Purpose: Evidence is lacking on the effect of different combinations of three stacked half-hitches and suture materials on the loop/ knot security of an arthroscopic knot under cyclic loading conditions. The specific aim of this study was to identify variables, such as stacked half-hitch configurations, suture materials, and testing environments, that affect knot strength and loop security under cyclic loading conditions.
Methods: Two suture materials (Orthocord and ForceFiber) were used to tie five differently stacked reversing half-hitches on alternating posts (RHAP) in an arthroscopic knot condition. All knots were evaluated in both dry and wet cyclic loading tests.
Results: Knots tied with three identical half-hitches stacked on the same post (Conf #1) resulted in 100% knot slippage regardless of suture material in dry environment. In the wet environment this knot configuration performed slightly better (ForceFiber: 20% survived; Orthocord: 40% survived). With knots tied with one of the half-hitches in the RHAPs reversed, a significant improvement occurred in knot holding compared to Conf #1 (p<0.05). Knots tied with the last half-hitches in the RHAPs reversed using ForceFiber were 100% secure in both test environments; whereas those tied with Orthocord had 70% and 80% security rates in the respective environments. Knots tied with two half-hitches of the RHAPs reversed demonstrated the best overall performance.
Conclusion: Significant effects for both stacked half-hitch configurations and suture materials on the knot loop and knot security were observed. Caution should be used when tying the 3 RHAPs in a knot using standard arthroscopic techniques. This study may provide a solution that might improve the maximum failure loads observed between orthopaedic surgeons, and achieve better clinical outcomes.
Clinical relevance: The findings of this study indicate the importance of three reversing half-hitches on alternating posts in performing arthroscopic knot tying, and provide evidence regarding discrepancies of maximum clinical failure loads observed between orthopaedic surgeons leading to better surgical outcomes.
Keywords: Alternating post; Arthroscopic; Cyclic loading; Environment; Half-hitches; Knot tying.