Finite element modelling of the femur bone of a subject suffering from motor neuron lesion subjected to electrical stimulation

Eur J Trans Myol - Basic Appl Myol, 2014 · DOI: · Published: January 1, 2014

Spinal Cord Injury Biomechanics Musculoskeletal Medicine

Simple Explanation

Bone loss is common in patients with motor neuron lesions due to lack of mechanical stimulation, increasing fracture risk. Functional electrical stimulation (FES) can activate muscles, potentially stimulating muscle growth and decreasing bone loss. A longitudinal study was conducted on a single patient over 6 years, using CT scans to create finite element models. These models calculated fracture risk under physiological loading conditions based on bone mineral density. The risk of fracture was estimated by calculating the ratio between predicted stress and ultimate tensile stress. The results showed that the risk of failure varied between years.

Study Duration

6 years

Participants

Single paralysed young male subject

Evidence Level

Not specified

Key Findings

1
The number of elements at risk of failure varied between years, suggesting changes in bone strength and response to loading.
2
The greatest proportion of elements exceeding the fracture threshold were low bone density elements, indicating that the greatest risk of fracture occurring in the cancellous bone.
3
In 2005, the bone showed an improved response to loading, with a decreased risk of fracture, potentially due to a rigorous treatment regimen.

Research Summary

This study used finite element models created from CT scans of a single paralyzed subject's femur over 6 years to assess fracture risk during electrical stimulation treatment. The analysis revealed that the risk of fracture varied from year to year, with low-density bone elements being the most vulnerable to exceeding the fracture threshold. The study highlights the potential of finite element modeling to evaluate bone quality in patients undergoing electrical stimulation therapies, but acknowledges limitations in boundary conditions and clinical application.

Practical Implications

Risk Assessment

Finite element analysis can be used to assess fracture risk in paralyzed individuals undergoing FES.

Treatment Monitoring

Changes in bone density and fracture risk can be monitored over time with this method.

Personalized Therapy

The models could be used to optimize FES parameters to improve bone health.

Study Limitations

1
Manual adjustment during edge detection may have introduced geometrical errors.
2
Boundary conditions are difficult to apply accurately, limiting the representation of real-world scenarios.
3
The study only included a single subject, limiting the generalizability of the findings.

Your Feedback

Was this summary helpful?

Back to Spinal Cord Injury