title: A biomechanical comparison of 2 femoral fixation techniques for anterior cruciate ligament reconstruction in skeletally immature patients: over-the-top fixation versus transphyseal technique.
abstract: OBJECTIVE
  The purpose of this study was to compare knee kinematics and in situ forces of the graft between 2 femoral fixation techniques of anterior cruciate ligament (ACL) reconstruction: the over-the-top (OTT) fixation and transphyseal (TP) techniques.
  
  
  METHODS
  ACL reconstruction in skeletally immature patients is a challenging procedure. Regarding the femoral fixation techniques, 2 methods are commonly used: the OTT fixation and TP techniques. Ten cadaveric knees (mean age, 57 years; range, 48 to 65 years) were tested with the robotic/universal force-moment sensor system by use of (1) an 89-N anterior tibial load at full extension and 15°, 30°, 60°, and 90° of knee flexion and (2) a combined 7-Nm valgus torque and 5-Nm internal tibial rotation torque at 15° and 30° of knee flexion.
  
  
  RESULTS
  Both OTT and TP ACL reconstruction techniques closely restored the intact knee kinematics and had a significant reduction in anterior tibial translation under an anterior tibial load and in coupled anterior tibial translation under a combined rotatory load when compared with an ACL-deficient knee. When both ACL reconstruction techniques were compared, the only difference found was that the in situ force of the ACL graft reconstructed with the OTT technique in response to a combined rotatory load at 30° of flexion was significantly lower than the ACL graft reconstructed with the TP technique (5.3 ± 3.3 N and 10.7 ± 6.0 N, respectively; P = .013).
  
  
  CONCLUSIONS
  This time 0 testing showed that both ACL reconstruction techniques, OTT and TP, can reproduce the kinematics of the intact knee in response to an anterior tibial load and a combined rotatory load.
  
  
  CONCLUSIONS
  Both femoral fixation techniques exhibited comparable time 0 kinematics when subjected to simulated clinical examination loading conditions.
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
authors.forename: Pisit
authors.initials: P
authors.lastname: Lertwanich
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kato
authors.forename: Cesar A Q
authors.initials: CA
authors.lastname: Martins
authors.forename: Akira
authors.initials: A
authors.lastname: Maeyama
authors.forename: Sheila J M
authors.initials: SJ
authors.lastname: Ingham
authors.forename: Scott
authors.initials: S
authors.lastname: Kramer
authors.forename: Monica
authors.initials: M
authors.lastname: Linde-Rosen
authors.forename: Patrick
authors.initials: P
authors.lastname: Smolinski
authors.forename: Freddie H
authors.initials: FH
authors.lastname: Fu
mesh_terms: D000368:Aged; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D001863:Bone Screws; D016025:Bone Transplantation / Q000379:methods*; D002102:Cadaver; D004838:Epiphyses / Q000293:injuries; D005269:Femur / Q000254:growth & development / Q000601:surgery*; D006801:Humans; D007431:Intraoperative Complications / Q000517:prevention & control; D008875:Middle Aged; D012371:Robotics; D012399:Rotation; D013536:Suture Techniques; D013710:Tendons / Q000637:transplantation*; D013977:Tibia / Q000254:growth & development / Q000601:surgery*; D019415:Torque; D016474:Weight-Bearing