Can sagittal parameters of the cervical spine be used to predict the postoperative outcome of anterior surgery in patients with multilevel cervical spondylotic myelopathy?
Authors: Wu Rongcan , Lin Taotao , Wang kang , Wang zhenyu , Liu Wenge 
Published: January 2024

Abstract
Objective.
(1) For patients with multilevel cervical spondylotic myelopathy undergoing anterior surgery, which three-level ACDF or ACHDF is more effective? (2) To investigate whether cervical sagittal plane parameters can be used to predict postoperative efficacy of anterior surgery in patients with multilevel cervical spondylotic myelopathy.
Methods.
This study was a retrospective study. From January 2017 to January 2020, a total of 57 patients with multilevel cervical spondylotic myelopathy who underwent three-level ACDF(n = 22) or ACDF + ACCF(n = 35) were enrolled, and the follow-up time was 2 years. The patients were divided into two groups according to the postoperative mJOA improvement rate: group A (excellent improvement group, mJOA improvement rate > 50%,n = 39) and group B (poor improvement group, mJOA improvement rate ≤ 50%,n = 18). The basic information studied includes: Age, gender, BMI, symptom duration (months), smoking history, drinking history, hypertension history, diabetes history, coronary heart disease history, comorbidities CCI score, CCI group, operation time, intraoperative blood loss, length of hospital stay, preoperative imaging parameters (CL, T1S, C2-7SVA, CL(F), CL(E), CL(ROM), SA) Preoperative), postoperative imaging parameters (CL, T1S, C2-7SVA, CL (postoperatively - preoperatively), SA (postoperatively - preoperatively)), and functional score (VAS, NDI, mJOA, mJOA recovery rate).。
Results.
By comparing the different surgical groups, we found that: Between different surgery group, age, gender, BMI, duration of symptoms, severity of preoperative symptoms and postoperative recovery of baseline data are not statistically significant (P > 0.05), only in SA, SA (postoperative preoperative and postoperative on operation time, blood loss was statistically difference (P < 0.05), so to explore the differences of postoperative recovery, There was comparability between different surgical groups. According to the group comparison of mJOA improvement rate at 2 years after surgery, we obtained: Age, sex, BMI, smoking history, drinking history, hypertension, diabetes mellitus, coronary heart disease, operation method, operation time, blood loss, length of hospital stay, CCI, CCI grade, CL, T1S, CL(F), CL(E), CL(ROM), SA (preoperative), CL(postoperative), T1S (postoperative), C2-7 in group A and group B There were no significant differences in SVA (postoperative), CL (postoperative to preoperative), Pre-VAS, Pre-NDI and Pre-mJOA (P > 0.05). There were significant differences in symptom duration, C2-7SVA, SA (postoperative), SA (postoperative - preoperative) (P < 0.05). In order to better evaluate the independent risk factors of symptom duration, C2-7SVA, SA (postoperative), and SA (postoperative - preoperative), binary logistic regression analysis was used to compare the symptom duration, C2-7SVA, SA (postoperative), and SA (postoperative - preoperative). We found that only C2-7SVA was an independent risk factor for differences in postoperative improvement. At the same time, the critical value calculated by ROC curve showed that when C2-7SVA > 25mm, the prognosis of patients was more likely to be poor, and the probability of poor prognosis increased by 0.103 times for every 1mm increase in C2-7SVA (P = 0.006, OR = 1.103).
Conclusion.
For patients with multilevel cervical spondylotic myelopathy treated with three-level ACDF or ACDF + ACCF, the efficacy of the two surgical methods is similar. Only preoperative C2-7SVA is an independent risk factor for poor postoperative outcome, which reminds clinicians to pay more attention to the influence of cervical sagittal parameters on patients.