title: Cartilage mechanics in the guinea pig model of osteoarthritis studied with an osmotic loading method.
abstract: OBJECTIVE
  To determine the material properties of articular cartilage in the Hartley guinea pig model of spontaneous osteoarthritis.
  
  
  METHODS
  Cartilage-bone samples from the medial femoral condyle and tibial plateau of 12 month-old guinea pig knees were subjected to osmotic loading. Site-matched swelling strains and fixed charge density values were used in a triphasic theoretical model for cartilage swelling to determine the modulus of the cartilage solid matrix. The degree of cartilage degeneration was assessed in adjacent tissue sections using a semi-quantitative histological grading scheme.
  
  
  RESULTS
  Decreased values for both moduli and surface zone fixed charge density were associated with increasing grades of cartilage degeneration. Decreases in moduli reflect damage to the collagen matrix, which give rise to greater swelling strains.
  
  
  CONCLUSIONS
  Histological evidence of cartilage degeneration was associated with impaired cartilage mechanics in the aging Hartley guinea pig.
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA.
authors.forename: Charlene M
authors.initials: CM
authors.lastname: Flahiff
authors.forename: Virginia B
authors.initials: VB
authors.lastname: Kraus
authors.forename: Janet L
authors.initials: JL
authors.lastname: Huebner
authors.forename: Lori A
authors.initials: LA
authors.lastname: Setton
mesh_terms: D000818:Animals; D002357:Cartilage Diseases / Q000503:physiopathology*; D002358:Cartilage, Articular / Q000502:physiology*; D004548:Elasticity; D006168:Guinea Pigs; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D009997:Osmotic Pressure; D010003:Osteoarthritis / Q000503:physiopathology*; D010329:Patella / Q000502:physiology*; D013314:Stress, Mechanical; D013718:Tensile Strength; D013977:Tibia / Q000502:physiology