title: The Influence of Knee Flexion Angle for Graft Fixation on Rotational Knee Stability During Anterior Cruciate Ligament Reconstruction: A Biomechanical Study.
abstract: To evaluate the effect of knee flexion angle for hamstring graft fixation, full extension (FE), or 30°, on acceleration of the knee motion during pivot-shift testing after either anatomic or nonanatomic anterior cruciate ligament (ACL) reconstruction using triaxial accelerometry.
  
  
  
  Two types of ACL reconstructions (anatomic and nonanatomic) using 2 different angles of knee flexion during graft fixation (FE and 30°) were performed on 12 fresh-frozen human knees making 4 groups: anatomic-FE, anatomic-30°, nonanatomic-FE, and nonanatomic-30°. Manual pivot-shift testing was performed at ACL-intact, ACL-deficient, and ACL-reconstructed conditions. Three-dimensional acceleration of knee motion was recorded using a triaxial accelerometer.
  
  
  
  The anatomic-30° group showed the smallest overall magnitude of acceleration among the ACL-reconstructed groups (P = .0039). There were no significant differences among the anatomic-FE group, the nonanatomic-FE group, and the nonantomic-30° group (anatomic-FE vs nonanatomic-FE, P = .1093; anatomic-FE vs nonanatomic-30°, P = .8728; and nonanatomic-FE vs nonanatomic-30°, P = .1093). After ACL transection, acceleration was reduced by ACL reconstruction with the exception of the nonanatomic-FE group that did not show a significant difference when compared with the ACL-deficient (P = .4537).
  
  
  
  The anatomic ACL reconstruction with the graft fixed at 30° of knee flexion better restored rotational knee stability compared with FE. An ACL graft fixed with the knee at FE in anatomic position did not show a significant difference compared with the nonanatomic ACL reconstructions.
  
  
  
  Knee flexion angle at the time of graft fixation for ACL reconstruction can be considered to maximize the rotational knee stability.
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A.
authors.forename: Aníbal
authors.initials: A
authors.lastname: Debandi
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A.
authors.forename: Akira
authors.initials: A
authors.lastname: Maeyama
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Hoshino
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A.
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Asai
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A.
authors.forename: Bunsei
authors.initials: B
authors.lastname: Goto
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A.; Department of Mechanical Engineering and Material Science, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A.
authors.forename: Patrick
authors.initials: P
authors.lastname: Smolinski
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A.; Department of Mechanical Engineering and Material Science, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A.. Electronic address: ffu@upmc.edu.
authors.forename: Freddie H
authors.initials: FH
authors.lastname: Fu
mesh_terms: D000368:Aged; D000070598:Anterior Cruciate Ligament Injuries / Q000601:surgery*; D059549:Anterior Cruciate Ligament Reconstruction / Q000009:adverse effects / Q000379:methods*; D001182:Arthroscopy / Q000009:adverse effects / Q000379:methods; D001696:Biomechanical Phenomena; D002102:Cadaver; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000517:prevention & control* / Q000601:surgery*; D007719:Knee Joint / Q000502:physiology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009068:Movement; D011183:Postoperative Complications / Q000517:prevention & control; D012399:Rotation; D013710:Tendons / Q000637:transplantation; D014184:Transplantation, Homologous