Does Prophylactic Foraminotomy Reduce Postoperative C5 Palsy in Posterior Reconstruction Surgery Using Cervical...

Background Postoperative C5 nerve palsy is a well-recognized complication following posterior cervical decompression and reconstruction; however, its precise mechanism remains unclear. Although prophylactic C4-5 foraminotomy has been proposed as a preventive strategy, its effectiveness remains controversial. Methodology A total of 37 patients who underwent cervical pedicle screw (CPS)-based corrective surgery (21 males and 16 females; mean age, 71 years) were included. Prophylactic foraminotomy at C4-5 was performed in patients with preoperative foraminal stenosis identified on CT. Patients were categorized into the following two groups: those who developed postoperative C5 palsy (P group) and those who did not (NP group). Radiographic parameters compared between the two groups included the preoperative C2-7 angle, C4-5 angle, anteroposterior diameter of the C4-5 intervertebral foramen, C2-7 and C4-5 correction angles, and posterior spinal cord displacement on MRI. The prophylactic effect of foraminotomy was evaluated using Fisher's exact test. The Mann-Whitney U test was used to compare continuous variables, and multivariate logistic regression analysis was performed to identify risk factors. Recovery time from C5 palsy was also evaluated. Results Postoperative C5 palsy occurred in nine patients (12 foramina). Patients who developed postoperative palsy showed significantly greater correction angles at C4-5 and smaller preoperative C4-5 foraminal diameters than those without palsy. No significant difference in the incidence of postoperative C5 palsy was observed between foramina with and without prophylactic foraminotomy. The mean recovery time from C5 palsy was 2.6 months in patients who underwent foraminotomy. Conclusions Prophylactic foraminotomy did not reduce the incidence of postoperative C5 palsy following posterior cervical correction surgery using CPS. However, most palsy cases were transient, with a mean recovery period of 2.6 months. The results suggest that a greater correction angle at C4-5 and the presence of preoperative foraminal stenosis are risk factors for C5 palsy in CPS-based corrective surgery. In cases with severe preoperative foraminal stenosis, the magnitude of the correction angle at C4-5 may contribute to the development of C5 palsy, even when prophylactic foraminotomy is performed.