Shoulder-arm-syndrome after radical neck dissection: its relation with the innervation of the trapezius muscle.

In a clinical and electromyographic follow-up of 54 patients who underwent radical neck dissection, vast differences in the individual severity of the shoulder-arm-syndrome were found: 31% experienced severe limitations of shoulder mobility combined with severe pain, whereas 41% suffered only mild discomfort and 28% were free of complaints. These clinical findings were compared to recent anatomical observations concerning individual patterns of innervation of the trapezius muscle. It could be shown that the role of the cervical plexus in the innervation of the trapezius muscle is of great importance and that its subfascial branches are able to maintain the motor supply following radical neck dissection in about 2/3 of patients.