Legg-Calvé-Perthes disease has a maximum incidence at age 5 to 10 years, is more common among boys, and is usually unilateral. About 10% of cases are familial, but contributing gene defects have not been identified.
Characteristic symptoms of Legg-Calvé-Perthes disease are pain in the hip joint and gait disturbance (eg, limping); some children complain of pain in the knee. Onset is gradual, and progression is slow. Joint movements are limited, and thigh muscles may become wasted.
Diagnosis of Legg-Calvé-Perthes disease is suspected based on symptoms. X-rays are usually obtained and, if needed, an MRI is done to confirm the diagnosis and extent of the lesion. X-rays initially may not be diagnostic, because they can be normal or show minimal flattening. Later x-rays can show fragmentation of the femoral head, which contains areas of lucency and sclerosis.
Orthopedic treatment of Legg-Calvé-Perthes disease includes prolonged bed rest, mobile traction, slings, and abduction plaster casts and splints to contain the femoral head. Some experts advocate subtrochanteric osteotomy with internal fixation and early ambulation. Bisphosphonates have been effective in initial trials, but further studies are needed.
Without treatment, the course is usually prolonged but self-limited (usually 2 to 3 years). When the disease eventually becomes quiescent, residual distortion of the femoral head and acetabulum predisposes to secondary degenerative osteoarthritis. With treatment, sequelae are less severe. Young children and children with less femoral head destruction when diagnosed have the best outcome.