The application of magnetic fields have a positive effect on fracture healing. - GreenMedInfo Summary

Aim of the study was to investigate the effect of magnetic fields on bone fracture healing and biochemical indices of bone turnover. Young male "White Newzealand Rabbits" were exposed after osteotomy of the femur of the hind-paw in narcosis for 31 days in a low-frequency magnetic field (field parameters: frequency 15.3 Hz, signal form: sine, magnetic field strength: 50 microT peak value). Eight animals each were assigned randomly for a single blind study to 3 groups. Controls were kept in a sham-exposition cage without magnetic field influence and were compared with a group in (Pseudo-) Helmholtz-coil arrangement with a horizontal magnetic field and a further group in a cylinder coil (vertical magnetic field). The daily duration of stay in the (sham-) exposition arrangements amounted to 30 minutes respectively. The activities of the alkaline phosphatase (AP) and creatinkinase (CK) were evaluated preoperatively, after the 19th and 31st experimental day, the callus density by means of computertomography after the 31st experimental day (two-tailed t-test). The densitometrically assessed callus densities of the magnetically treated groups were highly significant (p < 0.0001) compared with the controls. In spite of accelerated fracture healing the activities of the ALP were lower at both postoperative examinations than preoperatively, in the cylinder-coil the activity proved to be significantly lower (p < 0.05) compared with the controls after 31 days. Significant differences in CK were detected at no time. In conclusion, we confirm the positive magnetic field effects on fracture healing. The mechanisms of interaction of magnetic field and bone fracture healing remain to be clarified.