Electrical properties of bone. A review.

A review of the available data on the electrical properties (resistance, capacitance, dielectric constant, dielectric loss factor, and dissipation factor, etc.) of whole as well as standardized bone specimens suggest that impedance was lowest in the longitudinal direction and highest in the radial direction. This is further evidence of the anisotropic nature of bone. The electrical properties of fully hydrated bone were significantly different from those of dry and partially wet bone and these properties were highly frequency-dependent. Other variables that influence the electrical properties, such as moisture content, principles and methods of measurement, temperature, and pH and conductivity of the immersing fluid, etc., have also been reviewed. Delineation of these variables is important in reporting test results on the electrical properties of bone; only then can the data on different electrical properties of bone reported by various authors be compared. Future research is needed to characterize the effect of age, microstructure, mineral content, and various disease processes on the electrical properties of bone. Such information may lead to new insight on the role of electrical properties on bone remodeling. An understanding of the electrical behavior of bone is also important for the design of electrical stimulation devices and their proper use for maximum osteogenic effect.