title: Soft-tissue graft fixation in posterior cruciate ligament reconstruction: evaluation of the effect of tibial insertion site on joint kinematics and in situ forces using a robotic/UFS testing system.
abstract: BACKGROUND
  Surgical reconstruction of the posterior cruciate ligament (PCL) is recommended in acute injuries that result in severe tibial subluxation and instability. The surgical outcome level may be affected by the tibial fixation site. In response to a 110-N posterior tibial load, kinematics and in situ forces of anatomical soft-tissue graft fixation in single-bundle PCL reconstruction using an interference screw fixation are significantly closer to those in the intact knee than with extracortical fixation with two staples.
  
  
  METHODS
  Using a robotic/universal force moment sensor (UFS) testing system, we examined joint kinematics and in situ forces of porcine knees following single-bundle PCL reconstruction fixed at two different tibial fixation sites: anatomical interference screw and extracortical fixation.
  
  
  RESULTS
  The site of the tibial graft fixation had significant effect on the resulting posterior displacement and in situ forces of the graft. Both PCL reconstruction techniques reduced the posterior tibial translation significantly. Proximal fixation techniques provided significantly less posterior tibial translation than extracortical fixation. Single-bundle PCL reconstruction with an interference screw showed higher in situ forces of the graft than the extracortical fixation.
  
  
  CONCLUSIONS
  The kinematics and in situ forces of a single-bundle PCL reconstruction using an interference screw fixation technique are superior to the primary stability of an extracortical fixation with staples.
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Thore
authors.initials: T
authors.lastname: Zantop
authors.forename: Simon
authors.initials: S
authors.lastname: Lenschow
authors.forename: Thomas
authors.initials: T
authors.lastname: Lemburg
authors.forename: Andre
authors.initials: A
authors.lastname: Weimann
authors.forename: Wolf
authors.initials: W
authors.lastname: Petersen
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001863:Bone Screws; D016119:Posterior Cruciate Ligament / Q000601:surgery*; D012371:Robotics; D013537:Sutures; D013552:Swine; D013710:Tendons / Q000637:transplantation*