Abstract
Aims: Review short to medium term results of a metal-on-metal (M/M) hybrid surface arthroplasty (SA) for a young and active patient population. Methods: The þrst 400 hips (of 533) in 355 patients underwent M/M hybrid surface arthroplasty. Mean age 48.2; 73% males, 27% females; 198 Charnley Class A; 139 Class B and 18 Class C. Diagnosis at surgery: OA 64%, DDH 11%, ON 9%, Post-traumatic 8%, Inßammatory arthritis 3%, SCFE and LCP 4%, Melorheostosis 0.3%. Results: Mean follow-up 3.9 years (2.6–6.5). Average UCLA hip scores post-op: pain 9.4, walking 9.5, function 9.4, and activity 7.7. The SF-12 physical and mental components were respectively, 31.2 and 46.8 pre-op and 50.1 and 53.0 post-op. 12 hips were converted to THA (8 in the þrst 102): 2 neck fractures, 7 femoral loosenings, 1 socket protrusio due to over-reaming, 1 subluxation due to impingement and 1 sepsis. Conclusions: Clinical results are excellent despite very high activity levels. The experience with SA of all cemented metal/UHMWPE bearing demonstrated failure rates of 15%–33% at 3 years. At longer follow-up, the preliminary experience is encouraging (3% failure rate). Dislocation is rare, and acetab-ular þxation secure. Initial femoral þxation is critical as the þxation area is small, especially with osteopenia and cystic degeneration. The percent of complications and potentially adverse radiographic changes was much greater in the þrst 100 cases, during the time of development of instrumentation, technique, and bearing optimization.
Theses abstracts were prepared by Professor Dr. Frantz Langlais. Correspondence should be addressed to him at EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
