title: The effect of medial meniscal horn injury on knee stability.
abstract: OBJECTIVE
  This study investigated the effect of damage of the posterior and anterior horns of the medial meniscus on knee stability.
  
  
  METHODS
  Twenty fresh-frozen porcine knees were divided into two groups (anterior horn and posterior horn injury). Each group was tested in three states: intact medial meniscus, posterior or anterior horn of medial meniscus resection and total medial meniscectomy. A robotic testing system was used to test anterior tibial translation (ATT) at 30° (full extension), 60° and 90° of knee flexion with an external anterior tibial load of 89 N, internal rotation (IR) and external rotation (ER) at 30° and 60° of knee flexion under a 4 N m tibial rotation torque.
  
  
  RESULTS
  In response to an IR torque, there was a significant difference between the state of intact medial meniscus and anterior and posterior horn damage, except for anterior horn resection at 60° of knee flexion. In response to an ER torque, there were no significant differences between the state of intact meniscus and horn damage except for anterior horn resection at 30° of knee flexion. Meniscal damage had no significant effect on ATT.
  
  
  CONCLUSIONS
  The results indicated that the posterior horn was more important in controlling the IR stability than the anterior horn with knee flexion, and the anterior horn was more important in controlling the ER stability than the posterior horn at full knee extension in the anterior cruciate ligament-intact knee. These findings further the understanding of the mechanisms, the prevention of injuries and rehabilitation of meniscal horn injury in clinical practice.
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Lianxu
authors.initials: L
authors.lastname: Chen
authors.forename: Monica
authors.initials: M
authors.lastname: Linde-Rosen
authors.forename: Sun Chul
authors.initials: SC
authors.lastname: Hwang
authors.forename: Jingbin
authors.initials: J
authors.lastname: Zhou
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xie
authors.forename: Patrick
authors.initials: P
authors.lastname: Smolinski
authors.forename: Freddie H
authors.initials: FH
authors.lastname: Fu
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D007593:Joint Instability / Q000503:physiopathology*; D023421:Models, Animal; D016059:Range of Motion, Articular / Q000502:physiology; D013264:Stifle / Q000503:physiopathology*; D013552:Swine; D000070600:Tibial Meniscus Injuries; D019415:Torque