O3161 LONG-TERM RESULTS OF CEMENTLESS ZWEYMUELLER STEMS IN THA WITH 13 TO 18 YEAR FOLLOW-UP

Abstract

Aims: This study evaluates the long-term results of cementless Zweymueller stems in total hip arthroplasty (TKA) from 13 to 18 years. Methods: This study evaluated 171 cementless Zweymueller stems. Two different acetabular cups were utilised and the minimum follow-up was 13 years. Of 171 cases 62 had complete follow-up in 1999 with a mean follow-up of 15.1 years (13 to 18). The remaining 109 patients were lost to follow-up, most of which have either died or were not available for other reasons. Results: Of the 62 cases, 41 (66.1%) cases had excellent or good results, 11 cases had moderate (17.7%), and 10 (16.2%) cases had poor results. Radiographic assessment revealed distal migration of more than 3 mm in only one (1.6%) case and no stem demonstrated varus or valgus tilt. Radiolucent lines of 2 mm occurred in 19.4% of the cases, but were limited to less than three of seven zones. Osteolytic cysts were present in 5 cases (7%) and calcar resorption appeared in 5 (7%) cases as well. Of the 171 cases 16 (9.4%) required revision surgery of the stem after a mean of 5.2 years (1 to 15), 8 of which were due to PE wear and osteolysis, 5 due to undersizing of the stem, 3 due to increased thinning of the femoral cortices, and one incidentally at revision of the acetabular cup. Of the 56 cases in which an Endler PE cup was utilised, 29 (51.8%) were revised without revision of the stem. Conclusions: These long-term data support the utilisation of uncemented Zwey-mueller stems in THA.