title: Single- versus two-femoral socket anterior cruciate ligament reconstruction technique: Biomechanical analysis using a robotic simulator.
abstract: OBJECTIVE
  Although anterior cruciate ligament (ACL) reconstruction with multistrand autogenous hamstring tendons has been widely performed using a single femoral socket (SS), it is currently advocated to individually reconstruct 2 bundles of the ACL using 2 femoral sockets (TS). However, the difference in biomechanical characteristics between them is unknown. The objective of this study was to clarify their biomechanical differences.
  
  
  METHODS
  This is a cross-over trial using cadaveric knees.
  
  
  METHODS
  Seven intact human cadaveric knees were mounted in a robotic simulator developed in our laboratory. By applying anterior and posterior tibial load up to +/- 100 N at 0 degrees, 15 degrees, 30 degrees, 60 degrees, and 90 degrees of flexion, tibial displacement and load were recorded. After cutting the ACL, the knees underwent ACL reconstruction using TS, followed by that using SS, with 44 or 88 N of initial grafts tension at 20 degrees of flexion. The above-mentioned tests were performed on each reconstructed knee.
  
  
  RESULTS
  The tibial displacement in the TS technique was significantly smaller than that in the SS at smaller flexion angles in response to anterior and posterior tibial load of +/- 100 N, and the in situ force in the former was significantly greater than that in the latter at smaller flexion angles. Furthermore, in the TS technique, the posterolateral graft acted dominantly in extension, while the anteromedial graft mainly resisted against anterior tibial load in flexion. However, in the SS technique, the anteriorly located graft functioned more predominantly than the posteriorly located graft at all flexion angles.
  
  
  CONCLUSIONS
  The ACL reconstruction via TS using quadrupled hamstring tendons provides better anterior-posterior stability compared with the conventional reconstruction using a single socket.
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Medical School, Suita, Osaka, Japan. mae@ort.med.osaka-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Mae
authors.forename: K
authors.initials: K
authors.lastname: Shino
authors.forename: T
authors.initials: T
authors.lastname: Miyama
authors.forename: H
authors.initials: H
authors.lastname: Shinjo
authors.forename: T
authors.initials: T
authors.lastname: Ochi
authors.forename: H
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: H
authors.initials: H
authors.lastname: Fujie
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D001696:Biomechanical Phenomena; D002102:Cadaver; D005269:Femur; D006801:Humans; D007719:Knee Joint / Q000601:surgery; D008875:Middle Aged; D016059:Range of Motion, Articular; D019651:Plastic Surgery Procedures / Q000379:methods*; D012371:Robotics; D013977:Tibia / Q000502:physiology