THE ANATOMY OF OCCIPITAL CONDYLES AND FORAMEN MAGNUM AND THEIR SURGICAL IMPORTANCE: A MORPHOMETRIC STUDY

Background: Skull is the most complex osseous structure in the body.Foramen magnum is oval shaped and situated in an anteromedian position.Occipital condyles flanking the foramen magnum articulate with the superior articular facets of atlas vertebra.The dimensions of foramen magnum and the axial length of occipital condyles are very important for surgical exposure, such as in cases of tumor resection from foramen magnum area.Keeping in mind the importance of skull base in Anatomic, neurosurgical, medico legal and anthropological procedures, present study aims at performing morphometric analysis of occipital condyles and foramen magnum, two of the most prominent structures at the skull base.Materials and Methods: Present study was conducted on 80 dry adult human skulls (42 males and 38 females).They were obtained from department of Anatomy, Govt.Bundelkhand Medical College, Sagar and NSCB Medical College, Jabalpur, (M.P.).Measured parameters were: Axial length of occipital condyles, Anterior intercondylar distance, Anteroposterior diameter of foramen magnum, Transverse diameter of foramen magnum.The parameters were measured by digital sliding vernier caliper in mm.scale.Data was statistically analyzed.Results: The mean axial length of occipital condyle was found to be greater on left side as compared to right side but the difference was not statistically significant.The measurement was found to be greater in male skulls than female skulls for both sides and the difference was highly significant.Average intercondylar distance was found greater in female skulls than male skulls but the difference was not statistically significant.The average Anteroposterior diameter of foramen magnum was found to be greater in males as compared to females but the difference was not statistically significant.Similarly transverse diameter of foramen magnum was also found greater in males than that of females with statistically insignificant difference.The mean foramen index was found to be greater in males than females but the difference was not statistically significant. Conclusion:The purpose of the present study was to get an insight into the morphology of the base of skull especially bilateral and gender based differences in the basicranium.For better understanding of skull base morphology and possible anatomical variations, similar studies with larger sample size and use of advanced techniques like computer assisted image analysis system would be more enlightening.