Failure of total knee arthroplasty with or without patella resurfacing

Abstract

Background and purposePatella resurfacing during primary total knee arthroplasty (TKA) is disputed and new prosthesis designs have been introduced without documentation of their survival. We assessed the impact on prosthesis survival of patella resurfacing and of prosthesis brand, based on data from the Norwegian Arthroplasty Register.Patients and methods5 prosthesis brands in common use with and without patella resurfacing from 1994 through 2009 were included n = 11,887. The median follow-up times were 9 years for patella-resurfaced implants and 7 years for implants without patella resurfacing. For comparison of prosthesis brands, also brands in common use with only one of the two treatment options were included in the study population (n = 25,590). Cox regression analyses were performed with different reasons for revision as endpoints with adjustment for potential confounders.ResultsWe observed a reduced overall risk of revision for patella resurfaced (PR) TKAs, but the statistical significance was borderline (RR = 0.84, p = 0.05). At 15 years, 92% of PR and 91% of patella non resurfaced (NR) prostheses were still unrevised. However, PR implants had a lower risk of revision due to pain alone (RR = 0.1, p < 0.001), but a higher risk of revision due to loosening of the tibial component (RR = 1.4, p = 0.03) and due to a defective polyethylene insert (RR = 3.2, p < 0.001).At 10 years, the survival for the reference NR brand AGC Universal was 93%. The NR brands Genesis I, Duracon, and Tricon (RR = 1.4–1.7) performed statistically significantly worse than NR AGC Universal, while the NR prostheses e.motion, Profix, and AGC Anatomic (RR = 0.1–0.7), and the PR prostheses NexGen and AGC Universal (RR = 0.4–0.5) performed statistically significantly better. LCS, NexGen, LCS Complete (all NR), and Tricon, Genesis I, LCS, and Kinemax (all PR) showed no differences in this respect from the reference brand. A lower risk of revision (crude) was found for TKAs performed after 2000 as compared to those performed earlier (RR = 0.8, p = 0.001).InterpretationAlthough revision risk was similar for PR and NR TKAs, we found important differences in reasons for revision. Our results also indicate that survivorship of TKAs has improved.

International Comparative Evaluation of Fixed-Bearing Non-Posterior-Stabilized and Posterior-Stabilized Total Knee Replacements

“…Higher revisions rates with nonresurfaced patellas as seen in our study have been demonstrated by other authors as well 27,28,35 . Lygre et al found a higher revision rate in arthroplasties, although the finding was not significant.…”

“…Evidence from the study by Abdel et al indicates that this may not be important 11 . Significant differences in the surgical technique have been brought to light through this analysis 27,28,33 . Some registries contained relatively few posterior-stabilized procedures.…”

“…Lygre et al found a higher revision rate in arthroplasties, although the finding was not significant. Isolated patellar revision was most often performed for pain, not mechanical loosening, and these revision rates were design-specific 27 . The rate of patellar revision was substantially lower in the second half of the study period, as newer, ''patella-friendly'' designs were introduced 27 .…”

“…Isolated patellar revision was most often performed for pain, not mechanical loosening, and these revision rates were design-specific 27 . The rate of patellar revision was substantially lower in the second half of the study period, as newer, ''patella-friendly'' designs were introduced 27 . The higher failure rate associated with nonresurfaced posterior-stabilized knees compared with non-posterior-stabilized designs in the current study cannot be explained by our data.…”

“…Abdel et al reported that at fifteen years the non-posterior-stabilized knee replacements performed slightly better in the knees with deformities than in those without deformities and that the opposite was true for posterior-stabilized knee replacements, which performed better in the knees without deformities 11 . The role of patellar resurfacing in total knee arthroplasty has been investigated, often with contradictory results [27][28][29][30][31][32] . The results of our study indicate that the revision risk for posteriorstabilized knees is double that for non-posterior-stabilized knees in cases with nonresurfaced patellas.…”