Estimated Carbon Savings from Changing Surgical Trends in Primary Elective Total Hip Arthroplasty in England: A Retrospective Observational Study

Background The National Health Service (NHS) in England has set a target to be net zero for carbon emissions by 2045. The aim of this study was to investigate how changes in key aspects of clinical practice over the last 8 years have contributed towards reducing the per-patient carbon footprint of elective total hip arthroplasty (THA). Methods This was a retrospective analysis of administrative data. Data were extracted from the Hospital Episode Statistics database for all adult (≥ 17 years), primary, elective THA procedures conducted in England from 1 April, 2014 to 31 March, 2022. The estimated carbon footprint for key elements of the surgical pathway were calculated based on data from Greener NHS and the Sustainable Healthcare Coalition. Results Data were available for 537,441 THA procedures conducted during the study period. The per-patient carbon footprint associated with the primary THA (index) procedure fell by around 25% from 2014/15 to 2021/22. Length of stay was by far the largest contributor to this decline, falling from 169.1 kgCO2e to 117.6 kgCO2e per patient from 2014/15 to 2021/22. Absolute declines in the carbon footprint associated with emergency readmissions, revisions and outpatient attendances were more modest. If all patients in all years had the 2021/22 average carbon footprint, then carbon equivalent to powering 19,976 UK homes for 1 year would have been saved. Conclusions Improving per-patient efficiency of surgery is likely to contribute towards meeting the NHS's net-zero target whilst also helping to improve patient outcomes, reduce costs and cut waiting lists.