title: Tibial fixation in anterior cruciate ligament reconstruction: a prospective randomized study comparing metal interference screw and staples with a centrally placed polyethylene screw and sheath.
abstract: BACKGROUND
  The use of hamstring tendons for anterior cruciate ligament reconstruction has increased in popularity over recent years. However, concerns with the stability of graft fixation on the tibial side remain. Centrally placed interference screw/sheath implants have demonstrated promising results in biomechanical studies.
  
  
  OBJECTIVE
  Centrally placed, polyethylene screw and sheath implants will provide clinically equivalent fixation to the standard metal interference screw and supplemental staple fixation.
  
  
  METHODS
  Randomized controlled trial; Level of evidence, 1.
  
  
  METHODS
  A total of 113 consecutive patients undergoing isolated, unilateral, primary anterior cruciate ligament reconstruction with hamstring autografts were randomized to tibial fixation with metal interference screw and staples (RCI) or with a centrally placed polyethylene screw and sheath implant (INTRAFIX). Prospective assessment of subjective outcomes was performed using Lysholm, Mohtadi, and International Knee Documentation Committee (IKDC) scores.
  
  
  RESULTS
  At minimum 2-year follow-up, there were no significant differences between the 2 groups in terms of instrumented stability testing (KT-1000 arthrometer) or subjective assessment of knee outcomes (IKDC, Lysholm, Mohtadi). Both fixation methods demonstrated a significant, but not different, increase in outcomes scores from preoperative to postoperative evaluation. There were 7 failures (5 INTRAFIX, 2 RCI) caused by reinjury, but no statistically significant differences were observed between the 2 fixation methods.
  
  
  CONCLUSIONS
  The centrally placed polyethylene screw and sheath provided equivalent clinical outcomes at minimum 2-year follow-up to standard tibial fixation with metal interference screw and staples.
authors.affiliation: Sydney Orthopaedic Research Institute, Chatswood NSW, Australia.
authors.forename: Mathew
authors.initials: M
authors.lastname: De Wall
authors.forename: Corey J
authors.initials: CJ
authors.lastname: Scholes
authors.forename: Sandeep
authors.initials: S
authors.lastname: Patel
authors.forename: Myles R J
authors.initials: MR
authors.lastname: Coolican
authors.forename: David A
authors.initials: DA
authors.lastname: Parker
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D059549:Anterior Cruciate Ligament Reconstruction / Q000295:instrumentation / Q000379:methods*; D001863:Bone Screws; D005260:Female; D006801:Humans; D016268:Internal Fixators; D007593:Joint Instability / Q000601:surgery; D008297:Male; D008670:Metals / Q000627:therapeutic use; D008875:Middle Aged; D020959:Polyethylene / Q000627:therapeutic use; D013537:Sutures; D013710:Tendons / Q000637:transplantation; D013977:Tibia / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D008670:Metals; D020959:Polyethylene