Short Plate With High Angle Screw Has Better Imaging Results In ACDF

Background:Since the development of anterior cervical surgery technology,anterior cervical discectomy and fusion(ACDF)has become a common surgical method for the treatment of nerve root pain or cervical degenerative diseases related to myelopathy,and has been widely recognized by surgeons.However,there are few studies on the optimal size and position of intraoperative plate internal fixation system.The purpose of this study was to investigate the effects of different plate-screw systems on the height and angle of the surgical segment and on the adjacent segments.Objective:To study the effect of implanting different sizes and positions of steel plate-screw systems on the height,angle and adjacent segments of the surgical segment and the clinical results in patients undergoing single-segment ACDF surgery,so as to help doctors select the best internal fixation system of steel plate during surgery.Methods:The imaging and clinical data of 119 patients who underwent single-segment ACDF in China-Japan Friendship Hospital of Jilin University from January 2017 to December 2021 were analyzed.According to the distance between the distal end of the plate head and the adjacent upper endplate(L1),the patients were divided into the following two groups: group A(L1 ≥ 5 mm)and group B(L1 < 5mm).According to the distance between the distal end of the plate and the adjacent lower endplate(L2),the distal end of the plate was divided into the following two groups: group C(L2 ≥ 5 mm)and group D(L2 < 5mm).The imaging data included cephalic screw implantation angle(α1),caudal screw implantation angle(α2),C2-7Cobb angle(α3),local Cobb angle(α4),operative segment height(H)and adjacent segment ossification(ALOD).The evaluation of clinical treatment effect included JOA score,JOA score improvement rate and VAS score.The related data were analyzed by independent sample t-test,paired ttest and nonparametric test.Results:In the general basic condition of the patients,there were only gender differences between groups A and B and between groups C and D(P < 0.001,P=0.001).Through the correlation analysis of screw implantation angle,it was found that α1 was positively correlated with L1,and α2 was positively correlated with L2(0 < R < 1,all P < 0.05)in the II study.During the comparison within the group,the operative segment height,α3and α4 in group A and B and group C and D were significantly higher than those before operation(all P < 0.05).There was no significant difference in preoperative segment height and angle between group A and group B,group C and group D(all P > 0.05),Patients in group A and group C,respectively,compared with group B and group D,the loss of segment height and α4 and the incidence of ALOD were significantly lower(all P< 0.05),but there was no significant difference in α 3(all P > 0.05).As for the clinical results,the JOA score of each group increased significantly after operation and during follow-up(all P < 0.05),while the VAS score decreased significantly after operation and follow-up(all P < 0.05).There was no significant difference in JOA score and improvement rate between the two groups before operation,after operation and during follow-up.At the last follow-up,the VAS score of group A was better than group B and group C was better than group D(P=0.005,P=0.008).Conclusion:ACDF can effectively relieve the clinical symptoms of patients by decompression of spinal cord and nerve root,internal fixation system of steel plate and implantation of fusion cage.The distance between the two ends of the plate from the adjacent endplate is positively correlated with the angle of the screw.The choice of short plate can provide high-angle screw implantation.When choosing the combination of shorter plate and higher-angle screw,it can effectively reduce the loss of surgical segment height and angle,reduce the incidence of ALOD,and is expected to achieve better long-term clinical results.