title: The fixation strength of six hamstring tendon graft fixation devices in anterior cruciate ligament reconstruction. Part I: femoral site.
abstract: BACKGROUND
  Strength of graft fixation is the weakest link in anterior cruciate ligament reconstruction.
  
  
  OBJECTIVE
  There is no difference in initial fixation strength between different hamstring tendon graft femoral fixation devices.
  
  
  METHODS
  Randomized experimental study.
  
  
  METHODS
  Each of six devices was used in the fixation of 10 quadrupled human semitendinosus-gracilis tendon grafts in tunnels drilled in porcine femora and tested 10 times with a single-cycle load-to-failure test at a rate of 50 mm/min and 10 times with a 1500-cycle loading test between 50 and 200 N at one cycle every 2 seconds. The specimens that survived the cyclic loading were subjected to a single-cycle load-to-failure test.
  
  
  RESULTS
  The Bone Mulch Screw (1112 N) was strongest in the single-cycle load-to-failure test, followed by EndoButton CL (1086 N), RigidFix (868 N), SmartScrew ACL (794 N), BioScrew (589 N), and RCI screw (546 N). It also showed the lowest residual displacement (2.2 mm) and was strongest in the single-cycle load-to-failure test after cyclic loading.
  
  
  CONCLUSIONS
  The Bone Mulch Screw was superior to all other devices.
  
  
  CONCLUSIONS
  Caution may be warranted in employing aggressive rehabilitation after reconstruction with these devices. Preconditioning of the graft-implant complex before fixation is important.
authors.affiliation: Department of Surgery, University of Tampere and Tampere University Hospital, Tampere, Finland.
authors.forename: Petteri
authors.initials: P
authors.lastname: Kousa
authors.forename: Teppo L N
authors.initials: TL
authors.lastname: Järvinen
authors.forename: Mika
authors.initials: M
authors.lastname: Vihavainen
authors.forename: Pekka
authors.initials: P
authors.lastname: Kannus
authors.forename: Markku
authors.initials: M
authors.lastname: Järvinen
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D001863:Bone Screws; D019544:Equipment Failure Analysis; D005269:Femur / Q000601:surgery*; D006801:Humans; D016268:Internal Fixators; D008422:Materials Testing / Q000379:methods*; D011897:Random Allocation; D012421:Rupture; D013536:Suture Techniques; D013552:Swine; D013710:Tendons / Q000637:transplantation*; D013718:Tensile Strength; D016474:Weight-Bearing