Transpedicular spinal fixatiorı is a widely used method in vertebrai surgery, but it suffers from complications due to mismatches betvveen the screw and pedicle. Therefore, information of minimal canceiious (MCD) and minimal external diameters (MED) of the pedicle is highly important for vertebrai surgery. To determine these diameters and their ratios. 2.808 measurements of 1.404 pedicles of 702 human vertebrae were made from Th 11 to L5. We found that the mean ratio of MCD to MED was 72.2%. MCD to vertical diameter (VD) was 41.7%, and MCD to transvers diameter (TD) was 62.2% in ali levels. We recommend that these results be considered prior to pedicuier fixation operations and design of new implantable devices.
Keywords: morphometry, thoracolomber, spine