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Updated: Sep 24, 2026
Reverse Total Shoulder Arthroplasty
Published on: July 5, 2011
Risk factors for acromion and scapular spine fractures after reverse total shoulder arthroplasty: a time-to-event
Adam Kreutzer1,2, Christopher Baker3, Blake Han3,4
1Synergy Orthopedic Specialists, San Diego, CA, USA.
Background:
Acromion and scapular spine fractures are recognized complications following reverse total shoulder arthroplasty (rTSA). While prior studies have identified select risk factors, formal time-to-event analyses evaluating fracture hazard remain limited.
Methods:
This retrospective database study utilized the TriNetX US Collaborative Network. Data were queried in February 2026 and included data collected from February 2006 to February 2026. Any patient undergoing rTSA with at least 1 year of longitudinal health record data were included in the analysis. Kaplan-Meier survival analysis was performed to estimate fracture-free survival. Additionally, a multivariable Cox proportional hazards regression model was used to evaluate the association between several risk factors and time to acromion or scapular spine fracture among patients undergoing rTSA. Hazard ratios (HRs) were reported.
Results:
A total of 30,816 patients undergoing rTSA were identified. At 1 year, Kaplan-Meier estimated fracture-free survival was approximately 98.0%. Half of fractures occurred within 109 days post-operatively (interquartile range 55-190 days). Independent predictors of increased fracture hazard included older age (HR 1.02), female sex (HR 1.45), White race (HR 1.54), Pacific Islander race (HR 4.01), osteoporosis without concurrent fracture (HR 1.50), osteoporosis with concurrent fracture (HR 1.45), chronic kidney disease (HR 1.32), rotator cuff tear (HR 1.33), opioid-related disorders (HR 1.51), and chronic systemic steroid use (HR 1.32). Male sex (HR 0.69) and Black race (HR 0.55) were associated with decreased hazard.
Conclusion:
In this large time-to-event analysis, several patient-level factors were associated with increased hazard of acromion and scapular spine fractures within 1 year of rTSA. Because fractures were commonly diagnosed around 4 months post-operatively, surgeons should maintain a high index of suspicion for new acromial or scapular spine pain beyond the initial 3-month rehabilitation period. These findings may improve pre-operative risk stratification, post-operative surveillance, and earlier diagnosis in high-risk patients.
