Perthes disease factsheet

Introduction

Perthes disease is a childhood condition where the top of the thigh bone temporarily loses blood supply, causing hip pain and stiffness.

The hip joint is made up of the:

femoral head - round top of the thigh bone
acetabulum - socket in the pelvis.

In Perthes disease, the femoral head collapses and slowly regrows. This happens in stages over 18 months to 2 years. The new bone is soft while it heals and can become misshapen, causing pain and stiffness.

The cause is unknown, and it mostly affects children between 3 and 11 years old. In most cases, only one hip is affected.

Signs and symptoms

Symptoms can be hard to spot early and are sometimes mistaken for growing pains.

General symptoms may include:

an occasional limp in early stages
pain in the knee, thigh, or groin
pain with movement or putting weight on the leg
muscle thinning in the thigh
shorter leg on the affected side
decreased movement.

Perthes disease develops in three stages.

Stage 1 - first few months to 1 year

blood supply to the femoral head is interrupted
the joint becomes inflamed, stiff and painful.
parts of the femoral head start to die and may collapse, looking misshapen on x-rays.

Stage 2 - 1 to 3 years

the body absorbs the damaged bone tissue, and the femoral head starts to regrow
the new bone tissue is soft and can become misshapen as it grows
the joint can be painful, and limping is common.

Stage 3 - 1 to 3 years

the bone slowly hardens and returns to a round shape.

Diagnosis

Your child’s doctor will refer you to a bone and muscle specialist, called an orthopaedic specialist.

Diagnosis involves:

taking a medical history
a physical check
scans of the hip joint, like an X-ray or MRI.

Treatment

Treatment depends on your child’s age and how severe the disease is.

Perthes disease heals on its own over time, so the aim of treatment is to:

reduce pain
increase movement
help the bone heal in the right shape.

Most children recover fully, but it can take 2 - 5 years for the bone to heal. If the femoral head heals in the wrong shape, your child may have long-term stiffness or early arthritis in the hip.

For younger children (3 to 7 years)

mild cases often need no treatment
pain and stiffness can be managed with rest and reducing the amount of weight on the hip joint during movement
limit high-impact activities like running and jumping
replace with gentle, low-impact activities like swimming and bike riding
regular check-ups are needed to check growth of the hip joint.

For older children (7 to 11 years)

bones have started to set in place, so more detailed medical checks are needed
crutches or a wheelchair may be used for up to a year to help rest the joint and keep the femoral head snug inside the hip socket
children with pain or limited movement may need a brace or plaster cast to keep the joint in place.

Surgical treatment

surgery may be needed in severe cases where the bone has become misshapen or cannot be supported with a cast or brace
surgery helps hold the femoral head in the socket to heal properly and develop good hip movement.

Management

Physical activity

Recovery can be slow, and your child may feel frustrated and anxious about not being able to play and exercise as much as children. Support them to stay active with gentle, low-impact exercises.

Talk to your child’s doctor about safe activities and ways to adapt sports during recovery. You can also speak to your doctor about ways to support your child’s social development and mental health during recovery.

Long term outlook

Most children recover well. It may take up to five years for the bone to return to normal.

Recovery depends on:

your child’s age at diagnosis
how much of the bone was affected
how early treatment began.

Early diagnosis and treatment mean there is a higher chance of full recovery.

Even after recovery, some children may have hip issues as they grow. Your child will have regular appointments with their orthopaedic specialist to check their progress as they grow.