title: Pullout strength of all suture anchors in the repair of rotator cuff tears: a biomechanical study.
abstract: OBJECTIVE
  We evaluated the biomechanical strength of two all suture anchors (ASA) of reduced diameter (1.4 mm) and compared them with the standard screw anchor (SA) with larger diameter (5.5 mm) used in rotator cuff tears.
  
  
  METHODS
  We conducted 30 uniaxial vertical pullout tests using Material Testing System Instron 5566A until failure of the anchorage defined as rupture of the threads or anchor or detachment of the anchor. Anchor fixation was on tuberosities of fresh bovine humerus bone. ASAs were spaced four millimetres apart and were compared with a control SA implanted on the same greater tubercle at two centimetres. The tests were all performed at room temperature in a dry environment. Tensile loads (10 mm/min) were applied parallel to the axis of insertion. A preloading of 10 N was used to overcome loading artifacts of the test sample at the beginning of the test.
  
  
  RESULTS
  Student's t test showed no statistically significant difference between anchors in terms of load to failure (ASA: force 265.06 ± 87.25 N versus SA : 325.35 ± 113.46 N; p = 0.09) and mean elongation at rupture (ASA : 23 ± 7 mm versus SA : 21 ± 6 mm; p = 0.46).
  
  
  CONCLUSIONS
  In vitro, this experimental study showed no statistically significant difference in pullout strength and displacement between ASA and SA at a chosen level of significance (p < 0.05).
authors.affiliation: Institut du Mouvement et de l'appareil Locomoteur, 270 Bd Sainte Marguerite, 13009, Marseille, France, galland.alex@gmail.com.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Galland
authors.forename: Stéphane
authors.initials: S
authors.lastname: Airaudi
authors.forename: Renaud
authors.initials: R
authors.lastname: Gravier
authors.forename: Sophie
authors.initials: S
authors.lastname: Le Cann
authors.forename: Patrick
authors.initials: P
authors.lastname: Chabrand
authors.forename: Jean-Noël
authors.initials: JN
authors.lastname: Argenson
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001863:Bone Screws; D002417:Cattle; D004867:Equipment Design; D066298:In Vitro Techniques; D008422:Materials Testing / Q000379:methods*; D023421:Models, Animal; D017006:Rotator Cuff / Q000601:surgery*; D000070636:Rotator Cuff Injuries; D053441:Suture Anchors / Q000145:classification*; D013536:Suture Techniques; D013718:Tensile Strength