Electrical properties of bone:

Electrical potentials are generated in the bone in response to generation of stress. Piezoelectric effect and streaming potentials are the examples of stress generated potentials and

1. Piezoelectric effect: Charges in the tissues are displayed in response to mechanical stresses.
2. Streaming potentials: Occur when a electrically charged fluid is forced over a tissue ( cell membrane) with a fixed charge.
3. Transmembrane potentials are generated in response to cellular metabolic effects

Fracture healing depends on the variety of charged molecules. Devices intended to induce fracture healing by altering a variety of cellular activities has been introduced.

Types of electrical stimulation:

1. Direct current: stimulates an inflammatory like response (Stage one of bone healing)
2. Alternating current: affects the generation of cyclic AMP collagen synthesis and calcification during repair process.
3. Pulsed electromagnetic fields (PEMF’s): Initiate calcification of fibrocartilage and cannot induce calcification of fibrous tissue.