Biomechanical analysis of brachial plexus injury: Availability of three-dimensional finite element model of the brachial plexus

Abstract

Adult brachial plexus injuries frequently lead to significant and permanent physical disabilities. Investigating the mechanism of the injury using biomechanical approaches may lead to further knowledge with regard to preventing brachial plexus injuries. However, there are no reports of biomechanical studies of brachial plexus injuries till date. Therefore, the present study used a complex three-dimensional finite element model (3D-FEM) of the brachial plexus to analyze the mechanism of brachial plexus injury and to assess the validity of the model. A complex 3D-FEM of the spinal column, dura mater, spinal nerve root, brachial plexus, rib bone and cartilage, clavicle, scapula, and humerus were conducted. Stress was applied to the model based on the mechanisms of clinically reported brachial plexus injuries: Retroflexion of the cervical, lateroflexion of the cervical, rotation of the cervical, and abduction of the upper limb. The present study analyzed the distribution and strength of strain applied to the brachial plexus during each motion. When the cervical was retroflexed or lateroflexed, the strain was focused on the C5 nerve root and the upper trunk of the brachial plexus. When the upper limb was abducted, strain was focused on the C7 and C8 nerve roots and the lower trunk of the brachial plexus. The results of brachial plexus injury mechanism corresponded with clinical findings that demonstrated the validity of this model. The results of the present study hypothesized that the model has a future potential for analyzing pathological conditions of brachial plexus injuries and other injuries or diseases, including that of spine and spinal nerve root.

The Lateral Decubitus Body Position Might Improve the Safety of Ultrasound-Guided Supraclavicular Brachial Plexus Nerve Block

“…Mihara et al have stated that certain rotations of the spine and shoulder placement angles will influence the strain and traction forces on the brachial plexus. 9 …”

“…Studies that aim to improve the safety of ultrasound-guided supraclavicular brachial plexus block with the adjustment in body positioning are limited. 9 …”

“…Factors such as the degrees of spine retroflexion, lateroflexion, and rotational movements of the humerus can affect the traction force of the brachial plexus. 9 Body mass index (BMI) can influence the depth of the corner pocket. It was reported that BMI is positively correlated with the depth of the corner pocket when measured from the skin.…”

Finite Element Method Analysis of Compression Fractures on Whole-Spine Models Including the Rib Cage

“…Although there have been reports of finite element analysis of the spine as discussed elsewhere [5, 6], because the facet joints are small, constructing a model of the spine from medical images requires more time than constructing models of the knee and hip joints. However, we have analyzed disorders of the spine, examined the physical properties of the organs that are necessary for simulation, and elucidated the pathology of the disorders through simulation as discussed elsewhere [7, 8]. In recent years, advances in computer technology have led to an increase in reports of analysis of the spine as discussed elsewhere [9–14].…”

Reducing the Risk and Impact of Brachial Plexus Injury Sustained From Prone Positioning—A Clinical Commentary

“…It is appreciated that lateral flexion, creates tension across the trunks of the brachial plexus, affecting the upper trunk more than the middle and lower. 24 The current guidelines 9 recommend rotating the neck so the face turns toward the slightly abducted side. It The authors consider that this recommendation is protective of the plexus, as neck rotation toward the abducted arm blocks any lateral flexion away from the adducted arm and opens the neural foramina on the adducted arm side 25…”