title: Evaluation of rotational instability in the anterior cruciate ligament deficient knee using triaxial accelerometer: a biomechanical model in porcine knees.
abstract: OBJECTIVE
  To measure the acceleration in multiple directions of the rotational instability in ACL deficient models using porcine knees.
  
  
  METHODS
  Ten porcine knees were tested with ACL intact and tear models. The pivot shift test was performed manually, and the acceleration of the pivot shift phenomenon was recorded by the use of a triaxial accelerometer. Tests were repeated in four different ACL states: (1) intact; (2) partial AM deficient; (3) complete AM deficient, and (4) complete ACL (AM and PL) deficient. The acceleration in three directions and the magnitude of acceleration were measured to evaluate rotational instability and compare between different ACL conditions.
  
  
  RESULTS
  Significantly increased accelerations were observed in the complete deficient ACL model, while the partial ACL tear models demonstrated a slight increase without statistical significance. The accelerometer detected stepwise increases in the acceleration with the extent of ACL tear. Additionally, the PL bundle exhibited the largest contribution for rotational instability (80.4%) when compared with the AM (19.5%) bundles.
  
  
  CONCLUSIONS
  Triaxial accelerometer could serve as a quantitative evaluation of rotational instability. The present study demonstrated that PL bundle has the most important contribution for rotational instability (80.4%) when compared to IM bundle (0.01%) and AM bundle (19.5%) in porcine knee model.
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Fukuoka University, Fukuoka, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Maeyama
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Hoshino
authors.forename: Anibal
authors.initials: A
authors.lastname: Debandi
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kato
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Saeki
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Asai
authors.forename: Bunsei
authors.initials: B
authors.lastname: Goto
authors.forename: Patrick
authors.initials: P
authors.lastname: Smolinski
authors.forename: Freddie H
authors.initials: FH
authors.lastname: Fu
mesh_terms: D000054:Acceleration; D000818:Animals; D016118:Anterior Cruciate Ligament / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D007593:Joint Instability / Q000175:diagnosis*; D007719:Knee Joint; D023421:Models, Animal; D016059:Range of Motion, Articular / Q000502:physiology; D018709:Statistics, Nonparametric; D034421:Sus scrofa; D013552:Swine