Predictors of acromial and scapular stress fracture after reverse shoulder arthroplasty

Background: Acromial (ASF) and scapular spine (SSF) stress fractures are well-recognized complications of reverse shoulder arthroplasty (RSA), but much of the current data are derived from single-center or single-implant studies with limited generalizability. This study from the American Shoulder and Elbow Surgeons (ASES) Complications of Reverse Shoulder Arthroplasty Multicenter Research Group determined the incidence of ASF/SSF after RSA and identified preoperative patient characteristics associated with their occurrence. Method: Fifteen institutions including 21 ASES members across the United States participated in this study. Patients undergoing either primary or revision RSA between January 2013 and June 2019 with a minimum 3-month follow-up were included. All definitions and inclusion criteria were determined using the Delphi method, an iterative survey process involving all primary investigators. Consensus was achieved when at least 75% of investigators agreed on each aspect of the study protocol. Only symptomatic ASF/SSF diagnosed by radiograph or computed tomography were considered. Multivariable logistic regression was performed to identify factors associated with ASF/SSF development. Results: We identified 6755 RSAs with an average follow-up of 19.8 months (range, 3-94). The total stress fracture incidence rate was 3.9% (n = 264), of which 3.0% (n = 200) were ASF and 0.9% (n = 64) were SSF. Fractures occurred at an average 8.2 months (0-64) following RSA with 21.2% (n = 56) following a trauma. Patient-related factors independently predictive of ASF were chronic dislocation (odds ratio [OR] 3.67, P =.04), massive rotator cuff tear without arthritis (OR 2.51, P <.01), rotator cuff arthropathy (OR 2.14, P <.01), self-reported osteoporosis (OR 2.21, P <.01), inflammatory arthritis (OR 2.18, P <.01), female sex (OR 1.51, P =.02), and older age (OR 1.02 per 1-year increase, P =.02). Factors independently associated with the development of SSF included osteoporosis (OR 2.63, P <.01), female sex (OR 2.34, P =.01), rotator cuff arthropathy (OR 2.12, P =.03), and inflammatory arthritis (OR 2.05, P =.03). Conclusion: About 1 in 26 patients undergoing RSA will develop a symptomatic ASF or SSF, more frequently within the first year of surgery. Our results indicate that severe rotator cuff disease may play an important role in the occurrence of stress fractures following RSA. This information can be used to counsel patients about potential setbacks in recovery, especially among older women with suboptimal bone health. Strategies for prevention of ASF and SSF in these at-risk patients warrant further study. A follow-up study evaluating the impact of prosthetic factors on the incidence rates of ASF and SSF may prove highly valuable in the decision-making process.

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Work Title Predictors of acromial and scapular stress fracture after reverse shoulder arthroplasty
Subtitle A study by the ASES Complications of RSA Multicenter Research Group
Open Access
  1. Kuhan A. Mahendraraj
  2. Joseph Abboud
  3. April Armstrong
  4. Luke Austin
  5. Tyler Brolin
  6. Vahid Entezari
  7. Lisa Friedman
  8. Grant E. Garrigues
  9. Brian Grawe
  10. Lawrence Gulotta
  11. Michael Gutman
  12. Paul Anthony Hart
  13. Rhett Hobgood
  14. John G. Horneff
  15. Joseph Iannotti
  16. Michael Khazzam
  17. Joseph King
  18. Michael A. Kloby
  19. Margaret Knack
  20. Jon Levy
  21. Anand Murthi
  22. Surena Namdari
  23. Laurence Okeke
  24. Randall Otto
  25. Douglas E. Parsell
  26. Teja Polisetty
  27. Padmavathi Ponnuru
  28. Eric Ricchetti
  29. Robert Tashjian
  30. Thomas Throckmorton
  31. Clay Townsend
  32. Melissa Wright
  33. Thomas Wright
  34. Zachary Zimmer
  35. Mariano E. Menendez
  36. Andrew Jawa
  1. Acromial stress fracture
  2. Scapular stress fracture
  3. Reverse shoulder arthroplasty
  4. Multicenter
  5. Risk factors
  6. Delphi process
License CC BY-NC-ND 4.0 (Attribution-NonCommercial-NoDerivatives)
Work Type Article
  1. Journal of Shoulder and Elbow Surgery
Publication Date September 16, 2021
Publisher Identifier (DOI)
Deposited January 26, 2023




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Work History

Version 1

  • Created
  • Added Predictors_of_Acromial_and_Scapular_Stress_Fracture_after_Reverse_Shoulder_Arthroplasty_An_ASES_Multicenter_Study_from_the_Complications_of_Reverse_Arthroplasty_Group.pdf
  • Added Creator Kuhan A. Mahendraraj
  • Added Creator Joseph Abboud
  • Added Creator April Armstrong
  • Added Creator Luke Austin
  • Added Creator Tyler Brolin
  • Added Creator Vahid Entezari
  • Added Creator Lisa Friedman
  • Added Creator Grant E. Garrigues
  • Added Creator Brian Grawe
  • Added Creator Lawrence Gulotta
  • Added Creator Michael Gutman
  • Added Creator Paul Anthony Hart
  • Added Creator Rhett Hobgood
  • Added Creator John G. Horneff
  • Added Creator Joseph Iannotti
  • Added Creator Michael Khazzam
  • Added Creator Joseph King
  • Added Creator Michael A. Kloby
  • Added Creator Margaret Knack
  • Added Creator Jon Levy
  • Added Creator Anand Murthi
  • Added Creator Surena Namdari
  • Added Creator Laurence Okeke
  • Added Creator Randall Otto
  • Added Creator Douglas E. Parsell
  • Added Creator Teja Polisetty
  • Added Creator Padmavathi Ponnuru
  • Added Creator Eric Ricchetti
  • Added Creator Robert Tashjian
  • Added Creator Thomas Throckmorton
  • Added Creator Clay Townsend
  • Added Creator Melissa Wright
  • Added Creator Thomas Wright
  • Added Creator Zachary Zimmer
  • Added Creator Mariano E. Menendez
  • Added Creator Andrew Jawa
  • Published
  • Updated Keyword, Publication Date Show Changes
    • Acromial stress fracture, Scapular stress fracture, Reverse shoulder arthroplasty, Multicenter, Risk factors, Delphi process
    Publication Date
    • 2021-10-01
    • 2021-09-16
  • Deleted Predictors_of_Acromial_and_Scapular_Stress_Fracture_after_Reverse_Shoulder_Arthroplasty_An_ASES_Multicenter_Study_from_the_Complications_of_Reverse_Arthroplasty_Group.pdf
  • Added Predictors_of_Acromial_and_Scapular_Stress_Fracture_after_Reverse_Shoulder_Arthroplasty_An_ASES_Multicenter_Study_from_the_Complications_of_Reverse_Arthroplasty_Group_Redacted.pdf
  • Deleted Predictors_of_Acromial_and_Scapular_Stress_Fracture_after_Reverse_Shoulder_Arthroplasty_An_ASES_Multicenter_Study_from_the_Complications_of_Reverse_Arthroplasty_Group_Redacted.pdf
  • Added Predictors_of_Acromial_and_Scapular_Stress_Fracture_after_Reverse_Shoulder_Arthroplasty_An_ASES_Multicenter_Study_from_the_Complications_of_Reverse_Arthroplasty_Group_edited.pdf