Outcome of Lateral Mass Fixation and Fusion – A Comprehensive Analytical Study of 205 Lateral Mass Screws in 35 Patients at Punjab Institute of Neurosciences

Abstract

Objective: To see outcome, accuracy and expected complications in passing lateral mass screws in patients with cervical spine injury, degenerative disease at the cervical spine level and neoplastic lesions.Materials and Methods: In this study, 35 patients were included and 205 screws passed in lateral mass patients’age ranged from 12-70 years (25 males and 10 females) with trauma to the cervical spine, degenerative disease at the cervical spine level and Intradural extramedullary benigntumors and extradural malignant neoplasm.Patients less than 12 years and more than 65 years of age,patients with traumatic ruptured disc causingspinal cord compression anteriorly and operated for cervical spine were excluded from our study.In all patients,we did lateral mass fixation with polyaxial screws and rods under fluoroscopic assistance.For assessment of screws trajectory and position, CT scan cervical spine with 3D reconstruction was performed on a first post op day to confirm screw orientation and direction and for fascet, foraminal, foramen transversarium violations.Results: All screws were passed by using Megrel’s trajectories. Not a single patient had nerve root, cord injury nor vertebral artery injury. One patient had screw pullouts requiring reoperation.12 to 14mm size screws were used under fluoro guidance. On postoperative CT cervical spine with 3D reconstruction shows no breach or violations of any foramen transversarium, nerve root injury or neural foramen penetration by screws. In all patients polyaxial screw/rod construct was used. Conclusion: Cervical spine lateral mass fixation with polyaxial screws is a safe and effective technique in expert hands under fluoroscopic assistance.