Objective: In our study, the influence of PEMF on skeleton morphology and bone metabolism on rats with disuse osteoporosis was investigated, and the possibility of using it for the treatment of disuse osteoporosis was explored.
Methods: The rats in the ALN group were treated with alendronate, and the rats in the PEMF group were exposed to pulsed electromagnetic fields (3.82 mT, 10 Hz) for 40 mind-1. Rats were sacrificed by the end of 2, 4, 8 and 12 weeks, and serum and right leg bones were collected. Serum BMP-2, BGP concentrations and bone metabolism and biomechanical parameters were measured.
Results: The bone structural mechanical indices and material mechanical indices of the right femur in all groups of mice during weeks 2 and 4 were decreased. At week 8 the bone structural mechanical index and maximum stress of the right femur in the ALN group were markedly raised compared with the CON group (P< 0.01). Only maximum stress and strain were improved in the ALN group and had a significant difference (P< 0.05) at week 12. The serum BGP and BMP-2 concentration in the PEMF and ALN groups was increased (P< 0.05) at week 2, but this increase was not synchronized. After 8 weeks, BGP and BMP-2 level in the PEMF group was observably elevated (P<0.01) in contrast to the ALN group.
Conclusion: From the experimental time interval analysis, PEMF can improve the mechanical stability of bone structure more gently and permanently than alendronate.
Keywords: Pulsed electromagnetic field; bone biomechanics; bone morphogenetic protein-2 (BMP-2); osteocalcin; osteoporosis.