Patients Receiving a Primary Unicompartmental Knee Replacement Have a Higher Risk of Revision but a Lower Risk of Mortality Than Predicted Had They Received a Total Knee Replacement: Data From the National Joint Registry for England, Wales, Northern Ireland, and the Isle of Man

Background To determine unicompartmental (UKR) and total knee replacement (TKR) revision rates, compare UKR rates with what they would have been had received TKR instead, assess subsequent re-revision 90-day mortality rates. Methods Using National Joint Registry data, we estimated Flexible parametric survival modeling (FPM) was used to model failure in make estimates for UKR. Kaplan-Meier were cumulative revised UKRs TKRs. Results Ten-year 2.5 times higher than expected from TKR, equivalent 70 excess revisions/1000 cases within 10 years (5861 revisions this cohort). Revision the highest quartile volume surgeons compared same 3.9 lowest quartiles respectively. Re-revision of TKRs (10 = 17.5%, 95% confidence interval [CI] 16.4-18.7) similar (15.2%, CI 13.4-17.1) following primary (3.3%, 3.1-3.5). Ninety-day lower after (0.08% vs 0.33%) predicted patients a (0.18%), 1 fewer death per 1000 cases. Conclusion substantially even when demographics caseload differences accounted for; however, deaths occur This should be considered forming treatment guidelines commissioning services. between TKRs, but considerably therefore cannot an intermediate procedure.