title: Ligament and meniscus loading in the ovine stifle joint during normal gait.
abstract: BACKGROUND
  The ovine stifle joint is an ideal preclinical model to study knee joint biomechanics. Knowledge of the ovine ligamentous and meniscal loading during normal gait is currently limited.
  
  
  METHODS
  The in vivo kinematics of the ovine stifle joint (N=4) were measured during "normal" gait using a highly accurate instrumented spatial linkage (ISL, 0.3±0.2mm). These motions were reproduced in vitro using a unique robotic testing platform and the loads carried by the anterior/posterior cruciate ligaments (ACL/PCL), medial/lateral collateral ligaments (MCL/LCL), and medial/lateral menisci (MM/LM) during gait were determined.
  
  
  RESULTS
  Considerable inter-subject variability in tissue loads was observed. The load in the ACL was near zero at hoof-strike (0% gait) and reached a peak (100 to 300N) during early-stance (~10% gait). The PCL reached a peak load (200 to 500N) just after hoof-strike (~5% gait) and was mostly unloaded throughout the remainder of stance. Load in the MCL was substantially lower than the cruciate ligaments, reaching a maximum of 50 to 100N near the beginning of stance. The LCL carried a negligible amount of load through the entire gait cycle. There was also a major contribution of the MM and LM to load transfer from the femur to the tibia during normal gait. The total meniscal load reached a maximum average between 350 and 550N during gait.
  
  
  CONCLUSIONS
  Knowledge of joint function during normal motion is essential for understanding normal and pathologic joint states. The considerable variability in the magnitudes and patterns of tissue loads among animals simulates clinical variability in humans.
  
  
  METHODS
  III.
authors.affiliation: Department of Civil Engineering, Faculty of Engineering, University of Calgary, Calgary, AB, Canada. Electronic address: joshrosvold@gmail.com.
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Rosvold
authors.affiliation: McCaig Institute for Bone and Joint Health, Faculty of Medicine, University of Calgary, Calgary, AB, Canada. Electronic address: matarodp@ucalgary.ca.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Atarod
authors.affiliation: McCaig Institute for Bone and Joint Health, Faculty of Medicine, University of Calgary, Calgary, AB, Canada. Electronic address: bjheard@ucalgary.ca.
authors.forename: Bryan J
authors.initials: BJ
authors.lastname: Heard
authors.affiliation: McCaig Institute for Bone and Joint Health, Faculty of Medicine, University of Calgary, Calgary, AB, Canada. Electronic address: ejoobrie@ucalgary.ca.
authors.forename: Etienne J
authors.initials: EJ
authors.lastname: O'Brien
authors.affiliation: McCaig Institute for Bone and Joint Health, Faculty of Medicine, University of Calgary, Calgary, AB, Canada. Electronic address: cfrank@ucalgary.ca.
authors.forename: Cyril B
authors.initials: CB
authors.lastname: Frank
authors.affiliation: McCaig Institute for Bone and Joint Health, Faculty of Medicine, University of Calgary, Calgary, AB, Canada. Electronic address: ngshrive@ucalgary.ca.
authors.forename: Nigel G
authors.initials: NG
authors.lastname: Shrive
mesh_terms: D000818:Animals; D016118:Anterior Cruciate Ligament / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D004195:Disease Models, Animal; D005260:Female; D005684:Gait / Q000502:physiology*; D007718:Knee Injuries / Q000503:physiopathology*; D007719:Knee Joint / Q000503:physiopathology*; D017888:Medial Collateral Ligament, Knee / Q000503:physiopathology*; D008592:Menisci, Tibial / Q000503:physiopathology*; D009068:Movement / Q000502:physiology; D016119:Posterior Cruciate Ligament / Q000503:physiopathology*; D015203:Reproducibility of Results; D012756:Sheep
keywords: Gait; Kinematics; Loads; Ovine; Robotics