Neutral solute transport across osteochondral interface: A finite element approach

Area of Science:

• Biomedical Engineering
• Orthopedics
• Computational Biology

Background:

• Osteoarthritis (OA) progression is linked to solute transfer across articular cartilage and subchondral bone.
• Understanding these transport mechanisms is crucial for OA research.

Purpose of the Study:

• To investigate neutral solute transport in human (slight OA) and equine (healthy) articular cartilage and subchondral bone.
• To quantify diffusion coefficients across different cartilage zones and the subchondral bone plate.

Main Methods:

• Utilized computed tomography and biphasic-solute finite element modeling (FEM).
• Developed a multi-zone FEM accounting for cartilage inhomogeneity (superficial, middle, deep zones) and subchondral bone plate.
• Fitted FEM to experimental concentration-time data to determine diffusion coefficients.

Main Results:

• Human samples exhibited higher diffusion coefficients across all zones compared to equine samples.
• Diffusion coefficients decreased from superficial to deep cartilage zones and into the subchondral plate in both species.
• Specific diffusion coefficient ratios between zones varied between human and equine samples, indicating species-dependent transport rates.

Conclusions:

• Solute diffusion decreases gradually towards the subchondral bone plate.
• Species-specific differences in diffusion rates exist within articular cartilage and subchondral bone.
• FEM analysis provides valuable insights into solute transport relevant to osteoarthritis research.