ABSTRACT
PURPOSE: Long-term follow-up results of concurrent bilateral or unilateral cementless hip arthroplasty were compared. MATERIALS AND METHODS: Forty eight and 49 patients with concurrent bilateral and unilateral hip artrhoplasties who had more than a 17-year follow-up time were selected. At final follow-up, mean ages were 69.1 and 66.7 years old in the bilateral and unilateral groups, respectively. Mean follow-up times were 21.5 and 22.4 years in the bilateral and unilateral groups, respectively. Clinical results were attained using Harris hip score and standardized anteroposterior and lateral view X-rays. RESULTS: The bilateral group had mean Harris scores of 44.3(standard deviation 3.78) preoperatively, and 81.2 (10.75) at final follow-up. For the unilateral group, the mean scores were 46.5(3.27) preoperatively, and 80.1 (12.05) at final follow-up. At final follow-up, an acetabular cup was securely located in 78.9% and 82.8% of the bilateral and unilateral groups, respectively, and all cases showed firm fixation of the femoral stem in both groups. Osteolysis around the cup and stem were found in 26.3% and 31.4% of the bilateral group and 16.6% and 17.1% of the unilateral group, respectively. Polyethylene wear rate was 0.17 mm/yr and 0.16 mm/yr in the unilateral and bilateral groups, respectively. Using the Kaplan-Meier method, 17-year survival rates for cup and stem were 78% and 89% in the bilateral group, respectively, and 78% and 86% in the unilateral group, respectively. CONCLUSION: In 17-year long-term follow-up, concurrent bilateral hip arthroplasty was insignificantly different clinically and radiologically from the result of unilateral hip arthroplasty.