What is Legg-Calve'-Perthes Disease?

Legg-Calve'-Perthes Disease is a rare disease of the hip that effects approximately 1 in 1200 children. Of those children, only about one in four are girls. About 5% of all diagnosed develop the disease in both hips (bilaterally). Legg-Calve'-Perthes children tend to be of shorter stature due to delayed bone age. Legg-Calve'-Perthes Disease (LCPD) is a form of osteonecrosis of the hip that is found only in children. LCPD is of unknown origin. It is known that bone death occurs in the ball of the hip due to an interruption of blood flow. As bone death occurs, the ball develops a fracture of the supporting bone. This fracture signals the beginning of bone reabsorption by the body. As bone is slowly absorbed, it is replaced by new tissue and bone.

Four Stages of LCPD
1. Femoral head becomes more dense with possible fracture of supporting bone;
2. Fragmentation and reabsorption  of bone;
3. Reossification when new bone has regrown; and
4. Healing, when new bone reshapes.
Phase 1 takes about 6 months- 2 years, Phase 2 takes one year or more, and Phase 3 and 4 may go on for many years.

First Symptoms
The first symptoms characterized in LCPD are usually a limp and pain in the hip, groin, or knee. They usually cannot tell you an instance when they hurt themselves.

Extent of Disease
New bone growth typically reshapes better in younger children and it may improve with growth.

Types of Treatment
The physician may take a wait and see approach. As long as the patients symptoms are mild, the physician may only prescribe physical therapy exercises to help maintain good range of motion.

Non-Surgical Treatment:
Crutches, casts, traction, and braces help return range of motion and mobility. Range of motion exercises may be given to you by your physical therapist to do with your child in the home.

Surgical Treatment:
Tenotomy
A "tenotomy" is a surgery that is performed to release an atrophied muscle that has shortened due to limping. Once released, a cast is applied allowing the muscle to regrow to a more natural length.
Osteotomy
There are different types of "osteotomies" (cutting the bone to reposition it) and, depending on the need they are performed at different stages of the disease.
Looking to the Future
Studies on long-term results of LCPD indicate that the incidence of late degenerative osteoarthritis is dependent on two factors. If the ball reshapes well and fits well in the socket, arthritis is usually not a concern. If the ball does not reshape well, but the socket's shape still conforms to the ball, the patient will tend to develop mild arthritis in later adulthood. Patients who's femoral head does not shape well and does not fit well in the socket usually develop degenerative arthritis before the age of 50.

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