Bone Defect Healing Enhanced by Pulsed Electromagnetic Fields Stimulation: in Vitro Bone Organ Culture Model
Walter H. Chang,
Jimmy K. Li,
James Cheng-An Lin,
Pulsed Electromagnetic Field (PEMF) has many medical applications. Previous animal and clinical studies have clearly shown a positive effect of PEMF on the rate of osseous repair. The present in vitro study was designed to elucidate the specific response of bony tissue to PEMF treatment. Bilateral femora were obtained from 40 mature male Wistar rats, and a bone defect was created at the center of each distal metaphysis. The femora were maintained for 1, 2, or 3 weeks in vitro organ culture and received 8 hours of PEMF stimulation or sham-exposure. Healing of the osseous defect was evaluated by histomorphological examination. The prostaglandin E2 (PGE2) and alkaline phosphatase (ALP) concentrations in culture medium were harvested and analyzed by enzyme-linked immunosorbent assay reader and spectrophometer. The results showed that PEMF stimulation can accelerate defect healing. All the experimental femoral defects treated with PEMF stimulation healed faster than the untreated control defects, and the ALP concentration of supernatants was significantly elevated on 1- and 2-week periods. When an osseous defect was created at the femoral metaphysis, the synthesis and release of PGE2 was elevated and then decreased gradually. With PEMF stimulation, the PGE2 level in the culture medium of the experimental group was increased at the end of week 2 and 3 compared to the sham group. This highly controlled and well-studied model of PEMF stimulation of bone healing in vitro can be used to further examine the biological mechanisms involved.