Localization of thepoint of entry and morphometric characteristics of the pedicles of the lower dorsal and lumbar spines an experimental work

ABSTRACT

Human adult cadaveric disarticulated vertebrae from the tenth dorsal to the fifth lumbar were obtained from twenty-five dried cadavers. We localized the point of entry to the pedicles of these vertebrae [50 pedicles] using the intersection technique depending on anatomic landmarks. The transverse pedicle diameters and the transverse pedicle angles were measured by three methods: directly, radiologically and by CT scan of disarticulated vertebrae. The sagittal pedicle diameters and the sagittal pedicle angles were measured by direct measurement and by lateral view x-rays. The transverse pedicle diameters ranged from 6.1 mm at the eleventh dorsal to 17.9 mm at the fifth lumbar and the sagittal pedicle diameters were generally larger than the transverse slant ones, except in fifth lumbar vertebrae. The transverse pedicle angles were less than five degrees in the lower dorsal spines and progressively increase in the lumbar spines to a maximum of almost thirty degrees medial angulation at the fifth lumbar vertebrae. The sagittal pedicle angles were about ten to sixteen degrees cephalad for the majority of the lower dorsal spines and nearly neutral [less than eight degrees] for the majority of the lumbar spines except the fifth lumbar that angles caudally about twelve degrees in eighty-four percent of the pedicles