Osteochondral injury increases type II collagen degradation products (C2C) in synovial fluid of Thoroughbred racehorses.

The research article investigates the impact of exercise and osteochondral injury on the level of type II collagen degradation products in the synovial fluid of Thoroughbred racehorses. The study finds that such injuries cause a significant increase in these degradation products, which correlates to the severity of the joint injury.

Method of the Study

• The study collected synovial fluid from metacarpophalangeal/metatarsophalangeal (MCP/MTP) and carpal joints of three groups of Thoroughbred racehorses.
• The first group included 20 normal rested horses. The same horses, after 5-6 months of race training, formed the second group. The third group consisted of 27 horses with osteochondral injury resulting from racing.
• In the case of the third group, the researchers also determined radiographic and arthroscopic scores to gauge the severity of joint injury.
• The concentration of type II collagen degradation products, known as C2C, in the synovial fluid were determined using the ELISA (enzyme-linked immunosorbent assay) method.

Results of the Study

• The study found that the concentration of C2C in the synovial fluid from osteochondral injured carpal and MCP/MTP joints differed significantly when compared to rested and exercised joints, implying that osteochondral injury increased C2C levels.
• However, there was no significant difference in C2C levels between rested and exercised horses, indicating that exercise alone does not notably affect C2C levels.
• Arthroscopic scores, which represent the physical evaluation of the joint, were significantly higher for osteochondral injured carpal joints than osteochondral injured MCP/MTP joints.
• Notably, the levels of C2C in the synovial fluid of the horses correlated positively with radiographic (x-ray) and arthroscopic scores, thus suggesting a link between higher C2C levels and greater joint injury.

Conclusions and Implications

• The research concludes that an osteochondral injury significantly increases the concentration of C2C in the synovial fluid of horse’s carpal and MCP/MTP joints.
• The concentrations of C2C were found to be aligned with the severity of the joint injury, underscoring the role of this biomarker in indicating joint damages.
• The study findings suggest that analyzing synovial fluid C2C concentrations might be a useful approach in evaluating the severity of joint injuries in racehorses.