Core Weave Versus Krackow Technique for Achilles Tendon Repair: A Biomechanical Study

Background: The Krackow stitch, commonly used for Achilles tendon repair, leaves the bulk of the stitch on the surface of the tendon as a possible nidus for adhesion. The proposed core weave stitch leaves a minimal amount of suture material on the tendon surface. The functional strength of the core weave stitch compared with the Krackow and the optimal number of throws, or stitches crossing the surface of the tendon, with this stitch are not known. Materials and Methods: Twenty-one matched pairs of fresh-frozen cadaveric Achilles tendons were transected and randomly assigned to receive a 4-stranded stitch, either Krackow or core weave, with three, five, or seven throws. The samples were cyclically loaded to 75, 125 and 175 N for 1000 cycles at each load until failure, defined as 5 mm of elongation. Results: No significant difference in failure load was observed between the Krackow and core weave groups at any number of throws or within the groups based on number of throws. Failure load for the different number of throws in the Krackow group approached significance (p = 0.10), with higher failure load with three throws. Conclusion: Functional strength of the core weave stitch and the Krackow stitch did not differ between groups with three, five, and seven throws. There was no significant difference in strength based on throws in either group. Clinical Relevance: The proposed core weave stitch provides functional strength similar to that of the Krackow stitch for tendon repair with reduced suture material on the tendon surface.