Surgical Anatomy of the Spinal Accessory Nerve in the Posterior Triangle of the Neck

ObjectiveThe major complication of neck dissection and surgery at the posterior triangle of the neck is severe disability of the shoulder or “shoulder syndrome”, which results from spinal accessory nerve injury. Surgical landmarks of the nerve in this area were studied.MethodsFifty-six fresh Thai cadavers (112 necks) were dissected to identify the anatomical relationship of the spinal accessory nerve and its commonly used landmarks.ResultsThe spinal accessory nerve was found within 3.6 cm (mean, 1.43 cm) above Erb's point. The distance between the spinal accessory nerve entering the trapezius muscle and the clavicle was between 2.6 cm and 6.9 cm (mean, 4.5 cm).ConclusionOur data were different from those described in the literature. Reconsideration of these two important landmarks can help to minimize iatrogenic injury of the spinal accessory nerve