Evidence from the past links postoperative balance (cSVA ≤4 cm) with successful treatment of cervical kyphosis (CK). It is vital to learn what factors affect the success of ACMS in restoring cervical lordosis (CL) in patients with degenerative disease and mild to moderate CK. This research looks into the parameters that predict perioperative alignment changes and regional interdependencies following ACMS to better comprehend geometric changes. Examination of ACMS patients. The analysis focused on radiographic markers such as CL C2-7, fusion angle (FA), C7-Slope (C7S), T1-slope (T1S), T1-CL mismatch, and cSVA (cSVA ≤4 cm/>4 cm) in addition to patient baseline characteristics, demographics, and comorbidities. Researchers used multivariate logistic regression to try and foretell postoperative asymmetry cSVA more than 4 cm. The average age of the 126 patients included with 3- to 5-level ACMS was 56, and they had undergone 4 levels of fusion. Only 9% of patients had CK before surgery; the average FA-correction was 8 degrees, and the maximum was 46 degrees. About 14 patients had cSVA of more than 4 cm after surgery. Preoperative cSVA, preoperative CL, and FA correction were all factored into a neural network model for predicting cSVA more than 4 cm. Very good results were obtained from the model (positive predictive value=100%, negative predictive value=94%, specificity=100%, sensitivity=20%). In addition, postoperative cSVA at more than 4 cm rate was affected by factors such nonunion, prolonged lumbar discomfort, and thoraco lumbar multilevel fusion. C7S/T1S and cSVA/C2-tilt (r=0.06/r=0.7, P<0.0001) were found to have extremely high correlations, as was discovered using alignment analysis. A conversion formula from cSVA to C2-tilt was developed. In this study, investigators found that FA, which is within the surgeon’s control, is one of the independent variables that predict postoperative cSVA of more than 4 cm. Their model aids in making choices that lead to a postoperative cSVA of less than or equal to 4 cm. 

Source: journals.lww.com/jspinaldisorders/Abstract/2022/10000/Surgical_Realignment_After_Anterior_Multilevel.7.aspx