title: Biomechanical evaluation of the Nice knot.
abstract: BACKGROUND
  The Nice knot is a bulky double-stranded knot. Biomechanical data supporting its use as well as the number of half hitches required to ensure knot security is lacking.
  
  
  METHODS
  Nice knots with, one, two, or three half-hitches were compared with the surgeon's and Tennessee slider knots with three half hitches. Each knot was tied 10 times around a fixed diameter using four different sutures: FiberWire (Arthrex, Naples, FL), Ultrabraid (Smith and Nephew, Andover, MA), Hi-Fi (ConMed Linvatec, Largo, FL) and Force Fiber (Teleflex Medical OEM, Gurnee, IL). Cyclic testing was performed for 10 min between 10N and 45N, resulting in approximately 1000 cycles. Displacement from an initial 10N load was recorded. Knots surviving cyclic testing were subjected to a load to failure test at a rate of 60 mm/min. Load at clinical failure: 3 mm slippage or opening of the suture loop was recorded. Bulk, mode of ultimate failure, opening of the loop past clinical failure, was also recorded.
  
  
  RESULTS
  During cyclic testing, the Nice knots with one or more half-hitches performed the best, slipping significantly less than the surgeon's and Tennessee Slider (P < 0.002). After one half-hitch, the addition of half-hitches did not significantly improve Nice knot performance during cyclic testing (P > 0.06). The addition of half-hitches improved the strength of the Nice knot during the force to failure test, however after two half-hitches, increase of strength was not significant (P = 0.59). While FiberWire was the most bulky of the sutures tested, it also performed the best, slipping the least.
  
  
  CONCLUSIONS
  The Nice knot, especially using FiberWire, is biomechanically superior to the surgeon's and Tennessee slider knots. Two half hitches are recommended to ensure adequate knot security.
authors.affiliation: Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Shannon W
authors.initials: SW
authors.lastname: Hill
authors.affiliation: Division of Orthopaedic Surgery, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Chapman
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Samer
authors.initials: S
authors.lastname: Adeeb
authors.affiliation: Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Kajsa
authors.initials: K
authors.lastname: Duke
authors.affiliation: Division of Orthopaedic Surgery, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Lauren
authors.initials: L
authors.lastname: Beaupre
authors.affiliation: Division of Orthopaedic Surgery, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Bouliane
keywords: Biomechanics; Nice knot; cyclic loading; half-hitches; knot security; load to failure