Radial Nerve Palsy Associated with Humeral Shaft Fractures: Incidence, Recovery Patterns, and Functional Outcomes in...

Background and Objectives: Radial nerve palsy is one of the most clinically important neurological complications associated with humeral shaft fractures. This study aimed to evaluate the incidence of radial nerve palsy in adult humeral shaft fractures and to investigate recovery patterns and functional outcomes in surgically treated patients. Materials and Methods: This single-center retrospective observational study included adult patients with humeral shaft fractures treated between November 2022 and January 2025. All adult humeral shaft fractures during the study period were screened to determine the overall rate of radial nerve palsy. The final functional analysis included surgically treated patients with radial nerve palsy. Demographic data, fracture characteristics, injury energy, fracture type, timing of radial nerve palsy, treatment modality, operative time, radial nerve exploration, additional surgery, time to nerve recovery, and QuickDASH scores were evaluated. Conservatively managed patients with radial nerve palsy were included in the calculation of overall incidence and recovery rates but were not included in the final functional analyses. Results: A total of 469 adult patients with humeral shaft fractures were evaluated. Radial nerve palsy was identified in 77 patients, corresponding to an overall rate of 16.4%. The rate was 46.4% in open fractures and 14.5% in closed fractures. Among the 77 patients with radial nerve palsy, 49 underwent surgical treatment and constituted the final analysis cohort, whereas 28 were managed conservatively. Recovery was observed in 25 of 28 conservatively managed patients (89.3%) and in 35 of 49 surgically treated patients (71.4%). Overall, radial nerve function recovered in 60 of 77 patients (77.9%). New-onset postoperative radial nerve palsy developed in 29 of 129 surgically treated patients without preoperative palsy (22.5%); however, recovery occurred in 22 of these 29 patients (75.9%), and the rate of persistent postoperative palsy was 5.4% among patients without preoperative palsy. In the surgical cohort, open fracture, longer operative time, and higher initial Cobb angle were associated with non-recovery. Recovery of radial nerve function was the only factor independently associated with better QuickDASH scores. Conclusions: Radial nerve palsy was more frequent in open humeral shaft fractures. Although recovery was high among conservatively managed patients, surgically treated cases showed a lower recovery rate, likely reflecting greater injury complexity. New-onset postoperative radial nerve palsy was relatively frequent, but most cases recovered. Recovery of radial nerve function was strongly associated with better upper extremity functional outcomes.