Holographic interferometry in the biomechanical study of femoral behavior, with and without prosthesis.

The authors studied the strains acting on a normal femur, and on the same femur fitted with an uncemented screwed prosthesis, by means of the method of holographic interferometry. This modern optical method has the advantage of not requiring any preparation of the surfaces or modification of the bone to be studied. It is non-destructive and can be repeated. This study required 40 interferograms for each case, using two or even three views. Comparison of the images obtained showed major modifications: disappearance of the physiologic flexion of the diaphysis, overload of the upper third, and zones of excess constraint.