An Acta Orthopaedica educational article: Treatment of adult patients with a humeral shaft fracture.

This educational review outlines the core principles of humeral shaft fracture (HSF) management and is designed for orthopedic trainees, general orthopedic surgeons, emergency physicians, and allied health professionals who participate in the acute or postoperative care of patients with HSFs. The content integrates the authors' expert opinion with the current evidence. Humeral shaft fractures account for 1-3% of adult fractures, most often resulting from low-energy falls in older adults or high-energy trauma in younger patients. Although open fractures and neurovascular injuries are rare, primary radial nerve palsy (RNP) occurs in about 10% of cases. Diagnosis relies primarily on clinical evaluation and standard radiographs, with CT or MRI reserved for complex or pathological cases. Functional bracing has traditionally been the mainstay of nonsurgical treatment, achieving good long-term results but with nonunion rates up to 25%. Surgical fixation methods-including open reduction and internal fixation, minimally invasive plate osteosynthesis, and intramedullary nailing-allow earlier mobilization and more predictable fracture union but carry risks of iatrogenic RNP and infection. Management of primary RNP remains largely nonsurgical, with over 90% recovering spontaneously. Nonunion is frequently symptomatic and managed most often with compression plating. Surgery offers faster early recovery and lower nonunion rates, although long-term outcomes converge with successful bracing. Cost-effectiveness analyses suggest surgery may be more economical when productivity loss is considered, particularly for working-age patients. Optimal treatment selection depends on patient age, activity level, fracture characteristics, and patient preference, emphasizing shared decision-making.