EN-BLOC STAINING OF BONE UNDER LOAD DOES NOT IMPROVE DYE DIFFUSION INTO MICROCRACKS

Microdamage accumulation in bone has been implicated in the pathogenes is of some bone fractures, and in implant loosening. Standard techniqu es for staining microcracks may not allow all cracks to be stained. We tested the hypothesis that crack closure in bone cortices after remov al of a bending load may prevent diffusion of stain to sites of microc rack nucleation. Following cyclic loading, 26 canine femurs were divid ed into a group stained en bloc while applying a four point bending lo ad, and another group stained without an applied load. No differences in number or length of microcracks were observed, indicating that crac k closure does not prevent diffusion of stain to the crack location. S taining under load is unnecessary. (C) 1998 Elsevier Science Ltd. All rights reserved.