Shape and Size of the Transverse Foramina in Japanese

Abstract

he present paper aims to describe accurately the shape and size of the transverse foramina in all the cervical vertebrae based on 50 male and 50 female Japanese skeletons. An elliptical shape (about 54%) occurred most frequently, followed by a round shape (about 14%) in all the vertebrae except C2s (superior aspect) and C6. Double foramina (about 11%)were found most frequently in C6 and decreased progressively above and below that level. The main axis of the foramen generally took an anteromedial direction in C1, a frontal direction in C3-C5, and an anterolateral direction in C7. The axis changes its direction strikingly at two points, namely from anteromedial to anterolateral between C7 and C6, and from frontal to anterolateral in the foramen of C2, cranialward. The transverse foramina were significantly greater in males than in females, and on the left side in more than half cases. Its value was largest in C1, followed by C2 and C6, and smallest in C7, though it increased gradually from C3 to C6. Almost identical data were observed in Japanese, Chinese and Indian vertebrae.