A novel device to prevent osteoporosis by promoting bone metabolism using a newly developed double-loading stimulation with vibration and shaking.

In Japan, 13 million people have osteoporosis, including approximately 9 hundred thousand people who are bedridden owing to bone fractures from falls. Preventing osteoporosis is considered to be an important and effective way of preventing fall-related fractures. Thus, we developed a novel method of locomotor stimulation and analyzed its effectiveness in mice. Specifically, we created a double-loading device that combines vibration and shaking stimulation. The device was used to continuously stimulate ovariectomy-induced decreased bone density mouse models 30 minutes daily for 10 weeks. We then collected femur samples, created undecalcified tissue slices, calculated parameters using bone histomorphomtry, and conducted comparative testing. BS/TV (bone surface/tissue volume), N.Oc/ES (osteoclast number/eroded surface), Oc.S/ES (osteoclast osteoid surface/eroded surface), Omt (osteoid maturation time), Tb.N (trabecular number), Mlt (mineralization lag time) < (p < 0.01), N.Ob (osteoblast number), N.Ob/TV (osteoblast number/tissue volume), sLS (single labeled suface), N.Mu.Oc/ES (multinucle osteoclast number/eroded surface), and N.Mo.Oc/ES (mononucle osteoclast number/eroded surface) (p < 0.05) were significantly higher in the stimulation group than in the non-stimulation group. In addition, BS/BV (bone surface/bone volume), Tb.Sp (trabecular separation), MAR (mineral apposition rate), Aj.Ar (adjusted apposition rate) (p < 0.01), ES (eroded surface ), ES/BS (eroded surface/bone surface), and BRs.R (bone resorption rate) (p < 0.05) were significantly lower in the stimulation group than in the non-stimulation group. These results suggest that stimulation activated osteoblasts and osteoclasts, thereby leading to highly active bone remodeling. We anticipate that bone mineralization will subsequently occur, suggesting that this stimulation technique is effective in preventing osteoporosis by alleviating sudden bone density loss.

Effect of shaking and vibration stimulation on lumbar vertebrae in ovariectomized mice.

OBJECTIVES: Bone fractures affect the activities of daily living and lower quality of life, so investigating preventative measures is important. We developed novel stimulation equipment that combined a vibration stimulus with a shaking stimulus for preventing osteoporosis (one of the causes of bone fractures). We aimed to investigate the effect of this equipment on ovariectomized mice. METHODS: Oophorectomy of 8-week-old female mice was done. The stimulation group was stimulated for 10 consecutive weeks. RESULTS: The stimulation group showed significantly higher values (p<0.05) for osteoid thickness, osteoid volume-to-bone volume ratio and mineral apposition rate than those in the non-stimulation control group. The stimulation group showed significantly higher values (p<0.05) compared with the non-stimulation for expression of bone morphogenetic protein-2, interleukin-1ß, interleukin-6 and myogenic determination gene in quadriceps femoris muscles (QFMs). CONCLUSIONS: These data suggest that cytokine secretion by QFMs carried a humoral factor throughout the body via the blood and blood vessels and acted on bone and various organs. Development of this stimulation method and its clinical application, new methods for preventing and treating osteoporosis could ensue.