Shear deformation kinematics during cartilage articulation: effect of lubrication, degeneration, and stress relaxation.

摘要: During joint articulation, the biomechanical behavior of cartilage not only facilitates load-bearing and low-friction properties, but it also provides regulatory cues to chondrocytes. Elucidation kinematics under combined compression shearing conditions clarifies these in health disease. The objectives this study were elucidate effects lubricant, tissue degeneration, stress relaxation duration on shear during articulation. Human osteochondral cores with normal mildly degenerate surface structures isolated from lateral femoral condyles. Paired blocks each core apposed, compressed, allowed relax for 5 or 60 min, tested a mcro-scale video microscopy system using phosphate- buffered saline (PBS) synovial fluid (SF) as lubricant. applied motion, local overall strain (Exz) articular determined. displacement at which Exz reached 50% peak (Δx1/2) was Quantitatively, increased onset motion peaked just surfaces detached slid. With continued maintained. After short relaxation, lubrication Δx1/2 apparent. prolonged near markedly when PBS used Similar patterns observed Δx1/2. consistently higher all cases after motion. Thus, is affected by loading duration. Changes factors may be involved pathogenesis osteoarthritis.