Preliminary clinical application of anterior pedicle screw fixation of lower cervical spine / 中华创伤杂志

ABSTRACT

ObjectiveTo discuss the feasibility and safety of anterior pedicle screw (APS) fixation in treatment of lower cervical spine injuries.MethodsA total of 10 patients with lower cervical spine injuries were treated with APS fixation.All the patients received preoperative cervical CT scans,and then three-dimensional model was reconstructed by using Mimics software to measure the screw placement parameters (insertion point,screw placement angle,screw length and diameter).All APS fixations were performed through anterior cervical approach,and then centrums antetheca and bilateral outer edges were exposed to distinguish the vertebral end plates.Screw insertion was strictly operated under the fluoroscopic assistance and preoperative screw placement parameters.The postoperative efficacy of APS fixation was evaluated by radiologist and other orthopedist via anteroposterior and lateral radiation,CT scan,three-dimensional model reconstruction and MRI.A follow-up was carried out at 1,3,6 and 12 months after operation.ResultsExcept for one screw for C4 and one for C7,another 24 crews for C3-C7 were successfully inserted.Postoperative CT scan demonstrated four screws breaking the outer vertebral wall.Except for one patient suddenly died from acute myocardial infarction one week after operation,the other nine patients received follow-up.Of three trauma patients,one patient at Grade A did not get improvement but with no aggravation and two achieved improvement for 2-3 grades according to Frankel grade.Among six non-trauma patients,spinal function score by JOA was averagely elevated to 13.4 points,with improvement rate of 60.7％ according to Hirabayashi method.There were no serious complications except for two patients of dysphagia among the patients who were followed up. Conclusions APS fixation is feasible for lower cervical spine injuries.The keys to successful screw insertion are preoperative measurement of individualized screw insertion parameters and appropriate application of intraoperative fluoroscope technique.