Abstract
Introduction
The Oxford Total Meniscal Knee (TMK by Biomet), is a total knee replacement with a multidirectional mobile bearing. As part of the evaluation of the TMK we compared our group of TMK knee replacements with an equivalent cohort of AGC total knee replacements.
Methods
Patients recruited to AGC trial from 1994 to 2001. 254 AGC knee replacements sequentially recruited in 210 patients. Patients recruited to TMK trial from 2001 to 2007. 221 TMK knee replacements sequentially recruited in 193 patients. Patients prospectively randomised to having uncemented HA coated (HAC) or cemented versions in both groups. Each patient was reviewed pre-operatively, at 6 weeks, 6 months, 1 year and then annually.
All AGC & TMK TKR's were assessed clinically using HSS scores and radiographically. TMK group also assessed using AKSS and OKQ scores.
Results
AGC; 254 TKR (118 cemented, 136 HAC) Mean Age 67.5 (47–75yrs). Follow up 7–14 years (Mean 9.2yrs). 4 revisions TMK; 221 TKR (106 cemented, 115 HAC) Mean Age 67 (47–75yrs). Follow up 4–10 years (Mean 6.2 yrs). 8 revisions and 2 bearing exchanges. 4 revisions were for aseptic loosening, 1 for unexplained pain, 1 for bearing fracture and 2 for infection. 6 revisions in HAC group. No significant differences in functional outcome scores between cemented and HAC in TMK or AGC groups. HSS scores in the TMK group were lower than in the AGC group (82 vs 85, p = 0.007 2 tailed unequal variance t test)
Discussion
The TMK appears to have a higher revision rate that the AGC with shorter follow-up. This particularly affects the HAC group. Although Functional outcome scores for the TMK are good they are still lower than the AGC. We aim to continue to follow up the TMK knee replacement to assess its survival
