Comparison Of The Early Outcomes Of Cervical Total Disc Replacement （Prodisc-C Vivo） And Anterior Cervical Discectomy And Fusion （Zero-P） For The Treatment Of Single Level Cervical Spondylosis

Objective: To compare the early clinical outcomes and the impact on cervical segmental movement of Prodisc-C Vivo cervical disc replacement and Zero-P fusion in the treatment of single-segment cervical spondylosis.Methods: Fifty six patients with single-segment cervical spondylosis who received Prodisc-C Vivo cervical artificial disc replacement or Zero-P fusion at Peking University Shenzhen Hospital from January 2015 to December 2018 were retrospectively analyzed.The operation time,blood loss,length of postoperative hospital stay,time of returning to work,spinal nerve function JOA score,neck disability index（NDI）and pain visual analogue scale（VAS）were recorded and analyzed.The clinical efficacy of preoperative period,postoperative 3,12 months and last follow-up was compared and evaluated.Additionally,range of motion（ROM）of the overall cervical spine C2-7,the curvature of the cervical spine,ROM of the surgical segment and adjacent segments,the bone resorption after operation and heterotopic ossification were measured postoperatively.Results: All the patients from these two groups were followed up for more than 26 months.No postoperative complications such as hematoma,infection or dysphagia were found;also,all the wounds healed well in both groups.There were three cases（11%）of heterotopic ossification in the CVivo group（one each in grades I,II and III）and two cases（7.4%）of bone resorption in the operated segment（one each in grades I and II）.Additionally,in these two groups,no postoperative displacement,loosening or breakage of the internal fixation of the implants was recorded.The operation time in the CVivo group was 56.48±7.18 min,and the intraoperative blood loss was14.23±5.04 ml,which was not different with those in the Zero-P group（60.17±8.18 min,16.21±6.77ml）（P > 0.05）.The postoperative hospital stay of the CVivo group was 3.52±0.85 days which was notably less than that of the Zero-P group（4.48±0.95 days）（P<0.05）.During the follow-up period,the postoperative JOA score,NDI score and VAS score of the both groups were significantly improved when compared to those before surgery,but there were no statistical difference between the CVivo group and Zero-P groups（P>0.05）.Furthermore,no statistical difference between the upper and lower adjacent segment activity of the CVivo group at the last follow-up（9.94 ± 1.75 °,7.49 ± 1.38 °）and preoperative adjacent segment activity（10.02±3.04°,8.42±2.01°）was seen,while the upper adjacent segments of the Zero-P group increased significantly at the last follow-up when compared with the value before surgery（11.51 ± 1.73°VS 10.07 ± 2.69°）.Conclusion: Both the Prodisc-C Vivo disc replacement and Zero-P fusion have good early clinical outcomes;Prodisc-C Vivo is able to maintain the physiological mobility of the surgical and to avoid excessive movement of adjacent segments.