Legg-Calvé-Perthes disease

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at June 28, 2016
StartDiseasesLegg-Calvé-Perthes disease

Legg-Calvé-Perthes disease is a rare disease of the hip joint that afflicts children. Approximately 1 in 1,200 children have the disease, with over three-quarters of patients being boys. It is known to primarily affect boys between the ages of four and 12 and is most common between the ages of 5 and 7. Usually only one of the hip joints has the disease, though about five percent of the diagnosed develop the disease in both hips.


Definition & Facts

Legg–Calvé–Perthes (pronounced LEG-kahl-VAY-PER-theez) disease is a condition that affects children where the femur (the bone of the thigh) and pelvis meet in a ball and socket joint. In patients with this disease, the blood supply becomes temporarily disrupted, preventing blood flow to the femoral head (ball part) of the hip joint. With the disruption, the bone begins to deteriorate and die. The ball of the hip collapses. The child is left with a joint that can break easily and heal poorly.

There are four basic stages to Legg-Calvé-Perthes disease:

  • During the first stage, avascular necrosis takes place in which the bone tissue dies. This can take six months.
  • There is fragmentation and re-absorption in the bone. Osteoclasts remove dead bone and replace it with fibrous tissue which is still quite weak and unable to bear weight. This phase can last 12 months or more.
  • Reossification will occur where the new bone regrows. The osteoblasts work to create new bone tissue. This usually takes a little over five years.
  • The new bone has been grown and healing is complete.

While there have been extensive studies in the century that has passed since the disease was discovered, the medical community has made little progress in understanding Legg–Calvé–Perthes disease. Nevertheless, factors have been identified that affect prognosis: patient age, extent of compromise to the femoral epiphysis, and the potential for a premature closure of the epiphyseal growth plate.

Symptoms & Complaints

The most noticeable symptom of Legg–Calvé–Perthes is a sudden and unexplained limp. It can be an essentially painless limp, though there can be occasional mild pain that will come and go. It is important for parents and caretakers to pay attention to this as the child will likely ignore it.

Other symptoms can include: a stiffness that restrains hip movement, limited range of motion, pain in the knee, persistent pain in the groin or pain in the thigh, shortening of the leg, legs of unequal length, loss of muscle in the upper thigh, and inability to bear weight on the leg.

If a parent sees or the child complains about any of the above, it is important for him or her to make an appointment with the child's doctor immediately. Left unattended, the pain can increase and the child can become feverish. At this point, emergency medical treatment has to be sought out.


Legg-Calvé-Perthes disease is the result of too little blood reaching the ball portion of the femoral head (hip joint). The bone loses stability, leaving it weak, capable of breaking easily and healing poorly. Unfortunately, science has yet to determine what causes the reduction in blood flow. It has been noted the disease is more common among Caucasian, Eskimo and Asian children. There seems to be a lower occurrence among African-Americas, Australian aboriginals, Native Americas and Polynesians. One common trait seems to be patients are of shorter stature. There also may be a correlation between Legg-Calvé-Perthes and second hand smoke. In a small number of cases, the disease can be hereditary.

Diagnosis & Tests

Doctors will perform a physical examination of the child, and they will ask both caregiver and child about the patient's experiences with pain or discomfort. Practitioners will want to know when symptoms started, if they have gotten worse and if the child has suffered an injury. The child's legs will be gently moved, comparing movement on both sides and noting differences.

X-rays will likely be taken. If the X-rays do not indicate a problem, the doctor will ask for an MRI or bone scan. The diagnostic process can be involved and complex with this disorder.

Treatment & Therapy 

There is no cure for Legg-Calvé-Perthes disease. Treatment will center around keeping the femoral head's natural round shape as much as possible. There will be watchful waiting and close monitoring. The younger the child, the less likely surgery will be needed as, with the child's growth, the femoral head has time to repair itself sufficiently. A program may be designed that attempts to mitigate symptoms.

If the hip stiffens, physical therapy may be implemented to keep ligaments flexible and the hip in its socket. Physical therapy could encompass hip abductions and various other exercises that rotate the hip, isotonic exercises, stretching, and weight-bearing exercises depending on the condition of the patient. Crutches may be needed to limit weight on the hip. Severe pain may require bed rest.

An orthopedic cast may be set or a nightly brace may be administered. Surgery may be required to improve the hip joint's shape and prevent ailments like arthritis. (Many people with Legg-Calvé-Perthes develop arthritis as adults). Surgery can include joint replacement or removal of excess bone.

Prevention & Prophylaxis

There are no known measures for preventing Legg-Calvé-Perthes altogether. It has been suggested children spend no less than 15 minutes a day in the sun to ensure they absorb sufficient vitamin D, creating calcium which increases bone strength.

Smaller, underweight children need to consume a healthy diet. Foods should be high in protein and calcium. While it is near impossible, parents should be vigilant about minimizing the possibility of their child falling or hitting their knees. Wearing sturdy shoes during play can help avoid slips and falls.