An Anthropometric Study of Inferior Articular Facet of Atlas Vertebra and its Clinical Significance.

Abstract

Introduction: Atlas vertebra helps in complex biomechanical movements of the skull along with weight transmission of skull to spine. Vital centers of the medulla oblongata can get compressed by a dislocation or instability of the atlantoaxial joint. Recent developments in fixation technologies and minimally invasive surgical approaches have encouraged to knowing of various dimensions of atlas vertebrae which is very important for the development of instrumentation related to atlas vertebrae. Aim: To determine mean values of the following parameters bilaterally-Length of inferior articular facet (maximum Antero-Posterior (AP) Diameter), width of inferior articular facet (maximum transverse diameter). Materials and Methods: This morphometric study was conducted in Department of Anatomy, Shri Guru Ram Rai Institute of Medical and Health Sciences, SGRRU, Dehradun, Uttarakhand, India; In the time period from year 2020 to 2024, and included a total 120 dry, adult human atlas vertebrae of unknown age and gender which were examined for width and length of inferior articular facet on each side, in various medical colleges of North India. All dimensions were measured in bilateral manner using Digital Vernier Calliper. Results: The mean length or AP dimension of the inferior articular facet on right and left side were 18.39 ±2.83 and 17.91 ±2.19 mm. respectively, the width or transverse dimension of the inferior articular facet on right and left side were 15.12±1.36 and 15.04±1.41mm. respectively. Conclusion: The observations of present study helps in improving understanding of bony dimensions of inferior articular facet of atlas vertebra which could facilitate diagnosis and preoperative planning of atlantoaxial joint dysfunction.