Subject-specific finite element model of the pelvis: development, validation and sensitivity studies

Area of Science:

• Biomechanics
• Computational modeling
• Orthopedics

Background:

• Patient-specific finite element (FE) models of the pelvis are crucial for understanding three-dimensional mechanics.
• Previous FE models lacked validation with subject-specific strains and used simplified assumptions.
• Improved pelvic biomechanical understanding can lead to better treatment modalities.

Purpose of the Study:

• To develop and validate a realistic FE model of the pelvis using patient-specific data.
• To assess the sensitivity of FE strain predictions to variations in bone and cartilage properties.
• To compare computational predictions with experimental strain measurements.

Main Methods:

• Created a subject-specific FE model of a cadaveric pelvis from computed tomography (CT) data.
• Applied acetabular loading mimicking prosthetic femoral stem insertion.
• Measured cortical bone strains using rosette strain gauges and compared with FE predictions.

Main Results:

• Baseline FE predictions showed strong correlation with experimental results (r²=0.824).
• The model's best-fit line was not statistically different from y=x, indicating accurate prediction.
• Cortical bone thickness and elastic modulus significantly influenced FE strain predictions.

Conclusions:

• The developed and validated FE model provides accurate, patient-specific biomechanical insights into pelvic mechanics.
• This validated methodology is valuable for creating and analyzing patient-specific FE models.
• The findings support the use of FE modeling for improving pelvic treatment strategies.