Bone mass is preserved in a critical‐sized osteotomy by low energy pulsed electromagnetic fields as quantitated by in vivo micro‐computed tomography

Abstract

The effectiveness of non-invasive pulsed electromagnetic fields (PEMF) on stimulating bone formation in vivo to augment fracture healing is still controversial, largely because of technical ambiguities in data interpretation within several previous studies.To address this uncertainty, we implemented a rigorously controlled, blinded protocol using a bilateral, mid-diaphyseal fibular osteotomy model in aged rats that achieved a non-union status within 3 4 weeks post-surgery. Bilateral osteotomies allowed delivery of a PEMF treatment protocol on one hind limb, with the contralateral limb representing a within-animal sham-treatment. Bone volumes in both PEMF-treated and sham-treated fibulae were assessed simultaneously in vivo using highly sensitive, high-resolution micro-computed tomography (pCT) over the course of treatment. We found a significant reduction in the amount of time-dependent bone volume loss in PEMF-treated, distal fibular segments as compared to their contralateral sham-treated bones. Osteotomy gap size was significantly smaller in hind limbs exposed to PEMF over sham-treatment. Therefore, our data demonstrate measurable biological consequences of PEMF exposure on in vivo bone tissue.

Stromal cell‐derived factor‐1 and monocyte chemotactic protein‐3 improve recruitment of osteogenic cells into sites of musculoskeletal repair

“…Rodent fibula models can be used for studies testing efficiency of treatment intervention. 25,26 However, evaluation in larger defects presenting a more challenging biological setting and better defined region of interest are likely to be more sensitive assessment tools. Repair in less challenging models may not be limited by cell homing as a mechanism due to the presence of a sufficient population of local progenitor cells in adjacent tissues.…”

Pulsed electromagnetic field treatments enhance the healing of fibular osteotomies

“…The progress of bone healing in vivo was assessed twice weekly by simultaneous imaging of both PEMF-and sham-treated hind limbs via high-resolution micro-CT as described previously [25]. The timesequential fibular images were segmented from the surrounding background signal and were precision-registered to permit volumetric reconstruction of hard callus and woven bone newly formed within 5 mm proximal and distal to the osteotomy site.…”

“…Little is known about this aspect, but it has been reported that both human bone fractures and osteotomies in animal models responded more vigorously to PEMF treatments when treatment began soon after trauma [32], than when treatments began well after the bone trauma had progressed to a quiescent state [25]. Thus, variation in the time after bone trauma of when PEMF treatments were initiated may have contributed to some of the reported variability in healing effectiveness.…”

Effects of pulsed electromagnetic field vibration on tooth movement induced by magnetic and mechanical forces: a preliminary study

“…It appears that electrical energy, whether applied as a direct current or a pulsed electromagnetic field (PEMF), has the ability to affect both the depository and resorptive activities of bone and cartilage cells. [8][9][10] It is believed that orthodontic tooth movement is accompanied by site-specific bone remodelling with inflammatory nature. 11 Alveolar bone remodelling is essential for tooth movement and is characterized by tandem periods of osteoclastic recruitment, bone resorption, reversal and bone formation.…”