Total hip arthroplasty in patients with ankylosing spondylitis: challenges and midterm results

Purpose
To assess the effectiveness of total hip arthroplasty (THA) in patients with ankylosing spondylitis (AS).


Introduction
The prevalence of hip disease in AS ranges from 19 to 36%, with 90% of patients affected bilaterally. Hip involvement in AS patients represents a substantial clinical challenge. While THA using cemented and cementless implants offers a valid treatment option, the complexities of AS-related osteoporosis, diminished spinopelvic mobility, reduced bone union, and femoral deformities necessitate tailored surgical strategies.


Patients and methods
This retrospective case series study involved 11 patients (equating to 20 hip joints). These patients were diagnosed with AS that affected their hips and underwent THA. The study spans from 2012 to 2018, with a minimum follow-up 5 years. The mean age at the time of operation was 25.2 ± 4.6 years and the mean duration of follow-up was 5.6 ± 0.6 yrs. Follow-up was assessed using Harris Hip Score (HHS) preoperatively, 6 months, 1 year, and at last follow-up postoperatively with a mean period of 6.4 (5–8) years.


Results
The mean preoperative HHS was 15.3 ± 6.6, while in the last follow-up, the mean HHS was 76.3 ± 4.2. The comparison between preoperative mean HHS and the last follow-up was highly significant. There were no postoperative complications except an iatrogenic fracture of the acetabulum.


Conclusion
AS is a painful and debilitating disease. THA in patients with AS causes a significant improvement in patient’s pain and function. THA is a definitive solution for the crippling fate of these patients with advanced hip OA.