The Effect of Electrical Stimulation on Bone: An Experimental Study on Rabbits

Oh, In Suk; Lee, Duk Yong; Chung, Moon Sang; Lee, Soo Yong; Oh, Sang Bin

Abstract

Experiences of 26 cases of electrical bone stimulation on normal adult rabbits was documented in this paper. The cathodic electrode was introduced longitudinally into the medullary cavity of the proximal tibia and the anodic electrode was introduced transversely in the distal femur of the same side. The contralateral tibia was used as the control, of which the Teflon coated Kirschner wire was introduced longitudinally into the medullary cavity. 10uA of direct current was passed continuously through the fixed wires between the proximal tibia and distal femur. At the second, fourth and sixth week, random bone scan with 99m-Tc was performed and the animals were sacrificed. The specimen X-rays of the tibia and femur were taken and the specimens were prepared for the microscopic study. The followings are obtained from this experimental study. 1. The rate of new bone formation is 69.2% in the stimulated group and 7.7% in the control group. There were also fibrosis and cartilage formation as well as the new bone formation. The fibrosis and cartrilage formation are observed only in the electrically stimulated side and their occurances are 69.2% and 11.1% respectively. So The new bone formation and fibrosis are definitely increased in the bones of the cathodic electrical stimulation than those of the control side. 2. The intramembraneous ossification is the predominent feature of this electrically stimulated new bone formation. 3. Bone and soft tissue necrosis was the main microscopic feature in the anode side. 4. Since new bone, fibrous tissue and sometimes new cartilage were observed in this study, it seems that the cathodic electrical stimulation is not specific for the new bone formation, but induce crude tissues such as bone, cartilage, fibrous tissue or vessels. Furthermore, it can be postulated that the 10uA electrical stimulation is only one of the best electrical environment for the formation of the crude tissues, especially for bone and fibrous tissue.