title: The effect of strand configuration on the tensile properties of quadrupled tendon grafts.
abstract: OBJECTIVE
  To compare selected biomechanical properties of 4 different quadrupled tendon graft preparations applicable for anterior cruciate ligament reconstruction.
  
  
  METHODS
  Biomechanical investigation in a cadaver model.
  
  
  METHODS
  Graft strands were arranged in parallel, braided, bolo-plait, and twist configurations. Elongation of the graft was monitored during loading with an infrared optical measurement system, which measured the 3-dimensional position of twelve spherical reflective markers mounted within the camera field. Permanent elongation, stiffness, and ultimate strength of each graft configuration were determined.
  
  
  RESULTS
  Permanent graft strain after the first incremental loading cycle was 7.2% in braid, 6.6% in twist, 6.5% in bolo-plait, and 3.3% in parallel constructs (P <.0001). Permanent graft strain after a second incremental loading cycle was 1.2% in bolo-plait, 1.1% in braid, 0.7% in twist, and 0.7% in parallel preparations (P =.0012). Braid and bolo-plait grafts were less stiff than twist or parallel grafts (P <.0001). Differences in failure load were not significant (P =.171).
  
  
  CONCLUSIONS
  Variation in graft configuration from the conventional, parallel strand pattern lead to increased viscoelasticity and permanent elongation of grafts with repetitive loading. This deficit is expected to cause increased laxity of the reconstructed knee.
authors.affiliation: Baylor Sports Medicine Institute, Orthopedic Research Laboratory, Department of Orthopedic Surgery, Baylor College of Medicine, Houston, Texas, USA. merittmeister@aol.com
authors.forename: Markus
authors.initials: M
authors.lastname: Rittmeister
authors.forename: Philipp C
authors.initials: PC
authors.lastname: Noble
authors.forename: David M
authors.initials: DM
authors.lastname: Lintner
authors.forename: Jerry W
authors.initials: JW
authors.lastname: Alexander
authors.forename: Michael
authors.initials: M
authors.lastname: Conditt
authors.forename: Harold W
authors.initials: HW
authors.lastname: Kohl
mesh_terms: D000818:Animals; D016118:Anterior Cruciate Ligament / Q000601:surgery; D002417:Cattle; D004548:Elasticity; D013710:Tendons / Q000033:anatomy & histology / Q000502:physiology* / Q000637:transplantation; D013718:Tensile Strength; D016378:Tissue Transplantation / Q000379:methods