Anatomical Analysis of Occipital Condyle (OC) at the Posterior Part of the Base of the Skull in Dried Skull Bone

Abstract

Background: Most anatomical and biomechanical studies on the craniovertebral junction have involved morphological or morphometric analysis on the occipital condyles. Some of these studies have provided important findings based on different surgical procedures. The shape, size and angle of the occipital condyles and the locations of the intracranial and extracranial orifices of the hypoglossal canal are highly important because they may affect the lateral approaches to the craniovertebral junction.

Aim: To morphologically analyze the adult human occipital condyle, estimate the bilateral differences, sexual dimorphism and compare with the available data.

Methodology: A total 150 (86 male and 64 female) dry skulls of adult human being were studied. Anteroposterior diameters (APD) and transverse diameters (TD) of occipital condyle (OC) were calculated using vernier caliper and shapes were visually assessed. Additionally, the area and index of Occipital condyle (OCI)were also calculated using formulae (OCI =Length/Width).

Results: The anteroposterior diameter in right-side Occipital Condyles is 23.1±1.2mm &21.1±1.5mm, in male & female respectively and anteroposterior diameter in right-sideOccipital Condyles is 23.23±1.2mm &21.9±1.5mm, in male & female respectively. Oval shape of right-side Occipital Condyles was commonly seen (32.7%). This was followed by Kidney (20.7%), foot shaped (14.7%), eight shape (10.0%), Quadrangular Shape (6.7%), S-shape (4.7%). The distribution of shape of OC insignificantly distributed in both male and female groups (p>0.05). Right-sided Occipital Condyles Anteroposterior Diameter was noted significantly higher in oval, Kidney, Foot Shape, Eight Shapes, S-Shape, and Round Shape in male skulls; while in case of Triangular Shape, Two Portioned and Irregular shape it was lower significantly in male skulls in compare to female skulls.

Conclusion: Our study results will serve as an aid to neurosurgeons in evaluating the morphology of carnio-vertebral junction in lateral transcondylar surgical procedures in case of lesions in the middle and posterior part of cranial base. Our findings are also informative for the anatomists, radiologists, orthopaedic surgeon, anaesthetist, forensic experts and anthropologists.