OBJECTIVETo evaluate the clinical results of the total hip replacement in the treatment of severe deformity of the hip joint caused by advanced ankylosing spondylitis.

METHODSForty-five hips with severely deformities in 33 patients suffered from advanced ankylosing spondylitis treated by total hip replacement were followed-up from 1992 to 2005 in our department. The pain index, deformity angle, range of motion of the joint, changes of weight baring capacity of a single leg, and the postoperative complications were compared and analysed in this study.

RESULTSThe pain was complete released in 27 hips after surgery; the average pain index decreased 1 grade. The angle of flexion deformity of hip decreased by 44.17 degrees averagely. The average range of motion of the hip improved 58.4 degrees. Thirty-one operated hips could bare weight itself. Twenty-two hips occurred prosthesis Sinking of the femur head prosthesis occurred in 22 hips. The sciatic nerve was contused in one case because of violent reduction after the installation of prosthesis, and recovered in 8 months.

CONCLUSIONThe midterm clinical results of total hip replacement in the treatment of severe deformity of hip caused by advanced ankylosing spondylitis is satisfactory.