Application of anchoring of the projection point on the inner upper edge of the pedicle in posterior percutaneous endoscopic cervical discectomy

English Keywords:Posterior percutaneous endoscopic cervical discectomy  Pedicle  Vertical anchoring technique  Cervical spondylotic radiculopathy

English Abstract:

  【Abstract】 Objectives: To evaluate the safety and feasibility of the projection point on the inner upper edge of the pedicle anchoring method in the posterior percutaneous endoscopic cervical discectomy(PPECD). Methods: Data of 32 patients with cervical spondylotic radiculopathy who were treated with the PPECD in our hospital were collected, and the patients were divided into two groups. One group underwent conventional PPECD(the conventional group including 7 males and 4 females, with an average age of 49.9±13.2 years and symptom duration of 27.9±38.7 months) and the other group underwent PPECD combined with anchoring technique of the projection point on the inner and upper edge of the pedicle(the modified group including 13 males and 8 females, with an average age of 54.0±11.8 years and symptom duration of 18.4±27.3 months). Patients′ preoperative/postoperative neck and arm pain was evaluated by the visual analogue scale(VAS) scores. Neural function was assessed by Japanese Orthopaedic Association(JOA) scores. The postoperative efficacy was evaluated by modified MacNab criteria. The postoperative decompression effect was evaluated by CT and MRI. Fluoroscopy times and operative time were recorded. Cervical CT was performed to reconstruct cervical spine 3D image of the 32 patients. A cross section through the intersection of the inner and upper edges of the pedicle was used to measure the distance(a) between the projection point on the inner upper edge of the C3-7 pedicle and the V point(the transverse V-shaped structure with the tip outward at the medial junction of inferior margin of cephalic lamina and superior margin of caudal lamina). The measurement results were used to quickly locate and verify the V point. Results: The operations in the modified group were successfully completed. The number of fluoroscopy times and operative time were 4.0±0.9 and 70.1±20.0min in the modified group, and 10.7±2.4 and 117±44.5min in conventional group. There were significant differences in the number of fluoroscopy and operative time between the two groups(P<0.05). VAS, JOA score and modified MacNab score were significantly improved in two groups after operation, but there was no significant difference between the two groups(P>0.05). The values of a of C3-7 were 1.45±0.06-5.03±0.19mm. Conclusions: Anchoring of the projection point on the inner upper edge of the pedicle can reduce the fluroscopy times and operative time, which provides a new method for positioning and verification of the V point in PPECD.