The preservation of shoulder function after radical neck dissection.

The most disabling side effect of radical neck dissection is the 'shoulder syndrome', caused by denervation of the trapezius muscle. This is due to division of the spinal accessory nerve, the motor nerve to the trapezius. Using cadaver dissections the anatomy of the cervical spinal nerve supply to the trapezius has been studied. At radical neck dissection stimulation of these cervical spinal nerves produced contraction of the trapezius muscle. Thus a modified technique of radical dissection has been developed preserving the cervical spinal nerves to the trapezius. Comparison of patients undergoing this modified radical neck dissection with patients undergoing a classical radical neck dissection shows them to have better shoulder function.