In vivo diffuse damage in human vertebral trabecular bone

Accumulation of microdamage in vivo may lead to loss of bone quality. Until recently, linear microcracks were the only known form of in vivo microdama ge, but through the use of confocal microscopy an additional level of damag e (diffuse damage) has been identified. In this study, in vivo diffuse dama ge was characterized and quantified in human vertebral trabecular bone as a function of tissue morphology, age, race, gender, and previously quantifie d in vivo linear microcracks, Presence of diffuse damage in human vertebral tissue was confirmed and validated by simultaneous use of polarized, ultra violet, and laser confocal microscopy, Diffuse damage was found to occur pr eferentially within trabecular packets rather than in interstitial bone (p < 0.05), It was consistently higher in men compared with nomen (p < 0.05), but was not different by race or age group, Diffuse damage did not correlat e with linear microcracks, but both exhibited the same probability distribu tion in which the percentage of individuals having a particular amount of d amage decreased exponentially as damage content increased. These findings s uggest that diffuse damage accumulation and repair are governed by the same biological phenomena as microcracks, but diffuse damage contributes indepe ndently to the microdamage content of bone. (C) 2000 by Elsevier Science In c, All rights reserved.