Clinical evaluation of guiding apparatus assisted individual posterior cervical pedicle screw fixation / 中华创伤杂志

ABSTRACT

ObjectiveTo evaluate the clinical effects of guiding apparatus assisted individual posterior cervical pedicle screw fixation technique.MethodsThe study enrolled 24 patients treated with posterior cervical decompressive single open-door laminoplasty and transpedicular screw-rod fixation from January 2008 to December 2010.The point of screw penetration and screw path direction were confirmed by measuring the transverse nail angle (TNA) and sagittal nail angle (SNA) of nail channel on the pre-operative CT plain scan of cervical pedicle and sagittal two-dimensional imaging of transpedicular axis.According to the results of CT measurement,individual cervical pedicle screw was implanted with the assistance of self-made guiding apparatus and then fixed after decompression.Transverse screw angle ( TSA ) and sagittal screw angle ( SSA ) were determined on the CT scan of cervical pedicle and sagittal two-dimensional imaging of transpedicular axis one week postoperatively in order to analyze the accuracy of placement of pedicle screws.Periodical anteroposterior and lateral X-ray radiographs of cervical vertebra were taken postoperatively to detect the stabilization of internal fixation.ResultsA total of 223 pedicle screws were inserted successfully into the C3 ～ C7,of which 220 crews were inserted accurately but three had slight inclination according to the postoperative CT,with placement accuracy of 98.7％.The comparison between inclination angle of inserted screws and that of preoperative transpedicular axis showed insignificant statistical difference ( P ＞ 0.05 ).All the patients were followed up for 6-34 months ( mean,18.5 months),which showed no neurovascular complications related to screws perforation out of pedicle cortex or no screw loosening,prolapse or breakage.ConclusionPosterior cervical pedicle screw insertionperformed according to the individual CT measurement is easy and safe and has a high accuracy rate under the assistance of self-made guiding apparatus.