Nerve Injuries in Proximal Humeral Fractures

Abstract

Nerve injuries in proximal humeral fractures are not uncommon. Nerves of the shoulder region are close to skeletal structures, and some areas are intimately related to soft tissue. Injuries that occur after shoulder dislocation and/or fractures due to nerve elongation are the most common. Nerves can also be damaged during surgical reduction and fixation procedures; the most frequently involved mechanisms are traction on soft tissue, extreme shoulder movement, and screw implantation. It is essential to proceed with a clinical evaluation of possible nerve lesions immediately after trauma, after primary treatment, and at follow-up to identify nerve lesions. In the majority of cases, nerves present neurapraxia and axonotmesis damage, so recovery is frequently complete a few months after trauma. Neurophysiologic examination with EMG is indicated 25–30 days from trauma if neurological signs do not improve. Only a few cases need surgical exploration; open procedures are necessary 3–6 months from trauma. The most frequent surgical procedures are nerve grafting or neurotization that give good neurological recovery. Conducting complete cuff study with US and MRI before surgical procedure on nerves is of paramount importance to obtain good functional results. Tendon transfers are indicated in patients not experiencing neurological recovery 1 year after nerve repair or if the nerve repair was not possible for clinical conditions, comorbidities, or age.