Abstract：Objective To discuss the methods and clinical effects of phased treatment of ankylosing spondylitis (AS) combined with severe hip flexion contracture.Methods The study enrolled 8 cases (12 hips) of AS combined with severe hip flexion contracture hospitalized from September 2011 to November 2012.Phased treatments included lateral hip arthrolysis,articular capsulectomy,stripping of the reflected head of rectus femoris,femoral neck osteotomy,traction and stage Ⅱ biotype total hip arthroplasty (THA).Preoperative and postoperative Harris score,hip range of motion,and complication of femoral nerve injury were detected.Results Period of follow-up was 6-12 months (mean 10 months).One case developed heterotopic ossification,which affected postoperative hip activity and received resection one year later.One case sustained fissure fracture of calcar femorale during implantation of the prosthetic femoral stem,but no special handling was provided.Of all cases,active flexion and extension of the hip were both 0° before operation,but increased to (96.25 ± 4.33) ° and (24.17 ± 4.69)° respectively after operation ; mean Harris score was improved from (26.67 ± 2.39) points preoperatively to (90.92 ± 5.66) points postoperatively (P ＜0.01).Besides,no femoral nerve injury was observed.Conclusion Phased treatment of AS combined with severe hip flexion contracture restores hip function and minimizes femoral nerve injury following THA.
