Effect of a static magnetic field on bone healing in the dog: radiographic and histopathological studies

Although the promotional effects on bone healing of pulsed electromagnetic fields (PEMF) have been well demonstrated, the effects of static magnetic fields (SMF) remained unclear. In this study, effects of a custom-made magnetic wrap on radiographic and histopathological aspects of bone healing using a canine unstable osteotomy gap model were investigated. After an osteotomy of the midshaft radius, bone healing was evaluated over an 8-week-period in the control dogs (n = 5) and dogs exposed to SMF (1000 gauss) (n = 5). Bone healing was evaluated by qualitative and quantitative evaluation of serial radiographs every 2 weeks. Histopathological study was also performed on osteotomized radii upon completion of the experimental period. Dogs exposed to SMF had more advanced radiographic healing of osteotomy sites. Cellular morphology scores of the SMF group was significantly greater as compared with the control group (P<0.05). These results suggested that using the osteotomy gap model, SMF enhanced the radiographic and histopathological aspects of bone healing in dogs. Dogs at risk for delayed healing of fractures may benefit from treatment with SMF.