Postoperative Periprosthetic Humeral Fractures After Reverse Total Shoulder Arthroplasty Treated with Open Reduction and Internal Fixation: A Retrospective Case Series

Background and Objectives: Postoperative periprosthetic humeral fractures after reverse total shoulder arthroplasty (RTSA) are challenging injuries, particularly in older patients with reduced bone stock. We evaluated the radiographic and clinical outcomes of open reduction and internal fixation (ORIF) in a selected cohort and examined the uncertainty associated with humeral stem stability. Materials and Methods: This retrospective, single-centre case series comprised 12 eligible patients (nine women; mean age, 77.9 ± 7.5 years) treated with plate-based ORIF between January 2016 and October 2022 and with at least three years of documented follow-up. Four fractures were Wright and Cofield type A, six type B, and two type C. Nine stems were judged stable and three showed reproducible motion during intraoperative assessment. All stems were retained. Clinical and radiographic outcomes were summarized descriptively, with exact binomial 95% confidence intervals (CIs) for selected proportions. Results: All 12 fractures met predefined radiographic criteria for union (100%; exact 95% CI, 73.5–100.0%) after a mean of 4.0 ± 0.8 months. At a mean follow-up of 4.3 ± 0.7 years, no stem loosening, fixation failure, or reoperation was recorded. Three patients experienced complications (25.0%; exact 95% CI, 5.5–57.2%): two reported superficial incisional infections managed without reoperation and one transient radial nerve deficit. The mean Disabilities of the Arm, Shoulder and Hand (DASH) score was 12.8 ± 4.7 (range, 6–20). Clinical shoulder motion was considered comparable with the contralateral side in six patients and mildly limited in six; quantitative goniometry and pre-fracture baselines were unavailable. Conclusions: In this small, highly selected series, ORIF was associated with radiographic union and satisfactory recorded functional outcomes. Three cases of intraoperative stem motion were successfully managed without exchange, but the absence of a comparator and possible indication bias preclude a general recommendation to retain a genuinely loose stem. Incomplete case-level and infection-prophylaxis information further limits interpretation.