Radiological Studies On Modified Cervicothoracic Anterior Transpedicular Screw Fixation

Objective: Though the modified bilateral anterior cervical pedicle screws imaging study,analysis of its optimum value into the needle Angle,so as to guide the design of 3D-printing navigation template for modified cervicothoracic anterior transpedicular screwMethods:22 volunteers were scanned by cervical spine by CT,including 15 males and 7 females.CT scan data was imported into Mimics 17.0 software by DICOM format,After cervical vertebrae was 3D modeled,Switching the models to the semitransparent mode,and set the middle of vertebra posterior border as the center axis,5 degrees in turn in a rotation by rotation axis variation as vertebral body,geting the vertebral pedicle osseous channels projection on different extroversive-angle and caudal-angle,Record each experimental group pedicle osseous channel projection area,and obtained the largest ones though Auto CAD software,and the results as a reference to guide the corpse modified bilateral cervical pedicle screw guide template design.Results:all CT scan data of 22 volunteers had been collected,and through the measurement of imaging software,we got the different pedicle channel projections in different extroversive-angle and caudal-angle in each segment(C3-7).The largest pedicle projection 、maximun zones transverse and longitudinal diameter 、optimum extroversive-angle and caudal-angle from C3 to C7 in left were32.87±3.57mm2、6.99±1.02mm、6.99±1.02mm、44.71±2.34°、4.16±0.67°(superior)、11.67±0.41°(inferior);36.65±3.21mm2、5.73±0.94mm、7.34±1.22mm、46.13±3.11°、4.43±0.58°(superior)、12.38±0.63°(inferior);37.32±2.84mm2、5.88±0.86mm、7.62±1.31 mm 、 44.66±4.02° 、 4.02±0.61°(superior)、 11.88±0.77°(inferior);40.12±2.84mm2、 6.37 ± 0.86 mm 、 7.69 ± 1.19 mm 、 43.14±3.71° 、 3.52±0.39°(superior)、10.85±0.82°(inferior);46.12±2.84mm2、6.89±1.26mm、8.31±1.39mm、42.64±2.94°、3.07±0.47°(superior)、9.95±0.90°(inferior).The modified bilateral anterior cervical pedicle screws guide template which is based on the data had showed accuracy in corpses(95.8%).Conclusion : The optimum extroversive-angles and caudal-angles of modified cervicothoracic anterior transpedicular screw we have measured though method of vertebral pedicle passageway projection had guided the design of 3D-printing navigation guide plates that had demonstrated effectiveness of the date.