The importance of stair climbing for recovery after total hip arthroplasty in patients with hip ankylosis secondary to ankylosing spondylitis

Abstract Stair climbing is effective in improving hip function; We examined the importance of stair climbing for ankylosing spondylitis (AS) patients receiving Total hip arthroplasty (THA). Methods Retrospective analysis of 33 AS patients undergoing unilateral THA, Harris hip scores (HHS), hip range of motion (ROM), flexion, International Physical Activity Questionnaire-Short Form (IPAQ-SF), time to start and duration of stair climbing, were compared at 6 months, one year, and final follow-up. Multivariable regressions were utilized to adjust for differences in clinical outcomes and stair climbing time among patients. Results There was a significant correlation between stair climbing start time and HHS (r = -0.399, P = 0.011) at 6 months postoperatively. At one year postoperatively and at the final follow-up, stair climbing time was positively correlated with HHS (r = 0.456, P= 0.004) (r = 0.416, P = 0.008). The stepwise multiple linear regression analysis showed that HHS was independently associated with stair climbing start time (P = 0.003) at 6 months postoperatively. At one year postoperatively (P = 0.008) and the final follow-up (P = 0.016), HHS was associated with stair climbing time. The area under the receiver operating characteristic curve (AUROC) of stair climbing start time and one year stair climbing time was 0.795 (95 % CI: 0.644–0.947, P = 0.006) and 0.793 (95 % CI: 0.598–0.989, P = 0.027), respectively. Conclusion THA can improve hip function in AS patients undergoing THA. Sensible stair climbing exercise in the postoperative period can achieve better clinical outcomes.