AAOS Pediatric Orthopedics (Set 2): DDH, SCFE & Femur Fractures | Board Review

The newborn has posteromedial bowing of the tibia and calcaneal valgus deformity of the foot. Both are thought to be caused by abnormal intrauterine positioning. The foot deformity typically responds to stretching. The tibial bowing straightens with growth. The long-term problem is limb-length discrepancy. Heyman CH, Herndon CH, Heiple KG: Congenital posterior angulation of the tibia with talipes calcaneus. J Bone Joint Surg Am 1959;41:476-488.

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. 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.

The initial signs and symptoms of acute hematogenous osteomyelitis vary widely but usually include fever, bone pain, and impaired use of the involved extremity. In lower extremity infections, the child may limp or refuse to walk. Examination often reveals bone tenderness. In more advanced cases, erythema, warmth, and swelling may be present. The WBC and neutrophil counts are not always elevated, but the erythocyte sedimentation rate will be abnormal in more than 90% of patients. When the infection is diagnosed early, before a subperiosteal abscess has formed, antibiotics alone may be adequate to treat the infection. This patient has a more advanced infection, however, with the MRI scan revealing a subperiosteal abscess that was confirmed by aspiration. When an abscess is present, surgical drainage is generally indicated to remove devitalized tissue and to enhance the efficacy of the antibiotics. Further studies, such as bone or indium scans, are not necessary and will delay definitive treatment. Scott RJ, Christofersen MR, Robertson WW Jr, et al: Acute osteomyelitis in children: A review of 116 cases. J Pediatr Orthop 1990;10:649-652.

Focal scleroderma is characterized by the formation of patches of sclerotic skin, also known as morphea, or streaks of sclerosis (linear scleroderma). Systemic involvement in focal scleroderma is unusual; however, progression during childhood is common. Contracture of underlying tissues is common, often resulting in serious joint contractures. Bony changes similar to those seen in melorheostosis can be seen. This patient has characteristic skin changes, atrophy of the soft tissues, Achilles tendon contractures, and calcaneal deformities. There are no signs of arthrogryposis, which usually presents with bilateral congenital deformities, including equinovarus. Klippel-Trenaunay-Weber syndrome is characterized by venous malformation in association with focal overgrowth.

Isolated split posterior tendon transfer alone is best performed in a patient with cerebral palsy who is between the ages of 4 and 7 years and has a flexible equinovarus foot. Rigid deformities often must be managed with a combination of soft-tissue and bony procedures. Patients with out-of-phase activity may be best managed with a transfer of the posterior tibialis to the dorsum of the foot, while those with continuous activity are better candidates for an isolated split posterior tendon transfer. Drennan JC (ed): The Child's Foot and Ankle. New York, NY, Raven Press, 1992, pp 291-294. Green NE, Griffin PP, Shiavi R: Split posterior tibial-tendon transfer in cerebral palsy. J Bone Joint Surg Am 1983;65:748-754.

The differential diagnosis includes septic hip and transient synovitis. Both disorders may present with a joint effusion. The increased teardrop distance and loss of range of motion implies that there is excess fluid in the joint. While the other tests can confirm this, only aspiration can characterize the fluid further, thereby indicating the etiology of the effusion. Provided there is enough fluid obtained at aspiration, the joint fluid should be sent for Gram stain, culture, cell count, glucose, and protein studies.

Informed consent is generally considered to be a process of mutual decision making between the physician and patient. The physician is required to provide to the patient all material information that is needed for the patient to make an informed decision. The courts have held that a patient's choice of surgeon is as important to the consent as the procedure itself. Assistance by a surgical trainee with adequate supervision is permissible when there has been adequate disclosure. Adequate supervision may be defined as active participation by the attending during the essential parts of the procedure. Allowing a substitute surgeon to operate on a patient without the patient's knowledge "ghost surgery" may result in charges of battery against the substitute surgeon and malpractice against the surgeon to whom the patient gave consent. Kocher MS: Ghost surgery: The ethical and legal implications of who does the operation. J Bone Joint Surg Am 2002;84:148-150.

The patient has bilateral metatarsus adductus deformities. In a long-term follow-up study by Farsetti and associates, deformities that were passively correctable spontaneously resolved and no treatment was required. More rigid deformities were successfully treated with serial manipulation, with good results in 90%. There were no poor results. Therefore, observation is the management of choice for passively correctable deformities. In feet that are more rigid, serial manipulation and casting is the management of choice.

The presence of any curve greater than 20 degrees in a nonambulatory patient with Duchenne muscular dystrophy is an indication for posterior fusion with instrumentation. Because of progressive cardiomyopathy and pulmonary deficiency, waiting until the curve is larger can increase the risk of pulmonary or cardiac complications during or following surgery. There is some disagreement as to whether all such fusions must extend to the pelvis. Bracing or other nonsurgical management is ineffective and is not indicated in this situation. Sussman M: Duchenne muscular dystrophy. J Am Acad Orthop Surg 2002;10:138-151.

Chronic dislocation of the patella is occasionally seen in patients with Down syndrome. In early childhood, patellar realignment may restore stability of the patellae. In later childhood, bony changes in the patellar groove interfere with stability, even if surgical realignment is performed. Realignment can also lead to increased knee pain postoperatively. In asymptomatic patients who are able to extend their knees, continued observation is the management of choice. Dugdale TW, Renshaw TS: Instability of the patellofemoral joint in Down syndrome. J Bone Joint Surg Am 1986;68:405-413.

In patients with myelomeningocele, the presence of bilateral hip dislocation does not affect ambulation, bracing requirements, sitting ability, degree of scoliosis, or level of comfort. There is little evidence to support active treatment of bilateral hip dislocations in patients with myelomeningocele proximal to L4. Fraser RK, Hoffman EB, Sparks LT, et al: The unstable hip and mid-lumbar myelomeningocele. J Bone Joint Surg Br 1992;74:143-146.

Child abuse and OI are frequently both in the differential diagnosis of a child with multiple fractures. If OI is suspected, testing is appropriate to confirm this diagnosis. This may include skull radiographs to look for wormian bones and/or fibroblast culturing and collagen analysis of a punch biopsy. Unfortunately, because of the large number of mutations that can yield the disease, DNA testing is not commercially available for OI. In this patient, however, the physician suspects nonaccidental trauma and is legally obligated in most states to notify child protective services. Because the child may be at considerable risk of further injury, hospitalization is indicated to protect the child until child protective services can complete a home investigation and assess the degree of risk. Work-up for both OI and child abuse can be done during the hospitalization. Rockwood CA, Wilkins KE, King RE (eds): Fractures in Children. Philadelphia, PA, JB Lippincott, 1984, vol 3, pp 173-175. Kempe CH, Silverman FN, Stelle BF, Droegemueller W, Silver HK: The battered-child syndrome. JAMA 1962;181:17-24.

This clinical situation requires careful analysis because some data suggest infection and some a noninfectious inflammatory process. Bilateral hip involvement, the absence of significant fluid collection or fever, the streptozyme level, and the history of upper respiratory infection all suggest poststreptococcal toxic synovitis as the most likely cause for the clinical presentation. In the first 24 hours, this type of presentation might warrant incision and drainage given uncertainty of the diagnosis and the risks associated with missing an infection. However, 5 days after onset, surgery is not warranted, especially given that the patient remains afebrile and her symptoms are improving. Cardiology consultation would be appropriate. There is no evidence to suggest slipped capital femoral epiphysis. Treatment with antibiotics is not advised because there is no bacteriologic data on which to base treatment. De Cunto CL, Giannini EH, Fink CW, et al: Prognosis of children with poststreptococcal reactive arthritis. J Pediatr Infect Dis 1988;7:683-686.

With the patient standing, add blocks under the short leg until the pelvis is level, then measure the blocks to determine the discrepancy. This method is an accurate, simple, and inexpensive way to assess limb-length discrepancy. Differences of less than 2 cm need no treatment. Increasing discrepancy in a growing child should be followed clinically. Radiographic examination can include scanography, CT scanography, or a standing pelvic radiograph with the pelvis leveled. CT scanography is the most accurate diagnostic test when hip, knee, or ankle contractures are present. Herring JA: Tachdjian's Pediatric Orthopedics, ed 4. Philadelphia, PA, WB Saunders, 2002, pp 1041-1045. Schoenecker PL, Rich MM: The lower extremity, in Morrissy RT, Weinstein SL (eds): Lovell and Winter's Pediatric Orthopaedics, ed 5. Philadelphia, PA, Lippincott Williams and Wilkins, 2001, pp 1120-1122. Stanitski DF: Limb-length inequality: Assessment and treatment options. J Am Acad Orthop Surg 1999;7:143-153.

The patient's findings are consistent with an intermediate form of spinal muscular atrophy. Children with this condition appear normal at birth but are not able to walk. The disorder affects anterior horn cells. Fasciculations may be present, but deep tendon reflexes are typically absent. The development of scoliosis is almost universal with this type of spinal muscular atrophy. More than 90% of patients with spinal muscular atrophy have deletions in the telomeric survival motor neuron gene. Peripheral myelin protein 22 is abnormal in Charcot-Marie-Tooth type IA. Connexin 32 is abnormal in the X-linked type of Charcot-Marie-Tooth disease. Neurofibromin is affected in neurofibromatosis type 1. Friedreich's ataxia is secondary to a disorder of frataxin. Buckwalter JA, Einhorn TA, Simon SR (eds): Orthopaedic Basic Science, ed 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 111-131.

The diagnosis of neurofibromatosis may be based on the presence of at least six cafe-au-lait spots larger than 5 mm in diameter and the osseous lesion shown in Figure 18c. Neurofibromatosis occurs in 50% of patients who have an anterolateral bowing deformity of the tibia, and this bowing may be the first clinical manifestation of this disorder. The patient has anterolateral bowing of the tibia and fibula that warrants concern for a possible fracture and pseudarthrosis; therefore, the limb should be protected in a total contact orthosis to prevent fracture. In contradistinction to posteromedial bowing of the tibia and fibula, spontaneous remodeling of an anterolateral bowing deformity is not expected. Intramedullary nailing or the use of a vascularized fibula is reserved for the treatment of a congenital pseudarthrosis of the tibia. Crawford AH Jr, Bagamery N: Osseous manifestations of neurofibromatosis in childhood. J Pediatr Orthop 1986;6:72-88.

Errors in timing are by far the most common in this technically safe procedure. Incomplete growth arrest has been reported in up to 15% of patients versus timing errors in 61%. Fracture through the site has been reported rarely. Neurovascular and cartilaginous injury are extremely uncommon but always need to be considered when performing surgery in the vicinity of these structures. Blair VP III, Walker SJ, Sheridan JJ, Schoenecker PL: Epiphysiodesis: A problem of timing. J Pediatr Orthop 1982;2:281-284.

Diminished hip abduction can occur in normal children and is not always associated with hip pathology; therefore, initial management should consist of observation.

Children with spastic diplegic cerebral palsy often have contractures of multiple joints. Because the gait abnormalities can be complex, isolated surgery is rarely indicated. To avoid compensatory deformities at other joints, it is preferable to correct all deformities in a single operation. Isolated heel cord lengthening in the presence of tight hamstrings and hip flexors will lead to progressive flexion at the hips and knees, thus worsening a crouched gait. Split posterior tibial tendon transfer is used for patients with hindfoot varus, which is not present in this patient. Gage JR: Distal hamstring lengthening/release and rectus femoris transfer, in Sussman MD (ed): The Diplegic Child. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1992, pp 324-326.

Ligamentous laxity and muscle hypotonia seen in Down syndrome contribute to the incidence of hip subluxation and dislocation. These factors can be progressive and lead to degenerative arthritis in adults with Down syndrome. Because this patient has a progressive limp and decreased endurance, observation and a shoe lift are not options. Bracing may be an option in the younger child before significant bony changes occur. Surgical intervention is the treatment of choice in this patient; however, all components of the deformity need to be addressed. Because of the increased capsular laxity, there is a high likelihood of recurrence if capsulorrhaphy is not included with the pelvic and femoral osteotomies. Surgery in these patients is associated with a high rate of complications. Shaw ED, Beals RK: The hip joint in Down's syndrome: A study of its structure and associated disease. Clin Orthop 1992;278:101-107. Aprin H, Zinc WP, Hall JE: Management of dislocation of the hip in Down's syndrome. J Pediatr Orthop 1985;5:428-431.

The patient has an unstable slipped capital femoral epiphysis (SCFE). According to the classification system based on physeal stability, an unstable SCFE is one in which the patient is unable to walk, even with crutches. Ishemic necrosis, or osteonecrosis, of the femoral head is the most devastating complication of SCFE. One study found a 47% incidence of ischemic necrosis following unstable slips. This complication is most likely the result of vascular injury associated with initial femoral head displacement rather than the result of either tamponade from joint effusion or gentle repositioning prior to stabilization. Chondrolysis is a relatively uncommon complication following treatment of SCFE. This complication has been associated with persistent penetration of the hip joint with screws or pins used to stabilize the femoral head or with spica cast immobilization. There are no reports to suggest that osteochondritis dissecans, nonunion, or coxa magna follows treatment of SCFE. Loder RT, Richards BS, Shapiro PS, et al: Acute slipped capital epiphysis: The importance of physeal stability. J Bone Joint Surg Am 1993;75:1134-1140.

Patients with Becker muscular dystrophy have an abnormality in dystrophin, but unlike patients with Duchenne muscular dystrophy, some dystrophin is present. As a result, the progression of muscle weakness is slower, with the diagnosis typically made after age 8 years. Similar to patients with Duchenne muscular dystrophy, patients with Becker muscular dystrophy have pseudohypertrophy of the calves, markedly increased creatine kinase levels, and X-linked transmission of the condition. In addition, these patients are more prone to cardiomyopathy; a condition that should be carefully evaluated if any surgery is required. Patients with spinal muscular atrophy also have proximal muscle weakness, but the onset of weakness occurs earlier in childhood. These patients also have absent deep tendon reflexes and fasciculations, but pseudohypertrophy is absent and creatine kinase levels are normal. Patients with Emery-Dreifuss dystrophy may have a similar clinical picture to Becker's muscular dystrophy, but pseudohypertrophy is absent and creatine kinase levels are only mildly elevated. In addition, neck extension, elbow flexion, and ankle equinus contractures develop at an early age. Limb girdle dystrophy is a group of progressive muscular dystrophies that is not associated with pseudohypertrophy or a significant elevation of creatine kinase levels. Guillain-Barre syndrome is a condition associated with results from postinfectious demyelination of the peripheral nerve. These patients have the acute onset of weakness, hypotonia, and areflexia; creatine kinase levels are normal. Sussman MD: Muscular dystrophy, in Fitzgerald RH, Kaufer H, Malkani AL (eds): Orthopaedics. St Louis, MO, Mosby, 2002, pp 1573-1583.

The possibility of an open joint injury should be considered in any patient who has a small periarticular laceration. Failure to promptly diagnose and treat such injuries may lead to septic arthritis. The diagnosis of an open joint is easily made when there is visible communication of the joint through the traumatic wound, or when intra-articular air is present on a radiograph. In the absence of these findings, the diagnosis of an open joint may be established by the saline load test, in which a volume of saline is injected into the joint under sterile conditions. If fluid extravasates through the traumatic wound, the diagnosis of an open joint is established. Voit and associates used a saline load test in 50 patients with periarticular lacerations suggestive of joint penetration. When they compared the clinical prediction of whether or not the laceration had penetrated the joint and the test results, the authors reported a false-positive clinical result in 39% of patients and a false-negative clinical result in 43%. The authors concluded that the saline load test was valuable in evaluating periarticular lacerations. Voit GA, Irvine G, Beals RK: Saline load test for penetration of periarticular lacerations. J Bone Joint Surg Br 1996;78:732-733.

Developmental coxa vara develops in early childhood and results in a progressive decrease in the proximal femoral neck-shaft angle with growth. The characteristic radiographic features are seen in this patient and include a decreased neck-shaft angle, a more vertical position of the physeal plate, and a triangular metaphyseal fragment in the inferior femoral neck, surrounded by an inverted radiolucent Y pattern. The main goal of surgery is to correct the varus angulation into a more normal range. Valgus overcorrection is preferred. A recent study emphasized the importance of adequately correcting the Hilgenreiner physeal angle to less than 38 degrees to minimize the risk of recurrent angulation. No study has documented the use of any of the other listed radiographic measurements to the outcome of treating developmental coxa vara. Carroll K, Coleman S, Stevens PM: Coxa vara: Surgical outcomes of valgus osteotomies. J Pediatr Orthop 1997;17:220-224.

This form of severe kyphosis results in intractable difficulties with sitting position, compression of internal organs, and chronic skin breakdown. Kyphectomy and posterior fusion with instrumentation, while associated with a high rate of complications, provides one of the best solutions to this clinical dilemma. The other choices are either completely ineffective or inadequate in managing this degree of deformity. Lindseth RE: Spine deformity in myelomeningocele. Instr Course Lect 1991;40:273-279.