Legg-Calvé-Perthes disease is a temporary condition in children in which the ball-shaped head of the thigh bone loses its blood supply. This causes the head of the bone to collapse. The body will absorb the dead bone cells and replace them with new bone cells, eventually reshaping the femoral head. Legg-Calvé-Perthes disease causes the hip joint to become painful and stiff for a short period of time.
Approximately one in 1,200 children younger than 15 years is affected, usually at age two to 12 years. Legg-Calvé-Perthes disease typically affects one hip, but sometimes it develops in both hips. The disease affects both joints in 10-20 percent of children. When both hips are involved, they are usually affected one after the other and not at the same time.
How long does it take for the femoral bone to heal?
In the first phase of the disease, blood supply to the femoral head is lost and the hip joint becomes inflamed, stiff and painful. Parts of the bone turn into dead tissue. This phase can last from several months up to a year. The child will still be able to walk at this stage.
The body will then begin to clean up the dead bone cells and replace them with new, healthier cells. The femoral head will begin to remodel into a round shape again. The joint will still be irritated and painful. This phase can last from one to three years.
After the femoral head reshapes, it can take up to a few years to fully complete the healing process.
What are the causes and risk factors of Legg-Calvé-Perthes disease?
The underlying cause of Legg-Calvé-Perthes disease is not clear. In some cases, it may be due to injury or abnormal blood clotting, which can lead to a lack of blood flow to the bone.
Boys are affected three to five times more often than girls. The disease may be more likely in physically active children who are small for their age and those who are exposed to secondhand smoke.
Other risk factors include the presence of an inguinal hernia and genitourinary tract complications. An inguinal hernia is an intestinal bulge through a weak spot in the inguinal canal, which is a triangle-shaped opening between layers of abdominal muscle near the groin.
How is Legg-Calvé Perthes disease diagnosed?
The diagnosis of Legg-Calvé-Perthes disease should be made as early as possible.
Symptoms can include a child’s decreased mobility, pain or other complaints in the hip area. The child typically complains of pain in the hip that is made worse by activity. Sometimes, they will also experience pain in their thigh or knee area. Limping is often the earliest sign of Legg-Calvé-Perthes disease. Pain or stiffness in the hip, groin or knee is possible as well. For some children, the affected leg becomes shorter due to bone collapse.
Diagnosis of Legg-Calvé-Perthes disease is often based on a child’s signs and symptoms, a physical exam and imaging studies. The tests that a doctor may recommend include X-rays, magnetic resonance imaging (MRI) or bone scans to detect changes in the child’s bones. Sometimes Legg-Calvé-Perthes disease is detected by accident during an X-ray done for other reasons.
How is Legg-Calvé-Perthes disease treated?
Our pediatric orthopaedic specialists may recommend the following treatments:
- Anti-inflammatory medicines. Over-the-counter medicines such as ibuprofen can help relieve pain and reduce joint inflammation. These medications are often recommended for months at a time. The dosage may be decreased as the hip begins to heal. Side effects may include mild gastrointestinal upset. These medications should be taken with food.
- Physical therapy. Range of motion exercises can help maintain joint mobility by pivoting a joint in its full range. These exercises can be done at home or with the help of a physical therapist. Learn more about physical therapy at CHOC.
- Crutches. Crutches can ease pain by keeping the child’s weight off his or her hip.
- Casts and braces. Temporarily immobilizing the bone can help promote healing. This may be done with leg or hip casts or leg braces.
- 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.
With appropriate treatment, most children can return to their normal activities within 18 months to two years.