Knots Tied With High-Tensile Strength Tape Biomechanically Outperform Knots Tied With Round Suture.

Background: Tape-type suture material is well-accepted in arthroscopy surgery.

Purpose: To compare the knot security of a high-tensile strength round suture and high-tensile strength tape with commonly used arthroscopic knots.

Study Design: Controlled laboratory study.

Methods: We compared the performance of No. 2 braided nonabsorbable high-strength suture with that of 1.3-mm braided nonabsorbable high-strength tape. Five commonly used arthroscopic knots were investigated: the Roeder knot; the Western knot; the Samsung Medical Center (SMC) knot; the Tennessee knot; and a static surgeon's knot. Seven knots were tied for each combination of knots and suture types. Knots were tied on a 30-mm circumferential metal post, and the suture loops were transferred to a materials testing machine. After preloading to 5 N, all specimens were loaded to failure. The clinical failure load, defined as the maximal force to failure at 3 mm of crosshead displacement, yield load, and stiffness, were recorded. A 2-way analysis of variance was used to determine differences between the groups.

Results: Both suture type and knot type significantly affected the clinical failure load, yield load, and stiffness ( = .002). The high-strength tape resulted in a significantly greater clinical failure load than the high-strength suture in the case of the Roeder knot, Western knot, and SMC knot ( = .027, .005, and .016, respectively). When the high-strength round suture was used, the Roeder knot, Western knot, and SMC knot resulted in significantly smaller clinical failure loads compared with the Tennessee knot ( = .011, .003, and .035, respectively) and the static surgeon's knot ( < .001 for all). When the high-strength tape was used, the Roeder knot, Western knot, and SMC knot resulted in significantly smaller clinical failure loads compared with the static surgeon's knot ( = .001, .001, and .003, respectively).

Conclusion: The results of this study indicated that arthroscopic knots tied using 1.3-mm high-strength tape biomechanically outperformed knots tied using a No. 2 high-strength suture. While the static surgeon's knot exhibited the best biomechanical properties, the Tennessee knot resulted in generally better biomechanical properties among the arthroscopic sliding knots.

Clinical Relevance: Elongation and loosening of tied knots possibly affects the clinical results of repaired constructs.