Differences in the concentration of various synovial fluid constituents between the distal interphalangeal joint, the metacarpophalangeal joint and the navicular bursa in normal horses.

The study analyzes the various components found in the synovial fluid of different joints in 24 healthy horses, in order to identify potential markers for navicular disease.

Study Overview

• The research aims to identify potential markers for navicular disease, a debilitating condition in horses affecting the navicular bone and associated structures in the hoof.
• In order to do this, the researchers examined the concentration of cartilage oligomeric matrix protein (COMP), total glycosaminoglycans (GAG), hyaluronan, metalloproteinases (MMP) 2 and 9, and total protein in the synovial fluid of the distal interphalangeal joint (DIP), metacarpophalangeal joint (MCP), and navicular bursa in 24 healthy horses.

Main Findings

• The researchers found that the average levels of GAG, COMP, and total protein were notably higher in the DIP joint and the navicular bursa compared to the MCP joint.
• Conversely, the hyaluronan content was found to be lower in the DIP joint and navicular bursa compared to the MCP joint.
• MMP -2 activity was consistent across all the reviewed fluid samples, while MMP -9 appeared in 42% of the MCP joint samples, 58% of the DIP joint samples, and 58% of the navicular bursal samples.

Implications of the Research

• Based on the conducted measurements, the researchers found that the composition of navicular bursal fluid was akin to the articular synovial fluids, particularly that obtained from the DIP joint.
• The correlation between the components of DIP joint fluid and navicular bursal fluid drawn from the same legs was found to be statistically significant for all the parameters measured.
• This study’s findings could potentially aid in the detection and management of navicular disease by providing an understanding of the normal composition of synovial fluid in different joints of healthy horses.