Changes in synovial fluid biomarker concentrations following arthroscopic surgery in horses with osteochondritis dissecans of the distal intermediate ridge of the tibia.

This research article investigates whether the concentration of certain biomarkers found in a horse’s synovial fluid, namely cartilage oligomeric matrix protein (COMP) and fibromodulin, changes after arthroscopic surgery in horses afflicted with a type of bone and joint disease called osteochondritis dissecans (OCD). The study observed that there was a significant decrease in fibromodulin after surgery, suggesting it could potentially be a biomarker for joint inflammation in horses with OCD.

Research Aim and Methodology

• The study aimed to record the concentration of biomarkers COMP and fibromodulin in synovial fluid of tarsocrural joints (TCJs) of horses suffering OCD.
• The researchers hoped to identify if these concentrations changed after osteochondral fragments were removed through arthroscopic surgery, indicating these biomarkers’ possible role in joint inflammation.
• The study involved 115 client-owned OCD-affected horses and 29 control horses, euthanized for unrelated reasons.
• Concentrations of COMP and fibromodulin were measured both before and after surgery in synovial fluid from the affected horses’ TCJs, and in the control horses’ TCJs after euthanasia.
• Histological examination for evidence of inflammation was performed on synovial biopsy specimens from both the OCD afflicted and control horses.

Results and Findings

• Synovial fluid concentrations of COMP and fibromodulin in horses affected by OCD prior to surgery did not differ significantly from those in control horses.
• However, the concentration of fibromodulin, but not COMP, was found to significantly decrease after the surgical procedure.
• Fibromodulin concentration correlated strongly with joint effusion scores and the number of synoviocytes on the synovial surface in histology, but not with lameness scores, results of the flexion test, or the degree of inflammatory cell infiltration in the synovial membrane.
• COMP concentration in the synovial fluid did not exhibit any significant correlation with clinical or histological findings.

Conclusions and Implications

• The results suggest that fibromodulin, as opposed to COMP, could potentially be a useful biomarker for joint inflammation in horses suffering from OCD of TCJs.
• This could pave the way for further research that leverages this potential biomarker in assessing inflammatory conditions in horses, thereby contributing to improved diagnosis and treatment procedures.