Biomechanical Effect Of Low-Intensity Pulsed Ultrasound Stimulation On Maturation Of Regenerate Bone

Objective: This study was designed to investigate the biomechanical effect of low intensity pulsed ultrasound Stimulation(LIPUS) on maturation of regenerate bone in a rabbit limb lengthening model.Method: 60 skeletally mature female New Zealand White rabbits randomly assigned to LIPUS treatment group and the control group in a blinded fashion to test the effects of LIPU stimulation in fracture healing. All animals were underwent mid-diaphyseal tibial osteotomy and immobilized in an Orthofix M103 Mini lengther, Gradual distraction of 0.5 millimeters every twelve hours for a ten-day period performed following a seven-day latency period. A four weeks course of LIPU stimulation applied over the distraction site for a period of twenty minutes daily starting immediately after distraction. Took X-ray photography perform radiographic analysis at 4weeks, 8weeks and 12weeks. All animals sacrificed at 4 weeks, 8weeks and 12weeks, measured the bone mineral density (BMD) by DEXA, and performed biomechanical testing of torsion.Results: X-ray examination of 12 weeks showed LIPUS group bone callus grown faster and better than control group, two groups had statistical significance(P＞0.05). BMD analysis showed bone callus of LIPUS group was significantly more than control group at 8weeks and 12 weeks. And the biomechanical testing showed the LIPUS group was more stiffness than the controls at 8 weeks and 12 weeks.Conclusion: LIPUS as a biophysical stimulation could promote fracture healing of animal model in rabbit tibia.