The Imaging Anatomic Study Of The L5 Pedicle And Its Value In PVP Procedure

Objective To observe the angle of pedicle axis line of L5 vertebra with vertebral sagittal plane and horizontal plane, the space projective location at vertebral body of pedicle axis line and its angle of rectification. To probe into its role in helping PVP procedure. Material and Methods Thirty dry bone specimens of adult's L5 vertebra were used. The continuous volumetric data with spiral CT scan were got in all specimens. The widest layer was selected as pedicle's reconstructing plane during continuous images and the source images were reconstructed with multiplane reformation(MPR) in GE AW4.1 workstation. The following parameters were measured. (1)Angle between pedicle axis line and vertebral sigittal plane(E angle) (2)Angle between pedicle axis line and parallel line of upper endplate(F angle) (3)Angle of rectification of pedicle axis line(G angle) (4)space projective location at vertebral body of distal end of pedicle axis line. Statistic differences were analyzed. Results Through three-dimension measurement of thirty L5 vertebrae with spiral CT scan, the data of pedicle axis line are as follows: the sigittal angle of pedicle axis line (E angle) is 34.7±2.5°(left) and 34.9±3.0°(right) respectively, horizontal angle (F angle) 3.4±0.7°(left) and 3.0±0.8°(right), angle of rectification (G angle) 24.4±2.2°(left) and 24.0±2.5°(right). Statistic analysis shows that differences in dimensions between left and right pedicle were not found to be statistically significant. Space location at vertebral body of distal end of pedicle axis line all lie in the anterior upper part of the vertebral body. The tube of vertebral basilar vein all lie in the posterior center of the vertebral body. Conclusions Through dimensions study for L5 pedicle axis line with spiral CT scan and three-dimension reconstruction, reference values of E,F,G angle of pedicle axis line were established, and space projective location at vertebral body of distal end of pedicle axis line and tube of vertebral basilar vein were found. This information may prove to be of instructive significance in transpedicular PVP procedure.