title: The effect of notchplasty in anterior cruciate ligament reconstruction: a biomechanical study in the porcine knee.
abstract: BACKGROUND
  Notchplasty is frequently performed by many orthopaedic surgeons during anterior cruciate ligament (ACL) reconstruction. The effect of notchplasty on tunnel placement and knee biomechanics with ACL reconstruction is not known.
  
  
  METHODS
  Twelve (n = 12) porcine knees were tested using a robotic testing system. Four knee states were compared: (1) intact ACL, (2) ACL-deficient, (3) anatomic single bundle (SB) ACL reconstruction and (4) anatomic SB ACL reconstruction with a 5-mm notchplasty. The graft was fixed at 60° of flexion (full extension of porcine knee is 30°) with an 80-N tension. The knees were subjected to two loading conditions: an 89-N anterior tibial load (ATT) and 4 Nm internal (IR) and external tibial (ER) rotational torques. The kinematics and in situ force obtained from the different knee conditions were compared.
  
  
  RESULTS
  There were no significant differences between pre- and post-notchplasty in the ER at 30° and 60° of knee flexion (n.s.). However, a significant difference was found between pre- and post-notchplasty in ATT at 30° and 60° of flexion (p < 0.05). The in situ force in the anatomic SB reconstruction with notchplasty was significant lower than the intact and anatomic reconstructed ACL pre-notchplasty at 30°, 60° and 90° of knee flexion (p < 0.05). In response to the IR tibial torque, there were significant differences between pre- and post-notchplasty in IR at 60° (p < 0.05) of knee flexion.
  
  
  CONCLUSIONS
  Notchplasty had greater effect on anterior stability than rotational stability. This change in knee kinematics could be detrimental to a healing bone graft, ligamentization and could lead to failure of the reconstruction in early post-operative period.
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, 3471 Fifth Avenue Suite 1011, Pittsburgh, PA 15213, USA.
authors.forename: Kenan
authors.initials: K
authors.lastname: Keklikci
authors.forename: Can
authors.initials: C
authors.lastname: Yapici
authors.forename: Donghwi
authors.initials: D
authors.lastname: Kim
authors.forename: Monica
authors.initials: M
authors.lastname: Linde-Rosen
authors.forename: Patrick
authors.initials: P
authors.lastname: Smolinski
authors.forename: Freddie H
authors.initials: FH
authors.lastname: Fu
mesh_terms: D000818:Animals; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D001182:Arthroscopy; D001696:Biomechanical Phenomena; D007593:Joint Instability / Q000601:surgery; D016059:Range of Motion, Articular / Q000502:physiology; D013264:Stifle / Q000502:physiology* / Q000601:surgery*; D013552:Swine; D019415:Torque; D016474:Weight-Bearing / Q000502:physiology