title: Longitudinal measurement of tibial motion relative to the femur during passive displacements in the cat before and after anterior cruciate ligament transection.
abstract: Passive anterior-posterior displacement and medial-lateral rotation of the tibia on the femur in the feline knee were assessed before transection of the anterior cruciate ligament, immediately after transection, and 2 and 4 months after transection. Four anaesthetized experimental and three sham-operated control animals were positioned in a stereotaxic frame. Motions of the tibia relative to the femur were measured with use of 60-Hz video motion analysis, while a strain-gauged system allowed measurement of forces and moments applied to the tibia. Displacement at 15 N of anterior force and 30 degrees of knee flexion increased by an average of 6 mm following transection, and stiffness decreased by an average of 6 N/mm. At 2 and 4 months following transection, there were statistically significant reductions in this abnormal displacement. Stiffness during anterior displacement of the tibia at 30 degrees increased significantly from immediately after transection to 4 months. At 90 degrees, mean anterior displacement decreased from 5.1 mm immediately after transection to 2.9 mm at 4 months. Medial rotation at 30 degrees of knee flexion was significantly decreased from a mean of 16.5 degrees after transection to a mean of 10.7 degrees at 4 months. Changes in medial rotation at 90 degrees, lateral rotation at 90 degrees, and lateral rotation at 30 degrees were not statistically significant. These results indicate a significant change in secondary constraints to tibial motion in response to knee instability.
authors.affiliation: Sport Medicine Centre, Human Performance Laboratory, University of Calgary, Alberta, Canada.
authors.forename: M E
authors.initials: ME
authors.lastname: Maitland
authors.forename: T
authors.initials: T
authors.lastname: Leonard
authors.forename: C B
authors.initials: CB
authors.lastname: Frank
authors.forename: N G
authors.initials: NG
authors.lastname: Shrive
authors.forename: W
authors.initials: W
authors.lastname: Herzog
mesh_terms: D000818:Animals; D016118:Anterior Cruciate Ligament / Q000503:physiopathology; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D002415:Cats; D005269:Femur / Q000502:physiology*; D007593:Joint Instability / Q000503:physiopathology*; D007719:Knee Joint / Q000502:physiology*; D008137:Longitudinal Studies; D018583:Pliability; D016059:Range of Motion, Articular / Q000502:physiology*; D013977:Tibia / Q000502:physiology*; D013997:Time Factors; D014743:Videotape Recording