Pilla Arthur A
Department of Orthopaedics, Mount Sinai School of Medicine, New York, NY, USA.
J Orthop Sci. 2002;7(3):420-8. doi: 10.1007/s007760200073.
Signals from both electromagnetic fields (EMF) and ultrasound (US) have a clinically significant effect upon bone repair. Both modalities are now a common part of the orthopedist's armamentarium for the care of delayed union, nonunion, and fresh fractures. Dynamization or controlled weight bearing also enhances bone repair. Consideration of the dosimetry of both EMF and US modalities suggests a possible unifying mechanism for the bioeffects from EMF, US, and strain-generated potentials (SGP) signals based on the time-varying electric field, E(t), associated with each type of stimulus. The E(t) field is directly induced with EMF devices and indirectly induced via the streaming potentials associated with the mechanical movement of ionic fluids within bone caniculi or directly past cell surfaces from US and SGP signals. It is shown that both electrically and mechanically induced E(t) have common waveform characteristics at the treatment site and thus can deliver similar doses of electrical stimulation. It is proposed that the time-varying endogenous electric field, E(t), from a time-varying change in the mechanical environment of healing or remodeling bone, can act as a dose-dependent growth stimulus. Thus, the primary messenger affecting cellular activity is E(t), suggesting that bone repair or remodeling may be interchangeably modulated using mechanical (including US) or electromagnetic signals.
来自电磁场（EMF）和超声波（US）的信号对骨修复均具有临床上的显著影响。如今，这两种方式都是骨科医生用于治疗骨延迟愈合、骨不连和新鲜骨折的常用手段。动力化或控制性负重也能促进骨修复。对电磁场和超声波两种方式的剂量测定的考量表明，基于与每种刺激类型相关的时变电场E(t)，电磁场、超声波和应变产生电位（SGP）信号的生物效应可能存在一种统一机制。E(t)场由电磁场设备直接感应产生，也可通过与骨小管内离子流体的机械运动相关的流动电位间接感应产生，或者由超声波和SGP信号直接穿过细胞表面间接感应产生。研究表明，电感应和机械感应的E(t)在治疗部位具有共同的波形特征，因此能够传递相似剂量的电刺激。有人提出，愈合或重塑骨的机械环境的时变所产生的时变内源性电场E(t)，可作为一种剂量依赖性生长刺激。因此，影响细胞活性的主要信使是E(t)，这表明骨修复或重塑可能可以通过机械（包括超声波）或电磁信号进行互换调节。
