Abstract
Background and purpose - For more than half a century, stemmed hemiarthroplasty (SHA) has been used in the treatment of comminuted and displaced fractures of the proximal humerus. Reverse shoulder arthroplasty (RSA) has been increasingly popular in cases where it is difficult to obtain satisfactory fixation of the tuberosities. We report revision rates and reasons for revision after shoulder arthroplasty for acute fractures of the proximal humerus. Patients and methods - This study was based on a common dataset from the Nordic Arthroplasty Register Association (NARA), which includes data reported to the national shoulder arthroplasty registries in Denmark, Sweden, and Norway. We included 6,756 shoulder arthroplasties performed for acute fractures between 2004 and 2013. Results - There were 6,112 SHAs (90%) and 565 RSAs (8.4%). The cumulative arthroplasty survival rate after 5 years was 0.96 for both SHA and RSA. The relative risk of revision of RSA was 1.4 (95% CI: 0.9-2.2) with SHA as reference. For both types of arthroplasty, the most common reason for revision was infection (SHA 0.8%, RSA 2.1%). The relative risk of revision due to infection was 3.1 (95% CI: 1.6-5.9) for RSA with SHA as reference. The relative risk of revision for patients who were less than 75 years of age was 2.8 (95% CI: 2.0-3.8) compared to older patients. Interpretation - Revision after shoulder arthroplasty for acute fractures was rare. Survival rates were similar between SHA and RSA, but RSA had a statistically significant and clinically relevant higher risk of revision because of infection.