[Electromagnetic fields, electric current and bone healing - what is the evidence?].

For more than 30 years the potential effects of electrical stimulation on bone healing have been investigated. Up to now this therapy is controversial and not established as a standardised treatment option. This systematic review and metaanalysis focuses on the potential effects of electromagnetic fields and high-frequency electric fields on bony healing. In a systematic literature search randomised clinical trials were identified and analysed. Those studies with the primary endpoint "rate of bony healing" were combined in a metaanalysis which was performed with the "random effects" model. We found a total of 14 randomised clinical trials. These studies included a total of 915 patients. The majority of these studies used pulsed electromagnetic fields (PEMF). Out of the 14 studies nine were suitable for the metaanalysis which revealed a cumulative odds ratio of 3.5 and a 95 % confidence interval of 1.94-6.3. When performing a subgroup analysis a statistically significant result could not be confirmed by the studies with a higher methodological quality. In view of the heterogeneous physical parameters with different frequencies, time course, flux densities and in view of the methodological deficits, a general conclusion seems difficult. Recommendations or standards of therapy are so far not available.