Electrical phenomena associated with bones and fractures and the therapeutic use of electricity in fracture healing

Living bones have small electrical potentials on their surfaces, the magnitudes of which change only slightly with the reaching of adulthood. When using a limb stresses are put on the bones inside, and these create piezo-electric potentials which may themselves cause bone growth along the lines of stress, hence making the bone stronger. Voltages also appear at fracture sites and may be important in causing the bone to heal its wound. Fractures that have not healed properly can be stimulated into repair by the passage of small electric currents through them. The factors involved in these processes are discussed.