Issues in modern bone histomorphometry

This review reports on proceedings of a bone histomorphometry session conducted at the Fortieth International IBMS Sun Valley Skeletal Tissue Biology Workshop held on August 1, 2010. The session was prompted by recent technical problems encountered in conducting histomorphometry on bone biopsies from humans and animals treated with anti-remodeling agents such as bisphosphonates and RANKL antibodies. These agents reduce remodeling substantially, and thus cause problems in calculating bone remodeling dynamics using in vivo fluorochrome labeling. The tissue specimens often contain few or no fluorochrome labels, and thus create statistical and other problems in analyzing variables such as mineral apposition rates, mineralizing surface and bone formation rates. The conference attendees discussed these problems and their resolutions, and the proceedings reported here summarize their discussions and recommendations.

► Absence of fluorochrome bone remodeling markers in animal and human biopsies creates technical difficulties in analyzing results.
► This occurs rather frequently in animal or human studies of treatment with anti-resorptive agents.
► Calculation of mineral apposition rates, mineralizing surface and bone formation rates is not possible in these cases.
► Analysis of group data can be significantly biased in studies where fluorochrome labels are absent or rare.
► The manuscript discusses methods of reporting data in these situations.