THE EXTENT OF MICROCRACKING AND THE MORPHOLOGY OF MICROCRACKS IN DAMAGED BONE

Strain-induced damage in bovine laminar bone has been examined using l aser scanning confocal microscopy (LSCM). The specimens were loaded in a fluorescein solution, which penetrated the newly formed cracks in t he specimen. The microcracking, and the larger cracking, induced by st rain were very clearly visible. The microcracking occurred diffusely i n regions of high strain (stress), but was particularly obvious in the vicinity of large machined stress-concentrators. The microcracking co uld be shown not to be artefactual, that is, it was produced by strain , and not by specimen preparation. The microcracking interacted with t he structure of the bone, often having a wavy appearance related to th e histology. Microcracks seemed to be particularly associated with the most highly mineralized parts of the bone. LSCM is a technique holdin g great promise for the investigation of the initiation and developmen t of damage in mineralized hard tissues, and other translucent materia ls.