Alternating Current Stimulation Promotes Healing of Bone Fractures in Rabbits.

BACKGROUND: Bone fracture is a partial or complete break in the continuity of a bone, which poses a significant healthcare burden. It is important to discover a novel method to stimulate and speed-up the healing of bone fractures. AIM: This study aimed to investigate the effects and mechanisms of alternating current (AC) in promoting bone fracture healing. METHODS: A rabbit bone fracture model was used. X-ray and Micro-CT evaluated fracture healing, while HE staining and immunohistochemistry assessed morphological changes. In vitro, pre-osteoblastic cells were tested with alizarin red S staining and alkaline phosphatase (ALP) activity. RNA-seq analysis explored potential mechanisms. RESULTS: X-ray evaluation showed that alternating current stimulation (ACS) promoted bone formation and shaping by day 14 post-treatment. Micro-CT results revealed significant new bone formation as early as day 3 and day 7 (p < 0.05). HE staining indicated more trabecular bone formation in the ACS group compared to the model group at days 7 and 14. Immunohistochemistry showed higher expression of BMP-2 and VEGF in the ACS group by day 7. In vitro, ACS enhanced osteogenic differentiation, increasing calcified nodule formation and ALP activity. Gene expression analysis demonstrated significant changes in key osteogenic genes, confirmed by multiple immunohistochemical staining. CONCLUSIONS: ACS may be a novel method for treating bone fractures more rapidly, significantly relieving the patient's burden, particularly in the early stages of bone healing.