Effect of prophylactic C 4, 5 foraminal dilatation in posterior cervical open-door surgery on postoperative C 5 nerve root palsy syndrome

Abstract

To investigate the effect of prophylactic C 4, 5 foraminal dilatation in posterior cervical open-door surgery on postoperative C 5 nerve root palsy syndrome. The clinical data of patients with cervical spondylotic myelopathy (cervical spinal cord compression segments were more than 3) who met the selection criteria between March 2016 and March 2019 were retrospectively analyzed. Among them, 40 patients underwent prophylactic C 4, 5 foraminal dilatation in posterior cervical open-door surgery (observation group) and 40 patients underwent simple posterior cervical open-door surgery (control group). There was no significant difference between the two groups ( P>0.05) in gender, age, disease duration, Nurick grade of spinal cord symptoms, and preoperative diameter of C 4, 5 intervertebral foramen, Japanese Orthopaedic Association (JOA) score, and visual analogue scale (VAS) score. The occurrence of C 5 nerve root paralysis syndrome was recorded and compared between the two groups, including incidence, paralysis time, recovery time, and spinal cord drift. VAS and JOA scores were used to evaluate the improvement of pain and function before operation and at 12 months after operation. The incisions of the two groups healed by first intention, and there was no early postoperative complications such as cerebrospinal fluid leakage. Patients of both groups were followed up 12-23 months, with an average of 17.97 months. C 5 nerve root paralysis syndrome occurred in 8 cases in the observation group (3 cases on the right and 5 cases on the left) and 2 cases in the control group (both on the right). There was significant difference of the incidence (20% vs. 5%) between the two groups ( χ 2=4.114, P=0.043). Except for 1 case in the observation group who developed C 5 nerve root palsy syndrome at 5 days after operation, the rest patients all developed at 1 day after operation; the recovery time of the observation group and the control group were (3.87±2.85) months and (2.50±0.70) months respectively, showing no significant difference between the two groups ( t=-0.649, P=0.104). At 12 months after operation, the JOA score and VAS score of cervical spine in the two groups significantly improved when compared with those before operation ( P<0.05); there was no significant difference in the difference of the cervical spine JOA score and VAS score between at 12 months after operation and before operation and the degree of spinal cord drift between the two groups ( P>0.05). Prophylactic C 4, 5 foraminal dilatation can not effectively prevent and reduce the occurrence of postoperative C 5 root palsy, on the contrary, it may increase its incidence, so the clinical application of this procedure requires caution.