Morphometric Study of Lower Lumbar spinal canal and canal/body ratio Using Computed Tomographic Images among apparently normal adult Nigerians

Abstract

INTRODUCTION AND AIM: Lumbar spinal canal play an important role in causes of low back pain, with lumbar spinal canal stenosis being the major causative factor for back pain. Accurate morphometry of the Lumbar vertebrae may be needed for various purposes including spinal fixation in case of fracture. The aim of this study was to determine the morphometry of the lumbar spinal canal as well as the canal/body ratio.

MATERIALS AND METHODS: Four hundred (200 males and 200 females) adults Nigerians with age ranged from 18-65 years. Sagittal diameter of spinal canal (SDC) and Sagittal diameter of vertebral body (SDB) were measured from the third to fifth lumbar vertebrae (L3 to L5) and their ratio calculated. The sexes of 3^rd, 4^th and 5^th lumbar vertebrae were determined by demarking points using the formula: Mean ± 3×Standard Deviations. A probability value <0.05 were considered as statistically significant.

RESULTS: The results showed mean SDC and SDB increased gradually from L3 to L5 with minimum at L3 and maximum at L5. On comparing SDC and SDB between male and female subjects, it was observed that both SDC and SDB were greater at all levels in male subjects compared to female subjects and were all statistically significant (p<0.001). Canal/body ratio ranged between 0.56 to 0.59 in male subjects and 0.59 to 0.62 in female subjects from L3 to L5 respectively.

CONCLUSION: Transverse diameter was the largest dimension of spinal canal and proportional to the size of vertebral body at each level.