Study of the Shoulder Function after Neck Dissection

Background and Objectives:Radical neck dissection (RND has been a standard treatment for the head and neck cancer with metastasis to the cervical lymphatics. The sacrifice of the spinal accessory nerve which innervates the trapezius muscle creates a definite impairement of the shoulder function. Therefore, the modified radical neck dissection (MRND has been introduced in order to minimize the postoperative morbidities. But, even if the spinal accessory nerve has been preserved, the impaired shoulder function has been reported in some studies. The degree of the shoulder dysfunction after RND tended to be minimal in a few patients. The purpose of this study was to evaluate the shoulder function according to the various types of the neck dissection in 39 cases of 24 patients. Materials and Methods:The shoulder functions were evaluated using clinical examinations and the electrodiagnostic method of the trapezius muscles. The results of each test according to the types of neck dissection were compared. Results:We observed a significant correlation between the clinical parameters and electrodiagnostic results. The functional results of the trapezius muscle in the group of modified radical neck dissection were better than that of the radical neck dissection. In the RND group, 80% of the cases presented incomplete denervation of the trapezius muscle, so it might provide a evidence of innervation of the other nerves to this muscle. In the MRND group, 45% of the cases presented partial denervation of the trapezius muscle, indicating that it might have been caused by damage during the operations. Conclusion:We found that careful manipulation of the nerve should be required in order to preserve the spinal accessory nerve. Rehabilitative therapy can also improve the shoulder function after neck dissection. Further studies including anatomic dissection and intraoperative electrophysiologic evaluation of the innervation in the trapezius muscle should be performed. (Korean J Otolaryngol 1998;41(5 :647-652