The effects of electromagnetic field on distraction osteogenesis.

The effects of electromagnetic field on distraction osteogenesis and new bony tissue were investigated. Twenty-five New Zealand rabbits were divided into an experimental (12 rabbits) and a control (13 rabbits) group. An osteotomy was performed on the right tibia in the diaphyseal region in both groups. The experimental group was exposed to a magnetic field of 50 Hz 1.0 mT for 3 hours a day for 13 weeks. The control group was kept in a similar environment but with no electromagnetic field. The distraction was continued until an increase of 10 mm was achieved. At weeks 4, 8, and 13, radiography, scintigraphy, and a biopsy were performed in both groups, and the results were statistically analyzed. The X-ray results were similar in both groups at all times. On the other hand while the scintigraphic and histopathological results were similar at weeks 4 and 13 in both groups, the osteoblastic activity was significantly greater in the experimental group at week 8 (p < 0.01). In conclusion an electromagnetic field increases the osteoblastic activity and osteogenesis, but has little effect during the remodeling phase.