Microangiographic Comparison of the Effects of 3 Loop Pulley and 6 Strand Savage Tenorrhaphy Techniques on Equine Superficial Digital Flexor Tendon.

The research article investigates the impact of two surgical techniques used to repair equine tendons: the 3-loop pulley (3LP) and the 6-strand Savage (SSS). The researchers found that while SSS is biomechanically superior, it significantly reduces the blood supply to the tendon, potentially limiting its effectiveness.

Objective and Hypothesis

• The primary aim of this study was to examine the difference in intrinsic vasculature perfusion in horses’ superficial digital flexor tendons (SDFT) following 3LP and SSS surgical repair techniques.
• The researchers hypothesized that the SSS technique would cause a significant decrease in vascular perfusion when compared with the 3LP technique, despite its superior biomechanical performance.

Methodology

• The study involved horses that underwent surgery under general anesthesia. The researchers randomly assigned the type of surgery (either SSS or 3LP) each horse would receive.
• Two tendons were kept as baseline controls, while the rest went through either the SSS or 3LP surgical methods.
• Following the surgery, the horses were euthanized and their forelimbs perfused with a barium sulfate solution and then fixed with formalin under tension.
• To examine the microvascular impact of each surgical technique, the researchers took microangiographic images of tendon sections and analyzed these using a custom macro.
• A MANOVA test was used to assess the differences in vascular counts between the SSS and 3LP techniques.

Results

• The results showed a significant decrease in the number of perfused vessels in tendons treated with the SSS technique compared to the 3LP method.
• The SSS approach took on average 4.7±0.9 times longer to place, indicating it might be a more complex procedure.

Conclusions

• Despite being biomechanically superior, the SSS technique could lead to an acute reduction in tendon perfusion compared to the 3LP technique, limiting its clinical application.
• Further research is essential to unravel the clinical significance of this difference and understand how it could impact the choice of surgical technique for equine tendon repair.