2023, Vol. 27 ›› Issue (9): 1319-1324

Correlation of cervical sagittal force line parameters with degenerative segment and Pfirrmann classification in patients with cervical intervertebral disc degeneration

Cao Sheng, Kong Lingwei, Xu Kun, Sun Zhijie   

Abstract: BACKGROUND: The sagittal parameters of lumbar spine are significantly correlated with lumbar intervertebral disc degeneration and sagittal balance of lumbar spine, while the research on cervical spine is relatively lacking.
OBJECTIVE: To explore the correlation of cervical sagittal force line parameters cervical lordosis, T1 slope, and sagittal vertical axis with degenerative segment, Pfirrmann classification in cervical intervertebral disc degeneration patients and the value of therapeutic evaluation.
METHODS:   A total of 80 patients with cervical intervertebral disc degeneration in Affiliated Hospital of Chengde Medical College from July 2017 to December 2019 were selected as the study subjects, all of whom underwent minimally invasive spinal canal enlargement surgery through the posterior cervical approach. The patients were grouped according to the curative effect 6 months after the operation. Among them, there were 62 cases in the good curative effect group and 18 cases in the poor curative effect group. The clinical data, cervical sagittal force line parameters (cervical lordosis, T1 slope, and sagittal vertical axis) and cervical sagittal force line parameters of patients with different degeneration segments and Pfirrmann classification were compared between the two groups. The receiver operating characteristic curve was used to evaluate the value of the efficacy evaluation of the parameters of the cervical sagittal force line.  
RESULTS AND CONCLUSION: (1) There was a statistically significant difference in degeneration segments and Pfirrmann classification between the two groups (P < 0.05). (2) At 1 and 6 months after operation, the cervical sagittal force line parameters cervical lordosis and T1 slope of the patients in the good curative effect group were significantly higher than those in the poor curative effect group, and the sagittal vertical axis was significantly lower than that in the poor curative effect group (P < 0.05). (3) Cervical sagittal force line parameters cervical lordosis, T1 slope, and sagittal vertical axis were significantly different in patients with different degeneration segments and Pfirrmann classification (P < 0.05). (4) In cervical intervertebral disc degeneration patients, the cervical sagittal force line parameters cervical lordosis and T1 slope were positively correlated with degenerative segments and Pfirrmann classification (P < 0.05), while sagittal vertical axis was negatively correlated with degenerative segments and Pfirrmann classification (P < 0.05). (5) After controlling for sex, age, course of disease, body mass index, type of cervical spondylosis, degeneration segment, Pfirrmann classification, preoperative cervical sagittal force line parameters and other factors, the cervical sagittal force line parameters cervical lordosis, T1 slope and sagittal vertical axis were still significantly correlated with the efficacy of cervical intervertebral disc degeneration patients at 1 and 6 months after surgery (P < 0.05). (6) Cervical lordosis, T1 slope, and sagittal vertical axis all had higher area under the curve for evaluating curative effect, especially the highest in combined evaluation, reaching 0.815. (7) It is concluded that the parameters cervical lordosis, T1 slope, and sagittal vertical axis of the cervical spine sagittal force line in cervical intervertebral disc degeneration patients are related to the degenerative segment and Pfirrmann classification, and have a good therapeutic evaluation value. They can provide evidence for preventing the occurrence of cervical intervertebral disc degeneration and sagittal imbalance after surgery.
Key words: cervical lordosis, T1 slope, sagittal vertical axis, cervical intervertebral disc degeneration, degenerative segments, Pfirrmann classification