Comparison of carbon fibre and nylon suture for repair of transected flexor tendons in the horse.

This research looks at the efficacy of carbon fibre-polylactic acid composites versus monofilament non-absorbable suture material when used for the repair of surgically cut horse tendons. The study found that the tendons healed by both methods were enlarged but the ones with carbon fibre showed more fibrous thickening. Over time, sutured tendons were stronger than those repaired with carbon fibre.

Study Methodology

• The study used 10 horses, where their superficial digital flexor tendons were surgically cut and then repaired using either carbon fibre-polylactic acid composites or monofilament non-absorbable suture material.
• The recovery of the horses was monitored over a period of six to 24 weeks.

Findings

• All surgical wounds healed without issues regardless of the repair material used.
• The repaired tendons were enlarged with the carbon fibre ones being larger than the ones sutured.
• The use of carbon fibre resulted in a greater amount of fibrous thickening, especially 12 weeks after the surgery.
• There was a significant histological response observed in the carbon fibre-repaired tendons, demonstrating a high presence of macrophages, lymphocytes, plasma cells, eosinophils, and fibroblasts.
• The repair site’s fibrous tissue matured and the collagen aligned similarly, regardless of the method of repair.
• However, the tissue within and around the carbon bundles remained immature six months after the surgery.

Effects of Carbon Fibres

• The carbon filaments had minimal tendency to separate, and when they did, they were often surrounded by epithelioid macrophages forming a granuloma.
• Massive eosinophil concentrations were found between each granuloma.
• With each additional test period, the tendons repaired with sutures began to become increasingly stronger than those repaired with carbon fibre, possibly due to the immature core of tissue associated with the carbon bundles.
• No carbon particles were found in the horses’ draining lymph nodes.

The outcomes raised concerns about the long-term efficacy of using carbon fibre for tendon repair due to the immature tissue associated with carbon bundles and the fact that sutured tendons seemed to become stronger over time.