Bone architecture adaptations after spinal cord injury: impact of long-term vibration of a constrained lower limb

Abstract

Summary This study examined the effect of a controlled dose of vibration upon bone density and architecture in people with spinal cord injury (who eventually develop severe osteoporosis). Very sensitive computed tomography (CT) imaging revealed no effect of vibration after 12 months, but other doses of vibration may still be useful to test. Introduction The purposes of this report were to determine the effect of a controlled dose of vibratory mechanical input upon individual trabecular bone regions in people with chronic spinal cord injury (SCI) and to examine the longitudinal bone architecture changes in both the acute and chronic state of SCI. Methods Participants with SCI received unilateral vibration of the constrained lower limb segment while sitting in a wheelchair (0.6g, 30 Hz, 20 min, three times weekly). The opposite limb served as a control. Bone mineral density (BMD) and trabecular micro-architecture were measured with high-resolution multi-detector CT. For comparison, one participant was studied from the acute (0.14 year) to the chronic state (2.7 years). Results Twelve months of vibration training did not yield adaptations of BMD or trabecular micro-architecture for the distal tibia or the distal femur. BMD and trabecular network length continued to decline at several distal femur sub-regions, contrary to previous reports suggesting a “steady state” of bone in chronic SCI. In the participant followed from acute to chronic SCI, BMD and architecture decline varied systematically across different anatomical segments of the tibia and femur. Conclusions This study supports that vibration training, using this study’s dose parameters, is not an effective antiosteoporosis intervention for people with chronic SCI. Using a high-spatial-resolution CT methodology and segmental analysis, we illustrate novel longitudinal changes in bone that occur after spinal cord injury.

The Efficacy of Low-intensity Vibration to Improve Bone Health in Patients with End-stage Renal Disease Is Highly Dependent on Compliance and Muscle Response

“…For example, the most significant effect of the intervention in our study involved parameters related to microstructural connectivity —tibia stiffness and trabecular plate-to-rod ratio — which were not assessed in previous studies, except in Dudley-Javoroski et al (59). Furthermore, differences in DXA measures over the 6-month intervention were not discernable at spine or hip in our study.…”

Spinal Cord Injury as a Model of Bone-Muscle Interactions: Therapeutic Implications From in vitro and in vivo Studies

“…In the recent past, whole-body vibration (WBV) effects on bone architecture after SCI have been investigated with inconsistent results. In 2016, Dudley-Javoroski et al showed that 12 months of vibration training did not preserve BMD or trabecular architecture in subjects affected by chronic SCI, showing bone tissue insensitivity to mechanical loading interventions (63). These results are not in line with the previous studies performed on rats, where WBV seemed to attenuate the bone loss that commonly occurs during the early acute stages after SCI (64).…”

Vibration training after chronic spinal cord injury: Evidence for persistent segmental plasticity

“…All subjects provided written informed consent before participating in the study. Participants were recruited from an ongoing study of vibration training as an anti-osteoporosis measure after SCI [8]. In brief, these participants received twice-weekly vibration training (30 Hz, 0.6 g ) to one lower limb while seated in a wheelchair.…”

“…The loss of this pervasive source of load may play an important role in the precipitous decline of bone integrity experienced by patients with SCI [1]. Studies that reintroduce vibration as an antiosteoporosis countermeasure are underway [8, 17]. Vibration is also being investigated as a method to reduce spasticity [2, 14], one of the most prevalent and bothersome secondary heath conditions of SCI [6].…”