Osteochondral junction leakage and cartilage joint lubrication

Area of Science:

• Biomechanics
• Biomedical Engineering
• Computational Modeling

Background:

• Interstitial fluid exchange occurs between cartilage and subchondral bone, crucial for lubrication.
• Injury and diseases like osteoarthritis can increase fluid leakage across the osteochondral junction.

Purpose of the Study:

• To develop a numerical model to investigate how osteochondral junction leakage affects cartilage lubrication.
• To quantify changes in cartilage lubrication with varying degrees of fluid leakage.

Main Methods:

• A multi-phase coupled poroelastic model was developed, including cartilage and subchondral bone plate (ScBP).
• Coupling between domains was achieved through mass and pressure continuity.
• Parametric studies varied relative permeability between ScBP and cartilage to simulate leakage effects.

Main Results:

• Increased ScBP permeability significantly reduces mixed-mode lubrication duration (up to 52% in osteoarthritis conditions).
• Higher ScBP permeability accelerates cartilage consolidation time (from 2h to 0.8h in advanced OA).
• Initial friction coefficient can increase by over 60% in advanced osteoarthritis conditions.

Conclusions:

• Increased osteochondral junction leakage exacerbates cartilage wear.
• Rapid interstitial fluid depressurization in cartilage contributes to increased wear rates.
• Findings highlight the mechanical consequences of altered fluid dynamics in joint disease.