Computed Tomographic Morphometry of Thoracic and Lumbar Pedicles in South Indian Population

Pedicular fixation of the lumbar spine with screws is becoming increasingly popular. Anatomy of pedicle has become important because of accelerated use of pedicle fixation devices. Pedicle width and chord length are limiting factors for the transpedicular screw diameter and length. The present study desires to record the surgical relevant parameters of the thoracic and lumbar pedicles in South Indian population and also to compare results with similar studies among the global population. Total 100 computed tomographic [CT] scans of the lower thoracic and lumbar vertebrae using a scanner with 1.5mm cuts were reviewed in the study. Pedicle width, pedicle inclination in transverse plain and chord length of vertebrae from T9 to L5 were measured and mean values were calculated for each levels and both sexes separately. The study showed pedicle width increases from T9 to L5. Pedicle inclination angle and chord length was lowest at T12 and largest at L5 vertebrae. All measured pedicle parameters were larger in males compared to females. Pedicle morphometric parameters vary from values of other populations, hence knowledge of surgically relevant parameters of pedicles is necessary for success of transpedicular fixations.