Relationship between arthroscopic joint evaluation and the levels of Coll2-1, Coll2-1NO2, and myeloperoxidase in the blood and synovial fluid of horses affected with osteochondrosis of the tarsocrural joint.

Summary: Objective: To evaluate the levels of plasmatic and synovial Coll2-1, Coll2-1NO₂ and myeloperoxidase (MPO) in horses with osteochondral lesions of the tarsocrural joint and to investigate how these levels relate to arthroscopic findings of inflammation and degeneration. Materials and methods: Venous blood and synovial fluid samples were collected from 63 horses presented for arthroscopic removal of osteochondral fragments in the tarsocrural joint. Prior to removal of the osteochondral fragment, an exploration of the joint was performed and an inflammatory and degenerative score was determined. The blood and synovial levels of Coll2-1, Coll2-1NO₂ and MPO were also measured. The effects of the arthroscopic evaluation (inflammatory and degenerative classes) on the blood and synovial markers were evaluated using a linear model (GLM procedure), and correlations between biochemical markers in the blood and synovial fluid and the arthroscopic evaluation (inflammatory and degenerative classes) were established (Pearson’s correlations). Results: Significantly higher levels of Coll2-1 were detected in synovial fluid of higher degenerative classes. There was a significant correlation between the degenerative score and the synovial levels of Coll2-1 (r =0.27). According to the logistic regression model, there was a significant effect of the degenerative class on synovial levels of Coll2-1. Conclusions: Coll2-1 correlates well with the degenerative state of tarsocrural joints as evaluated by arthroscopy. This marker can therefore be classified as a burden-of-disease marker in the assessment of joint disease in horses. [ABSTRACT FROM AUTHOR]