Electroconductivity of bone in vitro and in vivo

In view of conflicting data in the literature regarding the electroconductivity of bone, measurements were performed both in vivo and in vitro by using alternating current of 100.0 mA and 1.0 mA at a frequency of 1000 cycles/second and the four-electrode method. Electrodes were inserted through all of the bone layers into the bone marrow space of the femora of seven rabbits. Bone electric resistance was measured also in situ 30 minutes after the death of the animals. A threefold increase in resistance of bone, from about 600 to about 1700 ohm, occurred in situ 30 minutes after the death of the animals, and an enormous resistance, about 10(10) ohm, was measured in vitro. It was also apparent that femora from the different rabbits had different values of electric resistance both in vivo and in vitro. If electroconductivity of bone is determined by body fluids rather than by the bone tissue per se, measuring the "specific resistance" of bone in vivo is meaningless.