Thoracolumbar Vertebral Pedicles: A Morphometric Study In North Indian Adult Male Population

Several systems of internal fixation of spine that attach through the pedicles are currently available. Hence, accurate anatomic descriptions of shape and orientation of pedicles are necessary for the development and use of implantable devices and spinal instrumentation. Thus, the present study has been conducted with the objective to find out the normal values of various pedicle dimensions in the North Indian population.

The material for present study comprised of 30 human adult male thoracolumbar vertebral columns, i.e., a total of 510 vertebrae. Four parameters, i.e., pedicle width, pedicle height, transverse pedicle angle and sagittal pedicle angle, were measured in all of these vertebrae.

The pedicle width, in thoracic region, decreased from T1 to T4 and then increases till T12, whereas in lumbar region it increased constantly from L1 to L5 with a marked increase from L4 to L5. Pedicle height increased from T1 to T12 with slight dips at different levels. However, in lumbar region, pedicle height showed no regular trend. Transverse pedicle angle, on the right side, first decreased from T1 to L1 with slight crests seen at T5, T9 and T11 and then increased till L5. On left side, it decreased from T1 to T12 with crests at T8, T10 and T11 and then increased till L5, with sudden increase by 3°–4° from L4 to L5 on both sides. The sagittal pedicle angle showed no regular trend.

The study provides the mean values and range of different parameters of thoracolumbar vertebral pedicles in the population of this region, which may be useful for the surgeons doing transpedicular screw implantation.