Finite element modelling of polymethylmethacrylate flow through cancellous bone

Area of Science:

• Biomedical Engineering
• Materials Science
• Computational Mechanics

Background:

• Acrylic bone cement is widely used in orthopedic surgery.
• Understanding cement flow in cancellous bone is crucial for successful implantation.
• Previous models often simplified the complex porous structure of bone.

Purpose of the Study:

• To develop a Finite Element Method model simulating non-linear acrylic bone cement flow.
• To investigate the influence of cancellous bone porosity on cement flow dynamics.
• To predict cement penetration depth in bone.

Main Methods:

• Developed a mathematical model using the Finite Element Method.
• Modeled cancellous bone as parallel capillaries with toroidal trabeculae.
• Simulated flow by manipulating torus and capillary dimensions to vary porosity.
• Utilized Darcy's law with an apparent permeability for acrylic cement flow.
• Employed a quasi-steady state approach to estimate penetration depth.

Main Results:

• Predicted cancellous bone permeability ranging from 5.6 x 10(-9) to 8.3 x 10(-9) m2 for linear flow.
• Demonstrated increased apparent permeability due to the non-linear behavior of acrylic cement.
• Achieved close agreement between model predictions and literature-based experimental results for penetration depth.

Conclusions:

• The developed model effectively simulates non-linear bone cement flow in cancellous bone.
• The model provides accurate predictions of cement penetration depth.
• This simulation tool can aid in optimizing surgical techniques and predicting outcomes.