Survivorship for modern total knee arthroplasties (TKA) is not precisely known from large series, other than registries. The present retrospective study therefore analyzed 846 TKAs at a minimum 10years’ follow-up.
Ten-year survivorship for TKAs in a multicenter study exceeds 90%, independently of design and level of prosthetic constraint.
Materials and methods
Eight hundred and twenty-eight patients (846 TKAs) were assessed on the Knee Society score. Mean age was 71years (range, 41–93years); 274 males and 554 females (67%); 496 patients (60%) were active; diagnosis was principally osteoarthritis (n=752 [89%]). Most TKAs were cemented (n=704 [83%]), replacing the patella (n=668 [79%]) and sacrificed the posterior cruciate ligament (PCL) (n=707 [84%]), 65% being posterior-stabilized and 35% ultracongruent, with fixed (39%) or mobile bearing (61%).
At a minimum 10years’ follow-up, mean knee score rose from 35 (15–55) to 83 points (74–95), and functional score from 24 (5–45) to 74 points (60–90); mean flexion rose from 105° (25–125°) to 112° (25–125°). Mean hip-knee-ankle angle was 179.5° (169–189°). Sixty-three (7.5%) revision surgeries were required, mainly for loosening (n=18 [2%]) or infection (n=18 [1.8%]). Overall 10-year survivorship was 92% (95% CI: 0.90–0.94). There was no significant difference in survivorship according to implant design or PCL retention. Activity level correlated with revision rate; mechanical complications were more frequent in active and infectious complications in sedentary subjects. Revision was not more frequent in TKA aligned outside the 177–183° range.
Ten-year TKA survivorship was 92%, independently of design and level of mechanical stress. Revision was mainly for infection or loosening, and not for greater than 3° axis misalignment. Mechanical complications were more frequent in younger and more active subjects, for whom therefore other treatment options or technical improvements should be sought.
Level of evidence
Level IV. Retrospective study.Le texte complet de cet article est disponible en PDF.
Keywords : Total knee arthroplasty, Minimum 10-year follow-up, Clinical results, Implant survivorship, Adult