Hybrid Rigid-Deformable Model for Prediction of Neighboring Intervertebral Disk Loads During Flexion Movement After...

Area of Science:

• Biomechanical Engineering
• Spinal Surgery
• Computational Modeling

Background:

• Understanding spinal loads post-interbody fusion is crucial for clinical decisions and treatment efficacy.
• Existing literature presents controversial findings on spinal load changes.
• There is a lack of efficient predictive models for intervertebral disc stresses (annulus fibrosus and nucleus pulposus).

Purpose of the Study:

• To develop and validate a hybrid rigid-deformable modeling workflow.
• To quantify mechanical stress changes in adjacent intervertebral discs (L1-2, L2-3, L4-5) after L3-4 interbody fusion.
• To compare stress behaviors with an intact lumbar spine model.

Main Methods:

• Established a novel hybrid rigid-deformable modeling workflow.
• Quantified mechanical stress within annulus fibrosus (AF) and nucleus pulposus (NP) regions.
• Validated simulation outcomes against computational models and in vivo measurements.

Main Results:

• Maximal stress changes of 10% were observed in the AF region of the L1-2 disc and the NP region of the L2-3 disc.
• Minimal stress change of 1% was noted in the NP region of the L1-2 disc.
• Simulation results showed good agreement with existing data.

Conclusions:

• The developed model accurately quantifies stress changes in intervertebral discs after fusion.
• This methodology provides a novel design guideline for spinal implants and surgical strategies.
• The findings contribute to better understanding and management of lumbar spine disorders.