THE MECHANICAL CONSEQUENCE OF ACTUAL BONE LOSS AND SIMULATED BONE RECOVERY IN ACUTE SPINAL CORD INJURY

Bone, 2014 · DOI: 10.1016/j.bone.2013.12.012 · Published: March 1, 2014

Spinal Cord Injury Biomechanics Musculoskeletal Medicine

Simple Explanation

Spinal cord injury leads to bone loss, increasing fracture risk, especially around the knee. This study quantifies how bone loss and simulated recovery affect bone stiffness and strength in the proximal tibia following acute SCI. Researchers used CT scans and finite element models to predict changes in bone stiffness and strength due to actual bone loss and hypothetical treatments that restored bone mineral to baseline levels. The study found that bone loss significantly reduces bone strength. Restoring bone mineral content doesn't always fully restore bone strength, especially with substantial initial bone loss.

Study Duration

Mean of 3.9 months (range 3.0 to 4.8 months)

Participants

Ten subjects with acute SCI

Evidence Level

Not specified

Key Findings

1
Subjects lost 8.3% of their bone mineral density during the acute period of SCI.
2
Reductions in torsional strength (15.8%) were approximately two times greater than reductions in bone mineral density.
3
Torsional strength was not necessarily recovered when bone mineral was fully restored, particularly with large initial bone loss.

Research Summary

This study investigated the mechanical consequences of bone loss and simulated bone recovery in the proximal tibia of individuals with acute spinal cord injury (SCI). The results indicated that SCI-related bone loss leads to significant reductions in torsional strength, which are disproportionately larger than the reductions in bone mineral density. The study suggests that therapeutic interventions to preserve bone strength after SCI may be more effective if initiated before substantial bone loss has occurred.

Practical Implications

Early Intervention

Implement therapeutic interventions soon after SCI to halt or attenuate bone loss and preserve mechanical integrity.

Targeted Therapies

Develop therapies that target 'mechanically important' skeletal regions, possibly through combined drug and mechanical loading therapy.

Personalized Treatment

Consider the degree of bone loss prior to treatment when designing interventions, as restoring bone mineral content alone may not be sufficient.

Study Limitations

1
Relatively small sample size
2
Inability to account for microstructural changes to bone
3
Simulated treatments do not reflect the effect of any existing drugs or therapies

Your Feedback

Was this summary helpful?

Back to Spinal Cord Injury