title: Comparison Between Intra- and Extra-articular Tension of the Graft During Fixation in Anterior Cruciate Ligament Reconstruction.
abstract: OBJECTIVE
  To evaluate the tension deprivation through the tunnels with and without preconditioning at the time of fixation, and the influences of cyclic loading and pretensioning on graft tension in anatomic single bundle anterior cruciate ligament (ACL) reconstruction using a hamstring tendon.
  
  
  METHODS
  Nine fresh-frozen cadaveric knees underwent anatomic ACL reconstruction using hamstring grafts. Each specimen was examined to ensure that there was no severe osteoarthritic change, ligament insufficiency, or torn menisci by manual and arthroscopic evaluation. Applied graft tension was measured at the tibial tunnel outlet using a graft tensor with a load cell. Intra-articular graft tension was evaluated by using an originally developed microforce sensor, which was sutured into the graft. Both tensions were simultaneously measured just after initial tensioning under 3 different conditions: condition 1, just after initial tensioning of 20 N at 20° of knee flexion without preconditioning; condition 2, after the same initial tensioning following 5 rounds of passive cyclic flexion-extension movement; and condition 3, after the same initial tensioning following 5 minutes of static pretensioning of 20 N.
  
  
  RESULTS
  The intra-articular tension was 12.7 ± 5.3 N in condition 1, 12.0 ± 4.8 N in condition 2, and 13.5 ± 4.8 N in condition 3. In these 3 conditions, intra-articular graft tension was significantly lower than the applied tension of around 20 N (no pretension: P = .009, cyclic pretension: P = .004, static pretension: P = .008), with no difference among the 3 conditions (P = .82).
  
  
  CONCLUSIONS
  The intra-articular graft tension was significantly lower than the applied tension from the outside of the joint, even after cyclic loading and pretensioning.
  
  
  CONCLUSIONS
  It is difficult to evaluate the intra-articular graft tension precisely on the basis of the extra-articular tension at time zero in ACL reconstruction.
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Nishizawa
authors.affiliation: Department of Orthopaedic Surgery, Kobe Kaisei Hospital, Kobe, Japan. Electronic address: you.1.hoshino@gmail.com.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Hoshino
authors.affiliation: Department of Human and Artificial Intelligent Systems, Graduate School of Engineering, University of Fukui, Fukui, Japan.
authors.forename: Kouki
authors.initials: K
authors.lastname: Nagamune
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Araki
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Kanto
authors.initials: K
authors.lastname: Nagai
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kurosaka
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kuroda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016118:Anterior Cruciate Ligament / Q000502:physiology / Q000601:surgery*; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D001696:Biomechanical Phenomena; D002102:Cadaver; D005260:Female; D005269:Femur / Q000601:surgery; D000070632:Hamstring Tendons / Q000637:transplantation*; D006801:Humans; D007718:Knee Injuries / Q000601:surgery*; D007719:Knee Joint / Q000601:surgery; D008297:Male; D016059:Range of Motion, Articular; D013977:Tibia / Q000601:surgery