Remplissage Using Interconnected Knotless Anchors: Superior Biomechanical Properties to a Knotted Technique?

ABSTRACT

PURPOSE: To evaluate the biomechanical fixation strength and gap formation of 2 different remplissage fixation methods (double pulley knotted construct and interconnected knotless repair construct) in cadaver specimens. METHODS: Seven matched pairs of human cadaveric shoulders were used for testing (mean age, 56 ± 10 years). A shoulder from each matched pair was randomly selected to receive a Hill-Sachs remplissage using either a knotted (No. 2 FiberWire double pulley with 3.0-mm SutureTak anchors) or knotless (coreless No. 2 FiberWire interconnected between 3.9-mm knotless CorkScrew anchors) double mattress construct. The tendon was cycled between 10 and 100 N at 1 Hz for 100 cycles, followed by a single-cycle pull to failure at 33 mm/s. Cyclic displacement, load to clinical failure (5 mm), yield load, and mode of failure were recorded. RESULTS: Neither construct demonstrated clinical failure under cyclic loading. Load to clinical failure was higher for the knotless repair than that of the knotted repair (788 ± 162 N vs 488 ± 227 N; P = .003). The yield load was higher for the knotless repair than that of the knotted repair (1,080 ± 298 N vs 591 ± 265 N; P = .008). The most common failure mode for the knotted repair was knot failure or tendon tearing, whereas the failure mode for the knotless repair was by anchor pull-out or tendon tear with no failures occurring via the interconnected suture construct mechanism. CONCLUSIONS: In this biomechanical study comparing cyclic and ultimate loading for 2 double mattress remplissage repairs, the construct using interconnected, knotless sutures outperformed the knotted construct. No failure of the interconnected suture construct mechanism by slippage or breakage was observed in the knotless group. CLINICAL RELEVANCE The use of the interconnected knotless suture technique might improve the biomechanical strength of arthroscopic remplissage repairs in treating shoulder instability.