regional cortical and trabecular bone loss after spinal cord injury

This article and any supplementary material should be cited as follows: Dudley-Javoroski S, Shields RK. Regional cortical and trabecular bone loss after spinal cord injury. J Rehabil Res Dev. 2012;49(9):1365-76. http://dx.doi.org/10.1682/JRRD.2011.12.0245

Slideshow ProjectDOI:10.1682/JRRD.2011.12.0245JSP

Regional cortical and trabecular bone loss after spinal cord injury

Shauna Dudley-Javoroski, PT, PhD; Richard K. Shields, PT, PhD, FAPTA



• Aim– Measure trabecular bone mineral density (BMD) and

cortical cross-sectional area (CSA) loss at several previously unexamined lower-limb sites in individuals with spinal cord injury (SCI).

• Relevance– SCI triggers rapid loss of trabecular BMD in bone

epiphyses and loss of cortical CSA in bone diaphyses, increasing fracture risk for people with SCI.



Method

• Using peripheral quantitative computed tomography, we scanned:– 13 participants with SCI longitudinally. – 16 participants with SCI once.– 21 controls (participants without SCI).

• We partitioned SCI data set into five time bins based on years post-SCI: – 0–0.5, >0.5–1, >1–2, >2–4, and >4.



Results

• BMD:– 1 year post-SCI, 15% to 35% of BMD was lost at

distal femur, proximal tibia, and distal fibula.– Bone loss at distal fibula accelerated between 1 and

2 years post-SCI. – BMD at these sites reached steady state value of

~50% of non-SCI value 4 years post-SCI.

• Cortical CSA:– At tibia diaphysis, decline was slower, eventually

reaching 65% of non-SCI value.



Results

Representative peripheral quantitative computed tomography images for participant with and participant without SCI.



Conclusion• Because of extensive loss of bone observed at

these sites, careful consideration needs to be given to dose of musculoskeletal stress delivered during rehabilitation interventions like standing, muscle electrical stimulation, and aggressive stretching of spastic muscles.

• Mechanical loading interventions that begin early after SCI, when BMD is nearly normal, may offer greater safety and efficacy than after chronic SCI.

regional cortical and trabecular bone loss after spinal cord injury

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