A Biomechanical Comparison of Varying Base Knot Configurations with Different Overhand/Underhand Combinations of...

Constructing a durable arthroscopic knot is critical for secure tissue fixation. The effect of various arthroscopic base knot configurations paired with various overhand/underhand stacking combinations of three reversing half-hitches on alternating posts (RHAPs) on knot strength and integrity remains unanswered.

Three common base knots (Surgeon's, Weston and, Tennessee Slider) followed by different overhand/underhand stacking combinations of three RHAPs were evaluated. Ten knots of each combination were tied by four subjects with varying levels of experience, resulting in the analysis of 480 total knots. A single load-to-failure test was performed to evaluate knot strength and integrity. The ultimate clinical failure load and mode of failure were recorded.

All knots created surpassed the estimated minimum required load per suture. There was, however, statistically large inter-subject variability for each base knot configuration. The Surgeon's base knot was found to vary the least in knot strength, while the Tennessee base knot was found to vary the most. Knot security was mostly influenced by the base knot configuration than the different overhand/underhand RHAP stacking combinations. Knot slippage failure mode was higher with knots tied with the Weston base knot compared to the other two configurations.

Arthroscopic base knot configurations paired with different overhand/underhand stacking combinations of RHAPs yielded knot capable of secure tissue fixation. A short instructional training period appears to be sufficient for inexperienced individuals to learn easier base knot configurations, more challenging and complicated knots, however, may require training in a more gradual fashion.

The findings of this study provide information that the importance of hands-on experience for inexperienced individuals, such as residents, in performing arthroscopic knot tying, and that can lead to improving the securely constructed arthroscopic knots, which increase positive outcomes related to strengthened soft tissue to bone fixation of post-operative patients.Level of Evidence: V.