An experimental study to compare inflammatory response due to liquid or gas joint distension in horses submitted to arthroscopy.

This research study is an investigation into the inflammatory responses in horses following arthroscopy using either CO2 (gas) or Ringer’s lactate (liquid) for the joint cap distension, with indicative results pointing to similar responses in both cases but with less intra-articular bleeding and leukocyte activation in the case of CO2 usage.

Study Objective and Method

• The study was conducted to compare the degree of inflammation triggered in horse joints after undergoing experimental arthroscopy using either CO2 or a liquid solution, Ringer’s lactate, for joint capsular distension.
• In the experimental setup, each horse was subject to a bilateral tarsocrural arthroscopy—where one joint was distended using gas and the opposite joint with fluid.
• The synovial fluid, a substance that reduces friction in the articular cartilage of joints, was examined at different post-operative intervals, 0, 6, 12, 24, and 48 hours to assess inflammation.

Results

• The study found that CO2 use in arthroscopy recreates an acute and mild inflammation (synovitis) similar to that which is caused by liquid capsular distension. This similarity is represented by equivalent increases in leukocytes, TP (Total protein), and TNF-alpha (a cell signaling protein involved in systemic inflammation) in the synovial fluid.
• Despite the synovial fluid PGE2 (Prostaglandin E2, a lipid compound that has an important role in inflammation) levels being higher in joints that underwent the CO2 distension, lower levels of hemoglobin and leukocytes oxidative burst were observed after surgery. The study suggests that the use of CO2 during arthroscopy might reduce intra-articular bleeding and the activation of infiltrating leukocytes (white blood cells).

Conclusions

• The results concluded that the use of CO2 for arthroscopic examination triggers an acute and mild synovitis, which is similar to that caused by liquid capsular distension. The use of CO2 also seemed to decrease intra-articular bleeding and the activation of leukocytes, suggesting it might be a more favorable option in arthroscopy.
• These findings have implications for equine surgery and could potentially improve post-surgical recoveries.