Prevention of Postmenopausal Bone Loss by a Low-Magnitude, High-Frequency Mechanical Stimuli: A Clinical Trial Assessing Compliance, Efficacy, and Safety

Abstract

A 1-year prospective, randomized, double-blind, and placebo-controlled trial of 70 postmenopausal women demonstrated that brief periods (<20 minutes) of a low-level (0.2g, 30 Hz) vibration applied during quiet standing can effectively inhibit bone loss in the spine and femur, with efficacy increasing significantly with greater compliance, particularly in those subjects with lower body mass.Introduction: Indicative of the anabolic potential of mechanical stimuli, animal models have demonstrated that short periods (Ͻ30 minutes) of low-magnitude vibration (Ͻ0.3g), applied at a relatively high frequency (20 -90 Hz), will increase the number and width of trabeculae, as well as enhance stiffness and strength of cancellous bone. Here, a 1-year prospective, randomized, double-blind, and placebo-controlled clinical trial in 70 women, 3-8 years past the menopause, examined the ability of such high-frequency, low-magnitude mechanical signals to inhibit bone loss in the human. Materials and Methods: Each day, one-half of the subjects were exposed to short-duration (two 10-minute treatments/ day), low-magnitude (2.0 m/s 2 peak to peak), 30-Hz vertical accelerations (vibration), whereas the other half stood for the same duration on placebo devices. DXA was used to measure BMD at the spine, hip, and distal radius at baseline, and 3, 6, and 12 months. Fifty-six women completed the 1-year treatment. Results and Conclusions:The detection threshold of the study design failed to show any changes in bone density using an intention-to-treat analysis for either the placebo or treatment group. Regression analysis on the a priori study group demonstrated a significant effect of compliance on efficacy of the intervention, particularly at the lumbar spine (p ϭ 0.004). Posthoc testing was used to assist in identifying various subgroups that may have benefited from this treatment modality. Evaluating those in the highest quartile of compliance (86% compliant), placebo subjects lost 2.13% in the femoral neck over 1 year, whereas treatment was associated with a gain of 0.04%, reflecting a 2.17% relative benefit of treatment (p ϭ 0.06). In the spine, the 1.6% decrease observed over 1 year in the placebo group was reduced to a 0.10% loss in the active group, indicating a 1.5% relative benefit of treatment (p ϭ 0.09). Considering the interdependence of weight, the spine of lighter women (Ͻ65 kg), who were in the highest quartile of compliance, exhibited a relative benefit of active treatment of 3.35% greater BMD over 1 year (p ϭ 0.009); for the mean compliance group, a 2.73% relative benefit in BMD was found (p ϭ 0.02). These preliminary results indicate the potential for a noninvasive, mechanically mediated intervention for osteoporosis. This non-pharmacologic approach represents a physiologically based means of inhibiting the decline in BMD that follows menopause, perhaps most effectively in the spine of lighter women who are in the greatest need of intervention.

Effect of supplemental vibrational force on orthodontically induced inflammatory root resorption: A multicenter randomized clinical trial

“…[24][25][26] In animal models, vibrational force has been shown to promote bony remodelling at sutures 27,28 and speed up orthodontic tooth movement. 29,30 Based on these data, several devices have been developed that are now commercially available and designed to deliver vibrational force directly to the dentition.…”

High-frequency loading positively impacts titanium implant osseointegration in impaired bone

“…The importance of using high-frequency (HF) mechanical loading, i.e., at a frequency beyond the physiological frequency (approx ∼3 Hz for mastication), is increasing because of the evidenced positive effect of HF loading on bone formation and fracture healing [16][17][18]. Furthermore, based on the clinical outcome of exercise studies [10,19,20], the advantages of using HF mechanical loading are considered to be safe and efficient. HF mechanical loading improves the bone's mechanical properties while being able to withstand the physiological demands [11].…”

Low‐level accelerations applied in the absence of weight bearing can enhance trabecular bone formation

“…20 Emphasizing the mechanical nature of the stimulus, vibrations do not produce systemic skeletal changes, but act in a local, sitespecific manner. 21 Despite successes of WBV in small-scale clinical trials, 22,23 an apparent limitation is its reliance on weight bearing as only bones of the lower and axial skeleton can be targeted by standing on a vibrating plate. Confining the anabolic response to weightbearing bones excludes skeletons incapable of bearing weight (e.g., patients with spinal injuries or muscular dystrophy) or clinically important sites not associated with weight bearing (e.g., distal radius).…”