Effect of NHS surgical hubs on elective hip-and-knee replacement volume, length of stay and waiting times: national longitudinal difference-in-differences study

Background Elective surgical hubs have been introduced across England to increase surgical capacity, improve productivity and reduce waiting times. Evidence on their effects remains limited, particularly beyond the early period of implementation. We evaluated the effect of surgical hubs on surgical volume, patient waiting times and length of hospital stay for elective hip and knee replacements in the English NHS. Methods We conducted a retrospective longitudinal study using Hospital Episode Statistics for NHS acute trusts in England from April 2014 to September 2024. The analysis included 76 trusts, of which 29 opened a surgical hub providing trauma and orthopaedic surgery during the study period and 47 did not. Outcomes were measured quarterly at trust level and comprised the number of elective hip and knee replacements, mean length of stay and mean waiting time from addition to the waiting list to admission. We used a difference-in-differences approach for staggered hub opening, with trust and quarter fixed effects and standard errors clustered at trust level. Results Surgical hub opening was associated with an increase of 43.75 hip and knee replacement procedures per quarter (95% CI 22.22 to 65.28), equivalent to a 19.1% increase relative to the pre-hub mean. Mean length of stay was 0.32 days lower following hub opening (95% CI -0.48 to -0.16), equivalent to a 7.8% reduction. There was no statistically significant overall change in mean waiting time (-14.96 days, 95% CI -33.11 to 3.19). Conclusions Surgical hub opening was associated with increased volumes of hip and knee replacement surgery and shorter hospital stays. We found no statistically significant overall reduction in waiting times. The findings suggest that surgical hubs can increase elective surgical activity, although additional capacity may not translate directly into shorter waiting times.