title: Biomechanical evaluation of the quadriceps tendon autograft for anterior cruciate ligament reconstruction: a cadaveric study.
abstract: BACKGROUND
  Recently, many surgeons have chosen the quadriceps tendon (QT) as an autograft for anterior cruciate ligament (ACL) reconstruction. However, there have not been biomechanical studies that quantitatively evaluated knee function after reconstruction using a QT autograft.
  
  
  OBJECTIVE
  To measure the 6 degrees of freedom knee kinematics and in situ graft forces after reconstruction with a QT autograft compared with a quadrupled semitendinosus and gracilis (QSTG) tendon autograft.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Ten human cadaveric knees (age, 54-64 years) were tested in 3 conditions: (1) intact, (2) ACL deficient, and (3) after ACL reconstruction using a QT or QSTG autograft. With use of a robotic/universal force-moment sensor testing system, knee kinematics and in situ forces in the ACL and autografts were obtained at 5 knee flexion angles under externally applied loads: (1) 134-N anterior tibial load, (2) 134-N anterior tibial load with 200-N axial compression, and (3) 10-N·m valgus and 5-N·m internal tibial torque.
  
  
  RESULTS
  Under the anterior tibial load, both autografts restored anterior tibial translation to within 2.5 mm of the intact knee and in situ forces to within 20 N of the intact ACL at 15°, 30°, and 60°. Adding compression did not change these findings. With the combined rotatory load, the anterior tibial translation and graft in situ forces were again not significantly different from the intact ACL. There were no significant differences between the grafts under any experimental condition.
  
  
  CONCLUSIONS
  Reconstruction of the ACL with a QT autograft restored knee function to similar levels as that reconstructed with a QSTG autograft under loads simulating clinical examinations.
  
  
  CONCLUSIONS
  The positive biomechanical results of this cadaveric study lend support to the use of a QT autograft for ACL reconstruction, as it could restore knee function immediately after surgery under applied loads that mimic clinical examinations.
authors.affiliation: Savio L-Y. Woo, DSc (Hon DEng (Hon), Musculoskeletal Research Center, Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, 405 Center for Bioengineering, 300 Technology Drive, Pittsburgh, PA 15219. ddecenzo@pitt.edu).
authors.forename: Norihiro
authors.initials: N
authors.lastname: Sasaki
authors.forename: Kathryn F
authors.initials: KF
authors.lastname: Farraro
authors.forename: Kwang E
authors.initials: KE
authors.lastname: Kim
authors.forename: Savio L-Y
authors.initials: SL
authors.lastname: Woo
mesh_terms: D000368:Aged; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D064592:Autografts; D002102:Cadaver; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology / Q000601:surgery; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery*; D008875:Middle Aged; D052097:Quadriceps Muscle; D016059:Range of Motion, Articular / Q000502:physiology; D012371:Robotics; D013710:Tendons / Q000637:transplantation*; D019415:Torque; D016474:Weight-Bearing / Q000502:physiology
keywords: ACL reconstruction; quadriceps tendon autograft; robotic/UFS testing system