Anatomical Of ALL On Lower Cervical Spine And The Effect Of ACDF Plate Position On Adjacent Segmental Degeneration

Objective:Through the measurement and observation of the anatomical data of the anterior longitudinal ligament C3-C7 of the lower cervical spine,and combining with clinical research,we explored the interference of titanium plate at different positions on the anterior longitudinal ligament,and then studied the influence of adjacent segment degeneration after ACDF.Methods:First,the anatomical data of the anterior longitudinal ligament of the lower cervical C3-C7 were measured and observed,and then a total of 41 patients(24 males and 17 females,aged 35 to 74 years,with an average age of 53.59 years)who underwent anterior cervical discectomy,decompression,interbody fusion and internal fixation(ACDF)in the Inner Mongolia Medical University Affiliated Hospital Orthopedics C Area from January 2020 to June 2022 were collected retrospectively;The follow-up time was 11-14 months,with an average follow-up time of 12.26 months.The position of the plate on the vertebral body was measured on the anteroposterior and lateral radiographs of the cervical spine after surgery.The ratio of the height of the adjacent intervertebral space(h)to the height of the adjacent vertebral body(H)at the last follow-up,the change of R value,and the angle between the upper and lower endplates of the adjacent intervertebral space were compared in groups αChanges and the degree of bone hyperplasia of adjacent segments.Results:The anatomical data of the anterior longitudinal ligament of the lower cervical C3-C7 were collected in four groups:the average length C3 13.90mm,C4 13.16mm,C5 12.845mm,C6 13.565mm,C7 14.57mm;The average width C3 7.46mm,C4 7.51mm,C5 12.27mm,C612.875mm,and C7 15.11mm.And the lower cervical spine C3-C7 anterior longitudinal ligament is closely connected with the front edge of the vertebral body,especially the upper and lower edges of the vertebral body,and the connection is relatively loose at the intervertebral disc.In group A,the plate position did not exceed 1/2 of the vertebral body,a total of 48 cases;In group B,the plate position was more than 1/2 of the vertebral body,a total of 27 cases.Measure the ratio R between the height of adjacent intervertebral space(h)and the height of adjacent vertebral body(H).Group A:the ratio R was 0.348± 0.033 for the first time after operation,and 0.353± 0.032 for the last follow-up,with a change of ratio R 0.005 ± 0.007;Group B:the ratio R was 0.355 ± 0.031 for the first time after operation,and 0.339 ± 0.025 for the last follow-up,and the change of ratio R-0.016 ± 0.015.The difference between the two groups was statistically significant(P<0.05)by using Independent Sample t-test.Angle between upper and lower endplates of adjacent intervertebral space α,Group A:included angle a was 2.927± 0.724 for the first time after operation,and 3.723±0.834 for the last follow-up,the change of angle change 0.7958 ± 0.4472;Group B:included angle a was 2.478± 0.5139 for the first time after operation,and 3.133± 0.5449 for the last follow-up,with a change of angle change 0.6556±0.4551.There was no statistically significant difference in the included angle between the two groups(P>0.05)by using Independent Samples t-test.At the last follow-up,the degree of hyperosteogeny in group A was 33 cases of grade 0,14 cases of grade 1,1 case of grade 2,and 0 case of grade 3;Group B:12 cases of grade 0,11 cases of grade 2,3 cases of grade 2 and 1 case of grade 3.The difference between the two groups was statistically significant(P<0.05)by using Fisher’s precision probability test.Conclusion:According to the anatomical characteristics of the relevant anterior longitudinal ligament in this study,it is better to consider that the end position of the titanium plate selected during the operation should not exceed 1/2 of the vertebral body,which can reduce the interference to the adjacent anterior longitudinal ligament bone attachment point and itself to a certain extent;Through postoperative follow-up,it was found that patients with a titanium plate end position not exceeding 1/2 of the vertebral body had a decrease in the height of the intervertebral space and the incidence of bone hyperplasia,and the incidence of ASD may also decrease accordingly.