Transposition of the apophysis of the greater trochanter for reconstruction of the femoral head after septic hip arthritis in children.

BACKGROUND AND PURPOSE

Total necrosis of the femoral head after infection in children during their first months of life gives a dislocated hip with severe leg shortening. A new femoral head can be achieved with subtrochanteric osteotomy and transposition of the apophysis of the greater trochanter into the acetabulum. Previous reports have dealt with short-term results (up to 12 years). Here I present some results of this procedure 15-24 years after operation.

PATIENTS AND METHODS

4 children aged 1-6 years with complete necrosis of the femoral head were operated on with transposition of the greater trochanter. Secondary shelf plasty was performed later in 1 child, distal femoral epiphysiodesis in another, and femoral bone lengthening in 1 child. The mean follow-up period was 19 (15-24) years.

RESULTS

A new femoral head developed in all hips. 2 of them had a spherical head with a good acetabular cover, and without any osteoarthritis except for slight reduction of cartilage height. These hips were painless, with a mobility that allowed good walking function after 16 and 24 years, respectively. In the other 2 patients, in which there was a severe acetabular dysplasia at the primary operation, the new femoral head was somewhat flattened; painful osteoarthritis led to hip replacement 15 and 21 years after trochanter arthroplasty. Even these patients had a relatively good walking function until the last couple of years before hip replacement. Maximum leg length discrepancy was 7 cm.

INTERPRETATION

Trochanter arthroplasty with subtrochanteric osteotomy in total femoral head necrosis after septic arthritis in children may give satisfactory long-term results provided adequate acetabular cover is obtained. Although the method cannot provide a normal hip, it can contribute to less length discrepancy, less pain, improved gait, and more favorable conditions for later hip replacement.