title: The fixation strength of six hamstring tendon graft fixation devices in anterior cruciate ligament reconstruction. Part II: tibial site.
abstract: BACKGROUND
  Tibial fixation is more problematic than femoral fixation in anterior cruciate ligament reconstruction.
  
  
  OBJECTIVE
  There is no difference in initial fixation strength among hamstring tendon graft tibial fixation devices.
  
  
  METHODS
  Randomized experimental study.
  
  
  METHODS
  Each of six devices used to fix 120 quadrupled human semitendinosus-gracilis tendon grafts into porcine tibiae was tested 10 times with a single-cycle load-to-failure test and 10 times with a 1500-cycle loading test. Specimens surviving cyclic loading were subjected to a single-cycle load-to-failure test.
  
  
  RESULTS
  Intrafix (1332 N) was the strongest in the single-cycle load-to-failure test, followed by WasherLoc (975 N), tandem spiked washer (769 N), SmartScrew ACL (665 N), BioScrew (612 N), and SoftSilk (471 N). After cyclic-loading tests, Intrafix showed the lowest residual displacement (1.5 mm) and was also strongest (1309 N) in the single-cycle load-to-failure test after the cyclic-loading test, followed by WasherLoc (3.2 mm; 917 N).
  
  
  CONCLUSIONS
  The Intrafix provided clearly superior strength in the fixation of hamstring tendon grafts to the tibial drill hole.
  
  
  CONCLUSIONS
  Some caution may be warranted when using the implants that showed increased residual displacement, especially if aggressive rehabilitation is to be used. Preconditioning of the hamstring tendon graft-implant complex before tibial fixation is needed.
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; 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; D013977:Tibia / Q000601:surgery*; D016474:Weight-Bearing