Inflamation of an epiphysis (growing area) of the head of the femur (thigh bone). The disease is a form of osteochondritis juvenilis, believed to be caused by disrupted blood supply to the bone.
The condition is most commonly seen in boys aged between 5 and 10 years old, and generally affects only one hip. Symptoms include pain in the groin and thigh area, and a limp on the affected side. Movement of the hip is painful and restricted.
Diagnosis is made with X-rays, which can show flattening, fragmentation and (in later stages) shrinking of the head of the femur. Treatment of the disease can be rest for a few weeks, followed by splinting of the hip, or surgery to fit the head of the femur more securely into the pelvis. The disease often clears up by itself within a few years, but the hip can be permanently deformed.