Abstract B22: A novel measurement neck brace for detecting range-of-motion changes with electromyography correlates in head and neck cancer patients undergoing neck dissection: A prospective pilot study

Introduction: Postoperative neck and shoulder dysfunction is recognized as a morbidity of neck dissection (ND) in head and neck cancer patients. However, the precise biomechanics and duration of neck mobility limitation have not been fully described. In current practices of more selective NDs, studies employing precise measurement techniques are needed to quantify the risk of postoperative neck range of motion (ROM) impairment in this patient population. Study Design: A prospective pilot study of five patients undergoing selective ND for head and neck cancer was conducted. A novel measurement brace was used to collect kinematic and concurrent EMG data on active ROM during standardized tasks for prespecified neck muscle groups at baseline and following ND. Methods: Patients without prior surgery or radiation undergoing unilateral ND for head and neck cancer were included. Patients were evaluated preoperatively and four weeks postoperatively. A novel neck brace developed for the purposes of this study was utilized to measure flexion, extension, lateral bending, axial rotation, and rolling movements. Angle of motion was measured from the neutral position to the end of each movement type as well as during total ROM from one movement type to the other (i.e., from neutral position to flexion as well as from flexion to extension). Baseline and postoperative EMG onset/offset data were collected for bilateral SCM, splenius capitis, and trapezius muscles to correlate muscle activation with angle of motion. Results: Five patients undergoing unilateral modified ND for cutaneous, oral cavity, or oropharyngeal squamous cell carcinoma completed preoperative and postoperative assessments. The average age was 57 years (54-60; sd 2.6). The greatest change in total ROM following surgery was seen in lateral bending, with a mean angle change of 17.3 (6.9-30.6; sd 8.5). Differences in lateral bending from neutral position were also seen for both the dissected and nondissected sides. Although degree of flexion and extension ROM were not affected by surgery overall, changes in the pattern of muscle group activation were evident. Conclusions: Measurement brace recordings suggest that active ROM limitation is most pronounced with lateral neck bending both to the ipsilateral and contralateral side of ND compared to other neck movements. EMG correlate data show increased variability in activation of muscle groups with flexion and extension movements. These preliminary results suggest that this device may serve as a useful diagnostic tool for patients undergoing ND. Additional data are needed to determine statistical and clinical significance of changes measured using this device. Future results may help guide clinicians in counseling patients about expectations following surgery as well as lead us to potential therapeutic targets from changes in muscle activation. Citation Format: Biing-Chwen Chang, Haohan Zhang, Ade Obayemi, Sallie Long, Scott Troob, Sunil Agrawal. A novel measurement neck brace for detecting range-of-motion changes with electromyography correlates in head and neck cancer patients undergoing neck dissection: A prospective pilot study [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr B22.