Electric Properties of Wet Whole Bone

Abstract

Although clinical applications of electrical stimulation of bone growth are of value in the treatment of nonunion and several other bony defects, the mechanism involved is still not fully understood. Knowledge of the electric properties of bone is helpful in this regard because it facilitates analysis of current flow in bone during electrical stimulation, In this study, the frequency dependence of the impedance and phase-angle in wet whole bovine bone were determined using a modified four-point technique. The measurements were made in both circumferential and longitudinal directions. In general, impedance in the circumferential direction was higher than in the longitudinal direction. Large differences in impedance were found between cortical bone and marrow. Bone resistance and capacitance were measured at 1 KHz, and the values were used to calculate impedance employing a parallel-model equivalent circuit. The calculated impedance values compared well with those obtained experimentally.