title: A biomechanical comparison of arthroscopic sliding and sliding-locking knots.
abstract: OBJECTIVE
  To evaluate biomechanical characteristics of 3 arthroscopic sliding and sliding-locking knots and the square knot, the gold standard used in open surgery.
  
  
  METHODS
  Biomechanical investigation.
  
  
  METHODS
  Four different knot types (Weston, square, Duncan loop, and Nicky's) were tested in 5 configurations in a closed-loop system on a materials testing device. Three of the 5 knots were backed up with 3 reverse half-hitches and alternating posts and all sliding and sliding-locking knots were tied using an arthroscopic technique. Twelve knots of each configuration were tested for loop security with a 7-N preload, and for knot security with load to failure at a strain rate of 1.25 mm/second and cyclic loading of a 30-N force for 50 cycles.
  
  
  RESULTS
  No knots subjected to the 7-N preload failed or slipped and all had similar elongation (0.1 +/- 0.1 mm) except Nicky's knot (0.3 +/- 0.2 mm). There was no significant difference in load at failure for the square knot (178 +/- 14 N), the Weston knot backed with 3 half-hitches (168 +/- 14 N), the Duncan loop (160 +/- 20 N), or Nicky's knot (148 +/- 13 N). Most knots with 3 half-hitches failed with rupture at the knot. Under cyclic loading, no knots failed and none elongated greater than an average of 0.3 mm.
  
  
  CONCLUSIONS
  All knot configurations maintained high loop security. All sliding and sliding-locking knots backed with 3 half-hitches had load at failure comparable to the square knot. With cyclic load testing, all knots tested elongated minimally. Additionally, this study confirms that all knots, even the sliding-locking Weston knot, are best backed up with 3 half-hitches alternating posts and directions of the throws.
  
  
  CONCLUSIONS
  Sliding and sliding-locking knots are becoming increasingly popular among arthroscopic shoulder surgeons. This study provides a biomechanical basis for the clinical use of these arthroscopic knots and compares them with the gold standard, the open square knot.
authors.affiliation: Fondren Orthopedic Group, Sugar Land, Texas, USA.
authors.forename: Hussein A
authors.initials: HA
authors.lastname: Elkousy
authors.forename: Jon K
authors.initials: JK
authors.lastname: Sekiya
authors.forename: Kathryne J
authors.initials: KJ
authors.lastname: Stabile
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: McMahon
mesh_terms: D001182:Arthroscopy / Q000379:methods*; D001696:Biomechanical Phenomena; D006801:Humans; D008422:Materials Testing; D011093:Polyethylene Terephthalates; D013536:Suture Techniques; D013718:Tensile Strength
chemical_list: D011093:Polyethylene Terephthalates