Shoulder complaints after neck dissection; is the spinal accessory nerve involved?

The purpose of the current study was to investigate the relation between shoulder morbidity (pain and range of motion), and the function of the spinal accessory nerve after neck dissection. Identifying dysfunction of the nerve gives insight in the mechanisms of post-operative shoulder complaints. In total 112 patients after neck dissection (73 males/39 females), mean (SD) age 61 (13) years, participated in the study. The mean duration of follow up was 3 (2) years. Five patients had radical, 43 modified radical, 48 supraomohyoid, and 16 posterolateral neck dissection. Thirty-nine complained of shoulder pain of whom 20 (51%) had dysfunction of the spinal accessory nerve, and 19 (49%) did not. In total 29 patients (26%) had dysfunction of the spinal accessory nerve of whom 20 (69%) had shoulder pain. Shoulder pain was significantly related to dysfunction of the nerve (P<0.001). Twenty-three patients had a difference in active range of motion in shoulder abduction of ≥40°, of whom 22 (96%) had dysfunction of the nerve. A difference in active shoulder abduction of ≥40° was significantly related to loss of function of the spinal accessory nerve (P<0.001). Conclusion: Shoulder pain after neck dissection can only be attributed to dysfunction of the spinal accessory nerve in about 50%. If patients experience shoulder pain after neck dissection examination of the trapezius muscle and active bilateral abduction of the shoulder should be made to find out if the spinal accessory nerve is involved.