Macroscopic assessment of cartilage shear: Effects of counter-surface roughness, synovial fluid lubricant, and compression offset

• Published in: Journal of biomechanics Vol. 43; no. 9; pp. 1787 - 1793
• Main Authors: Nguyen, Quynhhoa T, Wong, Benjamin L, Chun, June, Yoon, Yeoung C, Talke, Frank E, Sah, Robert L
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 18.06.2010; Elsevier; Elsevier Limited
• Subjects: Animals; Biological and medical sciences; Biomechanics; Biomechanics. Biorheology; Cartilage; Cartilage, Articular - physiology; Cattle; Compressive Strength - physiology; Computer Simulation; Elastic Modulus - physiology; Female; Fluids; Friction; Fundamental and applied biological sciences. Psychology; Hardness - physiology; Humans; Lubricants & lubrication; Lubrication; Male; Middle Aged; Models, Biological; Physical Medicine and Rehabilitation; Shear; Shear Strength - physiology; Shear tests; Skeleton and joints; Stress, Mechanical; Studies; Surface Properties; Surface roughness; Synovial Fluid - physiology; Tissues, organs and organisms biophysics; Vertebrates: osteoarticular system, musculoskeletal system; Biomechanics; Cartilage; Surface roughness; Shear; Friction; Human; Roughness; Lower limb; Mechanical properties; Compressive strength; Foot; Synovial fluid; Articular cartilage; Shear stress; Biomedical engineering
• ISSN: 0021-9290; 1873-2380
• DOI: 10.1016/j.jbiomech.2010.02.014

Abstract During joint articulation, cartilage is subjected to compression, shear, and sliding, mechanical factors that regulate and affect cartilage metabolism. The objective of this study was to use an in vitro material-on-cartilage shear test to elucidate the effects of counter-surface roughness ( P olished, M ildly rough, and R ough), lubricants (phosphate buffered saline (PBS) and bovine synovial fluid (bSF)), and compression offset on the shearing and sliding of normal human talar cartilage under dynamic lateral displacement. Peak shear stress ( σ xz,m ) and strain ( E xz,m ) increased with increasing platen roughness and compression offset, and were 30% higher with PBS than with bSF. Compared to PBS, bSF was more effective as a lubricant for P than for M and R platens as indicated by the higher reduction in kinetic friction coefficient (−60% vs. −20% and −19%, respectively), σ xz,m (−50% vs. −14% and −17%) and E xz,m (−54% vs. −19% and −17%). Cartilage shear and sliding were evident for all counter-surfaces either at low compression offset (10%) or with high lateral displacement (70%), regardless of lubricant. An increase in tissue shear occurred with either increased compression offset or increased surface roughness. This material and biomechanical test system allow control of cartilage σ xz,m and E xz,m , and hence, sliding magnitude, for an imposed lateral displacement. It therefore can facilitate study of cartilage mechanobiological responses to distinct regimes of cartilage loading and articulation, such as shear with variable amounts of sliding.