Neurologic Complications in Shoulder Surgery: Anatomy, Mechanisms, and Surgical Recommendations.

Intraoperative nerve injuries during orthopaedic shoulder procedures can cause pain, paresthesia, and muscle weakness. Iatrogenic nerve injuries are often transient or subclinical, and it is believed that many neurologic injuries go undiagnosed. Several risk factors predispose patients to intraoperative nerve injury, including local tissue stiffness, revision surgery, low body mass index, medications, and decreased range of motion. Apart from patient-specific risk factors, there are direct and indirect mechanisms of injury related to surgical technique, including device implantation, nerve traction, patient positioning, retractor placement, and portal placement. Cadaveric, clinical, and intraoperative neuromonitoring studies have advanced our understanding of surgical anatomy and intraoperative mechanisms underlying nerve injuries during shoulder surgery. The primary purpose of this article is to review the neurologic complications during common open and arthroscopic shoulder procedures. This review will detail the neuroanatomic proximities around the shoulder, as well as provide recommendations from the literature on avoiding nerve injury.