Abstract
To study the survival analysis of the Accord TKR and to analise the causes for its failure. 111 Accord knees were implanted in 106 patients between 1986 and 1996. All components were cemented. Eighty-seven patients were followed up and assessed according to the Knee Society Clinical Rating System.
Life table analysis of this implant using revision as the end point shows a survival of 25% at 11–12 years.
Of the 87 knees, only 31 were still in situ and of these 7 showed radiographic signs of severe loosening. However, the average knee score for these 31 was only 65/100 and average functional score was down to 42/100.
56 implants have been revised, 21 due to aseptic loosening, 11 due to gross valgus/varus instability, 9 due to deep infection, 8 due to loosening of the patella liner and 7 due to mobile bearing complications.
All 21 (24%) cases of aseptic loosening were found to have a loose femoral component; however, 56% of the total showed significant radiographic osteolysis around the stem of the tibial implants.
Retrieved implants in 5 patients showed significant delamination of the UHMWP at its margins and also revealed a track through the tibial baseplate into the medullary cavity of the tibia.
Conclusion: Early failure of this implant is due to increased debris formation from the UHMWP due to edge loading and early delamination probably as a consequence of the shape of its articulating surface. This situation was significantly aggravated by a design fault in the tibial baseplate, which encouraged unrestricted access of debris into the medullary cavity of the tibia and hence early and severe osteolysis.
The abstracts were prepared by Mr Tim Briggs. (Editoral Secretary 2003/4) Correspondence should be addressed to him at Lane Farm, Chapel Lane, Totternhoe, Dunstable, Bedfordshire LU6 2BZ, United Kingdom
