Abstract
Aims: To assess the failure rate at 5 years of the Elite Plus (DePuy) femoral stem and identify reasons for early failure. Particular attention was paid to the quality of the cement mantle.
Methods: A cohort of the first 241 primary THR performed in 234 patients were identified. Each patient completed the Oxford Hip Score (OHS), and had AP and lateral radiographs. The cement mantle was graded by Mulroy’s modification of Barrack’s system using all AP and lateral radiographs.
Results: At follow up 39 patients (42 hips) had died, 14 were lost to follow up and 35 (36 hips) too unwell/ unwilling to take part leaving149 hips in 146 patients available for independent assessment. The mean follow up was 60.2 months (range 48.3–75.8 months). Five hips (3.4%), have been revised, 1 after traumatic dislocation, 1 for deep infection and 3 for aseptic loosening. In a further 11 (7.4%) patients there was radiological evidence of progressive femoral loosening, although only 2 of the 7 available for review were symptomatic. The median OHS was 20 (range 12–51). All those revised or radiologically loose had defective cement mantles (C2). A cement mantle less than 1 mm thick was associated with early failure (p< 0.03).
Conclusions: The revision rate at 5 years is 3.4%. Loosening is related to suboptimal cement mantles in particular mantle thickness of less than 1 mm. We have documented the invisible cohort of those who have loosened radiologically but are asymptomatic. Regular surveillance of this cohort is mandatory to allow comparison with longer-term results of other prostheses.
Theses abstracts were prepared by Mr Peter Kay. Correspondence should be address to him at The Hip Centre, Wrightington Hospital, Appley Bridge, Wigan, Lancashire WN6 9EP.
