Surgical technique and outcome of uncemented THR using HA coated stems in fused and deformed hips due to ankylosing spondylitis.

Background: Uncemented Total Hip Replacement (THR) is at present an accepted treatment in patients with severe deformity of the hip caused by advanced ankylosing spondylitis.

Materials And Methods: We studied 20 patients, 2 female and 18 male, who had 29 THRs, all through a posterior approach. The patient's age at index surgery ranged from 20 to 47 years (mean 35.1). No trochanteric osteotomy was performed in any patient. A double cut of the femoral neck was performed for hips which were ankylosed in external rotation and flexion. Follow-up ranged from 18 to 46 months (mean 22.2 months).

Results: The mean preoperative Harris Hip Score (HHS) was 34.6. At last follow-up all hips were considered excellent, with a mean HHS of 90. Radiographs revealed that the acetabular and femoral components were satisfactorily positioned with no radiographic evidence of loosening. No heterotrophic ossification was found.

Conclusions: 1) Trochanteric Osteotomy was not found necessary to expose the hip through the posterior approach. 2) Uncemented THR using HA coated stem in the treatment of severe deformity of the hip caused by advanced ankylosing spondylitis allowed good lower limb function.