RESULTS OF CEMENTLESS TOTAL HIP REPLACEMENT FOR BONY ANKYLOSIS IN PATIENTS WITH ANKYLOSING SPONDYLITIS

Abstract

Introduction: The occurrence of bony ankylosis in ankylosing spondylitis (AS) is not precisely known. Bony ankylosis, especially in stiff spine may present several exclusive challenges in its management. The current study is an endeavor to evaluate the clinical and the radiological results of cementless THA in patients with bony ankylosis of hip due to ankylosing spondylitis.

Materials and Methods: We retrospectively reviewed 54 patients (92 hips) who underwent cementless total hip arthroplasty for bony ankylosis in ankylosing spondylitis between September 1988 and 2002. Clinical assessment was done at follow-up, which envisages assessment of the pain, function, deformities and range of motion using the Harris Hip Score. Radiographic analysis was done. Kaplan-Meier survivorship analysis was done at 5 and 8.5 years using the revision for the removal of femoral component, acetabular component or both due to any cause as the end point

Results: The mean age of the patients was 25.5 years. The mean duration of follow up was 8.5 years. The average preoperative Harris Hip Score of 49.5 improved to 82.6 post operatively. Post operatively 10 hips had mild to moderate pain. Anterior dislocation occurred in four hips (4.3 %) and sciatic nerve palsy in one hip. Heterotopic ossification was seen in 12 patients, reankylosis rate was 0%. Thirteen arthroplasties were revised due to aseptic loosening. Kaplan-Meier survivorship analysis with revision as end point revealed 98.8% survival at 5 years and 85.8% survival at 8.5 years 11 follow up

Discussion: Cementless THA in osseous ankylosis in ankylosing spondylitis is a worthwhile surgical intervention in bony ankylosis. Newfound mobility, maneuverability and improved ability to sit comfortably were the outcomes, which alleviated the patients’ daunted morale. However, the technically demanding nature of the procedure should not be underestimated