title: Indentation instrument for the measurement of cartilage stiffness under arthroscopic control.
abstract: Changes in the biomechanical properties of articular cartilage are one of the first signs of the tissue degeneration. We have developed a small size indentation instrument for the quantification of cartilage stiffness under arthroscopic control. During measurement, the indenter imposes a constant deformation on the cartilage and the maximal indenter force, by which the cartilage resists the deformation, is used as a measure for cartilage stiffness. The instrument has been tested in laboratory conditions with elastomer and cadaver knee joint cartilage samples. A linear relationship was found between indenter force and elastomer stiffness (r = 0.990, n = 14) as well as between indenter force and cartilage shear modulus obtained by a reference device (r = 0.879, n = 22). Also, the correlation between two repeated measurements at the measurement sites, used to evaluate the reproducibility, was linear (r = 0.953, n = 16). Quantitative detection of cartilage stiffness is possible with the instrument.
authors.affiliation: Department of Anatomy, University of Kuopio, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Lyyra
authors.forename: J
authors.initials: J
authors.lastname: Jurvelin
authors.forename: P
authors.initials: P
authors.lastname: Pitkänen
authors.forename: U
authors.initials: U
authors.lastname: Väätäinen
authors.forename: I
authors.initials: I
authors.lastname: Kiviranta
mesh_terms: D020679:Arthroscopes; D001182:Arthroscopy / Q000379:methods; D001696:Biomechanical Phenomena; D002358:Cartilage, Articular / Q000502:physiology* / Q000503:physiopathology*; D004548:Elasticity; D004867:Equipment Design; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D012044:Regression Analysis; D015203:Reproducibility of Results; D013314:Stress, Mechanical