Optimal Time Period of Wearing Protective Collar After Anterior Cervical Discectomy and Fusion

Background: There is still no consensus on the time period of wearing collar after anterior cervical discectomy and fusion (ACDF). We aim to investigate the optimal time period of wearing protective collar.Methods: We retrospectively reviewed patients with cervical spondylosis who underwent one to two segment ACDF during January 2016 and December 2017, and included 97 patients who meet inclusion and exclusion criterion. Patients were divided into three groups according to the actual time period of wearing collar after ACDF including 1-4 week group, 5-8 week group, and 9-12 week group. We analyzed Japanese Orthopedic Association (JOA) score, Axial Symptom (AS) score and Neck Disability Index (NDI) before surgery and at post-operative 3 months to investigate the optimal time period of wearing collar.Results: JOA score: All three groups have a better post-operative JOA score compared with that before surgery (paired t test, p<0.05). There is no significant difference among the three groups with respect to post-operative JOA (ANOVA, p>0.05).AS score: The post-operative AS scores of 1-4 week group and 5-8 week group were significantly better than that before surgery (paired t test, p>0.05). While the post-operative AS score of 9-12 week group was significantly worse than preoperative AS score (paired t test, p<0.05).NDI: All three groups have a better post-operative NDI compared with that before surgery (McNemar test, p<0.05). Of note, in 5-8 week group, the percentage of no deficit increased by 45%, and the percentage of mild deficit decreased by 45% accordingly. That percentage is 26% and 31% in 1-4 week group and 9-12 week group, respectively. There was significant difference among these three groups (Fisher's exact probability test, p<0.05)Conclusions: For cervical spondylosis patients who underwent 1-2 segment ACDF, the optimal time period of wearing protective is 5-8 weeks. This time period results in comparable neurological outcome, least axial symptom risk, and highest chance of no deficit on neck function.