Incidence and risk factors of acromial fracture following reverse total shoulder arthroplasty

Abstract

Background: The occurrence and related predictors of acromial fracture following reverse total shoulder arthroplasty (RTSA) have not been fully elucidated. The aim of this study was to determine the incidence and risk factors of acromial fractures after RTSA. Methods: We conducted a multicenter, retrospective case-control study of 787 cases (29 in acromial fracture group and 758 in control group) that underwent RTSA performed by 6 surgeons. The mean duration of follow-up after RTSA was 31.6 AE 21.8 months (range, 12-136 months). Demographic variables (age, sex, arm dominance, body mass index, working status, bone mineral density [BMD]), clinical variables (preoperative diagnosis, previous operation, implant design, preoperative clinical scores, screw size in glenoid fixation, postoperative rehabilitation), and radiographic variables (acromial thickness, critical shoulder angle, deltoid length, humeral offset to lateral acromion) were investigated. To determine risk correlation, univariate analysis and multivariate logistic regression analysis with calculated odds ratios (ORs) were performed. Results: Postoperative acromial fractures occurred in 29 of the 787 shoulders with RTSA (3.7%). Acromial fractures were detected at a mean of 10.0 months (range, 1-66 months) postoperatively. Univariate analysis revealed that the occurrence of an acromial fracture was significantly associated with a previous operation (38% [11 of 29] vs. 21% [156 of 758], P ¼.025) and BMD (-2.33 vs. -1.74, P ¼.013). Multivariate logistic regression analysis found that the occurrence of a postoperative acromial fracture was significantly associated with a previous operation (P ¼ .034; OR, 2.91; 95% confidence interval, 1.08-7.84) and deltoid length (P ¼ .004; OR, 1.04; 95% confidence interval, 1.01-1.07). Conclusion: Acromial fracture following RTSA is not an uncommon complication, with an overall incidence of 3.7%. A previous operation, increased deltoid length, and low BMD were risk factors of acromial fracture following RTSA.

Incidence, radiographic predictors, and clinical outcome of acromial stress reaction and acromial fractures in reverse total shoulder arthroplasty

“…The biomechanical influence of RTSA design and RTSA positioning on acromial stress remain controversial. 2,10,11,15,24,34,42,44 .…”

“…The current literature lacks identifying predictive radiographic factors for ASF and ASR with albeit contradicting study results. 11,15,42,44 Biomechanically, the RTSA works by medializing and distalizing the center of rotation 6 . Our data showed no effect of distalization on the incidence of ASF and ASR measured as ACHD and deltoid lengthening.…”

Mid- to long-term clinical outcomes after press-fit short stem reverse shoulder arthroplasty

“…The present study also revealed that patients with indication of trauma sequelae for RSA had lower absolute and age-/sex-adjusted CS compared to patients with indications of cuff tear arthropathy, massive rotator cuff tear, and primary osteoarthritis. Interestingly, Cowling et al 8 found that patients undergoing RSA for trauma sequelae had higher risks for intraoperative complications, while Cho et al 7 found higher risks for acromial fracture after RSA in patients that had prior surgery. It is noteworthy that 3 of the 7 patients that did not receive a substantial clinical benefit were treated for trauma sequelae after failed previous interventions, and 2 of the 3 also had postoperative fractures, one of the acromion and the other of the scapula.…”

Scapular Fractures After Reverse Shoulder Arthroplasty

“…Werthel et al 19 reported osteoporosis was significantly associated with acromial fracture group compared with the control group (46% versus 12%, P = 0.027). In addition, Cho et al 25 also recently found that osteoporosis was an independent predictor of ASF.…”