Quantitative Evaluation of Equine Articular Cartilage Using Cationic Contrast-Enhanced Computed Tomography

Area of Science:

• Veterinary Radiology
• Biomaterials Science
• Orthopedic Research

Background:

• Equine articular cartilage health is crucial for joint function.
• Degenerative changes in cartilage can lead to lameness and reduced athletic performance.
• Accurate assessment of cartilage integrity is vital for diagnosis and treatment.

Purpose of the Study:

• To investigate the diffusion characteristics of a cationic contrast medium (CA4+) in equine articular cartilage.
• To evaluate the utility of cationic contrast-enhanced computed tomography (CECT) for assessing normal and degenerative equine articular cartilage.

Main Methods:

• Experiment 1 (Exp1): Determined diffusion time constants and equilibrium times of CA4+ in healthy equine osteochondral specimens using serial CECT.
• Experiment 2 (Exp2): Created cartilage defects in equine joints, collected biopsies after 7 weeks, and analyzed them for CECT attenuation, glycosaminoglycan (GAG) content, mechanical stiffness (Eeq), and histology.
• Compared imaging, biochemical, and mechanical data between defect and control joints.

Main Results:

• Diffusion time constants varied between medial and lateral condyle cartilage in healthy specimens.
• Cationic CECT attenuation was significantly lower in defective cartilage compared to control cartilage.
• CECT attenuation strongly correlated with glycosaminoglycan content and mechanical stiffness, indicating its sensitivity to cartilage degeneration.

Conclusions:

• The time for CA4+ to equilibrate in equine articular cartilage is influenced by tissue volume.
• Quantitative cationic CECT imaging serves as a reliable indicator of the biochemical, biomechanical, and histological status of equine articular cartilage, distinguishing between normal and degenerative states.