Application Of Anchoring Of The Projection Point On The Inner Upper Edge Of The Pedicle In Posterior Percutaneous Endoscopic Cervical Discectomy

Objective: To describe a new modified PPECD,evaluate its feasibility/short-term efficacy and measure and analyze its related parameters.Methods: Data from 32 patients with cervical spondylotic radiculopathy who were treated with the PPECD were collected.One group underwent conventional PPECD,and the other group underwent modified PPECD.Patients’ preoperative/postoperative neck and arm pain were evaluated by the VAS,JOA and modified Mac Nab scores.The postoperative decompression effect was evaluated by CT and MRI.Cervical CT was performed for 3D reconstruction of the patients’ cervical spine.A cross section through the intersection of the inner and upper edges of the pedicle was used to measure the distance between the projection point on the inner upper edge of the C3-C7 pedicle and the V point(a)/the midline of the spinous process(b).This distance was also measured in human cadavers(c)/(d).Results: The operations in the modified group were successfully completed.The number of fluoroscopies in the modified group was significantly less than that in the conventional group.Both types of surgery significantly improved the symptoms of patients.According to the results of the follow-up period,there were no significant differences in VAS scores for neck and arm pain,JOA scores or the modified Mac Nab criteria between the two groups(P > 0.05).The values of a,b,c,and d for C3-C7 were 1.43 ± 0.07 ~ 4.98 ± 0.21 mm,14.00 ± 0.27 ~ 16.39 ± 0.48 mm,1.47± 0.08 ~ 5.07 ± 0.25 mm,and 14.04 ± 0.31 ~ 16.36± 0.41 mm,respectively.Conclusion: The number of fluoroscopies and the operative duration were reduced by the anchoring of the projection point on the inner upper edge of the pedicle.Overall this study describes a new method for positioning and verification of the V point in PPECD.