Lateral Mass Screw Fixation for Multilevel Cervical Degenerative Disease Associated with Instabilityq

Background: Posterior cervical fixation with lateral mass screws has been increasingly used since the concept was first described by Roy-Camille in 1979. Objective: Is to evaluate the efficacy of posterior cervical fixation by lateral masspolyaxial screws and rod system in the management ofsubaxial cervical instability associated with degenerative cervical spondylosis. Patients and Methods: During the period from October 2010 to September 2104, forty four patients (thirty four males ten females), and the age ranging from40 to 69years with subaxial cervical instability with degenerative spondylotic disease. All cases were admitted and operated upon for posterior cervical fixation by lateral masspolyaxial screw-rod system in the Department of Neurosurgery, Tanta University with a follow up period up to 12 months. Results: Thirty three patients (75%) had heaviness in their lower limbs and spasticity. Twenty two (50%) had neck pain and twenty eight patients (63.6%) had upper and lower limbs weakness. We didn t experience any vertebral artery injury or nerve root injury. During our period of follow up all patients were stable in the postoperative radiographs with no pullout of any screws. Three cases presented by postoperative C5 palsy that improved by medical treatment. Two cases had fractured lateral mass at one level. No failure in the system or adjacent level pathology was discovered. Conclusion: Posterior cervical fixation using polyaxial screw-rod system (Magrel technique) considered an effective procedure in producing immediate stability of the cervical spine, prevents kyphotic deformity, and probably prevents further development of spondylosis at fused levels. The technique requires proper selection of cases and meticulous attention during surgery to identify the correct starting point, screw orientation and length of screw.