Clinical and Radiographic Outcomes of Chronic Anterior Dislocations Treated with Reverse Total Shoulder Arthroplasty

Background Reverse total shoulder arthroplasty (rTSA) for chronic locked anterior shoulder dislocations (CD) remains challenging due to glenoid bone loss, soft-tissue contractures, and risk of postoperative stiffness and instability. Outcomes of rTSA for CD remain poorly defined, particularly compared with rTSA for proximal humerus fractures (PHF), another high-risk indication associated with inferior results relative to traditional rTSA indications. This study evaluated clinical and radiographic outcomes of rTSA for CD versus PHF. We hypothesized CD patients would demonstrate inferior postoperative outcomes compared with PHF patients. Materials & Methods A retrospective review was performed of all patients who underwent rTSA for CD or PHF between August 2015 and November 2024 at a single academic institution. CD patients were matched 1:3 to PHF controls using propensity scores, controlling for age at surgery, gender, body mass index, American Society of Anesthesiologists score, diabetes status, smoking status, insurance type, and follow-up duration.Collected variables included demographics, mechanism of injury, time to surgery after injury and preoperative radiographic findings. Postoperative outcomes included active forward elevation (AFE), active external rotation (ER), internal rotation (IR) score, complications and reoperations. Patient-Reported Outcomes Measurement Information System (PROMIS) scores, including PROMIS Upper Extremity (P-UE), PROMIS Pain Interference (P-Interference), and PROMIS Pain Intensity (P-Intensity) were also recorded. Results A total of 17 CD patients were included in this study. 11 patients had pure anterior dislocation, six patients had an associated glenoid fracture, and three had additional greater tuberosity fractures. The CD cohort collectively was then matched to 51 PHF controls. The mean follow-up was duration was 28.1 (CD) and 20.9 (PHF) months (p = 0.39).There were no differences in the postoperative AFE, ER, and IR measurements between the CD and PHF cohorts. Heterotopic ossification (capsular ossification) was more common in the CD group (23.5% vs. 3.9; p = .04) but there were no differences in other complications, revision or reoperation rate between the CD and PHF cohort. The CD cohort demonstrated lower P-UE scores compared with PHF patients (36.2 ± 8.6 vs 56.6 ± 9.8, P < .001). CD patients also had higher P-Interference scores (53.9 ± 9.0 vs 46.2 ± 10.1, P = .03). Conclusion rTSA for CD results in lower functional outcome scores and higher pain interference scores, but comparable range of motion compared to rTSA for PHFs. The presence of a glenoid fracture or greater tuberosity fracture did not affect outcomes of rTSA in patients with CD.