Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Key Features ++ Occurs when the vascular supply to the proximal femur is interrupted Highest incidence occurs between ages 4 and 8 years Prognosis for complete replacement of the necrotic femoral head in a child is excellent, but the functional result depends on the amount of deformity that has developed Better outcomes are observed for patients with an onset of symptoms before the age of 6 Generally, a poorer prognosis is expected for Patients in whom the disease develops late in childhood Those with more completed involvement of the epiphysial center Those with metaphysial defects Those who have more complete involvement of the femoral head +++ Clinical Findings ++ Persistent pain is the most common symptom Limp or limitation of motion may be present +++ Diagnosis ++ Radiographic findings correlate with progression of the disease and the extent of necrosis Effusion of the joint associated with slight widening of the joint space and periarticular swelling are the early findings Decreased bone density in and around the joint is apparent after a few weeks The necrotic ossification center appears denser than the surrounding viable structures, and the femoral head is collapsed or narrowed As replacement of the necrotic ossification center occurs, rarefaction of the bone begins in a patchwork fashion, producing alternating areas of rarefaction and relative density, referred to as "fragmentation" of the epiphysis Widening of the femoral head may be associated with flattening, or coxa plana If infarction has extended across the growth plate, a radiolucent lesion will be evident within the metaphysis If the growth center of the femoral head has been damaged and normal growth arrested, shortening of the femoral neck results Eventually, complete replacement of the epiphysis develops as living bone replaces necrotic bone by creeping substitution Serial radiographs help to distinguish this disease from transient synovitis of the hip +++ Treatment ++ Protection of the joint by minimizing impact is the principal treatment If the joint is deeply seated within the acetabulum and normal joint motion is maintained, a reasonably good hip can result Little benefit has been shown from bracing Surgical treatment is controversial Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.