Engineering criteria for biomaterials: some thought on in situ measurements

Several non-destructive techniques now exist which show promise of providing information about implant performance in situ. Surface wave ultrasonics have been used successfully in the laboratory to measure the anisotropic properties of bone. It has also been used clinically to assess rates of fracture healing. Acoustic emission has been used experimentally to investigate bone abnormalities such as microfracture and osteoporosis in vitro. Application of these techniques to clinical studies depends upon the establishment of the appropriate parameters for bone and the various biomaterials used as implants. Surface wave ultrasound may also provide information about tissue ingrowth into porous systems. Acoustic emission can be especially significant in the early detection of implant failure.