Sim S; Hadjab I; Garon M; Quenneville E; Hurtig MB; Buschmann MD; Hoemann CD
Transactions of International Cartilage Repair Society (ICRS), Chicago, 2015, 7-11 May 2015, e-Poster: P87
Les titres, résumés et légendes des publications sont présentés en anglais.
Purpose: To demonstrate the ability of non-destructive electromechanical device and automated indentation technique in assessing the quality of cartilage in a sheep model of cartilage repair.
Methods: Ex vivo electromechanical and mechanical mappings of articular surfaces (~40 positions/map) were performed over distal condyles from 5 treated sheep (8 – 9 y-o, 9 months post-surgery, bone marrow stimulation model) and 2 control sheep (8 y-o). Electromechanical measurements were performed manually with the Arthro-BST (Biomomentum, Laval) which calculates a quantitative parameter (QP) (in A.U.) based on compression-induced streaming potentials measured by 37 microelectrodes lying on a semi-spherical indenter (d=6.4mm). Mechanical assessments (structural stiffness) were conducted at the same positions using an automated indentation technique with a multiaxial tester (Mach-1 v500css, Biomomentum, Laval) equipped with a spherical indenter (d=1mm). Selected sites were additionally analyzed by histology and by unconfined mechanical compression tests.
Results: GAG-rich repair tissues displayed poroelastic mechanical behavior. According to electromechanical and mechanical properties mappings on control and treated articular surfaces, some para-defect articular surfaces showed lower average structural stiffness and weaker electromechanical properties (high QP) vs matching control regions. The QP was lower and structural stiffness higher in the repair site. Repair site soft tissue thickness varied from 0 to 1200 μm (mean thickness 315±260 μm, n=10) compared to ~1100 μm in flanking areas. Surface GAG depletion was observed at the defect border in some of the repaired medial condyles.
Conclusion: Mechanicalmeasures demonstrated poroelastic cartilage behavior in repair tissues of aged sheep. Measurements outside the repair sites are suggestive of modest cartilage GAG depletion and consistent with previous data.
Utilisation des équipements
Arthro-BST a cartographié manuellement le QP électromécanique à partir des potentiels d’écoulement induits par compression sur le cartilage condylien distal ovin réparé et témoin. Aux mêmes sites, le Mach-1 Mechanical Tester (v500css) a mesuré la rigidité structurale par indentation sphérique automatisée. Un Mach-1 Mechanical Tester a également réalisé des essais de relaxation des contraintes en compression non confinée sur des carottes ostéochondrales des sites réparés. Les extraits ne précisent pas d’adaptation de la trajectoire à la normale locale.
Configurations de test (6)
