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.