Reformatted computed tomographic evaluation of the thoracic pedicle in a Chinese population for the surgical application of transpedicular screw placement

Purpose To study the transverse thoracic pedicle diameter of a Chinese population and to determine the feasibility and safety of transpedicular screw fixation. Methods The authors studied the transverse pedicle diameter of the T1–T12 of the thoracic spine in a Chinese population using reformatted computed tomography. The data were compared with Caucasians and other Asians. Results The mean outer pedicle widths of the thoracic spine from T1 to T12 were 8.43, 6.65, 5.20, 4.44, 4.50, 4.87, 5.04, 5.32, 5.66, 6.65, 8.08 and 8.27 mm in males and 7.91, 6.03, 4.55, 3.91, 4.05, 4.31, 4.39, 4.60, 5.13, 5.67, 7.21 and 7.50 mm in females, respectively. Female patients have smaller dimensions compared with male patients. A significant percentage of patients have an outer pedicle width of less than 4.5 mm from T3 to T8, which is not suitable for transpedicular screw fixation with a 3.5 mm screw. Conclusions The results of this study suggest that transpedicular screw fixation may not be suitable for the mid-thoracic regions in most Chinese females and that modified pedicle screw techniques or modified type of fixation is required in these patients. CT evaluation is a must before this procedure is performed.