TOTAL HIP ARTHROPLASTY WITH CEMENT IN PATIENTS LESS THAN TWENTY YEARS OLD. LONG-TERM RESULTS

Abstract

Sixty-three consecutive total hip arthroplasties were performed with cement in fifty adolescent patients from 1972 through 1980, and the results were determined after a minimum of ten years. A polyethylene cup without a metal backing and a non-modular femoral component with a collar and a fixed neck length were inserted, with use of so-called first-generation cementing techniques, in each hip. Kaplan-Meier survival analysis of all sixty-three hips demonstrated that the probability of failure (defined as revision or symptomatic loosening) increased steadily over time and reached 45 per cent after fifteen years. A number of specific variables were associated with a significantly higher probability of failure: a history of more than one previous procedure involving the hip (p = 0.0002), unilateral arthroplasty (p = 0.006), previous trauma involving the hip (p = 0.01), the absence of other disease that limited function of the ipsilateral lower extremity (p = 0.03), a high postoperative level of activity (involving moderate or strenuous manual labor) (p = 0.03), and a preoperative weight of more than sixty kilograms (p = 0.03). The probability of failure in the patients who had inflammatory arthritis (11 per cent) was significantly lower than that in those who had previous trauma involving the hip (47 per cent) (p = 0.0006). Fifty-two hips (forty patients) were followed for a minimum of ten years or until revision. The mean duration of follow-up for these fifty-two hips was 12.6 years (range, 1.6 to 18.6 years). The result was evaluated clinically and radiographically with use of the Mayo hip-scoring system and was graded as excellent in ten hips (19 per cent), good in sixteen (31 per cent), fair in one (2 per cent), and poor in twenty-five (48 per cent). Most of the poor results were due to symptomatic loosening of the acetabular component. The probability of radiographic loosening after fifteen years was 60 per cent for the acetabular component and 20 per cent for the femoral component. Radiographic evidence of polyethylene wear was associated with probable loosening of the acetabular component (p = 0.03). The findings of the present study suggest that total hip arthroplasty in adolescents should be reserved for carefully selected patients for whom alternative procedures are contraindicated or unacceptable. Fixation of the acetabular component with cement is not recommended in this setting.