Measurement of articular cartilage stiffness of the femoropatellar, tarsocrural, and metatarsophalangeal joints in horses and comparison with biochemical data.

This research paper investigates the stiffness of cartilage in various joints in horses and compares it with the biological content. The researchers found that the stiffness varies at different sites, and a significant correlation was found between collagen or glycosaminoglycan (GAG) content and stiffness values at six out of thirteen sites.

Methodology

• The research team used eight equine cadavers from both males and females. The majority were Quarter Horses or of Quarter Horse type, with one being an Arabian.
• The cartilage stiffness of the femoropatellar (FP), tarsocrural (TC), and the metatarsophalangeal (MT) joints of the horses was measured. These measurements were then compared with the gross evaluation, collagen content, GAG content, and histologic appearance at each location.
• Arthroscopic indentation instruments were used at preselected sites in the FP (6 sites), TC (3 sites), and MT (4 sites) joints to in order to determine the stiffness.
• Each measurement site then underwent a biochemical composition analysis and a histologic evaluation.

Results

• All the cartilage from every site was considered normal based on macroscopic and histologic assessments. This means that there were no visible or microscopic signs of disease or damage in the cartilage.
• There were no significant correlations between the Mankin scores (a scoring system for the histopathological grading of osteoarthritis) and the measured cartilage stiffness values.
• However, significant differences in the stiffness of the cartilage were observed at different sites within all three joints studied.
• A significant positive correlation was found between either the collagen or the GAG content and the stiffness values at 6 of the 13 sites. These findings show that the amount of collagen or GAG in the cartilage can affect its stiffness in certain sites.

Conclusions

• The researchers concluded that cartilage stiffness values in healthy equine joints can be measured reliably using an indentation instrument. These values are dependent on the site and show a correlation with the GAG or collagen content.
• This instrument provides an objective way of determining the relative compressive stiffness of articular cartilage.
• Further research is suggested to confirm these findings in clinically normal horses and to determine if this method could be used to predict cartilage pathology in a clinical setting.