title: An implant-free double-bundle reconstruction of the anterior cruciate ligament: operative technique and influence on tibiofemoral kinematics.
abstract: BACKGROUND
  Reconstruction of the anterior cruciate ligament is a standard surgical procedure in sports traumatology. The widespread replacement method using hamstring tendons has an important shortcoming namely delayed or missing bony healing in contrast to patellar tendon grafts where implant-free fixation is established by using the adjacent bone blocks. The purpose of this study was to describe a new implant-free surgical procedure using hamstring tendon grafts and to analyse the influence on tibiofemoral kinematics in vitro.
  
  
  METHODS
  Nine human knee specimens with arthroscopically transected anterior cruciate ligaments were mounted on a dynamic knee simulator and weight-bearing muscle-loaded knee flexions were simulated while a robotic universal force sensor system was used to provide external tibial loads. Three different loading conditions were simulated including partial body weight only, an additional 50 N anterior tibial force or an additional Five Nm of internal rotational torque. After reconstruction of the anterior cruciate ligament using a tibial bone block hybrid technique these three trials were repeated. The kinematics was measured with an ultrasonic measuring system and different loading and ligament conditions were examined. Graft tunnel placement was verified by computed tomography.
  
  
  RESULTS
  Our fixation method achieved stability to anterior tibial drawer force whereas internal tibial rotation did not change before and after the reconstruction. Computed tomography confirmed anatomical graft and tunnel placement.
  
  
  CONCLUSIONS
  The presented operative procedure is technically feasible and leads to reproducible results concerning knee joint kinematics and graft placement.
authors.affiliation: Eberhard-Karls- University, Orthopedic Department, Hoppe-Seyler-Str. 3, D-72076 Tübingen, Germany. Markus.Wuenschel@med.uni-tuebingen.de
authors.forename: Markus
authors.initials: M
authors.lastname: Wünschel
authors.forename: Florian
authors.initials: F
authors.lastname: Treffler
authors.forename: Dominik
authors.initials: D
authors.lastname: Ketelsen
authors.forename: Jiahsuan
authors.initials: J
authors.lastname: Lo
authors.forename: Otto
authors.initials: O
authors.lastname: Müller
authors.forename: Andreas
authors.initials: A
authors.lastname: Suckel
mesh_terms: D000368:Aged; D016118:Anterior Cruciate Ligament / Q000503:physiopathology* / Q000601:surgery*; D001178:Arthroplasty / Q000379:methods; D002102:Cadaver; D005260:Female; D005269:Femur / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery*; D008297:Male; D016059:Range of Motion, Articular; D019651:Plastic Surgery Procedures / Q000379:methods*; D013977:Tibia / Q000503:physiopathology* / Q000601:surgery