Bipolar versus Total Hip Arthroplasty in the Treatment of Avascular Necrosis of the Femoral Head in Young Patients

Abstract

The authors evaluate medium-term results of bipolar and total hip arthroplasty as a treatment for avascular necrosis of the femoral head. Between 1990 and 2000, 57 hips (45 patients) were treated with a bipolar (BHA: 37 hips) or total hip arthroplasty (THA: 20 hips) depending on the radiographic and macroscopic aspect of the acetabulum. At surgery, all patients were under 65 years of age (average: 45.09 years). All had the same cementless hydroxylapatite coated femoral stem inserted through an anterolateral approach. The BHA were followed during a mean of 4.49 years. One BHA was lost to follow-up. Seven out of 36 hips (19.44%) were considered failures: three due to a poor functional result (Harris Hip Score (HHS) <70) and four which needed conversion to THA for groin pain. Two hips were revised for periprosthetic fracture. Twenty BHA (55.56%) had a good or excellent result (HHS 80).

The THA were followed for a mean of 4.32 years. One THA was lost to follow-up. Four out of 19 hips (21.05%) were considered as failures. Three due to a poor functional result (HHS<70) and one which needed cup revision for recurrent dislocation. Fifteen THA (78.95%) had a good or excellent functional result (HHS80).

BHA as a treatment of avascular necrosis of the femoral head in young patients preserves bone stock for later revisions and can lead to excellent results. But the outcome seems less predictable than after THA. Groin pain associated to BHA can be treated successfully with conversion to THA if necessary.