Linda P Hunt1, Ashley W Blom2, Gulraj S Matharu1, Setor K Kunutsor2, Andrew D Beswick1, J Mark Wilkinson3, Michael R Whitehouse2. 1. Musculoskeletal Research Unit, Bristol Medical School, University of Bristol, Southmead Hospital, Bristol, United Kingdom. 2. Musculoskeletal Research Unit, Bristol Medical School, University of Bristol, Southmead Hospital, Bristol, United Kingdom; National Institute for Health Research Bristol Biomedical Research Centre, University Hospitals Bristol and Weston NHS Foundation Trust and the University of Bristol, Bristol, United Kingdom. 3. Department of Oncology and Metabolism, The University of Sheffield, Northern General Hospital, Sheffield, United Kingdom; Centre for Integrated Research into Musculoskeletal Ageing, University of Sheffield, Sheffield, United Kingdom.
Abstract
BACKGROUND: To determine unicompartmental (UKR) and total knee replacement (TKR) revision rates, compare UKR revision rates with what they would have been had they received TKR instead, and assess subsequent re-revision and 90-day mortality rates. METHODS: Using National Joint Registry data, we estimated UKR and TKR revision and mortality rates. Flexible parametric survival modeling (FPM) was used to model failure in TKR and make estimates for UKR. Kaplan-Meier estimates were used to compare cumulative re-revision for revised UKRs and TKRs. RESULTS: Ten-year UKR revision rates were 2.5 times higher than expected from TKR, equivalent to 70 excess revisions/1000 cases within 10 years (5861 excess revisions in this cohort). Revision rates were 2.5 times higher for the highest quartile volume UKR surgeons compared to the same quartile for TKR and 3.9 times higher for the lowest quartiles respectively. Re-revision rates of revised TKRs (10 years = 17.5%, 95% confidence interval [CI] 16.4-18.7) were similar to revised UKRs (15.2%, 95% CI 13.4-17.1) and higher than revision rates following primary TKR (3.3%, 95% CI 3.1-3.5). Ninety-day mortality rates were lower after UKR compared with TKR (0.08% vs 0.33%) and lower than predicted had UKR patients received a TKR (0.18%), equivalent to 1 fewer death per 1000 cases. CONCLUSION: UKR revision rates were substantially higher than TKR even when demographics and caseload differences were accounted for; however, fewer deaths occur after UKR. This should be considered when forming treatment guidelines and commissioning services. Re-revision rates were similar between revised UKRs and TKRs, but considerably higher than for primary TKR, therefore UKR cannot be considered an intermediate procedure.
BACKGROUND: To determine unicompartmental (UKR) and total knee replacement (TKR) revision rates, compare UKR revision rates with what they would have been had they received TKR instead, and assess subsequent re-revision and 90-day mortality rates. METHODS: Using National Joint Registry data, we estimated UKR and TKR revision and mortality rates. Flexible parametric survival modeling (FPM) was used to model failure in TKR and make estimates for UKR. Kaplan-Meier estimates were used to compare cumulative re-revision for revised UKRs and TKRs. RESULTS: Ten-year UKR revision rates were 2.5 times higher than expected from TKR, equivalent to 70 excess revisions/1000 cases within 10 years (5861 excess revisions in this cohort). Revision rates were 2.5 times higher for the highest quartile volume UKR surgeons compared to the same quartile for TKR and 3.9 times higher for the lowest quartiles respectively. Re-revision rates of revised TKRs (10 years = 17.5%, 95% confidence interval [CI] 16.4-18.7) were similar to revised UKRs (15.2%, 95% CI 13.4-17.1) and higher than revision rates following primary TKR (3.3%, 95% CI 3.1-3.5). Ninety-day mortality rates were lower after UKR compared with TKR (0.08% vs 0.33%) and lower than predicted had UKR patients received a TKR (0.18%), equivalent to 1 fewer death per 1000 cases. CONCLUSION: UKR revision rates were substantially higher than TKR even when demographics and caseload differences were accounted for; however, fewer deaths occur after UKR. This should be considered when forming treatment guidelines and commissioning services. Re-revision rates were similar between revised UKRs and TKRs, but considerably higher than for primary TKR, therefore UKR cannot be considered an intermediate procedure.
Authors: Kevin Deere; Michael R Whitehouse; Setor K Kunutsor; Adrian Sayers; Andrew J Price; James Mason; Ashley W Blom Journal: Lancet Rheumatol Date: 2021-04-29