Abstract
Aim: To investigate the functional and radiological outcome of shelf acetabuloplasty in adults with significantly symptomatic acetabular dysplasia, with a minimum of a 5 year follow-up.
Material and Methods: 77 consecutive shelf procedures (68 patients) with an average follow-up of 10.9 years (range: 6ā17) were reviewed. The Oxford hip score (OHS) was used for clinical assessment. Centre-edge angle (CEA) and acetabular angle (AA) were measured as indicators of joint containment. The severity of osteoarthiritis was based primarily on the extent of joint space narrowing. Survivorship analyses using conversion to THR as an endpoint were performed. Logrank tests were used to compare the survivorship of the shelf procedure against the variables of age, preoperative osteoarthiritis, pre and postoperative AA, CEA angles.
Results: The average age at time of surgery was 33 years (range: 17ā60). At the time of the last follow-up, the mean OHS was 34.6 (maximum score: 48). Mean postoperative CEA was 55 (Pre-operatively: 13 degrees) while mean postoperative AA was 31 (Pre-operatively: 48 degrees). Thirty percent of hips needed THR at an average duration of 7.3 years. The survival in the 45 patients with only slight or no joint space narrowing was 97% (CI, 93%-100%) at 5 years and 75% (CI, 51%-100%) at 10 years. This was significantly higher (pā¤= 0.0007) than the survival in the 32 patients with moderate or severe osteoarthiritis, which was 76% (CI, 55%-89%) at 5 years and 22% (CI, 5%-38%) at 10 years. There was no significant relationship between survival and age, pre and postoperative AA, CEA angles (p> 0.05).
Conclusion: Shelf-acetabuloplasty offers symptomatic relief to adults with acetabular dysplasia but overall deteriorates with time. About 50% of the patients do not need THR for over 10 years. Best results with shelf-acetabuloplasty were achieved in patients with slight or no joint narrowing.
The abstracts were prepared by Mr Peter Kay, Editorial Secretary. Correspondence should be addressed to British Hip Society, The Hip Centre, Wrightington Hospital, Appley Bridge, Wigan, Lancashire WN6 9EP.