Biochemical characterisation of navicular hyaline cartilage, navicular fibrocartilage and the deep digital flexor tendon in horses with navicular disease.

The research article discusses a study conducted on horses with navicular disease, which is believed to be similar to degenerative joint disease in humans. The researchers examined changes in the cartilage and tendon composition, specifically looking at various proteins and biochemical components. They concluded that these changes may have implications for the understanding and management of the disease.

Objective and Hypothesis of the Study

• The primary aim of this research was to examine the biochemical composition of the navicular articular and palmar cartilages in horses, specifically those with navicular disease.
• The hypothesis guiding the research was that navicular disease in horses is a process similar to degenerative joint disease, causing changes in navicular fibrocartilage and the composition of the deep digital flexor tendon (DDFT).
• The researchers also believed that this process could extend to the adjacent distal interphalangeal joint.

Research Methodology

• In this study, samples were collected from 18 horses with navicular disease and 49 horses with no history of front limb lameness for comparison.
• These samples were compared not only to each other but also with the medial meniscus of the stifle and collateral cartilage of the hoof.
• The researchers analyzed the content of various substances in tissues, such as Cartilage oligomeric matrix protein (COMP), deoxyribonucleic acid (DNA), total glycosaminoglycan (GAG), metalloproteinases MMP-2 and MMP-9, and water.

Findings of the Study

• The study revealed that hyaline cartilage had the highest content of COMP and that the COMP content in both hyaline cartilage and tendon was more in lame horses compared to sound horses.
• Also, the concentration of MMP-2 in hyaline cartilage in lame horses was higher than that in healthy horses. Similarly, tendons had a significantly higher amount of MMP-2 compared to other tissue types.
• About 79% of lame horses with lesions had MMP-9 in their tendons, which was more compared to sound horses.
• These findings suggest significant matrix changes in navicular hyaline and fibrocartilage as well as the DDFT in horses with navicular disease. This provides additional insights into the pathogenesis of the condition and has potential implications for its management.