Hesperian Health Guides

Hip Problems Due to Destruction or Slipping of the Cap of the Thigh Bone

There are 2 different hip problems that occur most often in active children, usually boys.

  1. Destruction of the cap or ‘growth center’ on the ‘head’ of the thigh bone is called Legg-Perthes disease. It usually begins between 2 and 12 years of age. It occurs in less than 1 of every 1,000 boys.
  2. Slipping of the cap on the head of the thigh bone is less common. It happens, suddenly or little by little, usually between 11 and 16 years of age (when the child is growing fast).

The cause in both cases is unknown.

Destruction of the growth center results from a temporary loss of blood supply. This causes death of the bone.

Destruction of the growth center is usually not related to other diseases. A similar kind of destruction of the growth center from loss of blood supply may be caused by tuberculosis of the hip, sickle cell anemia, HIV, hypothyroidism, or use of corticosteroid medicines. A careful medical study is advisable.

normal ‘growth center’ (cap on head of thigh bone)
a normal hip bone and a damaged hip bone
pieces of damaged growth center in Legg-Perthes disease
sockets of hip bone

DIAGNOSIS: If a child has signs of one of these hip problems, try to get an X-ray to find out the cause.

Treatment and progress of slipped growth center
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slipped growth center

When the growth center slips, if possible it should be put back into place surgically, and pinned. When surgery is impossible, the child should avoid all strenuous exercise, running, and jumping in the hope that the growth center will not slip farther until it becomes fused to the thigh bone (normally when the child is 16 to 18 years old). Without surgery, and especially if the slippage is severe, a progressive, destructive arthritis is likely to result.

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flattened, deformed growth center
Treatment and progress of Legg-Perthes disease

Many ways to treat Legg-Perthes have been tried. Most methods try to restrict movement and to keep the legs wide apart, a position that makes the growth center form a round and normal shape again.

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full-leg braces upper-leg braces only

Any of 3 different hip surgeries can make the head of the thigh bone fit more completely into the socket so the new growth center forms a rounder, normal shape.

Surgery is expensive and has more risks than braces. But it is much quicker: only 6 weeks in bed with a cast. Then the child can lead a more or less normal life. But it still takes 2 years for the new growth center to form, and during this time the pain and/or limp may continue.

Canes or crutches may be used to keep pressure off the hip joint and reduce pain. Moderate exercise, like swimming, can help to maintain and increase range of movement.

There is a lot of debate about whether any of these methods—casts, braces, or surgery—are worth it. Especially for children under 6 years old, their pain and limp gradually go away with or without treatment. The best advice in these cases may be to do nothing. (This is a hard decision for parents to accept, but will make life happier for both the child and family.) Let the child remain active, but do not make him run, jump, or walk far if it bothers him. For older children, surgery may be the best option.

If the growth center heals to be rounded and fits well in the hip socket, the child will probably not have problems with arthritis later in life. But if the growth center does not reshape itself well, and especially if it doesn’t fit well into the socket, he might develop arthritis earlier and more severely.

X-rays can help you decide what to do and what to expect when a child has Legg-Perthes.

This page was updated:21 Nov 2019