Vol. 4, Issue 3 (2018)
A gender based approach to study the morphometric variations of the neural arch in the thoracic vertebrae of adult human skeleton in north Indian population
Author(s): Sonu Tyagi, Ravi Kant Narayan
Abstract: For surgical procedures to be carried out on the human spine, the clinicians require accurate measurements of the vertebral parameters. This study was taken up to measure various linear parameters of the neural arch of all Thoracic vertebrae (T1 to T12) of adult human skeleton in different genders. The thoracic vertebrae of 30 of North Indian population (23 males and 7 females) were measured and analyzed. A Digital Vernier Caliper is used to measure the dimensions of the spinous (SP) and transverse (TP) processes, vertebral canal (VC), laminae, and isthmus. Most of the parameters are greater in males. Isthmus length increases from T1 to T12 in both males and females but bilateral comparison of the isthmus shows that in females the left side lengths are greater than the right side but that of males doesn’t have a continuous variation with some of the vertebrae having longer isthmus on the right side while some on the left side. Both Spinous Process Length (SPL) and Transverse Process Length (TPL) were found to be increasing in upper thoracic vertebrae from T1 to T6 and then decreasing from T7 to T12 in both males and females. Bilateral evaluation of TPL shows that in females the right sided transverse processes are longer than their left counterpart while in males the variation of bilateral TPL was not continuous. Vertebral Superior Canal Width (VSCW) is greater than Vertebral Superior Canal length in thoracic vertebrae in both the genders. In both the sexes, VSCW was found to be decreasing from T1 to T7 and then increasing from T8 to T12. The difference of width and length is decreasing from T1 (8.7 mm) to T5 (2.82 mm), becomes minimum from T6 (1.91 mm) to T9 (2.93 mm) then it increases from T10 (5.3 mm) to L5 (9.28 mm). The shape of vertebral canal is oval in upper thoracic vertebrae, round in middle thoracic vertebrae and again oval in lower thoracic vertebrae. In conclusion, the neural arch is systematically asymmetrical and dynamic in shape along the thoracic and lumbar spine.