Total amount: € 0,00
Online ISSN 1827-1707
Copuroglu C., Ciftdemir M., Yilmaz A., Ozcan M., Kaya M., Yalniz E.
Trakya University, Edirne, Turkey
AIM: The aim of this paper was to demonstrate the relation between the distance of the midline of the corpus and the screw entry point on the pedicle and the maximum screw length that can be applied in the pediculocorporeal screw trajectory.
METHODS: The distance between two pedicular screw entry points and the distance between screw entry point and the anterior cortex of the vertebra corpus in the midline, on computed tomography (CT) sections and the same distances on cadaveric bony L1 specimens, were measured. Interpedicular distance was divided into two and the distance between the midline and the screw entry point was found. These measurements were compared and a constant ratio was observed. The pedicular screw entry point was accepted as the point just lateral to the inferior articular process at the mid level of the transverse process.
RESULTS:When these measurements were compared, a constant ratio was observed. The ratio between the distance of the midline of the vertebra and the screw entry point and the distance between the screw entry point and the midline anterior cortex of the vertebral body, was 2.5 cm. When the distance between the midline of the vertebra and the screw entry point during the operation or by measuring half of the interpedicular distance on plane roentgenograms, is measured, the maximum length of the pedicular screw can be estimated.
CONCLUSION:In this study, we described an easy method of determining the maximum pedicular screw length by measuring the distance between the midline level of the vertebra corpus (spinous process level) and pedicle screw entry point on coronal section.