| Study Design: Retrospective study.Objectives: To analyze the sagittal balance after single-level cervical disc replacement(CDR)and anterior cervical discectomy and fusion(ACDF)Methods: We retrospectively analyzed 22 cases of single-stage anterior cervical discectomy and bone graft fusion and 22 cases of single-stage cervical disc replacement from July 2013 to July 2017 in the First Affiliated Hospital of Fujian Medical University.Clinical and radiographic data of patients with cervical degeneration.The Japanese Orthopaedic Association’s Scores(JOA)and improvement rate were used to evaluate the recovery of cervical nerve function,and the cervical disability index(NDI)was used to assess neck function and disability.The preoperative,postoperative and final follow-up parameters were obtained from the whole cervical sagittal balance,including T1 slope,C2-C7 SVA(C2-C7 sagittal vertical axis),C2-C7 Cobb angle,and the partial sagittal balance parameters of the cervical spine,including: Functional spine unit angle(FSU),Disc Angle(DA),Anterior Spacing(AS);Posterior distance(PS).Cervical vertebrae activity parameters,including: total cervical range of motion(ROM),The activities of the cervical spine in the upper and lower segments of the operation were analyzed.Results: A total of 22 CDR cases were included in the research,of which C5-6 was the most common operative segment of the CDR(68%),with C4-5 accounting for 18% and C3-4 accounting for 14%.At the same time,22 cases of ACDF were included.C4-5 was the most common surgical segment of ACDF(36%),C5-6 accounted for 27%,C3-4 accounted for 23%,and average follow-up was 6.7(3-40)months.Before surgery,the whole sagittal balance of the cervical was comparable between the two groups.At the time of postoperative and final follow-up,there was no statistically significant difference in the whole sagittal balance of the cervical spine between the two groups.In the observation of the partial cervical sagittal balance of the replacement group,FSU increased from preoperative(0.35±5.23°)to postoperative(3.95±5.16°),and DA increased from preoperative(2.78±2.3°)to postoperative(4.32±2.42°),and AS increased from preoperative(2.09±0.27cm)to postoperative(2.31±0.21cm),and PS increased from preoperative(2.01±0.20cm)to postoperative(2.11±0.19cm).All have statistical significance.In the fusion group,AS increased from preoperative(1.91±0.27cm)to postoperative(2.16±0.30cm),and PS increased from preoperative(1.82±0.20cm)to postoperative(2.02±0.22cm).The DA and FSU were not statistically significant at postoperative and final follow-up.In terms of cervical mobility,the preoperative replacement group was similar to the cervical ROM and adjacent segment ROM of the fusion group.At the final follow-up,the total ROM of the fusion group decreased from preoperative(47.9±13.1°)to(37.4±11.3°),the was statistically significant.There was no significant difference in the total ROM of the cervical spine between the preoperative group and the last follow-up group.It was found in the ROM of the adjacent segment of the fusion group was preoperatively(6.32±0.53°)increased to the final follow-up(7.98±0.69°),ROM of the inferior adjacent segment increased from preoperative(6.23±0.42°)to(8.12±0.58°)at the final follow-up,and it was statistical significance,but ROM of the adjacent segment of the replacement group was not statistically different between preoperation and the last follow-up.At the last follow-up,the ROM of the adjacent segment of the fusion group was lower than that of the replacement group(P<0.05).The JOA scores of the two types of surgery were significantly improved compared with preoperative,and were more statistically significant than those before the treatment.[ACDF:(13.95)±1.32)vs(16.32±0.71),P<0.05;CDR group:(13.77±1.41)vs(16.27±0.76),P<0.05].The NDI scores of the fusion group and the replacement group at the last follow-up were significantly lower than before the surgery,with statistically significant differences.[ACDF group:(29.53±6.69)vs(7.57±2.88),P<0.05;CDR group:(31.33±8.59))vs(8.19±3.75),P<0.05].Conclusions: Single-segment anterior cervical discectomy fusion and cervical disc replacement had no significant effect on the whole sagittal balance of the cervical spine after surgery and at the final follow-up.In the partial cervical segmental sagittal balance of the surgical segment,cervical disc replacement can increase the cervical lordosis of the surgical segment and has advantages over the ACDF in restoring the partial sagittal balance of the cervical spine.Cervical disc replacement can make the whole cervical spine more flexible.As the activity of the surgical segment is preserved,the activity in the adjacent segment is reduced,the stress is reduced,and may help reduce Adjacent Segment Degeneration occurrence rate. |
