Idiopathic chondrolysis of the hip

Idiopathic chondrolysis is a rare condition characterized by the ultimate loss of femoroacetabular articular cartilage seen in a child with no history of trauma, slipped capital femoral epiphysis, infection, prolonged immobilization, or any other previously described disorder. The diagnosis is often delayed secondary to the insidious onset of symptoms, progressive radiographic findings, and the absence of diagnostic laboratory test. Typical radiographic features include localized osteoporosis, subchondral erosions, femoral head changes, and reduction of the joint space. Later changes include complete loss of the joint space, subchondral cysts, trochanteric and epiphyseal physeal closure, osteophytes, and in severe cases, protrusio acetabuli, ankylosis, and osteoarthritis. Magnetic resonance imaging of the hip demonstrates cartilage loss, joint effusion, marrow edema, femoral and acetabular remodeling, significant regional muscle atrophy, and synovial enhancement. We report a case of Idiopathic chondrolysis of the hip in an 11-year-old Indian girl.