Perthes Disease

Legg-Calve' Perthes disease, frequently referred to simply as Perthes, usually is seen in children 2-12 years of age and is five times more common in boys than girls. It originally was described as peculiar form of childhood arthritis of the hips. Research has shown, however, that Perthes is not a disease. Rather, it is a condition characterized by a temporary loss of blood supply to the hip. When the blood supply is diverted, the femoral head in the hip joint dies and intense inflammation and irritation develop.

The condition usually is diagnosed when the child is brought to the pediatrician and /or orthopaedic surgeon because of pain and /or limping. (An elevated temperature usually is not experienced with this condition.) The child may have had these symptoms intermittently over a period of weeks or even months. Pain sometimes is caused by pathologic fracture or by muscle spasms that accompany hip irritation. The pain may have spread to other parts of the leg such as the groin, thigh or knee. When the hip is moved, the pain worsens. Rest often relives the pain.

Evaluation by the orthopaedic surgeon may not be limited to the irritable hip. The physician may order x-rays of the spine and lower extremities as well. Laboratory (i.e., blood) studies may be necessary to evaluate for related skeletal abnormality or metabolic bone disease.

The child with Perthes can expect to have several x-rays made over the approximate two-year course of treatment. The x-rays usually will look worse and worse before gradual improvement is noted.

Once a diagnosis of Perthes is confirmed, the child will require careful orthopaedic treatment. Although Perthes is self-healing as well as self-limiting. Failure to properly treat this condition may lead to significant femoral head deformity.

Girls tend to have more extensive involvement and, therefore, have a generally poorer prognosis than boys. Usually, treatment for very young children (i.e., those 2-5 years of age) with minimal x-ray changes consists of observation. For the older child in whom the hip is completely involved, vigorous treatment is necessary to maintain the hip and minimize development deformities during the healing process. (Figure 1: Photo of X-Rays)

Treatment includes four stages:

  • Traction—The first step may be in-hospital traction. Traction is used to relieve spasms, stretch out the contractures and restore hip motion. One type of traction frequently used is a modified split Russell traction called "wide abduction traction." Your child may also be shown some simple exercises to do at home. Hip Abduction: The child will lie on his back, keeping knees bent and feet flat. Place your hands on the child's knees and resist as he pushed out, then resist as he squeezes knees together.
  • Hip Rotation—With the child on his back and legs out straight, roll the entire leg inward and outward.
  • Ambulation—Traction may be followed by a period of partial or protected weight bearing with the use of crutches or a cane. This also aids in resolution of the spasm.
  • Casting/Bracing—If the range of motion (ROM) cannot be maintained or if x-rays indicate a preventable deformity is developing, a brace or cast may be used to keep the femoral head (ball) contained within the acetabulum (socket). The application of the initial Petrie cast usually is performed in the operating room. During the procedure, the surgeon usually will place a small amount of dye into the hip joint (arthrogram) to aid in evaluating the degree of "flattening" or femoral head deformity. Occasionally, the adductor longus muscle in the groin must be lengthened through a small incision to permit placement of the hip in a more favorable position. Following removal of the cast (in approximately four to six weeks), the patient is reassessed for the appropriateness of continuing brace treatment with the cast or a removable orthosis such as the Scottish Rite brace. Protected weight bearing may be recommended.

Surgical treatment realigns the bony structures so that the head of the femur is placed deep within the acetabulum. Fixation is maintained within with screws and plates which will be removed at a later date. In some cases, the socket must also be deepened because the ball actually has enlarged during the healing process and no longer fits snugly within. After either procedure, the child is placed into a hip spica (body cast) for approximately six to eight weeks. A reclining wheelchair will provide mobility for the casted child. A rental hospital bed may be necessary for the casted child.

Following cast removal, the child will participate in physical therapy with protected weight bearing of the affected extremity until x-rays reveal the final stages of healing are under way.

Perthes is a complex process in children, and the stages and various forms of treatment may be confusing. Treatment of Perthes may require otherwise healthy children to submit to periods of immobilization or alterations in their usual activities.

Long-term prognosis is good in most cases. After 18 months to two years of treatment, the majority of children return to normal activities without major limitations.