title: Biomechanical analysis of posterior cruciate ligament reconstruction with aperture femoral fixation.
abstract: The goal of this study was to determine whether single-tunnel-double-bundle-equivalent posterior cruciate ligament (PCL) reconstruction using an aperture femoral fixation device better replicated normal knee kinematics than single-bundle reconstruction. Eight fresh-frozen human cadaver knees underwent arthroscopically assisted PCL reconstruction and were examined with a robotic testing system to assess knee joint kinematics under combinations of applied internal, neutral, and external rotational tibial torque and anteroposterior translational forces at 0°, 30°, 60°, 90°, and 120° flexion. Three conditions were tested: (1) intact PCL; (2) single-tunnel PCL reconstruction with anterolateral and posteromedial bundle fixation at 90°/90° (single bundle); and (3) 90°/0° (double-bundle equivalent), respectively. Posterior tibial translation was the primary outcome measure. Compared with the intact knee, double-bundle-equivalent reconstruction under external tibial torque allowed greater posterior translation across the flexion arc as a whole (P=.025) and at 30° flexion (P=.027) when results were stratified by flexion angle. No other kinematic differences were found with single-bundle or double-bundle-equivalent fixation, including mediolateral translation and both coupled and isolated tibial rotation (P>.05). Single-bundle PCL reconstruction closely approximated native knee rotational and translational kinematics, whereas double-bundle-equivalent reconstruction permitted increased posterior translation with applied external tibial torque, particularly at lower flexion angles. Single-bundle PCL reconstruction provides knee stability similar to the intact condition, making it a practical alternative to conventional double-bundle PCL reconstruction. The authors found that double-bundle-equivalent reconstruction provided no advantage to justify its clinical use.
authors.forename: Amar
authors.initials: A
authors.lastname: Mutnal
authors.forename: Brian M
authors.initials: BM
authors.lastname: Leo
authors.forename: Luis
authors.initials: L
authors.lastname: Vargas
authors.forename: Robb W
authors.initials: RW
authors.lastname: Colbrunn
authors.forename: Robert S
authors.initials: RS
authors.lastname: Butler
authors.forename: John W
authors.initials: JW
authors.lastname: Uribe
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D005269:Femur / Q000601:surgery*; D006801:Humans; D007718:Knee Injuries / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000379:methods*; D016119:Posterior Cruciate Ligament / Q000503:physiopathology / Q000601:surgery*; D016059:Range of Motion, Articular / Q000502:physiology*; D019651:Plastic Surgery Procedures / Q000379:methods*; D012399:Rotation; D019415:Torque