Cancellous bone minimodeling-based formation: a Frost, Takahashi legacy

The current dogma is that in adult human beings, remodeling creates nearly all the new cancellous bone tissue. However, Frost, Takahashi and colleagues hypothesized that minimodeling can go on in trabeculae throughout life. The current perspective will review the available reports on minimodeling-based formation to determine whether there is any support for his hypothesis. One: describe the methodology employed to characterize remodeling and minimodeling formation sites or packets, which restrict the analyses of these packets to a known age of the specimen. Two: present quantitative minimodeling data on cancellous bone of aging rats and transiliac bone biopsy of adult humans. Three: describe the occurrence and quantitation of mixed remodeling-minimodeling formation sites that could be misinterpreted as minimodeling sites. Fourth: present irrefutable evidence that bone anabolic agents initiate minimodeling-based formation sites. Fifth: discuss the mechanism of minimodeling-based formation may be the resumption of osteoblastic activity by bone lining cells to increase cancellous bone mass and trabecular connectivity. The findings of minimodeling is a rare activity in normal individuals, but may occur in a select population, and bone anabolic agents can initiate minimodeling-based formation are in support of Frost's hypothesis that minimodeling can continue throughout human life. Thus, another Frost, Takahashi legacy lives on.