The Anatomic And Radiological Investigation Of The Pedicle Internal Structure

Study Design.The internal architecture of spine pedicles was investigated by computerizedtomogram..Background DateTranspedicle screw fixation is one of the most sophisticated procedures forwidly use, which demands high degree of safty. The pedicle plays the mostimportant role in connecting the vertebrae body and posterior structure.Although there have been a number of studies presenting the externaldimension of the pedicle, little is known about the internal structure of thepedicle systematically. The dimension data of the pedicle internal structure ofChinese peple is blank.ObjectivesTo provide quantitative information on the internal dimensions and corticalshell and spongy bone center thicknesses, and there change in differentsegment.Methods.Twenty human spine (C1-L5) were gathered totlely from Twentypreservatized corpus. Computerized Tomogram was used. After scaning,Muti-plan reconstruction was execute with the software combined in the CT.In the transcross setion of of the pedicle isthmus, the pedicle hight, pedicle width, up cortical thickness, down cortical thickness, internal cortical thickness, larteral cortical thickness, spongy bone diameter, sponey bone hight was messured thought the softeware combined in the CT. Results.The parameter of the pedicle in the right and left side were not significantly different. Between the male and female, man's lateral cortical thickness was significantly thicker than the female's LCT/PW was 20.72±5.77%, ICT/PW was 32.87±7.47%, UCT/PH was 24.33±6.07%, DCT/PH was 22.51±5.17%, SBW/PW was 46.41 ±11.76%, SBH/PH was 53.17±10.15%. the lateral wall cortical thickness was significantly smaller than the medial wall thickness in all segment. In the cervical spine, the thickness of the cortical shell was 1.5 times as thick as the spongy bone in the center. In the thoracic spine, except T4, the hight of the spongy bone was as large as cortical shell, however, the thickness of the spongy bone was 0.87 times as thick as the cortical bone. In the lumbar spine, the spongy bone was more than 1.4 times as thick as the cortical shell. Parameters were more variable in the C6-T1 and T8-T12, when compared with the adjacent segment. Conclusions.The pedicle is a complex, three dimensional structure exhibiting extensive variability in internal morphology. Characteristics of the cervical pedicle at different spinal levels must be noted before transpedicular screw fixation.