[Measurements of the deformation of the femur using speckle interferometry]

A new method for measuring the surface displacement in bones is described. Speckle interferometry was used to study the deformation behaviour of embalmed human femoral bones. The bones were measured under varying loads and conditions. It was shown that the magnitude and direction of displacement could be ascertained at selected points and the strain between any two points could be calculated. The present findings differ from those derived from mathematical models for the femoral bone published so far. The practicability of this technique is outlined. The present results indicate that the technique of speckle interferometry can also be applied to femoral bones with prostheses or external fracture fixations.