title: Mechanical comparison of two suture constructs for extra-capsular stifle stabilization.
abstract: OBJECTIVE
  Mechanical evaluation of 2 suture constructs for extracapsular stifle stabilization.
  
  
  METHODS
  In vitro study.
  
  
  METHODS
  Crimped interlocking loop constructs (ILC) of 45 kg nylon leader line (NLL) and Orthofiber® (OF).
  
  
  METHODS
  ILC were tightened to 100 N, then crimp secured. Ramp to failure (n=10/group)-Data were derived from force/displacement plots. Stress-relaxation testing (n=10/group)-ILC's were nondestructively loaded and held at resultant displacement as force data were recorded. Incremental, cyclic loading (n=10/group)-ILC's were loaded (5 cycles/set) starting at 100 N and incrementally increased by 50 N (1 and 3 Hz protocols). Loop tension and elongation were recorded after each set.
  
  
  RESULTS
  Ramp to failure-initial loop tension was similar (NLL 75.5 ± 9.5 N; OF 68.7 ± 10.4 N, P=.140). Tested OF constructs were stiffer (NLL 125.7 ± 4.0; OF 234.6 ± 25.0 N/mm, P≤.001), had lower yield load (NLL 193.6 ± 13.8; OF 137.3 ± 94.3 N, P≤.001), lower peak load (NLL 873.7 ± 68.6; OF 653.6 ± 80.2 N, P≤.001), and lower elongation at failure (NLL 19.1 ± 1.4; OF 5.2 ± 1.0 mm, P≤.001) and at yield (NLL 1.52 ± 0.2; OF 0.3 ± 0.6 mm, P=.003) than NLL constructs. Yield in NLL ILC's was variable knot tightening/crimp slippage, but only crimp-suture slippage in OF. Stress-relaxation testing-OF demonstrated greater relaxation. Incremental, cyclic loading-induced ILC elongation and tension loss in both groups, independent of loading frequency. NLL lost tension at lower rate, but elongated more than OF.
  
  
  CONCLUSIONS
  NLL construct is mechanically superior to OF construct.
authors.affiliation: Department of Clinical Sciences, Veterinary Medical Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA.
authors.forename: Nic R
authors.initials: NR
authors.lastname: Cabano
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Troyer
authors.forename: Ross H
authors.initials: RH
authors.lastname: Palmer
authors.forename: Christian M
authors.initials: CM
authors.lastname: Puttlitz
authors.forename: Brandon G
authors.initials: BG
authors.lastname: Santoni
mesh_terms: D000818:Animals; D004285:Dogs; D008422:Materials Testing / Q000662:veterinary*; D013264:Stifle / Q000601:surgery*; D013314:Stress, Mechanical; D013537:Sutures / Q000662:veterinary*