JSES - 2026-06-17 - Journal Article
Acromial stress fractures and reactions after reverse total shoulder arthroplasty: a case-control study.
Wiemer F, Coghlan JA, Bell SN
Topics
Key Takeaway
Acromial stress fractures/reactions occur in 11% of rTSA patients and are independently associated with corticosteroid use (aOR 9.6) and prior shoulder surgery (aOR 7.2), with significantly worse functional outcomes at final follow-up.
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Summary
This case-control study assessed incidence, risk factors, and outcomes of acromial stress fractures/reactions in 220 rTSA patients at a single Australian center. Incidence was 11% (24/220), with 75% being true fractures; multivariable analysis identified corticosteroid use (aOR 9.6) and prior shoulder surgery (aOR 7.2) as independent risk factors. Cases managed exclusively conservatively demonstrated significantly worse ASES, SPADI, DASH scores, forward elevation, and internal rotation compared to matched controls.
Key Limitation
Single-center Australian cohort with no operative management cases limits generalizability and prevents determination of whether surgical fixation of acromial stress fractures improves outcomes over conservative care.
Original Abstract
BACKGROUND
Acromial stress fractures can occur after reverse total shoulder arthroplasty (rTSA). We performed this study to assess the incidence, risk factors, characteristics, and outcome of acromial stress fractures and reactions after rTSA.
METHODS
We determined the incidence of acromial stress fractures and reactions in a cohort of patients who underwent rTSA, and assessed risk factors using a case-control design. Each patient who developed an acromial stress fracture or reaction after rTSA (case) was matched by date of rTSA with 2 patients who did not develop acromial stress fractures/reactions after rTSA (control subjects); univariate and multivariable analyses were performed to identify risk factors. Characteristics of acromial stress fractures/reactions are described. Outcomes were compared between cases and control subjects.
RESULTS
The incidence of acromial stress fracture/reaction after rTSA was 11% (24/220 rTSAs). Acromial stress fractures/reactions occurred at a median time of 5.5 months after rTSA (range: 20 days-118 months) and most were fractures (18/24, 75%). Using a multivariable analysis, we found 2 factors to be independently associated with the occurrence of an acromial stress fracture/reaction after rTSA: corticosteroids use (adjusted OR: 9.6, 95% confidence interval: 1.1-86.1, P = .04) and previous shoulder surgery (adjusted OR: 7.2, 95% confidence interval: 1.4-36.6, P = .02). In this cohort, in which the management was exclusively conservative, the occurrence of post-rTSA acromial stress fracture/reaction was associated with a significantly worse functional outcome at last follow-up visit, as compared with control subjects. This was illustrated by significantly lower American Shoulder and Elbow Surgeons Shoulder score, higher Shoulder Pain and Disability Index and Disabilities of the Arm, Shoulder and Hand scores, and worse forward elevation and internal rotation as compared with control patients who did not develop acromial stress fracture/reaction after rTSA.
CONCLUSIONS
In our Australian cohort, acromial stress fractures/reactions were relatively common after rTSA, and independently associated with corticosteroids use and previous shoulder surgery. The occurrence of acromial stress fracture/reaction was associated with a significantly worse functional outcome, as compared with patients who do not develop this complication after rTSA.