Skip to content
View commentaries on this research

This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.

Researchers analysed data on more than 39,000 people who had a shoulder replacement. They found that:

  • patients whose surgeon performed more than 10 shoulder replacements per year were less likely to need revision surgery than those whose surgeon performed fewer
  • the more shoulder replacements a surgeon performed per year, the lower the risk of serious medical complications, other reoperations and of prolonged hospital stay.

These findings could prompt commissioners and NHS decision makers to plan hospital resources to ensure that surgeons who carry out shoulder replacements are able to perform at least 10 per year.

For more information on shoulder replacements, visit the NHS website.

The issue: does it matter how many shoulder replacements a surgeon performs?

People who have pain and disability due to severe arthritis in their shoulder may be offered a shoulder replacement. More than 8,000 replacements are performed in the UK every year, and numbers are rising.

Sometimes complications after surgery mean people spend additional time in hospital or need further surgery. This can be difficult for patients and their families; it also adds to NHS waiting times and cost.

Other studies in arthritis of the hip or knee, suggest that when surgeons perform more joint replacements (surgeon volume), patients have better outcomes, such as shorter hospital stays and fewer infections. Some countries set targets for the number of these replacements a surgeon should perform each year.

However, there is little similar evidence for shoulder replacements. This study therefore explored the impact of surgeon volume on shoulder replacements.  

What’s new?

Researchers analysed data on more than 39,000 people who had a shoulder replacement. Procedures were carried out in NHS and private clinics by 638 surgeons across England, Wales, Northern Ireland, the Isle of Man and Guernsey, between 2012 and 2020.

The main outcome was the need for an additional procedure to add, remove, or modify the artificial shoulder joint (revision surgery) after initial surgery.

The researchers found that:

  • patients whose surgeons performed more than 10 shoulder replacements per year on average were less likely to need revision surgery (compared with those whose surgeons performed 10 or fewer)
  • the fewer shoulder replacements a surgeon performed, the more likely revision surgery became; when surgeons performed less than 1 procedure per year on average, their patients were twice as likely to need revision surgery (compared with patients whose surgeons performed the most)
  • the more shoulder replacements a surgeon performed per year on average, the lower the risk of serious medical complications, other reoperations (such as removing infected tissue) and of prolonged hospital stay.

Year-on-year differences in the number of shoulder replacements a surgeon performed did not impact any of the outcomes.

Why is this important?

The findings suggest that outcomes are best when surgeons who carry out shoulder replacements perform more than 10 procedures per year. This could inform resource planning for bone and joint surgery.

The researchers note that social circumstances and other factors could have influenced the length of hospital stay; these factors were not captured in the study.

What’s next?

The NHS National Director for Clinical Improvement and Elective Recovery has been awaiting these results.

The study was part of a larger project, which aims to improve patient outcomes for shoulder replacements. A related study found an increase in shoulder replacements in England, regional variation in care, and, overall, an increasing risk of serious adverse events, especially for people in more deprived groups.

The team is investigating which shoulder replacement procedures give the best outcomes for certain groups of patients.

You may be interested to read

This is a summary of: Valsamis, EM and others. Association between surgeon volume and patient outcomes after elective shoulder replacement surgery using data from the National Joint Registry and Hospital Episode Statistics for England: population based cohort study. British Medical Journal 2023; 381: 1 – 10.

Patient information from the British Elbow and Shoulder Society.

Information on improving UK surgeries from Getting It Right First Time.  

Information on taking part in NIHR studies regarding joint health.

Most shoulder replacements last longer than a decade: patients can be reassured by new research.

Funding: This study was supported by an NIHR doctoral fellowship and the NIHR Oxford Biomedical Research Centre.

Conflicts of Interest: No relevant conflicts of interest.

Disclaimer: Summaries on NIHR Evidence are not a substitute for professional medical advice. They provide information about research which is funded or supported by the NIHR. Please note that the views expressed are those of the author(s) and reviewer(s) at the time of publication. They do not necessarily reflect the views of the NHS, the NIHR or the Department of Health and Social Care.


  • Share via:
  • Print article
Back to top