Perthes' disease affects children, most commonly aged between four and eight, but can also occasionally occur in younger children and teenagers.
Symptoms of Perthes' disease include tiredness and pain in the groin and sometimes in the knee. Pain can be felt in the knee only even though the disease only affects the hip. The child may have stiffness and reduced range of motion at the hip joint and may walk with a limp. The affected leg may appear shorter than the other leg.
Perthes' disease affects children between the age of 4 and either although it can also occasionally occur in older children and teenagers. The condition is sometimes also called Legg Calve Perthes' Disease. The cause of the disease is not known.
It affects the hip joint, where the top of the femur or thigh bone meets the socket of the pelvis or acetabulum. The blood supply to the head of the femur is disrupted, resulting in necrosis where the bone softens and begins to break down. Once the blood supply returns to normal, the bone tissue is laid down and the femoral head reforms and hardens.This will occur over a period of 1 to 3 years.
Due to the joint being a ball and socket, one of the main problems is that the re-growth may not form in a spherical shape as before. The severity of deformity of the head of the femur determines the degree of symptoms and if there are likely to be any future problems such as a permanently decreased range of motion at the joint and arthritis.
Boys are far more likely to develop this condition than girls, although girls tend to suffer with more severe symptoms and future problems. Symptoms are usually only in one hip, although occasionally can affect both sides.
Seek medical advice if you suspect this disease. A correct and early diagnosis is important. Pain in the knee or hip joints in children should always be looked at by a medical professional who will X-ray the hip. In the early stages an x-ray may appear normal and so other investigations such as MRI or bone scans may be performed.
Depending on how bad the injury is will determine whether it requires conservative treatment or surgery. Treatment is aimed at maintaining hip mobility and promoting healing in the correct position. Treatment will depend on the age of the child and the severity of the condition, but may include bed rest, crutches, traction, a plaster cast, leg brace or surgery in extremely severe cases.