可调频脉冲电磁场促进骨折愈合的实验研究

Effects of Frequency modulation Pulse Electromagnetic Fields on Fracture Union in Rabbits

目的探讨脉冲电磁场促进骨折愈合的机理及脉冲重复频率变化对骨折愈合的影响。方法健康雄性新西兰大耳白兔３０只，手术造成双侧桡骨中段３ｍｍ缺损，术后随机分为两组：治疗组，手术后早、中、后期分别予２Ｈｚ、１５Ｈｚ、２Ｈｚ的脉冲电磁场刺激，每天持续５小时；对照组，同样处理但治疗线圈不通电。术后２、４、６周心脏采血，处死取材，行Ｘ线、组织学、生物力学检查及血清激素放免测定，以评价骨折愈合。结果从Ｘ线、组织学、生物力学检查显示，治疗组的骨痂形成、骨愈合及弯曲强度恢复均优于对照组。其血清骨钙素（ＢＧＰ）在第２、４周高于对照组，血清甲状旁腺激素（ＰＴＨ）在第２周高于而第４周低于对照组。结论可调频脉冲电磁场可促进骨折愈合。其可能作用为：促进骨盐沉积，促进成骨细胞形成和活性及频率变化符合细胞频率窗效应。

Objective To explore the effect of frequency modulation pulse electromagnetic fields (FMPEMF) on fracture union and its mechanism.Methods Experimental fractures with 3mm defect were modelled at the mid shaft of bilateral radii of 30 healthy male New Zealand rabbits.The animals were randomly divided into two groups:experimental group,stimulated with pulse electromagnetic fields in 2Hz,15Hz and 2Hz in the early phase,mid phase and post phase,respectively;and control group,applied with the same protocol but the coil was not switched on.2,4 and 6 weeks after operation,the animals were sacrificed and the healing of fractures was evaluated with X ray,histological and biomechanical examinations,and radioimmunoassay for serum hormones.Results The callus formation,bony union and bending strength in the experimental group were better than those in the control.Bone gla protein (BGP) in the experimental group was higher than that in the control at 2 and 4 weeks after operation.And PTH in the experimental group was higher at 2 weeks and lower at 4 weeks than that in the control.Conclusion FMPEMF can markedly promote fracture healing.It might be the contribution to its effect of increasing mineral deposition,stimulating formation and activity of osteoblast,and modulating frequency according to the frequency window effect of bone cells.