Perthes is a disease of the hip joint. We do not know why Perthes disease occurs.
Key points to remember
- Perthes is a disease of the hip joint
- it is not known why Perthes disease occurs
What is it?
Perthes disease is also known as Calve-Perthes disease or Legg-Calve-Perthes disease. This is a disease of the hip joint.
What causes it?
We do not know why Perthes disease occurs.
We do know that the blood supply to the growing end of the head of the femur breaks down and this causes the bone of the head of the femur to become soft and break up. This is a process doctors call avascular necrosis.
How long could it last?
Over a period of 2-3 years, your child’s hip starts to repair the blood supply and new bone starts to form in the hip joint. This process is called “remodelling”.
The repair is not always perfect and the smooth round head of the ball of the hip joint may become slightly flattened.
How infectious is it?
It is not infectious and your other children can not catch it.
What puts my child at risk of getting Perthes disease?
Perthes disease is more common in boys than girls (4:1) and in children aged from 4 to 11 years old. Perthes disease usually occurs in children who are fit and well with no other illnesses.
What are the signs and symptoms?
- pain in the hip or knee
- stiffness in the hip joint
- after some time there may be muscle wasting in the leg
It can occur in both hips but this is less common.
How is it diagnosed?
Perthes is diagnosed by the doctor listening to the symptoms your child describes and examining them.
An x-ray of the hips will be ordered first and this usually confirms the diagnosis. If there is any doubt, an MRI scan may be ordered.
Further x-rays and scans may be ordered to monitor the progress of the disease in the affected hip.
When should I seek help?
If your child has been limping for more than 48 hours, you should see your family doctor.
What are the complications?
As your child gets older and becomes an adult, they may develop arthritis in their hip.
What treatment is available / required?
There is no cure for Perthes disease and the treatment aims to contain the ball of the hip joint in the socket until your child has stopped growing.
Treatment depends on the age your child develops Perthes and how bad the disease is.
Can I care for my child at home?
Yes, it is unusual for children with Perthes disease to stay in hospital.
How can this be prevented?
We do not know what causes Perthes disease, so there is nothing that should be avoided in a normal child.