Ex vivo investigation of the use of hydrothermal energy to induce chondrocyte necrosis in articular cartilage of the metacarpophalangeal and metatarsophalangeal joints of horses.

The research explores the use of hydrothermal energy for arthrodesis in horses by investigating the effects of joint washing with saline solution on chondrocyte viability in the joints of horse limbs.

Sample Population and Experimental Method

• The study worked with 7 pairs of metacarpophalangeal and 8 pairs of metatarsophalangeal joints from 8 Thoroughbreds.
• The horses were put down for reasons unrelated to musculoskeletal disease, providing an unbiased sample population.
• One joint of each pair was subjected to intra-articular lavage — a cleaning process involving the internal irrigation of the joint — for 5, 10, or 15 minutes with heated saline solution.
• The other joint went through a sham treatment of equivalent duration with saline solution at 22 degrees Celsius, serving as a control.
• Sample cartilage from various parts of the bone structure were examined for chondrocyte viability through confocal microscopy and viability staining after enzymatic digestion.

Research Findings

• The findings indicated a notable decrease in the percentage of sites containing viable chondrocytes in heat-treated joints when compared with the control joints.
• The estimated treatment hazard ratios were 0.048 (as identified through confocal microscopy) and 0.2 (through digestion assay). This metric measures the effect of treatment on the risk of experiencing the event of interest, in this case, chondrocyte death. The results indicate that the heat treatment considerably increased the risk of chondrocyte death.
• On a histological level, the study observed minimal detrimental effects on the periarticular soft tissues post heat treatment, demonstrating the safety of the intra-articular lavage process.

Conclusion

• The research concluded that ex vivo intra-articular lavage with saline solution at 80 degrees Celsius led to the death of almost all articular chondrocytes in the joint.
• Thus, this technique could potentially be a satisfactory method for extensive cartilage ablation, which is the reduction or removal of cartilage tissue when performing arthrodesis using minimally invasive techniques.