Serious adverse events rare after arthroscopic shoulder surgery, but snags do occur

Common shoulder arthroscopy procedures seldom lead to serious adverse events, but serious complications do happen, including the risk of reoperation within a year in some patients, results of a recent study have shown.

“The number of many arthroscopic shoulder procedures are increasing, with patients opting for these types of operation despite limited evidence of effectiveness in some cases, and a lack of reliable data on serious adverse events and reoperation rates,” the researchers said. [N Engl J Med 2002;347:81-88; Osteoarthritis Cartilage 2014;22:734-741; Cochrane Database Syst Rev 2019;1:CD005619]

“Our findings are therefore overdue and important and will better inform patients, clinicians, and healthcare providers,” they added.

This population-based cohort study was conducted using Hospital Episode Statistic for NHS England, including civil registration mortality data from the Office for National Statistics. The researchers assessed a total of 288,250 arthroscopic shoulder procedures performed in 261,248 patients aged ≥16 years between 1 April 2009 and 31 March 2017.

Elective procedures were categorized as follows: subacromial decompression, rotator cuff repair, acromioclavicular joint excision, glenohumeral stabilization, and frozen shoulder release.

Overall, the rate of complications within 90 days following arthroscopic shoulder surgery (including reoperation) was low (1.2 percent, 95 percent confidence interval [CI], 1.2‒1.3), with one in 81 patients being at risk. [BMJ 2022;378:e069901]

The risk also varied depending on the type of procedure: from 0.6 percent (95 percent CI, 0.5‒0.8) for glenohumeral stabilization to 1.7 percent (95 percent CI, 1.5‒1.8) for frozen shoulder release. Procedure type, however, conferred no significant effect after adjustment for age, sex, and comorbidities.

Pneumonia was the most common adverse event at 0.3 percent (95 percent CI, 0.3‒0.4), corresponding to one in 303 patients at risk. On the other hand, pulmonary embolic events rarely occurred at 0.1 percent (95 percent CI, 0.1‒0.1), corresponding to one in 1,428 patients at risk.

“The reasons for the observation of an increased rate of pneumonia within 90 days of arthroscopic shoulder surgery compared with arthroscopic knee surgery are unclear and therefore further research would be needed to identify causation and preventive measures,” the researchers said.

In terms of reoperation, the overall rate at 1 year was 3.8 percent (95 percent CI, 3.8‒3.9), occurring in one in 26 patients at risk and ranging from 2.7 percent (95 percent CI, 2.5‒3.0) for glenohumeral stabilization to 5.7 percent (95 percent CI, 5.4‒6.1) for frozen shoulder release.

Moreover, there was a low rate of further surgery for deep infection (0.1 percent, 95 percent CI, 0.1‒0.1), with one in 1,111 patients at risk. However, the rate was slightly higher following rotator cuff repair (0.2 percent, 95 percent CI, 0.2‒0.2), with one in 526 patients at risk.

“Further research should consider factors associated with the increased infection rates after rotator cuff repair, along with preventive measures,” the researchers said.

Of note, the number of arthroscopic shoulder procedures rose over the study period, except for subacromial decompression, which decreased.

“Until further high-quality evidence on the effectiveness of other procedures is available, we have presented the risk of serious adverse events that require hospital readmission after the most common elective shoulder arthroscopy operations,” the researchers said.