Prior subacromial decompression is a significant risk factor for development of acromial stress fracture after reverse total shoulder arthroplasty

Background

As the use of reverse total shoulder arthroplasty (rTSA) has steadily increased since Food and Drug Administration approval in 2003, there have been a number of unique complications recognized, including postoperative acromial stress fractures (ASFs). The incidence of ASF after rTSA is rare; however, the impact on clinical outcomes and patient satisfaction can be devastating. Despite a growing body of literature exploring risk factors for ASF following rTSA, there has been minimal investigation into prior subacromial decompression/acromioplasty (SAD) as a risk factor. The purpose of this study was to review a large patient database to determine if prior SAD increases the risk for ASF after rTSA.

Methods

The PearlDiver database was used to perform a retrospective cohort study of patients undergoing primary rTSA between 2010 and 2022. International Classification of Diseases and Current Procedural Terminology codes were used to identify patients undergoing rTSA and determine the incidence of ASF. Demographic characteristics and independent risk factors, including prior SAD, were compared between patients with and without ASFs.

Results

A total of 106,599 patients undergoing primary rTSA were identified. The overall incidence of ASF was 0.90%. Prior SAD was identified as a significant independent risk factor with logistic regression analysis showing that prior SAD conferred a 26% higher risk of sustaining a postoperative ASF (odds ratio, 1.26 [95% confidence interval, 1.03-1.54]; P < .01). Additional independent risk factors for ASF following rTSA included increased Charlson Comorbidity Index, history of a rotator cuff tear, osteoporosis and inflammatory arthropathy.

Conclusion

This study represents one of the largest cohorts of ASFs to date and is the first database study specifically investigating prior SAD as an independent risk factor for ASF after rTSA. Our results support that prior SAD is indeed an independent risk factor for ASF after rTSA. Further high quality, multicenter studies investigating prior SAD as a risk factor for ASF following rTSA are needed as our results supplement a sparse compendium of literature with mixed results pertaining to the hazard that SAD poses for development of this rare complication.