The integrity of the spinal accessory nerve is fundamental to thoracoscapular function and essential for scapulohumeral rhythm. This nerve is vulnerable along its superficial course. This study assessed the delay in diagnosis and referral for management of damage to this nerve, clarified its anatomical course and function, and documented the results of repair. From examination of our records, 111 patients with lesions of the spinal accessory nerve were treated between 1984 and 2007. In 89 patients (80.2%) the damage was iatropathic. Recognition and referral were seldom made by the surgeon responsible for the injury, leading to a marked delay in instituting treatment. Most referrals were made for painful loss of shoulder function. The clinical diagnosis is straightforward. There is a characteristic downward and lateral displacement of the scapula, with narrowing of the inferior scapulohumeral angle and loss of function, with pain commonly present. In all, 80 nerves were explored and 65 were repaired. The course of the spinal accessory nerve in relation to the sternocleidomastoid muscle was constant, with branches from the cervical plexus rarely conveying motor fibres. Damage to the nerve was predominantly posterior to this muscle.

Despite the delay, the results of repair were surprising, with early relief of pain, implying a neuropathic source, which preceded generally good recovery of muscle function.

Intraspinal re-implantation after traumatic avulsion of the brachial plexus is a relatively new technique. Three different approaches to the spinal cord have been described to date, namely the posterior scapular, anterolateral interscalenic multilevel oblique corpectomy and the pure lateral. We describe an anatomical study of the pure lateral approach, based on our clinical experience and studies on cadavers.