Long-Term Clinical Outcomes and Complications after Open Reduction and Internal Fixation (ORIF) with Locking Plate for Proximal Humerus Fractures: A Systematic Review and Meta-Analysis

Background Open reduction and internal fixation (ORIF) with locking plates remains a widely used head-preserving treatment for displaced proximal humerus fractures in adults. While short-term outcomes are well documented, long-term functional performance, complication burden, and implant survivorship beyond five years remain poorly defined. This systematic review and meta-analysis aimed to synthesise long-term (≥ 5 years) functional outcomes, complication rates, and reoperation rates following locking plate ORIF for proximal humerus fractures. Methods A protocol-registered (PROSPERO CRD420251156067) systematic review was conducted in accordance with PRISMA 2020 guidelines. PubMed, Scopus, and the Cochrane Library were searched for English-language randomized and non-randomized clinical studies reporting ≥ 5-year follow-up after ORIF with plate fixation for two-, three-, or four-part proximal humerus fractures in adults. Functional outcomes (Constant–Murley, DASH, UCLA, and Oxford Shoulder Score), complications, and reoperation rates were extracted. Random-effects meta-analyses were performed, with heterogeneity assessed using the I² statistic. Risk of bias was evaluated using RoB 2 and ROBINS-I, and certainty of evidence was graded using GRADE. Results Twelve studies encompassing 1,007 patients met the inclusion criteria. Follow-up ranged from 5 to nearly 15 years. Pooled analyses demonstrated no statistically significant long-term differences in Constant–Murley, DASH, or UCLA scores, although the Oxford Shoulder Score favored ORIF (mean difference 5.00; 95% CI 1.31–8.69). Long-term complications were common, particularly avascular necrosis (5–23%), screw penetration (9–15%), stiffness, and glenohumeral osteoarthritis (5–16%). Meta-analysis suggested a lower pooled risk of reoperation (RR 0.27; 95% CI 0.10–0.70) and complications (RR 0.07; 95% CI 0.04–0.12), though heterogeneity was substantial across all outcomes (I² 91–100%). Overall certainty of evidence was rated very low. Conclusion Locking plate ORIF for proximal humerus fractures provides acceptable but highly variable long-term functional outcomes, with a considerable burden of late complications and secondary procedures. These findings highlight the importance of careful patient selection, meticulous surgical technique, and long-term follow-up. High-quality prospective studies with standardized outcome reporting are needed to better define the durability of ORIF in this challenging injury.