Electromagnetic stimulation on the bone growth using backscattered electron imaging.

The events at the hydroxyapatite implant material/tissue interface following electromagnetic stimulation were studied in the rabbit. Two kinds of hydroxyapatite were used: natural (NA) and synthetic (HA) both with a grain size of <50 microm. Bone defects, artificially created in rabbit tibiae, were filled with the material examined. One group of animals was exposed immediately after surgery and every 12h thereafter to 30-min treatments with electromagnetic fields (PEMFs). A second group was used as a control (untreated). Two and 4 weeks after implantation, animals were sacrificed and bone samples processed for LM, TEM and SEM using a backscatter electron detector for the evaluation of bone growth. This study indicates that HA has more osteoconductivity than NA, and shows that PEMF-treatment results in a benefit in accelerating bone formation at early time periods.