Comparison of two bone trephine instruments used for quantitative histomorphometry.

Transilial bone samples were obtained at necropsy using trephine instruments with internal diameters of 2 mm and 7 mm. Undecalcified histological sections were prepared and two structural histomorphometric variables (percentage of trabecular bone volume and surface density of bone) were estimated by a Quantimet 720 image analyser. The differences between the variables measured from the two adjacent cores were due to differences in biopsy site rather than the size of the sample. The smaller diameter needle is therefore recommended for use as the biopsy procedure is simpler and tissue sections can be prepared sooner than is the case with the larger needle.