Prognostic factors for radial nerve palsy associated with humeral shaft fracture

Abstract

Background: Radial nerve palsy (RNP) associated with humeral shaft fracture is a common injury pattern in trauma patients. The management of RNP associated with humeral fractures in high-energy trauma is controversial and poses a challenge to surgeons treating it. Purpose: Based on a review of our experience over the past 15 years, we determined the prognostic factors of radial nerve recovery after humeral fractures, evaluated the diagnostic role of nerve conduction studies and electromyography (EMG), and compared the outcomes of different treatment strategies. Materials and Methods: The data of 26 patients having RNP associated with humeral shaft fractures over a 15-year period were collected for a retrospective review. For statistical analysis, the patients were divided into groups on the basis of their recovery from RNP and the treatment strategies used. Results: The incidence of RNP associated with humeral fractures was 2.05%. In total, 91.3% of patients with primary RNP in this series experienced high-energy trauma. Spontaneous recovery was observed in 9 of 26 patients (34.6%). Radial nerve lesions were found in 7 of 8 patients with high-energy trauma. The severity of humeral shaft fractures was found to be a significant prognostic factor for spontaneous recovery from RNP. The rate of spontaneous recovery was significantly higher in the AO Foundation and Orthopaedic Trauma Association Type A humeral shaft fractures (P = 0.028) and lower in Type C fractures (P = 0.055). The median time to detect initial radial nerve recovery using EMG was 34 and 75 days after injury (P = 0.033). In high-energy trauma, tendon transfers were associated with more predictable outcomes than nerve reconstruction (favorable functional recovery: 100% for tendon transfers vs. 25% for nerve reconstruction, P = 0.007). Moreover, tendon transfers were associated with a shorter overall treatment duration (median treatment duration: 190 days for tendon transfers vs. 422 days for nerve reconstruction, P = 0.007). Conclusion: The prognosis of RNP associated with humeral shaft fractures in high-energy trauma is less favorable, with a low rate of spontaneous recovery. EMG is helpful for the early detection of initial nerve recovery. The outcomes of tendon transfers in high-energy trauma are predictable and the treatment duration is shorter. First-intention tendon transfer is a reasonable treatment strategy in patients with difficult nerve exploration, lower requirement for functional recovery, and lower compliance with treatment.