Morphometric Analysis of Lumbar Vertebrae for Identification of Intervertebral Spaces During Spinal Anesthesia: An Osteological Study

Background: Accurate identification of lumbar intervertebral spaces is essential for successful spinal anesthesia. Variations in lumbar vertebral morphology influence needle placement and the safety of neuraxial procedures. Despite their clinical importance, osteological morphometric data on the Indian population remain limited. This study evaluated the morphology of lumbar vertebrae with reference to identification of intervertebral spaces for spinal anesthesia. Material and Methods: A descriptive osteological study was conducted on 68 intact adult dry lumbar vertebrae (L1–L5) obtained from the Department of Anatomy, Santosh Medical College, Ghaziabad. Vertebral body transverse diameter, anteroposterior diameter, vertical height, and vertebral canal dimensions were measured using a digital Vernier caliper. Each measurement was recorded three times, and the mean value was used for analysis. Statistical analysis was performed using SPSS version 30.0, with results expressed as mean ± standard deviation. Results: Vertebral body dimensions increased progressively from L1 to L5. The mean transverse diameter increased from 41.2 ± 2.8 mm at L1 to 52.1 ± 3.8 mm at L5, while the anteroposterior diameter increased from 28.9 ± 1.9 mm to 35.2 ± 2.7 mm. Vertebral body height also increased across successive lumbar levels. Conversely, the anteroposterior diameter of the vertebral canal decreased from 17.5 ± 1.5 mm to 14.8 ± 1.2 mm, whereas the transverse canal diameter increased. Conclusion: Progressive morphometric changes in lumbar vertebrae from L1 to L5 have important clinical implications for accurate localization of intervertebral spaces during spinal anesthesia and may improve procedural success while reducing complications.

Keywords: Lumbar vertebrae; morphometry; spinal anesthesia; vertebral canal; intervertebral space; osteology.