Mid-term results of bilateral synchronous total hip arthroplasty for bony ankylosis in patients with ankylosing spondylitis

Abstract

Abstract Background Total hip arthroplasty (THA) for bony ankylosis is technically challenging in patients with ankylosing spondylitis (AS). This study aimed to determine the mid-term results of bilateral synchronous THA for bony ankylosis in patients with AS. Methods Nineteen cases of bony ankylosis in patients with AS who received bilateral synchronous THA were included in this study (17 males and 2 females, mean age 49.2 years). Disease duration was 5–38 years (mean 18 years and 6 months). All patients received cementless THA. Intraoperative blood loss, visual analog scale (VAS) score, and complications were assessed. Harris hip scores evaluated the clinical effect. Results Patients were followed up for 62–98 months (mean 82.5 months). VAS score decreased from 7.42 ± 0.92 to 2.42 ± 0.83, Harris hip score improved from 21.8 ± 7.2 to 80.3 ± 6.5, and the flexion-extension range of the hip improved from 0 to 142.3 ± 6.2°. One patient with septum bronchiale had a fracture intraoperatively and was treated with wire strapping. One patient had a traction injury of the femoral nerve postoperatively and recovered 1 year after the operation. Loosening and subsidence were not observed in all patients. Heterotopic bone formation was noted in 3 patients. No complications such as joint dislocation, acute infection, and deep vein thrombosis were found. Conclusion Bilateral synchronous THA was effective for bony ankylosis of the hip in patients with AS because it improved patients’ quality of life and had satisfactory mid-term outcomes.