Legg-Calve-Perthes disease, often just called Perthes Disease, is a childhood condition where the blood supply to the hip joint is disrupted leading to degeneration of bone that makes up part of the joint (osteonecrosis). The part of the hip joint affected is the head of the femur. This is the ball part of the ball and socket hip joint.
Legg-Calve-Perthes occurs most commonly in children between the ages of 4 to 10 and is more common in boys than girls. The disease usually affects one hip but both hips can be affected. The first sign of Perthes is usually a painful limp that comes on for no apparent reason in a child.
Symptoms
Signs and symptoms of Legg-Calve-Perthes disease include:
- Limping
- Pain or stiffness in the hip, groin, thigh or knee
- Limited range of motion
- Shortened leg on the affected side (in some children)
In some cases, pain and stiffness get better when your child is resting, only to reappear once your child is active again.
Causes
The underlying cause of Legg-Calve-Perthes disease — also known as ischemic (avascular) necrosis of the hip — isn’t clear. But what happens is this: There’s a temporary loss of blood supply to the ball portion of the hip joint (femoral head). Without an adequate blood supply, the bone in the femoral head deteriorates. As dying bone cells are replaced with new cells, the bone becomes unstable, and may break easily and heal poorly.
Risk Factors
Legg-Calve-Perthes disease can affect children of nearly any age, but it’s most common among boys ages 4 to 8. In fact, it’s about five times more common in boys than in girls. However, when girls develop Legg-Calve-Perthes disease, it tends to be more severe.
In addition, Legg-Calve-Perthes disease is most common in white people. The disease may be more likely in physically active children who are small for their age or who have delayed skeletal maturity and in those who are exposed to secondhand smoke.
Investigations
Diagnosis of Legg-Calve-Perthes disease is often based on:
- Your child’s signs and symptoms: These usually include pain, a limp and stiffness of the hip.
- A physical exam: On examination, the hip will be assessed to see if there is tenderness around the hip. The hip will be moved to see if there is any restriction or pain on certain movements. Usually moving the leg to the side (abduction) and turning the hip in (internal rotation) are the movements that will be restricted. There may be weakness of the muscles on the side of the hip which may make it difficult to stand on one leg on the affected side. The affected hip may also appear shorter than the unaffected hip.
- Imaging studies: An X-ray of the hip is the most important first step in confirming the diagnosis of Perthes. Your child’s doctor may also recommend a magnetic resonance imaging (MRI) or bone scans to detect changes in the bones. Sometimes Legg-Calve-Perthes disease is detected incidentally during an X-ray done for other reasons.
Complications
Many people who suffer Legg-Calve-Perthes disease recover without any long term complications. The younger the person is when Perthes starts, the more chance there is that they will recover without complications. However if complications do occur, they may include the following:
- Permanent hip deformity: Legg-Calve-Perthes disease may cause a permanently deformed hip joint, especially if the condition develops after ages 6 to 8.
- Increased chance of osteoarthritis: Severe cases of Legg-Calve-Perthes disease may increase the risk of osteoarthritis as an adult.
Treatment
If your child is diagnosed with Legg-Calve-Perthes disease, he or she may be referred to a pediatric orthopaedic specialist for treatment.
Treatment is designed to protect the hip from further stress and injury and keep the ball of the thighbone in the hip socket. While resting the joint may help, prolonged bed rest isn’t recommended. Depending on the severity of the condition, treatment options may include:
- Anti-inflammatory medications. Over-the-counter medications, such as ibuprofen can help relieve pain. They can also reduce joint inflammation when used for months at a time. The dosage may be decreased as your child’s hip begins to heal. Although it is an anti-inflammatory medication, aspirin isn’t recommended for use in children.
- Physiotherapy. Range-of-motion exercises can help maintain joint mobility. These exercises can be done at home or with the help of a physiotherapist.
- Crutches. Crutches can ease pain by keeping your child’s weight off his or her hip.
- Casts, braces or traction. Temporarily immobilizing the bone can help promote healing. This may be done with leg or hip casts, leg braces or traction (applying a pulling force to the bone).
- Surgery. If a groin muscle has shortened due to excessive limping, it may be surgically released from the bone. After surgery, the affected leg is put in a cast for six to eight weeks to allow the muscle to grow to a more normal length. Sometimes the hip ball must be replaced within the socket. In other cases, the hip socket is repositioned.
Legg-Calve-Perthes disease can’t be prevented. But with appropriate treatment, most children can go back to normal activities within 18 months to two years.
Seeking Advice
Your Family Doctor (GP)
Your Family Doctor will be able to diagnose and help treat your problem. He or she will be able to
- tell you about your problem
- advise you of the best treatment methods
- prescribe you medications
- and if necessary, refer you to Specialists (Consultants) for further treatment
Talk to your child’s doctor if your child:
- Begins limping
- Complains of hip, groin or knee pain
Prevention
Unfortunately Legg-Calve-Perthes disease can’t be prevented. With appropriate treatment, however, most children can go back to normal activities within 18 months to two years. It is important to seek medical attention if your child:
- Begins limping
- Complains of hip, groin or knee pain