INVESTIGATION ON THE FEASIBILITY OF BONE STIFFNESS ASSESSMENT FROM IN-VIVO TESTS

The application of the mechanical vibration approach to fracture healing assessment was proposed in the 90ies. Promising results were initially obtained also in in-vivo tests. However, maybe due the complexity of the experimental instrumentation and of data processing, it did not reach the clinical practice. In the last years, a collaboration between orthopedic surgeons and engineers has started, focused on the re-evaluation of this approach to monitor fractures treated with an external fixator. This paper describes the main results achieved in this research. A first test campaign was performed on a tibia phantom with the aim of defining a reliable procedure. Such a procedure was then applied to a simulated healing process, on the same phantom. In-vivo test were performed on a healthy tibia and also on two case studies, very different one from the other. Results indicate that variations in the resonant frequencies can be identified every two weeks, thus enabling a more frequent control with respect to the actual X-ray solution. A wider test campaign is necessary to validate these preliminary observations.