Perthes' disease

Reviewed by Mr Daniel Reed, Specialist Paediatric Orthopaedic Surgeon

What is Perthes' disease?

Legg-Calve-Perthes’ disease, usually just referred to as Perthes’ disease, is a rare condition that can affect your child's hip joint. It starts by restricting blood supply to the top of their thigh bone, leading to inflammation, irritation and some difficulty with walking. 

With the right expert treatment, your child will form a newer, stronger bone and they are likely to regain normal movement with time.

What are the four stages of Perthes’ disease?

Onset stage

The blood supply to the top of your child’s thigh bone - called the femoral head - becomes restricted. This causes their bone cells to die, leading to intense inflammation and irritation, potentially affecting how your child walks. This stage may last a few months.

Fragmentation stage

During this period, your child’s body works to remove the dead part of the thigh bone and replaces it with a softer bone. However, the bone is in a weaker state during this time. This makes it prone to collapsing into a flatter position. On an X-ray, it might appear as though it’s in several pieces. This stage lasts one to two years. 

Reconstitution stage (reossification)

This phase is often the longest and can extend over several years. At this point, new, stronger bone tissue starts to form at the top of your child’s thigh bone. As the bone regains strength it will gradually take on a more normal, rounded shape.

Residual stage (healed)

At this point, the bone regrowth is complete, and the top of the thigh bone will have reached its final shape. It may not be fully round again, depending on your child’s age and how damaged their bone became.

Managing and treating Perthes’ disease 

There are a number of ways we can help your child to manage their condition:

• Physiotherapy sessions to help strengthen the hip joint and increase movement.
• Crutches to assist with walking.
• Providing a temporary plaster cast or special brace to reposition the femoral head into the hip socket. To achieve this, your child's consultant may perform an arthrogram. This involves inserting a small amount of dye into your child’s hip joint to view the injury more clearly.

Surgery for Perthes’ disease

Sometimes, depending on the severity of the condition, your child’s consultant may recommend an osteotomy. This is when an area of the bone is cut slightly, so it can be realigned with the hip socket. If your consultant thinks it is a good option for your child, they’ll discuss it with you and answer any questions you may have.