Complication Rates After Shoulder Replacement Higher Than Previously Believed

The rate of shoulder replacement surgery is on the rise, but this procedure once thought to be low-risk may have a high likelihood of adverse events, according to new research.

“Although the number of [shoulder] replacements do not yet match those of the hip and knee, recent trends from international joint replacement registries show a rapid increase in the incidence of primary shoulder replacements performed and the rapid adoption of newer implant technologies,” the study authors wrote. “Despite this growth, no large scale trials and very few published studies have been carried out on the long term outcomes across different age groups, including the risks of revision surgery.”

Researchers collected National Health Services (NHS) England data on 58,054 elective shoulder replacements performed on 51,895 patients aged ≥ 50 years between April 1998 and April 2017. Mean age at time of primary surgery was 72.2 years, 72% of procedures were performed in women, and the mean Charlson comorbidity index score was 1.05. The majority of indications for shoulder surgery were for osteoarthritis or rotator cuff arthropathy (n = 39,895, 69%), followed by inflammatory (n = 6,251, 11%) or other conditions (n = 6,251, 11%), previous trauma (n = 4,784, 8%), and osteonecrosis (n = 763, 1%). A total of 6,159 patients underwent bilateral shoulder surgery. Nearly all procedures (n = 57,601, 99%) resulted in an overnight hospital stay with a mean length of stay of three nights. Mean follow-up was 5.6 years, with the longest follow-up being 19 years.

Shoulder Replacements Increase Significantly—Which Patients Are High-risk?

During the study period, the researchers observed a 5.6-fold increase in shoulder replacement surgeries—from 1,018 surgeries in 1999 to 5,691 surgeries in 2017.

Revision surgery risk varied significantly in different groups: 1 in 37 (2.7%, 95% confidence interval 2.6% to 2.8%) women aged 85 years and older, compared to 1 in 4 (23.6%, 23.2% to 24.0%) in men aged 55-59 years. Patients have the highest revision risk during the first five years after surgery.

Younger patients were at significantly increased risk for future surgery compared to older patients; across age groups, men were at slightly greater risk. Lifetime implant revision risk was 2.7% (95% confidence interval 2.6% to 2.8%) in women aged 85 years and older compared to 23.6% (23.2% to 24.0%) in men aged 55 to 59 years; in the same respective groups, lifetime reoperation risk was 3.7% (3.6% to 3.8%) and 31.9% (31.3% to 32.4%).

The following patient factors were associated with serious adverse events: older age, comorbidity, and male sex. About a fifth (21.2%) of men aged 85 years and older experienced at least one serious 90-day adverse event.

“The risk of any serious adverse event at 30 days post-surgery was 1 in 28 (3.5%, 3.4% to 3.7%), and at 90 days post-surgery was 1 in 22 (4.6%, 4.4% to 4.8%),” the researchers wrote. “At 30 days, the relative risk of pulmonary embolism compared with baseline population risk was 61 (95% confidence interval 50 to 73) for women aged 50-64.”

“Serious adverse events have been considered low after this operation, but we found that they are more common than previously described,” they added. “Inpatient care for serious medical adverse events or all cause death occurred in 46 per 1000 procedures. The most common events were lower respiratory tract infections, urinary tract infections, and acute kidney injury.”

The study authors said that their study warrants further research in order to safely treat patients and minimize the risk of adverse events.

Kaitlyn D’Onofrio is a digital medical writer. She is interested in musculoskeletal health, the effect of exercise on health, and mental health awareness. When she’s not writing for DocWire, Kaitlyn is teaching yoga classes in her community, promoting wellness to her students.