The effect of pulsing electro magnetic Fields on the Fracture repair

为确定脉冲电磁场（PEMFs）促进骨愈合的最佳照射条件，研制便携式PEMFs治疗仪，以兔和狗骨折模型为实验对象，确定PEMFs的最佳照射条件为：磁场强度2高斯，脉冲宽度25 μ sec，频率10 Hz。临床试验的PEMFs与这种照射条件下，适用于3个玩具犬骨折不愈合。手术稳定骨折，然后在前6周内连续照射，此后每天照射12小时。照射8 ~ 9周后获得临床愈合。临床应用PEMFs治疗23匹赛马新鲜骨折，并与未照射的结果进行比较。与未辐照动物相比，20匹（87%）马的X线片显示早期临床愈合。实验结果表明，脉冲电磁场能加速动物骨愈合过程，对治疗骨不连或新鲜骨折有较好的疗效。最后，成功研制了便携式无线脉冲电磁场动物治疗仪。照射条件的固定和使用具有小电池（AM 3）的简单电路使得小而轻（8 × 5.5 × 1.5cm和100 g重量）的装置成为可能。

This study was aimed to establish the optimal irradiation condition for pulsing electromagnetic fields(PEMFs)to accelerate the bone healing process,and to develop the portable PEMFs apparatus for animals.The optimal irradiation conditions of PEMFs obtained in the studies using the fracture models of rabbits and dogs were 2 gauss of magnetic field intensity, 25 musec of pulse width, and 10 Hz of frequency. Clinical trials of PEMFs with this irradiation condition were applied to 3 toy breed dogs with nonunion fractures. The fractures were stabilized surgically, then irradiated continuously during the first 6 weeks and for 12 hours/day thereafter. Clinical unions were obtained after 8 to 9 weeks of irradiation. PEMFs were also applied clinically for treatment of fresh fracture in 23 racing horses, and the results were compared to those without irradiation. Earlier clinical unions demonstrated radiographically were obtained in 20(87%) horses compared to non-irradiated animals. These results suggest that PEMFs accelerate bone healing process in animals and quite effective as the treatment of nonunion or fresh fractures.Finally, the portable and wireless type PEMFs apparatus for animals was successfully developed. Fixation of irradiation condition and a use of simple electric circuit with small batteries(AM3) made a small and light(8 by 5.5 by 1.5 cm and 100g weight) apparatus possible.