March 5, 2022
Pulsed electromagnetic fields (PEMFs) are a type of biophysical stimulation that has been shown to be effective in improving bone regeneration and preventing bone loss. Their use dates back to the 1970s, but a gold standard treatment protocol has not yet been defined. PEMF efficacy relies on the generation of biopotentials, which activate several molecular pathways. There is currently no clear understanding of the effects on bone healing and, in addition, there are several animal models relevant to this issue. Therefore, drawing guidelines and conclusions from the analysis of the studies is difficult. In vivo investigations on PEMF stimulation are reviewed in this paper, focusing on molecular and morphological improvements in bone. Currently, there is little knowledge about the biological mechanism of PEMF and its effect on bone healing. This is due to the variability of crucial characteristics of electro-magnetic fields, such as amplitude and exposure frequency, which may influence the type of biological response. Furthermore, a different responsiveness of cells involved in the bone healing process is documented. Heterogeneous setting parameters and different outcome measures are considered in various animal models. Therefore, achieving comparable results is difficult.
The versatility of using PEMFs in those situations in which bone metabolism can be compromised appears evident in the light of the results shown. In fact, it has proved useful both in situations where the bone has been directly damaged in a traumatic way and in conditions of bone metabolic impairment (such as osteoporosis induced by diabetes, corticosteroids or ovariectomy), as well as in the prevention of osteoporosis from disuse. In addition, this review provides an effective and concise synthesis of both the parameters set that have proved effective, and of the molecular and morphological variables studied so far in this field.