Additive effects of prostaglandin E2 and pulsed electromagnetic fields on fracture healing

Bone formation of fractured fibulae stimulated by pulsed electromagnetic fields (PEMF), PGE2, and combination of both was assessed with roentgenography and fluorescent labelling compounds, tetracycline, xylenol orange, and calcein. A total of 72 male New Zealand rabbits was osteotomized by creating a 1 mm-gap at fibulae and randomly divided into 8 groups: one control, one treated with PEMF, three treated with PGE2 of various dosages, and three treated with combined treatments of PEMF and PGE2 of specified dosages. PEMF had positive effects on bone formation. Exogenous PGE2 mimicked the effect of PEMF on linear bone growth. The effect of PGE2 on bone formation or bone remodelling was dose-related (5, 15, 50 micrograms/kg), with 5 micrograms/kg body weight as the optimal dosage in this study. Combination of PEMF and PGE2 exhibited a trend of additive effect on bone formation, especially at 15 micrograms/kg of PGE2. It is hypothesized that PEMF may exert its action on bone healing by increasing the endogenous PGE2. We therefore concluded that external stimulation such as PEMF and PGE2 was beneficial and stimulatory towards bone formation and healing in our animal model. However, the effects were somehow specific in electrical waveforms and dosage. Similar to PEMF, PGE2, therefore, may be a potential agent in promoting bone formation in the clinical treatments of fractures or perhaps non-union.