Evaluation of thoracic pedicle morphometry in a Chinese population using 3D reformatted CT

The aim of this study was to investigate the detailed three-dimensional morphology of the pedicles from T1 to T12 in 120 Chinese patients using a light-speed Vct CT (General Electric). After reformatting the original images, the following parameters were studied: outer pedicle width (OPW), outer pedicle height (OPH), pedicle chord length (PCL), pedicle cortical thickness (PCT) of the isthmus, and transverse pedicle angle (TPA). The mean outer pedicle width, outer pedicle height, and pedicle chord length were significantly smaller in females than in males at all levels (P < 0.01). The percentage of outer pedicle width ≤ 5.0 mm and ≤ 4.5 mm was high at mid-thoracic pedicles. No significant differences were found in transverse pedicle angle and pedicle cortical thickness in males and females. Pedicle cortical thickness was significantly thinner in patients over 50 years old compared with patients below 50 years old at most levels. The results showed that a screw of larger than 4.5 mm would be too large for mid-thoracic segments in Chinese population, especially for female patients. Considering the amount of variation between individuals and the complicated structure of the thoracic pedicles, the use of the transpedicular screw fixation must be individualized for each patient and based on detailed preoperative assessment. Reformatted CT assessment is essential before this procedure is performed.