Adaptations of Trabecular Bone to Low Magnitude Vibrations Result in More Uniform Stress and Strain Under Load


Extremely low magnitude mechanical stimuli 10 microstrain induced at high frequencies are anabolic to trabecular bone. Here, we used finite element FE modeling to investigate the mechanical implications of a one year mechanical intervention. Adult female sheep stood with their hindlimbs either on a vibrating plate 30 Hz, 0.3 g􏰀 for 20 min/d, 5 d/wk or on an inactive plate. Microcomputed tomography data of 1 cm bone cubes extracted from the medial femoral condyles were transformed into FE meshes. Simulated compressive loads applied to the trabecular meshes in the three orthogonal directions indicated that the low level mechanical intervention sig- nificantly increased the apparent trabecular tissue stiffness of the femoral condyle in the longitudinal 17%, p 0.02) , anterior – posterior 29%, p 0.01) , and medial-lateral 37%, p0.01) direction, thus reducing apparent strain magnitudes for a given applied load.