Risk factors of C5 nerve root palsy after anterior cervical discectomy and fusion

English Keywords:Anterior cervical discectomy and fusion  C5 nerve root palsy  Risk factors

English Abstract:

  【Abstract】 Objectives: To investigate the risk factors of C5 nerve root palsy after anterior cervical discectomy and fusion(ACDF), and to provide references for the prediction of postoperative C5 nerve root palsy. Methods: Clinical data of 99 patients who underwent ACDF for cervical spondylosis in our hospital from August 2020 to August 2021 were collected and a case-control study was conducted. The patients were divided into the C5 nerve root palsy group(C5 palsy group) and the non-C5 nerve root palsy group(non-C5 palsy group) according to whether the patients had C5 nerve root palsy after surgery. Basic information of patients, such as gender, age, body mass index(BMI), history of hypertension, and history of diabetes; clinical indicators, such as Japanese Orthopaedic Association(JOA) score, visual analogue scale(VAS) and neck disability index(NDI); and imaging parameters of cervical X-ray, CT and MRI examinations, such as cervical physiological curvature, and the height of C4/5 intervertebral space before operation and on postoperative 1d, the preoperative transverse diameter of C4/5 intervertebral foramen, surgical levels, and the preoperative high-intensity zone at C4/5 segment of the cervical spine MRI T2 image of patients, were collected. Chi-square test and logistic regression analysis were used to explore the risk factors of postoperative C5 nerve root palsy. Results: 9 out of 99 patients developed C5 nerve root palsy within 7d after surgery. The preoperative transverse diameter of C4/5 intervertebral foramen(2.70±0.88mm vs 3.93±1.06mm, P=0.001) and the change of height of C4/5 intervertebral space(postoperative height - preoperative height)(3.02±2.03mm vs 1.33±1.45mm, P=0.002) between the two groups had significant difference, but there were no significant differences in other indicators. Multivariate logistic regression analysis showed that the changes in the height of C4/5 intervertebral space[OR=1.698(1.041-2.769), P=0.034] and the preoperative transverse diameter of C4/5 intervertebral foramen[OR=0.207(0.064-0.672), P=0.009] were the risk factors for the C5 nerve root palsy. Conclusions: For patients underwent ACDF for cervical spondylosis, those with a smaller transverse diameter of C4/5 intervertebral foramen before surgery and an increased height of C4/5 intervertebral space after surgery are more likely to develop C5 nerve root palsy after surgery. Avoiding over-enlargement of C4/5 intervertebral space and choosing appropriately sized cage during operation to insure that C4/5 intervertebral space is reasonable after operation and is properly decompressed, so as to reduce the incidence of postoperative C5 nerve root palsy.