Morphometry of the osteodural bridge and the myodural bridge of the rectus capitis posterior major in a black Kenyan population

Abstract

The connective tissue between the rectus capitis posterior major and the cervical dura, popularly known as the myodural bridge has been postulated to contribute to dural tension monitoring. It prevents dural enfolding thus preventing stimulation of dural nociceptors which would result in cervicogenic headaches. Its length may be an indicator of its effectiveness; however, determination of its length radiographically is difficult. The osteodural bridge, the connective tissue between the axis and dura can be measured radiographically. The aim of the study was therefore to determine if there is a relationship between their lengths. Thirty formalin fixed cadavers were meticulously dissected at the department of Human Anatomy, University of Nairobi, to expose the suboccipital triangle. The lengths of the bridges were measured using a pair of digital vernier caliper. The data was recorded, coded and analyzed using Statistical Package for Social Sciences (SPSS) version 21.0. The means and standard deviations were determined. Histograms and probability plots were generated to determine the normality of the data. A Pearson’s correlation coefficient was generated to determine a correlation between the length of the myodural bridge and osteodural bridge. Of the 30 cadavers dissected, all had the myodural bridge and Osteodural bridge present. The mean length of the myodural bridge was 4.02+/- 0.395 mm. Mean length of the osteodural bridge was 2.71 +/- 0.311 mm. There was a linear relationship of the equation y=1.02x + 1.26 (R² =0.640). The length of the osteodural bridge may be used as a predictor of the myodural bridge’s length.

Keywords: Myodural, Rectus Capitis Posterior Major