Analyzing Brachial Plexus Injury using FEM

Overview

Yamaguchi University in Japan use Simpleware as part of their biomechanics research and studies of spinal injuries. 3D modeling and simulation enables detailed analysis of potential clinical solutions. In this study, adult brachial plexus injuries are examined using a complex 3D Finite Element model (FEM) of the spine, dura mater, roots, and the brachial plexus. The authors looked at the mechanism of injury for the brachial plexus, particularly for stress and strain distribution, and how useful the model is for other applications.

Characteristics:

  • 3D image data obtained from Visible Human Project
  • Simpleware ScanIP used to build model
  • Simpleware FE Module used to generate FE mesh
  • Boundary configurations configured in Jvision
  • Simulation carried out in LS-DYNA

Thanks to:

Building the Model

Simpleware ScanIP was used to generate a 3D FEM using the dura mater, vertebrae, and intervertebral disc from CT and MRI images provided by the Visible Human Project (U.S. National Library of Medicine, Bethesda, MD, USA). The rib bones and costicartilage were constructed as the thoracic cage due to its importance in studying the motion properties of the spine. The model was also built to look at the scapula, clavicle, and humerus in relation to motion of the upper limn. As there were no images available of the brachial plexus, parts were built into the model based on research data.

The spinal nerve roots were extended in proportion to its anatomical form as the brachial plexus

Mesh Generation

All parts of the model were meshed in Simpleware using 20-node elements. The boundary conditions were configured using Jvision (JSOL, Tokyo, Japan), while LS-DYNA was used for simulation. Four analysing conditions were set: retroflexion of the cervical, left lateroflexion of the cervical, left rotation of the cervical, and abduction of the right upper limb. Measurement of distribution and the size of strain applied to the brachial plexus for each case was carried out to determine where there was an increase of strain.

Simulating brachial plexus injury conditions

Simulation Results

Simulation of lateroflexion of the spine

Simulation of lateroflexion of the spine

The study’s results indicated good agreement with clinical findings, making the model a valid research tool. Protective approaches to biaxial plexus injuries can therefore be developed to help reduce physical disabilities and psychological distress. Future research could add more realistic threshold values for strain, while the FE model could be made more complex to reproduce other forms of damage, including blood flow.