Safety and efficacy of day-case hip and knee arthroplasty in the NHS: a nationwide UK cohort study
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Introduction
In recent years, day-case hip and knee arthroplasty has emerged as a potential solution to the elective backlog within the NHS. While international literature on this topic is extensive, only a handful of single-centre studies have been conducted in the United Kingdom. This study aimed to examine the safety and efficacy of day-case hip and knee arthroplasty in the UK using a 20-year linked national NHS dataset.
Methods
A cohort study was conducted using the Clinical Practice Research Datalink (CPRD), linked to Hospital Episode Statistics (HES) and the Office for National Statistics death registry. Adults undergoing primary hip or knee arthroplasty between 1998 and 2021 were included. Procedures were classified as day-case or inpatient, using two distinct approaches: patient classification and length of stay. Day-case is defined as discharge on the same day of the procedure, while inpatient procedures involve undergo at least one overnight stay in hospital. The primary outcomes assessed were A&E attendance, readmission, and critical care admission within 90-days post-operatively. Secondary outcomes included 90-day complication rates and survival analysis. Propensity score matching was implemented to adjust outcomes for age, gender, comorbidity burden, deprivation index, and ethnicity.
Results
In total, 1,822 (0.16%) procedures were classified as day-case, while 4,355 (0.37%) had a recorded length of stay of 0 days. On average, patients undergoing day-case arthroplasty were younger, more often male, and had fewer comorbidities than their inpatient counterparts. Higher rates of A&E attendance (12% vs 9.1%; P = 0.001) and readmission (5.7% vs 3.7%; P < 0.001) were observed in the day-case cohort. In contrast, deep vein thrombosis (0.5% vs 0.9%; P = 0.010) and infection rates (1.0% vs 1.9%; P = 0.014) were lower in this patient group. Survival analyses demonstrated significantly higher adjusted survival probabilities associated with day-case arthroplasty (HR: 0.84; [95% CI: 0.72–0.99]; P = 0.034) over a 20-year follow-up period.
Conclusion
Day-case hip and knee arthroplasty has been demonstrated to be safe and feasible, with comparable complication rates to the traditional inpatient setting. However, within the context of the NHS, it is currently associated with higher rates of 90-day A&E attendance and readmission. While increasing day-case volumes may help address elective backlogs, it is important to ensure that the appropriate patient selection criteria, optimised peri-operative care, and post-discharge support are in place before this approach is expanded in the UK.
In recent years, day-case hip and knee arthroplasty has emerged as a potential solution to the elective backlog within the NHS. While international literature on this topic is extensive, only a handful of single-centre studies have been conducted in the United Kingdom. This study aimed to examine the safety and efficacy of day-case hip and knee arthroplasty in the UK using a 20-year linked national NHS dataset.
Methods
A cohort study was conducted using the Clinical Practice Research Datalink (CPRD), linked to Hospital Episode Statistics (HES) and the Office for National Statistics death registry. Adults undergoing primary hip or knee arthroplasty between 1998 and 2021 were included. Procedures were classified as day-case or inpatient, using two distinct approaches: patient classification and length of stay. Day-case is defined as discharge on the same day of the procedure, while inpatient procedures involve undergo at least one overnight stay in hospital. The primary outcomes assessed were A&E attendance, readmission, and critical care admission within 90-days post-operatively. Secondary outcomes included 90-day complication rates and survival analysis. Propensity score matching was implemented to adjust outcomes for age, gender, comorbidity burden, deprivation index, and ethnicity.
Results
In total, 1,822 (0.16%) procedures were classified as day-case, while 4,355 (0.37%) had a recorded length of stay of 0 days. On average, patients undergoing day-case arthroplasty were younger, more often male, and had fewer comorbidities than their inpatient counterparts. Higher rates of A&E attendance (12% vs 9.1%; P = 0.001) and readmission (5.7% vs 3.7%; P < 0.001) were observed in the day-case cohort. In contrast, deep vein thrombosis (0.5% vs 0.9%; P = 0.010) and infection rates (1.0% vs 1.9%; P = 0.014) were lower in this patient group. Survival analyses demonstrated significantly higher adjusted survival probabilities associated with day-case arthroplasty (HR: 0.84; [95% CI: 0.72–0.99]; P = 0.034) over a 20-year follow-up period.
Conclusion
Day-case hip and knee arthroplasty has been demonstrated to be safe and feasible, with comparable complication rates to the traditional inpatient setting. However, within the context of the NHS, it is currently associated with higher rates of 90-day A&E attendance and readmission. While increasing day-case volumes may help address elective backlogs, it is important to ensure that the appropriate patient selection criteria, optimised peri-operative care, and post-discharge support are in place before this approach is expanded in the UK.
Date Issued
2026-03-13
Date Acceptance
2026-02-19
Citation
Arthroplasty, 2026, 8
ISSN
2524-7948
Publisher
BMC
Journal / Book Title
Arthroplasty
Volume
8
Copyright Statement
© The Author(s) 2026. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/41827088
PII: 10.1186/s42836-026-00377-8
Subjects
Ambulatory
Arthroplasty
Day case surgery
Safety
Publication Status
Published
Coverage Spatial
England
Article Number
20
Date Publish Online
2026-03-13