Morphometric Analysis of Sub-axial Cervical Vertebrae and Its Surgical Implications.

Background: The predilection of the cervical spine to a wide array of traumatic, degenerative and neoplastic diseases necessitates frequent surgical interventions. For successful surgical management of these conditions, a detailed anatomical knowledge of the cervical spine is required but variability in vertebral dimensions exists amongst different races and prevents the standardization of measurements. Aim: The aim of this study was to present a morphometric reference database for cervical vertebrae of the Indian population and enable comparisons with other populations. Materials and Methods: The study was conducted on 203 typical (C3-C6) cervical vertebrae. Linear measurements of the vertebrae were taken with the help of digital Vernier caliper and angular measurements were determined with software Image J. Statistical Analysis: Mean and standard deviation of the morphometric parameters taken into account were analysed. The comparison of morphometric dimensions of the right and left sides was performed using Student's t-test and p-value was calculated. Results: The morphometric analysis of the cervical vertebrae demonstrated that when compared with other races, the mean height (11.39 +/- 1.08 mm) and transverse diameters (22.18 +/- 2.52 mm) of the vertebral body were larger but antero-posterior diameter was less, making the vertebral bodies in Indians transversely longer. The dimensions of the pedicle, laminae, articular processes and spinous process were smaller when compared to other populations. There existed a highly significant difference (p=0.002) between the widths of the right and left superior & inferior articular processes. A great disparity of the pedicle transverse angle was noted in different populations but in Indians the angle was 44.47 +/- 2.81. Conclusion: The present morphometric study in Indian population would be valuable for the successful instrumentation of the cervical spine as smaller dimensions of the cervical vertebrae pose a challenge to the surgeons during application of plates and screws. The data would be helpful in designing spinal implants and permit identification of osteological remains.