Robust Suture Combination for Rat Flexor Tendon Repair Model

PURPOSE: We aimed to develop a rat flexor tendon repair model that could be applied to experiments in similar clinical settings. METHODS: We prepared 3 different combinations of sutures in rat flexor tendons: group A had 3 single peripheral sutures plus a 2-strand core suture; group B had 3 figure-of-eight peripheral sutures alone; and group C had 3 figure-of-eight peripheral sutures plus a 2-strand core suture. We examined the in vitro tensile strength of the repaired tendons by a biomechanical test, the rerupture rate within 3 weeks, and histological findings in vivo. RESULTS: Group C displayed the greatest ultimate strength by the mechanical test. The flexor tendons in group C did not rerupture within 3 weeks after surgery, whereas many of those in groups A and B reruptured. Fibrous scar tissue was observed in the gap of the tendon stumps in groups A and B, but not in group C. CONCLUSIONS: The combination of figure-of-eight peripheral sutures and a 2-strand core suture provided the repaired rat flexor tendon with enough strength to prevent rerupture without cast fixation or immobilization after surgery. CLINICAL RELEVANCE: This combination of sutures is useful to reproduce flexor tendon repair similar to that performed in clinical settings and will contribute to various translational experiments in vivo.