title: Tibial displacement with stifle joint flexion and cranial cruciate ligament transection in the dog. An ex vivo study using a robotic simulator.
abstract: OBJECTIVE
  The aim of this study was to investigate the biomechanical effects of cranial cruciate ligament (CrCL) transection on stifle stability at three different stifle joint flexion angles using a robotic system.
  
  
  METHODS
  This was an ex vivo biomechanical study. Stifles (n = 6) were collected from the cadavers of Beagles weighing 10.5-12.0 kg. Six stifle joints were dissected, potted, and secured to the manipulator arms of a robotic simulator. With the stifle joint angle maintained at either hyperextension (151°), 135° or 90°, stability was assessed by application of a 50 N load in either the cranial-caudal (CrCd test) or proximal-distal (PD test) directions. The stifle was given a cranial-caudal load of 50 N (CrCd test). A proximal-distal compression load of 50 N was then administered by the manipulator (proximal-distal test: PD test). The change in three-dimensional kinematics of the intact and the CrCL-transected stifles was compared between hyperextension, and 135° and 90° flexion for the CrCd and PD load conditions. A value of p <0.05 was considered statistically significant.
  
  
  RESULTS
  The cranial tibial displacements in the PD tests of the CrCL-transected stifles at 135° (8.4 ± 1.2 mm) and at 90° (8.1 ± 1.9 mm) were significantly greater than the displacement at 151.5° (5.1 ± 1.6 mm) (p = 0.004 and p = 0.012 respectively).
  
  
  CONCLUSIONS
  The canine stifle exhibited the most instability when the stifle flexion angle was 135°.
authors.affiliation: Nobuo Kanno, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo 180-8602, Japan, Phone: +81 422 90 4000, Fax: +81 422 34 8235, E-mail: n.kanno7@gmail.com.
authors.forename: N
authors.initials: N
authors.lastname: Kanno
authors.forename: Y
authors.initials: Y
authors.lastname: Hara
authors.forename: S
authors.initials: S
authors.lastname: Fukano
authors.forename: H
authors.initials: H
authors.lastname: Fujie
authors.forename: H
authors.initials: H
authors.lastname: Ochi
authors.forename: Y
authors.initials: Y
authors.lastname: Fujita
authors.forename: H
authors.initials: H
authors.lastname: Yasuji
authors.forename: Y
authors.initials: Y
authors.lastname: Nezu
authors.forename: T
authors.initials: T
authors.lastname: Yogo
authors.forename: M
authors.initials: M
authors.lastname: Tagawa
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002102:Cadaver; D004285:Dogs; D007593:Joint Instability / Q000662:veterinary; D012371:Robotics; D013264:Stifle / Q000502:physiology*
keywords: Stifle; biomechanics; cranial cruciate ligament; robotic simulator; six degrees of freedom