Shoulder surgery risks are low overall but risk of re-operation is significant: The BMJ study

The paper's lead author is Jonathan Rees, a professor at the University of Oxford-based Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences. The study was based on 288,250 arthroscopic shoulder procedures performed on 261,248 patients, who were aged 16 years and over, from 1 April 2009-31 March 2017. 

Serious adverse events needing inpatient care within 90 days of surgery were death, pulmonary embolism, pneumonia, heart attack, acute kidney injury, stroke, and urinary tract infection, and re-operations (including for deep infection) within one year.

The overall rate of complications within 90 days after arthroscopic shoulder surgery (including reoperation) was low at 1.2 per cent, with one patient in 81 at risk. Complication rates varied according to type of procedure, but these differences disappeared after accounting for age, sex and underlying conditions (comorbidities). The most common adverse event was pneumonia (one in 303 patients at risk), while pulmonary embolism was rare (one patient in 1,428).

Re-operation rates

One patient in 26 had a reoperation within one year, suggesting either an ineffective procedure or a complication. Reoperation due to infection was low (one in 1,111 patients) but was higher for rotator cuff repair (one in 526 patients). Particularly high reoperation rates were found after frozen shoulder release surgery, which probably highlights the poorly understood and unpredictable nature of this condition, note the researchers.

Over the study period, the number of arthroscopic shoulder procedures increased. However, subacromial decompression (surgery to treat shoulder impingement) operations decreased in number.

The findings suggest that risks of serious adverse events associated with common shoulder arthroscopy procedures are low. Nevertheless, serious complications do occur, and include the risk of reoperation in one in 26 patients within one year [Jonathan Rees et al.]

Cause not established

As the study was observational in nature, cause cannot be established, the researchers acknowledge. They did not capture complications that were mild enough to be treated in primary care settings. Nevertheless, the results are based on a large sample of population level data, ensuring more precise estimates of adverse events and reoperation rates.
 
Conclusion

In their conclusion, Professor Rees and his colleagues note: ‘The findings of this study suggest that risks of serious adverse events associated with common shoulder arthroscopy procedures are low. Nevertheless, serious complications do occur, and include the risk of reoperation in one in 26 patients within one year.'

They add: ‘As the numbers of other arthroscopic shoulder procedures continue to increase, this study provides real world generalisable estimates of serious adverse events and reoperation rates that should better inform surgeons and patients.'

Linked editorial

In a linked editorial, two orthopaedic surgeons note that safety data are welcome. But they pose the following question: do these procedures actually work?

Their editorial points out that recent trials have shone the light of science on arthroscopic shoulder procedures, typically finding most of them to be no better than non-surgical care for most patients. They note: ‘If arthroscopic shoulder surgery is to continue, high quality research must be done to find out which procedures are truly effective, and work according to patients and their conditions.’

In the meantime, they say this study ‘gives clinicians and patients confidence that if an arthroscopic shoulder procedure is known to be effective, it is likely to be safe as well’.

To read the full version of the paper, titled Serious adverse event rates and reoperation after arthroscopic shoulder surgery: population based cohort study, visit: https://www.bmj.com/content/378/bmj-2021-069901
To read the linked editorial, visit: https://www.bmj.com/content/378/bmj.o1571