. at least two more attempts at closed reduction in the emergency department before the patient’s sedation wears off.

Explanation

The widening of the physis associated with incomplete reduction of this fracture suggests that periosteum is interposed at the fracture site. Clinical and animal study findings suggest that the interposed periosteum may lead to premature physeal closure. Repeated forceful attempts at reduction may subject the physis to further injury and should be avoided. Growth problems are common in children with Salter-Harris type I fractures of the lower extremities. Nonunions are rare in children with Salter-Harris type I fractures.

Question 1468

Topic: 4. Pediatrics

A newborn girl with an isolated unilateral dislocatable hip is placed in a Pavlik harness with the hips flexed 100 degrees and at resting abduction. Figure 23 shows an ultrasound obtained 2 weeks later. What is the next step in management? Review Topic

. Reposition the harness to hold the hips in 70 degrees of abduction
. Closed reduction and arthrography under anesthesia
. Open reduction and a spica cast
. Continued harness treatment in the current position
. Spica cast

Correct Answer & Explanation

. Reposition the harness to hold the hips in 70 degrees of abduction

Explanation

The infant has a well-positioned hip in the Pavlik harness and treatment should be continued in the current position. The success rate is over 90% with the use of this device for a dislocatable hip. Ultrasound is a useful tool to confirm appropriate positioning of the cartilaginous femoral head during treatment. If the femoral head isnot reduced after 2 to 3 weeks in the harness, this mode of treatment should be abandoned. Forceful extreme abduction can cause osteonecrosis of the femoral epiphysis and should be avoided. Closed reduction, arthrography, and spica casting are indicated if the hip cannot be maintained in a reduced position with the harness.

Question 1469

Topic: 4. Pediatrics

Which of the following findings is most prognostic for the ability of a young child with cerebral palsy to walk?

. Ability to sit independently by age 2 years
. Ability to creep by age 2 years
. Ability to roll by age 2 years
. Pattern of cerebral palsy (quadriplegia, diplegia, hemiplegia)
. Type of motor dysfunction (spastic, ataxic, dyskinetic, hypotonic)

Correct Answer & Explanation

. Ability to sit independently by age 2 years

Explanation

DISCUSSION: Several studies have shown that sitting ability by age 2 years is highly prognostic of walking.  Molnar and Gordon reported that children not sitting independently by age 2 years had a poor prognosis for walking.  Wu and associates reported that children sitting without support by age 2 years had an odds ratio of 26:1 of walking compared with those unable to sit.  This was far higher than the odds ratios for cerebral palsy location, motor dysfunction, crawling, creeping, scooting, or rolling.REFERENCES: Molnar GE, Gordon SU: Cerebral palsy: Predictive value of selected clinical signs for early prognostication of motor function.  Arch Phys Med Rehabil 1976;57:153-158.Wu YW, Day SM, Strauss DJ, et al: Prognosis for ambulation in cerebral palsy: A population-based study.  Pediatrics 2004;114:1264-1271.

Question 1470

Topic: 4. Pediatrics

A 2-day-old infant has the hyperextended knee deformity shown in Figure 7. No other deformities are found on examination. A radiograph shows that the ossified portion of the proximal tibia is slightly anterior to that of the distal femur. Management should consist of

. gentle stretching and serial casting.
. Bryant traction for 1 to 2 weeks, followed by closed reduction.
. percutaneous quadriceps recession, followed by serial casting.
. delayed open reduction at age 6 months to avoid iatrogenic damage to either the distal femoral or proximal tibial physes.
. a renal ultrasound.

Correct Answer & Explanation

. gentle stretching and serial casting.

Explanation

DISCUSSION: Congenital dislocation of the knee is an uncommon deformity that varies in presentation from simple hyperextension to complete anterior dislocation of the tibia on the femur.  Treatment varies with the age at presentation and the severity of the deformity.  Most authors recommend early nonsurgical management.  A recent study of 24 congenital knee dislocations in 17 patients found that satisfactory results were obtained in most instances using closed treatment.  Based on their findings, the authors concluded that immediate reduction or serial casting should be performed when the patient is seen early after birth.  If the patient is seen late and correction cannot be achieved by serial casting, traction followed by closed or open reduction may be necessary.  Early percutaneous quadriceps recession has been described for complex congenital knee dislocations associated with underlying disorders, such as arthrogryposis and Ehlers-Danlos syndrome.REFERENCES: Ko JY, Shih CH, Wenger DR: Congenital dislocation of the knee.  J Pediatr Orthop 1999;19:252-259.Johnson E, Audell R, Oppenheim WL: Congenital dislocation of the knee.  J Pediatr Orthop 1987;7:194-200.Roy DR, Crawford AH: Percutaneous quadriceps recession: A technique for management of congenital hyperextension deformities of the knee in the neonate.  J Pediatr Orthop1989;9:717-719.

Question 1471

Topic: Pediatric Hip

A 7-year-old patient has had a painless limp for several months. Examination reveals pain and spasm with internal rotation, and abduction is limited to 10° on the involved side. Management consists of 1 week of bed rest and traction, followed by an arthrogram. A maximum abduction/internal rotation view is shown in Figure 40a, and abduction and adduction views are shown in Figures 40b and 40c. The studies are most consistent with

. Catterall II involvement.
. tubercular synovitis.
. Herring type A involvement.
. hinge abduction.
. osteochondritis dissecans.

Correct Answer & Explanation

. Catterall II involvement.

Explanation

DISCUSSION: The radiographs show classic hinge abduction.  The diagnostic feature is the failure of the lateral epiphysis to slide under the acetabular edge with abduction, and the abduction view shows medial dye pooling because of distraction of the hip joint.  Persistent hinge abduction has been shown to prevent femoral head remodeling by the acetabulum.  Radiographic changes are characteristic of severe involvement with Legg-Calve-Perthes disease.  The Catterall classification cannot be well applied without a lateral radiograph, but this degree of involvement would likely be considered a grade III or IV.  Because the lateral pillar is involved, this condition would be classified as type C using the Herring lateral pillar classification scheme.REFERENCE: Reinker KA: Early diagnosis and treatment of hinge abduction in Legg-Perthes disease.  J Pediatr Orthop 1996;16:3-9.

Question 1472

Topic: 4. Pediatrics

A 5-month-old girl with arthrogryposis has a limb-length discrepancy. Examination and radiographs reveal unilateral hip dislocation. Management should consist of

. a Pavlik harness.
. observation.
. closed reduction and a spica cast.
. open reduction and femoral shortening.
. open reduction.

Correct Answer & Explanation

. a Pavlik harness.

Explanation

DISCUSSION: In this age group of patients with arthrogryposis, open reduction through a medial approach is generally recommended.  Open reduction through an anterior approach is reserved for patients in which a medial approach has failed or for older patients who require simultaneous femoral shortening and/or pelvic osteotomy.  Closed treatment of unilateral hip dislocation in association with arthrogryposis is rarely successful.  In bilateral hip dislocation associated with arthrogrypsis, the consensus is that the hips are best left unreduced because of the difficulty in obtaining excellent clinical and radiographic results bilaterally.REFERENCES: Staheli LT, Chew DE, Elliot JS, Mosca VS: Management of hip dislocations in children with arthrogryposis.  J Pediatr Orthop 1987;7:681-685.Szoke G, Staheli LT, Jaffe K, Hall JG: Medial-approach open reduction of hip dislocation in amyoplasia-type arthrogryposis.  J Pediatr Orthop 1996;16:127-130.Richards BS (ed): Orthopaedic Knowledge Update: Pediatrics.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1996.

Question 1473

Topic: 4. Pediatrics

A 7-year-old boy sustains an acute injury to the distal radial metaphysis, along with a completely displaced Salter-Harris type I fracture of the ulnar physis, as shown by the arrows in Figure 12. After satisfactory reduction of both injuries, what is the major concern?

. Loss of reduction of the ulnar physis
. Loss of reduction of the radial metaphysis
. Physeal arrest of the distal radius
. Physeal arrest of the distal ulna
. Osteonecrosis of the ulnar epiphysis

Correct Answer & Explanation

. Loss of reduction of the ulnar physis

Explanation

DISCUSSION: While injury of the distal radial metaphysis is a rather common occurrence, the incidence of physeal arrest is only about 4% to 5% of patients.  While injury of the distal physis of the ulna is rare, the incidence of physeal arrest is greater than 50% in fractures of this structure.  These patients need to be followed closely both clinically and radiographically to look for the signs of distal ulnar/physeal arrest such as loss of the prominence of the ulna and ulnar deviation of the hand.  Radiographically, progressive shortening of the ulna is observed.REFERENCES: Nelson OA, Buchanan JR, Harrison CS: Distal ulnar growth arrest.  J Hand Surg Am 1984;9:164-170.Ogden JA: Skeletal Injury in the Child.  New York, NY, Springer-Verlag, 2000, pp 632-635.

Question 1474

Topic: 4. Pediatrics

Figure 12 shows the radiograph of a patient who has anterior knee pain. History reveals a femoral fracture at age 5 years. What is the most likely cause of the deformity?

. Osgood-Schlatter disease
. Patellar tendon rupture
. Posterior cruciate ligament rupture
. Overlengthened hamstrings
. Tibial tubercle growth arrest

Correct Answer & Explanation

. Osgood-Schlatter disease

Explanation

DISCUSSION: The radiograph shows a recurvatum deformity of the proximal tibia with growth arrest of the tibial tubercle apophysis.  This deformity has been described in association with femoral shaft fractures in children and has been attributed to a clinically silent, concommitant injury to the proximal tibial physes and also to iatrogenic injury associated with a proximal tibial traction pin.  Overlengthened hamstrings and rupture of the posterior cruciate ligament may lead to knee hyperextension; however, these problems should not cause bone deformity.  Osgood-Schlatter disease occurs when growth is nearly complete and usually leads to prominence of the tibial tubercle.  Patellar tendon rupture is rare in children and would not cause this deformity unless the repair was performed with screws across the apophysis.REFERENCES: Hresko MT, Kasser JR: Physeal arrest about the knee associated with non-physeal injuries of the lower extremity.  J Bone Joint Surg Am 1989;71:698-703.Bowler JR, Mubarak SJ, Wenger DR: Tibial physeal closure and genu recurvatum after femoral fracture: Occurrence without a tibial traction pin.  J Pediatric Orthop 1990;10:653-657.

Question 1475

Topic: 4. Pediatrics

Figure 17 shows the AP radiograph of a 5-year old child who has mild short stature and a painless bilateral gluteus medius lurch. Initial work-up should include

. a bone scan.
. a skeletal survey.
. MRI of the hips.
. CT of the hips.
. a CBC count and a C-reactive protein.

Correct Answer & Explanation

. a bone scan.

Explanation

DISCUSSION: Bilateral flattening of the femoral heads suggests multiple epiphyseal dysplasia; therefore, a skeletal survey is indicated to look for involvement of other epiphyses.  Unilateral flattening of the femoral head would suggest Legg-Perthes disease.REFERENCES: Sponseller PD: Skeletal dysplasias, in Morrissy RT, Weinstein SL (eds): Lovell and Winter’s Pediatric Orthopaedics, ed 5.  Philadelphia, PA, Lippincott Williams & Wilkins, 2001, pp 269-270.Herring JA: Tachdjian’s Pediatric Orthopaedics, ed 3.  Philadelphia, PA, WB Saunders, 2002, vol 1, pp 689-691.

Question 1476

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?

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

Correct Answer & Explanation

. cm limb-length discrepancy with the right femur longer

Explanation

DISCUSSION: 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.REFERENCES: Little DG, Nigo L, Aiona MD: Deficiencies of current methods for the timing of epiphysiodesis.  J Pediatr Orthop 1996;16:173-179.Moseley CF: Assessment and prediction in leg-length discrepancy.  Instr Course Lect 1989;38:325-330.

Question 1477

Topic: 4. Pediatrics

Progressive paralysis is most likely to be seen in association with what type of congenital vertebral abnormality?

. Anterior failure of formation
. Anterior failure of segmentation
. Posterior failure of formation
. Posterior failure of segmentation
. Lateral failure of segmentation

Correct Answer & Explanation

. Anterior failure of formation

Explanation

DISCUSSION: Anterior failure of formation results in a progressive kyphosis that may lead to cord compression and progressive neurologic deficit.  Anterior failure of segmentation can also produce progressive kyphosis but usually is not severe enough to cause cord compression.  Posterior failure of formation is seen in conditions such as myelomeningocele in which the neurologic deficit is generally stable.  Lateral abnormalities and posterior failure of segmentation are rarely associated with progressive neurologic deficit.REFERENCES: McMaster MJ, Singh H: Natural history of congenital kyphosis and kyphoscoliosis: A study of one hundred and twelve patients.  J Bone Joint Surg Am 1999;81:1367-1383.Dubousset J: Congenital kyphosis and lordosis, in Weinstein SL (ed): The Pediatric Spine: Principles and Practice, ed 1.  New York, NY, Raven Press, 1994, pp 245-258.

Question 1478

Topic: Pediatric Upper Extremity & Spine
  • The Injury Severity Score (ISS), using point scores from five different body systems, is a method that aids in predicting the chances of mortality in a patient with multiple injuries by
. adding the scores, in all five body systems
. adding the squares of the scores in the three most severely injured systems
. doubling the cumulative score for head and chest injuries
. combining the scores from the most and least injured systems
. correcting the score in the most severely injured system for age

Correct Answer & Explanation

. adding the scores, in all five body systems

Explanation

The Abbreviated Injury Scale (AIS) is made up of scores from 5 body systems (head/neck, face, chest, abdomen, extremity/pelvis) graded from 1 minor to 5 critical. The ISS is the sum of the squares of the highest AIS grade in each of the three most severely injured areas. The AIS pertains to individual injuries. The ISS is used for multiple injuries. Using the ISS dramatically increased the correlation between severity of injury and mortality.

Question 1479

Topic: 4. Pediatrics

Figure 19 shows the radiograph of a 12-year-old boy who sustained an injury to his hand when another child fell on him. Management should consist of

. early motion and muscle strengthening.
. immobilization in a thumb spica cast with the thumb abducted.
. open reduction and internal fixation through a volar approach.
. open reduction and internal fixation through a dorsal approach.
. closed reduction and percutaneous pin fixation.

Correct Answer & Explanation

. early motion and muscle strengthening.

Explanation

DISCUSSION: The patient has a Salter-Harris type III fracture of the proximal phalanx of the thumb.  It is usually caused by an abduction injury where the ulnar collateral ligament avulses a fragment away from the proximal epiphysis and is the most common childhood gamekeeper’s injury.  If there is greater than 1 mm of separation or a significant articular step-off, an open reduction, performed through an extensor aponeurosis-splitting approach, is required to reestablish joint congruity and stability.  Percutaneous or closed methods of reduction are usually ineffective.  The dorsal approach avoids the volar neurovascular structures.  Since the ulnar collateral ligament is still attached, this area does not need to be visualized.  The major goal is to reestablish joint congruity and bony stability.  This can be easily performed via the dorsal approach.REFERENCES: Carey TP: Fracture and dislocations of the phalanges, in Letts RM (ed): Management of Pediatric Fractures.  New York, NY, Churchill Livingstone, 1994, pp 435-436.Ogden JA: Skeletal Injury in the Child.  New York, NY, Springer-Verlag, 2000, p 668.

Question 1480

Topic: 4. Pediatrics

What acetabular procedure for developmental dysplasia of the hip does not require a concentric reduction of the femoral head in the acetabulum?

. Salter innominate osteotomy
. Pemberton innominate osteotomy
. Dega innominate osteotomy
. Triple innominate osteotomy
. Staheli shelf procedure

Correct Answer & Explanation

. Salter innominate osteotomy

Explanation

DISCUSSION: All of the reorientation innominate osteotomies require a concentric reduction of the hip.  The Staheli shelf procedure may be performed even with the hip subluxated, but it is a salvage procedure that covers a portion of the femoral head with capsular fibrocartilage rather than hyaline cartilage.REFERENCES: Staheli LT, Chew DE: Slotted acetabular augmentation in childhood adolescence.  J Pediatr Orthop 1992;12:569-580.Herring JA: Tachdjian’s Pediatric Orthopaedics, ed 3.  Philadelphia, PA, WB Saunders, 2002, vol 1, pp 618-650.

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