Perthe’s Disease

What is Perthe’s Disease? 

Perthe’s Disease or Legg-Calve Perthe’s disease is a hip condition which causes pain and dysfunction around the hip, groin and pelvis of children. It most commonly affects boys, but can affect girls as well usually between the age of 4 and 10. 

How does Perthe’s Disease occur?

Perthe’s disease occurs when the blood supply to the head of the femur (the top of the thigh bone) is disrupted. The head of the femur is a ball shape which sits within the socket of the hip joint, creating a ‘ball and socket’ joint. This type of joint allows for a large range of motion at the hip. 

If there is restricted blood flow to the bone it prevents important nutrients and oxygen from reaching the bone. This causes the bone to weaken and to break down, a term known as avascular necrosis. This process flattens the head of the femur. This flattened shape prevents the femur from being able to sit properly inside the hip joint. Over time the bone will re-grow and reform but this can take some time. 

What does Perthe’s Disease feel like?

Pain is usually felt in the hip and groin area, but can extend down to the knee.

The hip joint may also feel stiff and harder to move compared to the non-affected side. 

Perthe’s disease often causes the child to limp and this limp can put stress and strain on other areas of the leg and foot. The affected side may seem shorter than the other side. 

How is Perthe’s Disease treated?

It is important that this condition is diagnosed as early as possible. Your medical expert will likely begin by referring for an x-ray to examine the condition of the hip joint. 

Treatment usually involves rest and regular rehabilitation by a qualified professional, such as a physiotherapist. The goal of this therapy will be to maintain good motion at the joint and to improve the alignment. They will provide exercises to strengthen the muscles around the hip to stabilise the joint.

In more severe cases the child may require a cast to immobilise the hip and leg and in rare cases surgery may be required to help reshape the hip joint.

Can a podiatrist help?

Perthe’s disease is a condition that develops in childhood, however the lasting effects of Perthe’s disease can be life-long. This condition can result in a leg length difference where the affected leg is shorter than the non-affected side. It can also lead to poor alignment of the hip and the lower limbs. There is also an greater risk of earlier onset hip arthritis on the affected side.

The body tends to find ways to ‘compensate’ for this alignment change or imbalance. These compensatory changes often include walking on the ball of the foot or tiptoes, walking with the knee fixed in a flexed position, or walking with a curvature in the spine. When the body tries to compensate it can cause secondary problems such as issues with the Achilles tendon, the knee or back.   

Orthotics may be useful in the treatment of biomechanical changes caused by Perthe’s disease. A pair of custom foot orthosis can help to balance a leg length difference by providing a ‘lift’ to the shorter leg to restore a preferred alignment. This can reduce these problematic compensatory changes. 

Perth’s disease may also affect the alignment of the hip in adulthood. This altered hip position can also affect the joints around it and can also affect the way that the leg, knee and foot function. A pair of custom foot orthotics can support and stabilise the position of the hip by correcting improving the alignment of the foot.