Objectives: To measure the dimensions of the pedicles of Tl to L5 in the Greek population.

Methods:A total of 12 whole human cadaver spines were evaluated regarding pedicle dimensions (5 women and 7 men). The mean age at the time of death was 69,6 (range 62 to 84 years).

The transverse and sagittal out side pedicle isthmus widths, the internal transverse diameter and cortex width were measured with electronic calipers both on the right and left pedicles.

The data collected were statistically analyzed with the t- test.

Results.The widest transverse diameter was at the L5 level with a mean of 11,3mm (range 7,55-15,46mm). The narrowest transverse diameter was at the T5 level with a mean of 5,37mm (range 4,10 – 6,88mm). The widest sagittal diameter was at the Tl 1 level with a mean of 17,23mm (range 14,84-19,57mm), while the narrowest one was at T l level with a mean of 9,1mm (range 7,18-11,37mm). The maximum internal transverse diameter was at the L4 level with a mean of 8,26 mm (range 7,10-9,23mm) while the minimum was at the T5 level with a mean of 3,9mm (range 3,14-4,78mm).

The maximum cortex width was at the L5 level with a mean of 2,55mm (range 2,15-3,02mm) and the minimum at the T5 level with a mean of 1,30mm (range 0,40-2,10mm).

Conclusions .From the statistic analysis of the above data it was found that regarding the internal diameter there was statistically significant difference between males and females especially at T3, T7, T8 and L3 levels (P<0,05), and almost in all levels regarding the cortex width. There was also statistically significant difference between right and left pedicles regarding the transverse and the sagittal widths (P<0,05). The narrowest pedicle was at the T5 level and the widest was at the L5.