Porth's Essentials of Pathophysiology, 4e

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Musculoskeletal Function

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principal goals for treatment of children 6 months to 2 years of age are to obtain and maintain reduction of the hip without damaging the femoral head. Closed reduction is often performed under general anesthesia, followed by several months of immobilization in a hip spica cast, plas- ter splints, or an abduction splint. Surgical treatment may be required for children who fail to maintain a stable hip with closed reduction methods. The most serious com- plication of any treatment is avascular necrosis of the femoral head as a result of the forced abduction. 63 This most often occurs as a complication of a closed or open reduction in an older child. In addition, hyperflexion has the potential to cause femoral nerve palsies. Congenital Clubfoot Clubfoot, or talipes, is one of the most common pediat- ric orthopedic conditions. The clubfoot deformity may be positional, congenital, or associated with a variety of other underlying congenital conditions. 56,57 The positional club- foot is a normal foot that has been held in a deformed posi- tion in utero and is found to be flexible on examination in the nursery. The congenital clubfoot involves a spectrum of severity, while the clubfoot associated with other con- genital conditions is typically rigid and difficult to treat. Congenital clubfoot has an incidence of approximately 1 to 2 cases per 1000 live births, is bilateral in about 50% of cases, and affects boys more often than girls. 56,57 Like developmental dysplasia of the hip, its occurrence follows a multifactorial inheritance pattern. 68,69 Clubfoot may be associated with chromosomal abnormalities or congenital syndromes that are transmitted by mendelian inheritance patterns. However, it is most commonly idiopathic and found in normal infants in whom no genetic or chromo- somal abnormality or other extrinsic cause can be found. In forefoot adduction, which accounts for approxi- mately 95% of idiopathic cases, the foot is plantar flexed and inverted or twisted toward the midline of the leg. 56 This is the so-called equinovarus type of clubfoot (Fig. 43-22). The other 5% of cases are of the equinovalgus type, or reverse clubfoot, in which the foot is dorsiflexed and everted. Reverse clubfoot can occur as an isolated condition or in association with multiple congenital defects. At birth, the feet of many infants assume one of these two positions, but they can be passively overcorrected or brought back into the opposite position. If the foot cannot be overcor- rected, some type of correction may be necessary. Treatment of clubfoot is begun as soon as the diag- nosis is made. When treatment is initiated during the first few weeks of life, a nonoperative procedure may be effective. Serial manipulations and casting are used gently to correct each component of the deformity. One method, called the Ponseti method, involves weekly gentle stretching and manipulation of the misaligned bones followed by application of a well-molded long leg plaster cast with the knee held at a right angle. 56,57,69–71 The cast maintains the correction and allows for further relaxation of tight structures in anticipation of the next week’s casting. Correction of the deformity is usually obtained within 6 to 8 weeks. Frequently, a percutaneous Achilles tendon lengthening is performed using a topical

anesthetic cream before application of the final cast to allow for complete correction of the equinus deformity. The correction is maintained by wearing a brace full time for 3 months and part-time wear during napping and at night for approximately 2 to 3 years. 56 Surgery may be required for severe deformities or when nonopera- tive treatment methods are unsuccessful. It is performed most commonly between 6 and 12 months of age. 56 Juvenile Osteochondroses Juvenile osteochondroses are a group of children’s dis- eases in which one or more growth ossification centers undergo a period of degeneration, necrosis, or inactivity that is followed by regeneration and usually deformity. The osteochondroses are separated into two groups according to their causes. The first group consists of the true osteonecrotic osteochondroses, so called because the diseases are caused by localized osteonecrosis of an apophyseal or epiphyseal center (e.g., Legg-Calvé-Perthes disease, Freiberg infraction, Panner disease, Kienböck disease). The second group of juvenile osteochondroses is caused by abnormalities in ossification of cartilagi- nous tissue resulting from a genetically determined nor- mal variation or from trauma (e.g., Osgood-Schlatter disease, Blount disease, Sever disease, Scheuermann disease). The discussion in this section focuses on Legg- Calvé-Perthes disease from the first group and Osgood- Schlatter disease from the second group. Slipped capital femoral epiphysis is a disorder of the growth plate. Legg-Calvé-Perthes Disease Legg-Calvé-Perthes disease is an idiopathic osteone- crotic disease of the proximal (capital) femoral epiph- ysis with later reabsorption. 72–74 The disorder usually FIGURE 43-22. Newborn with clubbing of the left foot. (From the Centers for Disease Control and Prevention Public Health Images Library. No. 2632. Courtesy of JamesW. Hanson.)