Abstract
Background Non-operative management of humeral shaft fractures, which is a common challenging upper limb injury, using a functional brace, remains widely practiced. However, modern reported outcomes vary, and actual union rates may differ from the historic benchmarks. Objective To evaluate the union rate and overall success of humeral shaft fractures treated conservatively in a functional brace, and to analyse how fracture level and pattern may influence outcomes. Methods This retrospective audit included adult patients with closed humeral shaft fractures managed in a functional brace between January 2012 and January 2019. The study was conducted at University Hospitals Birmingham NHS Foundation Trust, including two major teaching hospitals, and was registered under the institutional clinical governance system (Audit Code: CARMS-19262). Data were obtained from orthotics records across both sites. Demographics, fracture characteristics, complications, and outcomes were analysed. Failure was defined as surgical fixation for malalignment or non-union, or persistence of non-union at final follow-up. Results Eighty-eight patients met the inclusion criteria (mean age 61.8 years, 58% female). Union was achieved in 78.4% of cases, and the overall success rate, defined as union without subsequent surgery, was 67 %. Conversely, 33% of patients (n=29) failed brace treatment, with 25% (n=22) ultimately requiring surgical fixation. Proximal and mid-shaft fractures showed higher rates of delayed or non-union compared with distal shaft fractures. Fracture pattern (transverse, oblique, spiral, comminuted) did not significantly influence union or failure. Conclusion Functional bracing achieved a modest union rate compared with historical data. Fracture level, particularly proximal and mid-shaft involvement, was associated with a significantly higher rate of non-union. Future studies should assess the influence of patient compliance, initial alignment, and brace fit on union potential.