Radial nerve injuries in humeral fractures: case series and medico-legal implications.

Introduction: Radial nerve injury following humeral fracture is the most common peripheral nerve injury associated with long bone fractures. The purpose of this study is to analyse our treatment protocols and long-term outcomes of humeral fractures associated with radial nerve injury which were surgically treated at the I.R.C.C.S. Orthopaedic Institute Galeazzi (Milan, Italy).

Materials and methods: The study was designed to evaluate retrospectively 30 patients, 15 men and 15 women, affected by humeral fracture associated with radial nerve palsy, treated at Orthopaedic Institute Galeazzi (Milan, Italy) from 1st January 2012 to 31st December 2022. Radial nerve injury was diagnosed based on the clinical evaluations of the neurological deficit. The cases were analyzed for any documented sensory impairment, wrist extensor weakness and/or finger weakness, with or without a "drop-hand" posture described in the patient's medical record at admission or throughout the hospital stay. Patients with pathological humeral shaft fractures were excluded. All patients, accounted for the study, were operated under general anaesthesia, and no peripheral nerve block was performed.

Results: The treatment of this clinical condition represents a challenge for orthopaedic surgeons. Most patients (86.7%, 26 patients) experienced total recovery of the radial nerve function during the follow-up period, whereas only 4 patients achieved a partial nerve function recovery, with lingering weakness when extending the fingers.

Conclusions: The chronic outcomes arising from surgical treatment of the humeral fracture with related radial nerve injury can lead to impairment sequelae of greater clinical-functional significance, with possible medico-legal implications. Radial nerve injury constitutes one of the most common complications arising from humeral fracture. The course of the nerve and its close relationship with the humerus are likely to entail a high risk of injury with shaft fractures. A treatment algorithm should be recommended for the management of radial nerve injury associated with humeral shaft fracture.