Evaluation of a New Surgical Treatment for Equine Hind Limb Proximal Suspensory Desmitis.

The research explores the effectiveness of a new microfracture and ligament splitting surgery for treating horses with hind limb proximal suspensory desmitis, a common equine leg condition. Magnetic Resonance Imaging (MRI) was used to monitor the healing process of the ligaments.

Methodology

• The study was conducted in vivo, involving six healthy adult horses that showed no signs of lameness and had normal hind limb proximal suspensory ligaments (PSL).
• The researchers created lesions at the origin of both hind limb PSLs by injecting them with collagenase. Two weeks later, an MRI was performed.
• Each horse then underwent the new surgical procedure on one leg, while the other leg was left as the sham-operated control.
• Over time, regular lameness and MRI examinations were conducted. After 210 days, the horses were euthanized, and the PSLs were harvested for further examination, including histology, biochemistry, and gene expression.

Findings

• The MRI images revealed that the lesions created by collagenase injections were comparable to those seen in clinical cases.
• The MRI scans indicated that abnormal signal intensity vanished in the microfracture sites within the third metatarsal bone, indicating healing.
• The treated limbs showed histological evidence of new connective tissue formation that seemed to originate from the small perforations and blended into the ligament. However, the differences were not statistically significant.
• The treated limbs showed a significant increase in gene expression for cartilage oligomeric matrix protein and decorin compared to the control limbs.

Conclusion

• The findings suggest that the new surgical treatment induces a tissue response. However, more research is required to establish if this tissue remodeling at the bone-ligament interface results in improved clinical outcomes.
• This study suggests that MRI can be a useful tool for monitoring recovery in horses undergoing treatment for hind limb proximal suspensory desmitis.