A Comparison of the Surgical Practice of Potential Revision Outlier Joint Replacement Surgeons With Non-outliers: A Case Control Study From the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man

Background The National Joint Registry for England, Wales, Northern Ireland and the Isle of Man (NJR) has monitored performance consultant surgeons performing primary total hip (THR) or knee replacements (KR) since 2007. aims this study were: 1) To describe surgical practice replacement in England Wales (NJR), stratified by potential outlier status revisions. 2) compare revision non-outlier surgeons. Methods We combined NJR THR KR data from 2008-2017 separately with relevant anonymised notification records. described outliers non-outliers workload, implant choice, patients’ clinical demographic characteristics. explored associations between surgeon-level factors conditional logistic regression models. Results included 764,888 THRs 3213 889,954 KRs 3084 performed 2008-2017. One hundred eleven (3.5%) 114 (3.7%) were outliers. Surgeons who used more types had increased odds being an (KR: OR/additional = 1.35, 95%CI 1.17-1.55; THR: OR 1.12, 1.06-1.18). Conclusions use is associated risk a outlier. Further research required to understand why many different implants what extent responsible effects observed here.