Static magnetic field effects on bone formation of rats with an ischemic bone model.

Effects of a static magnetic field were studied on bone formation using an ischemic rat femur model. Metal rods were prepared from magnetized and unmagnetized samariun cobalt to have tapered structure, both with the same geometrical dimension, and were implanted transcortically into the middle diaphysis of 88 rat femurs. Both sides of the rat femoral artery were ligated to create an ischemic bone model, followed by implantation of the tapered rod to the femur. The bone mineral density (BMD) and weight of the femurs were measured at 1st and 3rd week after implantation. The result at the 3rd week post-implantation revealed that the BMD and weight of the ischemic bone model rats were significantly reduced, compared with that of non-operated femur. It was also found that the magnetized group had significantly higher bone weights than the unmagnetized (p<0.05). The BMD of the rats implanted with the magnetized rods were similar to those of the non-operated (p>0.05). This enhancement of the femoral bone formation of the ischemic rat model by the static magnetic field seems to be due to the improved blood circulation of the femur.