3D morphometric analysis of calcified cartilage properties using micro-computed tomography.

Area of Science:

• Biomedical Engineering
• Radiology
• Orthopedics

Background:

• Osteoarthritis (OA) is a degenerative joint disease characterized by changes in cartilage.
• Quantifying morphometric properties of calcified cartilage (CC) is crucial for understanding OA.
• Micro-computed tomography (microCT) offers high-resolution imaging for detailed analysis.

Purpose of the Study:

• To establish microCT-based methods for quantifying calcified cartilage (CC) morphometric properties.
• To evaluate the feasibility of these methods in assessing OA-related changes.
• To investigate relationships between OA, tidemark surface morphology, and open subchondral channels (OSCCs).

Main Methods:

• Human tibial plateau samples (n=15) were analyzed using microCT.
• Conventional roughness and 3D surface variation parameters quantified CC surface morphology.
• Subchondral channel properties (percentage, density, size) were calculated.
• Histological sections were graded using Osteoarthritis Research Society International (OARSI) and CC/subchondral bone thickness was measured.

Main Results:

• OARSI grade correlated with decreased tidemark surface 3D variations and roughness.
• Specific surface patterns and entropy were associated with channel area fraction and density.
• Tidemark roughness (TMR) showed strong associations with channel area fraction and average channel size.
• Statistically significant differences in CC topography were observed between early OA and healthy samples.

Conclusions:

• A novel microCT imaging method was developed to quantify 3D CC topography and perforations.
• The established methods successfully detected topographical changes in the tidemark and CC perforations associated with OA.
• These findings highlight the potential of microCT for OA research and diagnostics.