Study On The Correlation Between Cervical Sagittal Balance Parameters Of Undergoing Posterior Cervical Laminoplasty Patients And Postoperative Complications

Object:Aims to explore whether the change of cervical sagittal balance parameters after posterior cervical laminoplasty is relate with postoperative complications or not.Method:Retrospective analysis of 60 cases with complete follow-up data,all patients were visited in the Department of Orthopedics,Affiliated Hospital of Inner Mongolia Medical University.All cases were performed by the same skilled and experienced physician,the surgical procedure is the posterior cervical single-door expansion laminoplasty,collect patients’standard cervical anterior and lateral X-rays before surgery and during follow-up,cervical sagittal balance parameters are C_2-7Cobb angle,C_2-7SVA and T₁S,all of them should be measured on imaging data,and calculate the difference of these parameters between preoperative and follow-up,mark the value as（35）C_2-7Cobb angle,（35）C_2-7SVA,（35）T₁S,the measurement is performed by two physicians who are proficient in the knowledge of cervical sagittal balance parameters,and the results are averaged,select axial symptoms and C₅palsy as indicators of complications.First,apply statistical analysis to determine whether the changes of CSB parameters before and after surgery are meaningful;Secondly,take the study of the correlation between C_2-7Cobb angle and complications as an example,according to the median of（35）C_2-7Cobb angle,the cases were divided into high（35）C_2-7Cobb angle group and low（35）C_2-7Cobb angle group,use statistical methods to compare whether there is a difference in the occurrence of complications between the high and low group,to show that the relationship between the change of C_2-7Cobb angle and complications,use the same method to discuss the correlation between C_2-7SVA,T₁S and complications;Finally,because the median of preoperative T₁S in this study is similar to the T₁S imbalance alert value,so the cases were divided into T₁S imbalance group and non-imbalance group to explore whether the preoperative T₁S imbalance would affect the occurrence of complications.Result:（1）After the posterior cervical single door opening laminoplasty,the change of CSB parameters is affirmative,C_2-7Cobb angle decreased significantly after operation（P<0.05）,C_2-7SVA increased significantly（P<0.05）,and T₁S increased significantly（P<0.05）,but none of three CSB parameters showed serious imbalance after surgery.（2）There was no significant difference between the high（35）C_2-7Cobb angle and the low（35）C_2-7Cobb angle in the occurrence of axial symptoms and C₅nerve root palsy（P>0.05）,there was no significant difference in the occurrence of complications between the high and low（35）C_2-7SVA group（P>0.05）,the occurrence of the two complications in the high（35）T₁S group was not significantly different from that in the low（35）T₁S group（P>0.05）;（3）In cases of preoperative T₁S imbalance,the occurrence of axial symptoms was higher than that of the other group,and the difference was statistically significant（P<0.05）,but the occurrence of C₅palsy between T₁S balanced and unbalanced groups was no difference.Conclusion:The influence of posterior single door surgery on the parameters of cervical sagittal balance is positive,and also negative,however,the overall CSB is still in a balanced state after the operation,the whole cervical spine is still in the compensable range.And the resulting changes in CSB will not lead to an increase in the incidence of postoperative complications.However,for patients with preoperative T₁S imbalance,The incidence of axial symptoms in posterior surgery is higher,but does not increase the probability of C₅palsy.