title: The impact of tensioning device mal-positioning on strand tension during anterior cruciate ligament reconstruction.
abstract: BACKGROUND
  In order to confer optimal strength and stiffness to the graft in Anterior Cruciate Ligament (ACL) reconstruction, the maintenance of equal strand tension prior to fixation, is desired; positioning of the tensioning device can significantly affect strand tension This study aimed to determine the effect of tensioning device mal-positioning on individual strand tension in simulated cadaveric ACL reconstructions.
  
  
  METHODS
  Twenty cadaveric specimens, comprising bovine tibia and tendon harvested from sheep, were used to simulate ACL reconstruction with a looped four-strand tendon graft. A proprietary tensioning device was used to tension the graft during tibial component fixation with graft tension recorded using load cells. The effects of the tensioning device at extreme angles, and in various locking states, was evaluated.
  
  
  RESULTS
  Strand tension varied significantly when the tensioning device was held at extreme angles (p < 0.001) or in 'locked' configurations of the tensioning device (p < 0.046). Tendon position also produced significant effects (p < 0.016) on the resultant strand tension.
  
  
  CONCLUSIONS
  An even distribution of tension among individual graft strands is obtained by maintaining the tensioning device in an unlocked state, aligned with the longitudinal axis of the tibial tunnel. If the maintenance of equal strand tension during tibial fixation of grafts is important, close attention must be paid to positioning of the tensioning device in order to optimize the resultant graft tension and, by implication, the strength and stiffness of the graft and ultimately, surgical outcome.
authors.affiliation: Comparative Orthopaedic Research Surgical Facility, School of Medicine, Flinders University, South Australia, Australia.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Maharjan
authors.forename: John J
authors.initials: JJ
authors.lastname: Costi
authors.forename: Richard M
authors.initials: RM
authors.lastname: Stanley
authors.forename: David
authors.initials: D
authors.lastname: Martin
authors.forename: Trevor C
authors.initials: TC
authors.lastname: Hearn
authors.forename: John R
authors.initials: JR
authors.lastname: Field
mesh_terms: D000818:Animals; D059549:Anterior Cruciate Ligament Reconstruction / Q000295:instrumentation* / Q000379:methods*; D001696:Biomechanical Phenomena; D002102:Cadaver; D002417:Cattle; D004864:Equipment and Supplies; D006801:Humans; D007719:Knee Joint / Q000601:surgery; D012756:Sheep; D013314:Stress, Mechanical; D013710:Tendons / Q000601:surgery / Q000637:transplantation; D013977:Tibia / Q000601:surgery; D016378:Tissue Transplantation / Q000379:methods*