4. Pediatrics MCQs

The rate of complications increases as the pin moves farther from the ideal position, which is the center of the head. This is the strongest argument for the use of a single pin. The highest rate of complications, primarily osteonecrosis and pin penetration, is associated with pin placement in the anterior superior quadrant.

The status of the hips (located or dislocated) in children with thoracic-level myelomeningocele has no effect on the functional outcome of these patients. Management of unstable hips in this population should be limited to treatment of the contractures that may lead to poor limb positioning in either braces or a wheelchair. The use of the Pavlik harness and/or spica cast is contraindicated because they would promote flexion and abduction contractures. In the past, open reduction either through an anterior or medial approach had been performed with a high incidence of redislocation and other complications, with little functional gain for the child.

DISCUSSION: Physiologic bowing is common and benign. Bowing is typically symmetric, involves both the femur and tibia, and is usually most prominent in toddlers. It usually resolves by 2 years of age but there is great variability. By age 36 months, almost all children will correct spontaneously. In children with physiologic bowing, the screening examination is typically normal and a family history is absent; therefore, radiographs are not necessary. If the deformity has not resolved by age 2 years, an AP radiograph of the lower limbs should be obtained. This provides documentation of the severity of the bowing, permits measurement of the metaphyseal-diaphyseal angle and/or Langenskiold grade, and allows evaluation for conditions such as rickets or bony dysplasia. No treatment is indicated for physiologic bowing. REFERENCES: Abel MF (ed): Orthopaedic Knowledge Update: Pediatrics 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, p 7. Salenius P, Vankka E: The development of the tibiofemoral angle in children. J Bone Joint Surg Am.

The acetabulum remodels until age 8 y/o and it is preferable to treat hip dysplasia (whether it is from DDH or CP) as a child with open growth plates. If hip dysplasia presents as an adolescent, there are two main types of pelvic osteotomies: medial displacement and rotational periacetabular.Medial displacement osteotomies are Salter, Triple and Shelf / Chiari. The acetabulum itself remains unchanged. These osteotomies can be used for an incruent hip. They provide only lateral acetabular coverage and can be preformed with or withoutinternal fixation. They often involve multiple incisions. A triple osteotomy involves a Salter cut with cuts of both the superior and inferior rami. The Shelf / Chiari osteotomy is a salvage procedure and is only used as a last resort for femoral containment.A rotational periacetabular osteotomy is called a Ganz or Bernese. It allows acetabular reorientation and either medial or lateraldisplacement. The advantages of this procedure is that it provides hyaline cartilage coverage (ans. 4)over the adolescent hip, can be performed with a single surgical approach and preserves the normal shape of the pelvis—permitting normal vaginal delivery. An additional advantage is preservation of blood supply to the acetabular fragments. No complete cut is made, so it is very stable. The disadvantage is that it is technically demanding and often additional training is needed for the surgeon to become comfortable.Reshaping (incomplete) osteotomies include the Pemberton and Degas require an open triradiate cartilage and can achieve posterioror posterolateral femoral head coverage. This question asked about the adolescent hip.There is a good review in JAAOS Sept / Oct 1999 pp.325-336.For the Atlanta crew, remember: God loves a Pemberton.

While all of the answers may be appropriate, radiating pain from hip pathology must be excluded. At this age, a slipped capital femoral epiphysis is likely. Therefore, the hip must be examined.

Figure 37a shows a completely displaced supracondylar humerus fracture. The first step in the situation described, which involves a pink pulseless hand, is to perform an urgent closed manipulation and pinning. The vascular examination should be reassessed following the reduction. When adequate reduction has been achieved and the pulse remains nonpalpable but the hand is pink and capillary refill is normal, the fracture may be splinted and the patient observed closely in the hospital. Arteriography is not useful and may delay revascularization or increase vessel spasm. Although some investigators have concluded that exploration of the brachial artery may be indicated, the algorithm that includes observation only is the most supported and the most commonly practiced treatment.

These triplets exhibit genu varum and internal tibial torsion that can be part of normal development. Fetal packing is the likely major contributing cause for these triplets, however. Observation and follow-up will be sufficient. Bowing and torsion can be clinical features of vitamin D deficiency, Blount disease, and short-stature syndromes, but these are not the most likely diagnoses. Radiographic diagnosis of Blount disease may not be accurate at this age.(SBQ13PE.56) A 22-month-old female is hospitalized with a fever and malaise. She is found to be bacteremic, and blood cultures grow methicillin-sensitive Staphylococcus aureus (MSSA). During her hospitalization, the pediatrician notices her arm is slightly swollen and appears painful to use. MRI is obtained and demonstrated in figure A. Which feature of the MRI suggests the need for surgical management?Review TopicBrodie's AbscessOsteomyelitis of the humeral metaphysisSubperiosteal abscess of the humerusPresence of subcutaneous airHigh risk of proximal humeral growth arrestThis patient has osteomyelitis of the humerus with a large subperiosteal abscess. The presence of subperiosteal abscess necessitates surgical intervention for irrigation and debridement (I&D).The diagnosis of acute osteomyelitis in children is made based upon a constellation of findings including pain, systemic signs of infection, elevated serum inflammatory markers, and imaging studies demonstrative of osseous infection. It is most commonly hematogenously spread to the metaphysis of immature bone, which is highly vascular prior to skeletal maturity. Treatment involves obtaining specimen for culture, empiric antibiotic treatment, and surgical irrigation and debridement of known abscesses. The end-point of treatment is return of pain-free functionality and the resolution of local/systemic signs of infection.Conrad reviewed the management of acute hematogenous osteomyelitis and emphasized that surgical intervention in the presence of abscess can be both therapeutic and diagnostic: I&D can obtain culture and narrow the antibiotic plan.Jones et. al. reviewed chronic pediatric osteomyelitis and report that surgery is the mainstay of treatment because removal of dead bone is essential for resolution of infection. This may be performed with sequestrectomy and curettage, with an emphasis on prevention of pathologic fracture, growth disturbances, bone loss, joint involvement, and permanent loss of function.Figure A is a coronal STIR MRI image of the humerus demonstrating osteomyelitiswith extensive subperiosteal abscess.Incorrect Answers:Brodie's abscess is a type of subacute osteomyelitis which remains indolent and creates a focal intra-osseous abscess. This is not demonstrated in the clinical image.The patient does have osteomyelitis of the humeral metaphysis, but this alone is not the indication for surgery. Uncomplicated osteomyelitis may be treated effectively with antibiotics alone.Presence of subcutaneous air is suggestive of necrotizing fasciitis, which is a surgical emergency. The MRI however does not demonstrate this finding.The infection and its surgical management both increase risk of injury to the proximal humeral physis and has the potential for growth arrest or angular deformity.(SBQ13PE.3) Figure A demonstrates a physical examination maneuver in a 1 month old infant. What is this maneuver?Review TopicOrtolani TestBarlow TestGaleazzi SignPatrick testTeratologic SignFigure A shows a schematic image of the Ortalani test.The Ortolani test, or Ortolani maneuver, is part of the physical examination for developmental dysplasia of the hip. It is used alongside the Barlow test to detect subluxated hips that are either reducible or irreducible. A positive sign is a distinctive 'clunk' which can be heard and felt as the femoral head relocates anteriorly into the acetabulum.Guille et al. showed that the use of Pavlik harness has become the mainstay of initial treatment for the infant who has not yet begun to stand. If concentric reduction of the hip cannot be obtained, surgical reduction of the dislocated hip is the next step before they are able to stand.Video V is a lecture discussing the hip examination of the infant. Incorrect Answers:pressure on the knee, directing the force the femoral head posteriorly. A positive Barlow test would result in posterior subluxation/dislocation of the hip. Answer 3: Galeazzi test is performed by flexing an infant's knees in the supine position so that the ankles touch the buttocks. If the knees are not level then the test is positive, which indicates a potential congenital hip issue (e.g. DDH). Answer 4: Patrick or Faber test (flexion, abduction, external rotation) has been described both for stressing the SI joint and for isolating symptoms to the hip Answer 5: Teratologic dislocation of the hip is a term used to imply that the hip joint did not develop normally in utero, thus the hip is in a fixed dislocated position at birth.

Age at presentation and range of motion of the hip are the two most significant predictors of long-term outcome. Younger patients and patients who maintain range of motion of the hip are more likely to have a good outcome. In Herring's study, children with a chronologic age of younger than 8 years or a bone age of less than 6 years had significantly more favorable outcomes compared with older children. Limited hip range of motion may be due to muscle spasm early on, or synovitis; but in late disease, it may reflect incongruity of the joint. Classifications based on femoral head shape have also been correlated to prognosis. Significant shortening of the affected hip is not common.(SBQ13PE.87) A 4-week-old child is suspected to have classic arthrogryposis, also known as amyoplasia. Clinical examination and hip ultrasound reveal a unilateral, non-reducible, hip dislocation. What do you recommend to reduce the hip?ReviewTopicPavlik harness applicationSemi-rigid abduction brace applicationSkeletal tractionEarly closed reduction and spica castingDelayed open reduction with or without pelvic and femoral osteotomyDelayed open reduction with or without pelvic and femoral osteotomy is recommended in the management of unilateral hip deformities associated with amyoplassia. This procedure should be performed at 6-9 months of age. In order to proceed with reduction, there must be a reasonable arc of flexion/extension and active movement of the lower limbs.Amyoplasia is the most common recognizable form of arthrogryposis. It most commonly occurs as a sporadic symmetric contracture syndrome that is characterized by symmetrical limb involvement, normal to above-average intelligence, and often a midline facial hemangioma. Approximately 80% of children with amyoplasia will have involvement of the hip ranging from soft tissue contractures to unilateral or bilateral hip dislocations.Bevan et al. reviewed arthrogryposis. They state that open hip reduction is recommended for the management of unilateral dislocation. There is more controversy with regard to the treatment of bilateral hip dislocations. Open reduction can be performed by a medial or anterolateral approach, with or without pelvic andfemoral osteotomy. This procedure is generally delayed for 6-9 months to facilitate the procedure.Bernstein et al. also reviewed arthrogryposis. They state that the term 'arthrogryposis' encompasses a broad spectrum of diseases, all with the common phenotype of multiple congenital contractures.Illustration A shows the characteristic features of an infant with severe arthrogryposis. Note the internal rotation of the shoulders, elbow and knee hyperextension, flexed and ulnarly deviated wrists, flexed finger, external rotation of hips and bilateral clubfeet.Incorrect answers:

DISCUSSION: The child has an injury involving both the growth plate and the articular surface of the ankle. Because of the significant displacement, open reduction and internal fixation is indicated to realign the physis and joint surface. The best method of fixation to avoid growth arrest is one that does not cross the physis. This is usually achieved by a transverse epiphyseal screw parallel to the physis.

DISCUSSION: Streeter’s dysplasia is clearly related to rupture of the amnion in utero and is now most commonly referred to as premature amnion rupture sequence. The deformities arise from amniotic bands that wrap about protruding parts and from uterine packing because of the accompanying oligohydramnios. The disease is not genetic and has not been related to teratogen exposure or to iatrogenic influences.

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.

A supracondylar fracture of the femur that occurs after total knee replacement can be treated effectively by a number of methods. For this fracture, the use of a retrograde supracondylar nail has been found to be effective in several series. The treatment of these complex injuries needs to injuries needs to be individualized based on the stability of the implant, the quality of the bone, and the extent of comminution of the fracture.

Salter-Harris III and IV fractures of the medial aspect of the distal tibia commonly cause growth disturbances unless an anatomical reduction of the physis is obtained. According to Spiegel, any of these fractures with 2 mm or more of displacement should be openly reduced. The recommended treatment is ORIF, consisting of small, smooth Kirschner wires from one epiphyseal fragment to the other. They do not recommend crossing the physis with fixation devices, as this may lead to further injury.

DISCUSSION: The patient has a bucket-handle fracture of the distal femur with bilateral corner fractures of the distal femur and a transverse fracture of the proximal tibia. These fractures are virtually pathognomonic of child abuse. The infant should be admitted to the hospital, and child protection services should be notified for investigation of possible abuse. A skeletal survey should be obtained, along with laboratory studies that include a CBC, a platelet count, a prothrombin time, a partial thromboplastin time, and a bleeding time. REFERENCES: Akbarnia BA: The role of the orthopaedic surgeon in child abuse, in Morrissy RT, Weinstein SL (eds): Lovell & Winter’s Pediatric Orthopaedics, ed 4. Philadelphia, Pa, Lippincott-Raven, 1996, pp 1315-1334. Black GB: Child abuse fractures, in Letts RM (ed): Management of Pediatric Fractures. New York, NY, Churchill Livingstone, 1994, pp 931-944.

Flexion contractures and angular deformities of a limb cause inaccurate limb-length measurement results with most clinical methods. A CT scanogram is more accurate than standard scanograms for determining limb length in patients with knee flexion contractures of 30° or more. The cost and time necessary to complete the examinations are comparable, but the CT scanogram delivers only 20% of the radiation needed for standard scanograms.

Discussion: Radial deficiency is associated with other abnormalities. 40% of patients with unilateral and 77% of bilateral involvement will have associated malformations:Holt-Oram syndrome – Radial deficiency and cardial septal defect.Fanconi syndrome – Severe aplastic anemiaTAR syndromeTrisomy 17VATER syndromeBecause of the association with severe aplastic anemia, a platelet count should be done before any surgical intervention.

DISCUSSIONEarly radiographic findings of avascular necrosis (AVN) of the hip include sclerosis and a subchondral lucency. A common presentation of Legg-Calve-Perthes disease (idiopathic pediatric hip AVN) is intermittent pain in the thigh, groin, or knee with an examination localizing to the hip; a Trendelenburg gait or sign; and painful, restricted passive hip range of motion. AVN also may be observed in association with a slipped capital femoral epiphysis (SCFE). AVN risk is highest in the setting of an unstable SCFE (10%-60%); risk is 0% to 1.4% when the SCFE is stable. A multicenter review of the modified Dunn procedure for treatment of unstable SCFE noted an AVN rate of 26%.The most common deformity associated with SCFE is proximal femoral varus, flexion, and external rotation leading to an abnormal femoral head-neck junction offset. This causes a loss of passive hip flexion and internal rotation and the phenomenon of obligate externalrotation with flexion. The residual deformity frequently results in femoroacetabular impingement. Labral tears also are associated with cam impingement secondary to underlying osseous abnormalities including abnormal femoral head-neck junction offset.Endocrinopathies potentially are associated with SCFE because of hormone-related physeal changes and subsequent mechanical insufficiency of the proximal femoral physis. With renal osteodystrophy, the physeal widening results from secondary hyperparathyroidism and progressive proximal femoral deformity may develop. Optimal medical management of hyperparathyroidism is essential. Surgical stabilization via in situ fixation of the proximal femur is indicated when SCFE is diagnosed.The proximal femoral epiphysis secondary ossification center commonly appears between the ages of 4 and 7 months. In the setting of developmental hip dislocation, the appearance of the secondary ossification center is commonly delayed. After closed or open reduction of developmental dysplasia of the hip, failure of the femoral head ossific nucleus to appear within 12 months following the reduction is a sign of proximal femoral growth disturbance and AVN.

The occurrence of a forearm fracture in a 9-month-old child has a greater than 50% chance that the injury is due to child abuse. It is mandatory to report this to child protective services unless there is some compelling reason that it is definitely not child abuse. In addition, a skeletal survey should be requested to look for other injuries. A bone scan would show other injuries, but a skeletal survey is a moreefficient way to evaluate for other fractures. A MRI of the brain is not indicated unless fundoscopic examination reveals an abnormality.

DISCUSSION: The radiograph shows changes that are most consistent with Legg-Calvé-Perthes disease. Valgus extension osteotomy is the salvage procedure of choice in patients with late symptomatic Perthes disease with severe joint incongruity. Prerequisites for valgus extension osteotomy include an adequate range of hip adduction and proof of improved congruity in the new position. Total hip arthroplasty is not a good alternative in the young patient. Varus osteotomy would further shorten the extremity and place a flattened portion of the femoral head in the acetabulum. A prerequisite of the innominate osteotomy is a congruent reduction.

DISCUSSION: The clinical scenario describes infantile tibia vara (Blount’s disease). The radiograph shows severe deformity with the characteristic Langenskiold stage 3 changes of the medial proximal tibial metaphysis that distinguish it from physiologic bowing. The preferred treatment is proximal tibiofibular osteotomy with acute correction into slight valgus to unload the damaged area of the physis. This method provides the best results in patients younger than age 4 years. Continued observation would result in progressive deformity. Bracing is most effective in younger children with less severe deformity. Lateral proximal tibial hemiepiphysiodesis relies on growth of the injured medial physis for correction and would result in severe tibial shortening in this young child. Complete epiphysiodesis also produces severe shortening and requires multiple lengthening procedures. REFERENCES: Johnston CE II: Infantile tibia vara. Clin Orthop 1990;255:13-23. Richards BS, Katz DE, Sims JB: Effectiveness of brace treatment in early infantile Blount’s disease. J Pediatr Orthop 1998;18:374-380.