Patients treated by surgeons who average more than 10 shoulder replacements a year have a lower risk of further operations and serious complications, and a shorter hospital stay than those treated by surgeons who do fewer operations, according to a study by Oxford researchers.
These findings, published in the BMJ, build on similar evidence for hip and knee replacements and should help guide future resource planning in this area, say the researchers.
Shoulder replacements are becoming increasingly common globally, particularly in high-income countries as populations continue to age. In the UK alone, more than 8,000 shoulder replacements are carried out each year.
Previous studies of hip and knee replacement surgery show that patients treated by “high volume” surgeons experience better outcomes than patients of lower volume surgeons. This has prompted some providers to introduce minimum volume thresholds for surgeons to improve patient outcomes, but evidence for other types of joint replacement surgery is more limited.
To fill this knowledge gap, a team of UK researchers, supported by the NIHR Oxford Biomedical Research Centre (BRC), set out to explore the association between surgeon volume and outcomes after elective (non-urgent) shoulder replacement surgery.
“Improving outcomes and reducing complications after joint replacement surgery is of clear benefit to patients and their families,” said Markos Valsamis, NIHR Doctoral Research Fellow at the University of Oxford’s Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS).
“But these results also provide timely evidence for healthcare systems that are overburdened, under-resourced and in need of recovery planning post-pandemic.”
The findings are based on data from the National Joint Registry and Hospital Episode Statistics in England for 39,281 elective shoulder replacements performed by 638 consultant surgeons at 416 public and private hospitals from 2012 to 2020.
Statistical models were used to investigate the effect of annual surgeon volume on revision, reoperation within 12 months, serious adverse events after 30 and 90 days, and prolonged hospital stay (more than three nights). All participants were aged 18 or over and were receiving shoulder replacement surgery for the first time.
After adjusting for a range of potentially influential factors, the researchers identified a mean annual volume threshold of 10.4 procedures, below which there was a significantly increased risk of revision surgery.
Annual variations in case volume did not affect patient outcomes, suggesting that a surgeon’s average annual volume of procedures over the course of their career is more important for better patient outcomes than variation in annual procedure volumes.
“This study offers evidence for local hospitals and national healthcare services that informs workforce and resource planning to ensure the best outcomes for patients undergoing shoulder replacement surgery,” concluded Markos.
In a linked editorial, researchers say this study is a useful addition to current knowledge of the association between surgeon volume and patient outcomes, but argue that the association between surgeons and patient outcomes is a complex one that can be difficult to evaluate scientifically.