Bifurcation of the Radial Nerve in the Arm as a Cause of Traumatic Partial Nerve Palsy: A Case Report

Abstract

Purpose: To describe the case of a traumatic partial nerve palsy following an open crushing arm injury. The partial palsy was due to the presence of radial nerve bifurcation in the proximal arm. Methods: A 23-year-old male was involved in a motor vehicle accident, where his motorbike crushed against a steel road divider sustaining multiple injuries in the spine, thorax, and right arm. On clinical examination, the patient presented a deep, blunt trauma on the posterior aspect of the proximal arm and partial radial nerve palsy was diagnosed with preservation of the brachioradialis and the extensor radialis longus muscle function. Surgical exploration was carried out. Results: An extensible posterior approach to the arm was performed and two main radial nerve branches were found. The lateral, more sizeable nerve, had an epineural hematoma without any distal response during intraoperative stimulation. The medial, thinner nerve trunk was preserved and, when stimulated, elicited response from the brachioradialis. Conclusion: We describe an uncommon variation of the radial nerve which was associated with partial palsy following blunt force trauma. This anatomical variation should be kept in mind in cases like the one described.