The Experimental Study Of Lower Cervical Transpedicular Fixation With The Individualized Measurement Of Spiral CT Scan.

Objective To assess the accuracy of cervical transpedicular screw placement with the help of dates from spiral CT scan.Method 10 adult cervical cadavers were scanned with spiral CT and the images were reconstructed with multiplanar reformation .and the ideal routine of screw placement was designed on the images .the point of the posterior pedicle projection on the lateral mass is O point, the distance between the 0 point and the peripheral anatomical landmark were measured ,which included H_LH_o,H_u or H_T. A_m is the angle between the line of screw placement and vertebral body midline axis ,another angular measurement of A_e is the angle between the pedicle axis and the upper endplate of the vertebra in the sagittal plane. The inner height (IL) and width (IS)of the pedicle isthmus ,along with the angle of the medial inclination of the isthmus (f) were measured. then the pedicles of these specimen were instrumented with nails from C3 to C7 according to above dates with the assistance of self-made position-finding device and angular-measuring devices. The accuracy rate of placement was then assessed according to the films...