osteons directly imply more cement lines per region of bone. A significant literature exists that promotes cement lines as feature that arrest and deflect microcracks in osteonal bone [2,13,15,23,28,45,47].

       Mechanical testing was performed to generate damage so that correlations could be drawn between it and the morphometric parameters. To that end, methods of test preparation were developed that exposed the foramen and a drilled hole to the same mechanical duress, that minimized damage due to processing, and provided a control for existing damage. Specifically, the foramen and the drilled hole resided in the constant moment region of a four point bending beam. The drilled holes (as well as the control hole) were meticulously sculpted to provide the same topology as the foramen and to remove surface damage due to their drilling. Finally, the control holes were located in an overhanging unloaded region of each beam. In this way, the damage states near the foramen and the drilled hole could be "normalized" with respect to the control hole.

       Mechanical testing was performed on more beams than were analyzed

morphometrically and for damage. The reason for this was due to the laborious and time consuming nature of the analyses. Nevertheless, interesting conclusions can be drawn from the mechanical test results themselves. The apparent initial elastic modulus of the beams containing the foramen in the current work was 14.2 ± 1.4 GPa (mean ± standard deviation). The apparent initial modulus of four point beams from the palmer aspect of the equine MC3 (but not containing the foramen) has previously been reported to be 14

2 GPa [6]. The similarity between the current and previous results is encouraging and reflects the local nature of the special microstructure near the foramen.