Development, calibration and validation of a comprehensive customizable lumbar spine FE model for simulating fusion...

Area of Science:

• Biomechanics
• Spine Engineering
• Finite Element Analysis

Background:

• Surgical instrumentation significantly alters spinal biomechanics, necessitating accurate predictive models for clinical applications.
• Patient-specific finite element models can reduce development time and cost for analyzing spinal instrumentation effects.

Purpose of the Study:

• To develop a comprehensive hexahedral morphological finite element model of the lumbosacral spine.
• To predict range of motion, disc pressures, and facet contact forces for intact and instrumented spine conditions.
• To validate the model against extensive in vitro experimental data.

Main Methods:

• Development of a hexahedral morphological finite element model of the lumbosacral spine.
• Simulation of intact and instrumented spinal segments under various physiological loading conditions (pure moment, compression, combined loading).
• Validation of model predictions against experimental data from six literature studies.

Main Results:

• The model demonstrated statistically significant agreement with experimental corridor results for moment-rotation curves in flexion, extension, and bending.
• Axial torque moment-rotation curves were comparable to in vitro results for most lumbar functional units.
• Facet contact force predictions aligned well with in vitro experimental findings.
• The model is computationally efficient, using fewer elements without compromising predictive accuracy.

Conclusions:

• The developed finite element model accurately predicts spinal biomechanics for intact and instrumented conditions.
• This computationally efficient model aids in understanding the impact of surgical instrumentation on the lumbar spine.
• The model serves as a valuable tool for predicting the effects of different spinal instrumentation techniques.