CHAPTER 5
    OSTEON TRAJECTORIES NEAR THlE EQUINE METACARPUS NUTRIENT FORAMEN

                                   Introduction

       The purpose of this study is to describe osteon trajectories near a natural hole - the primary nutrient foramen - in the equine third metacarpus (MC3).

                              Materials and Methods

       Four equine third metacarpi were obtained from an animal tissue service for this and a related study. The bones came from skeletally mature animals less than five years of age and without skeletal abnormalities. All procedures involving animal tissue use was conducted under the approval and auspices of our Institutional Animal Care and Use Committee. The bones were cleaned of soft tissue and stored at -26'C until further preparation.

       Rough cuts were made first with a diamond blade band saw (Gryphon) to separate the palmar from the dorsal aspects. Three longitudinal sections, 2 mm thick in the endoperiosteal direction, were cut with a precision diamond blade band saw (Exakt) from the palmar aspect with the foramen centrally located. One parasagittal section (approximately 5 mm thick in the mediolateral direction) was cut from the palmar aspect with the foramen centrally located. Each section was mounted on a petrographic glass slide, ground (Buehler Minimet) with 600 grit silicon carbide waterproof sand paper in combination with a 3 tm diamond slurry (Buehler METADI Supreme) and polished manually (Buehler TEXiVIET 1000) until no scratches were visible under the microscope.