Pulsed electromagnetic field (PEMF) therapy is used as an adjuvant therapy for promoting fracture healing. We performed this study in an animal model to determine the efficacy of PEMF therapy in fracture healing and to identify and quantify growth factor TGF-ß1 and TGF-ß2 by quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis.
The study was conducted in Wistar rats, with six study and six control animals. The right midshaft femur of all 12 animals was osteotomized to create a gap of 5 mm and transfixed with a Kirshner wire. Baseline quantitative RT-PCR analysis was done with the removed bone. The six animals from the study group were given PEMF of 1 hour duration, twice a day for 6 weeks. Radiographic images were obtained in all animals at 1, 3, and 6 weeks. At 6 weeks all the animals were euthanized, and 1.5 cm of bone, including the previous osteotomy site, were analyzed. RT-PCR analysis for TGF-ß1 and TGF-ß2 and histological analysis was done to compare bone healing between the control and study animals. The bone weight also was measured.
A significant increase in bone formation was shown by histomorphometry in the study group. Increased expression of TGF-ß1 and TGF-ß2 was present in the study animals. Although bone weight had increased in the study group, it was not statistically significant.
PEMF therapy may be useful as an adjuvant treatment for fracture healing. The mechanism of healing seems to be secondary to local expression of growth factor TGF-ß at the fracture site.