Bilaterally primary cementless total hip arthroplasty in patients with ankylosing spondylitis

Background: The purpose of this study was to document the clinical and radiographic results of a consecutive series of patients with ankylosing spondylitis (AS) who had undergone bilaterally primary THA using non-cemented components. Methods: Twenty-six hips of 13 patients with bilateral ankylosis of the hip caused by AS were converted to THA from January 2000 to January 2008. The mean age of the patients was 33.7 years (range, 22-57 years). There were 11 males and 2 females. All the patients had bilateral bony ankylosis with 0 degrees range of motion. The average Harris Hip Scores (HSS) was 22.1 (10-38). Results: At a mean follow-up of 128.4 months, the mean HSS at the latest follow-up examination was 91.7 points (range, 75-98 points). All the patients reported marked relief of painful symptoms. Three (11.5%) of the 26 hips were outside the Lewinnek acetabular cup inclination safe range, and 5 (19.2%) of the 26 hips were outside the Lewinnek acetabular cup anteversion safe range. The probability of survival of the prostheses was 100% at 5 years and 92.3% at 10 years, but it dropped sharply to 73.1% at 13 years. Conclusion: Cementless THA is a worthwhile treatment for the osseous ankylosed hip joint caused by AS. Newfound mobility, maneuverability, and improved ability to sit comfortably were the outcomes that alleviated the patients' daunted morale. However, the technically demanding nature of the procedure should not be underestimated.