AUGMENTATION OF TRABECULAR BONE BY LOW MAGNITUDE STRAIN

通过低强度应变增强骨小梁

• 批准号: 2607929
• 负责人: CLINTON T RUBIN
• 金额: $ 28.07万
• 依托单位: STATE UNIVERSITY NEW YORK STONY BROOK
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-12-01 至 2000-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2607929
• 关键词: bone density; bone development; electrostimulus; femur; mechanical stress; osteopenia; photon absorptiometry; sheep; statistics /biometry; substantia spongiosa; tibia

Preliminary work in this laboratory has demonstrated that extremely low magnitude (<30 Microstrain) mechanical signals can be osteogenic if applied at a high frequency (5 to 50 Hz). Such high frequency low magnitude strains comprise an important constituent of a bone's strain history, suggesting that these mechanical events could represent a significant determinant of bone morphology. We hypothesize that small increases in high frequency loading, introduced non-invasively into the skeleton via vibration, will stimulate an increase in bone mass without sacrificing bone quality. Considering these strain levels are well below (<1/100th) those which may cause damage to the tissue, we believe these signals hold great potential as a mechanical prophylaxis for osteopenia. Using skeletally mature sheep, a randomized, partial 5x4x3 factorial experimental design, evaluating frequency (7.5, 15, 30, 60 or 120 Hz), duration (5, 10, 20 or 40 min), and intensity (0.1, 0.2 or 0.4g) will be used to determine the efficacy of a non-invasive mechanical device to augment the trabeculae of the tibia and femur. A series of in vivo and ex vivo protocols will be used to quantify the ability of this twelve month mechanical intervention to affect both bone mass and morphology. Dual energy x-ray absorptiometry will determine changes in density as a function of time, dynamic and static histomorphometry will quantify the site-specificity, quality, and extent of the response, and mechanical testing will be used to determine if this treatment influences strength and stiffness of the treated regions of the skeleton. Finally, the most osteogenic mechanical signals will be used to determine if bone density, strength, and stiffness can be recovered in the osteopenic skeleton. These experiments may yield new insights into the mechanisms by which mechanical factors control bone morphology, as well as lead to a novel treatment for osteoporosis.

该实验室的初步工作表明，极低 幅度（<30微应变）机械信号可以是成骨的，如果 以高频（5 至 50 Hz）应用。如此高频低频 应变大小是骨应变的重要组成部分 历史，表明这些机械事件可能代表 骨形态的重要决定因素。我们假设小 高频负载的增加，非侵入性地引入 通过振动刺激骨骼，会刺激骨量增加，而无需 牺牲骨质量。考虑到这些应变水平远低于 (<1/100th)那些可能对组织造成损害的，我们相信这些 信号作为骨质减少的机械预防具有巨大的潜力。 使用骨骼成熟的绵羊，随机、部分 5x4x3 阶乘 实验设计，评估频率（7.5、15、30、60 或 120 Hz）， 持续时间（5、10、20 或 40 分钟）和强度（0.1、0.2 或 0.4g）将为 用于确定非侵入性机械设备的功效 增强胫骨和股骨的小梁。一系列体内和 离体协议将用于量化这十二个的能力 一个月的机械干预，以影响骨量和形态。 双能 X 射线吸收测定法将密度变化确定为 时间的函数，动态和静态组织形态计量学将量化 地点特异性、响应的质量和程度以及机械 测试将用于确定这种治疗是否会影响力量 和骨骼处理区域的刚度。最后，最 成骨机械信号将用于确定骨密度， 骨质疏松的骨骼可以恢复强度和刚度。 这些实验可能会对机制产生新的见解 机械因素控制骨形态，并导致新的 治疗骨质疏松症。