The study of median and lateral articular facets of atlas vertebra for dens.

ABSTRACT

As atlanto- axial joints are the most complex joints of the axial skeleton, both anatomically and kinematically, comprehensive knowledge of spinal kinematics is of paramount importance for an understanding of all aspects of clinical analysis of radiographs , in understanding clinical effects of fusion and orthotic prescriptions. In the present study the workers have tried to study median and lateral articular facets of atlas vertebra for dens. The study was conducted with an aim to evaluate the changes occurring with cleft posterior arch of atlas along with lateral atlanto-axial joint. The study was conducted on 200 dried, unsexed adult human atlas and 200 axis vertebrae. In the present study the incidence of cleft posterior arch of atlas is 2%. There is no difference in surface area of the lateral articular facets of both sides in all atlas vertebrae. Smooth lateral articular facets are found on the medial side of the lateral masses of all atlas vertebrae in dried bones as well as in cadaveric dissections. In the present study it is also observed that in the cleft posterior arch of atlas, surface area of median articular facet of anterior arches significantly more than in normal atlas vertebra.