New Concept to Restore Normal Cell Responses in Osteoarthritic Knee Joint Cartilage.

Prediction of osteoarthritis progression does not exist. Cartilage "health" and degeneration during osteoarthritis depend on the signals perceived by chondrocytes. We hypothesize that biomechanical responses of chondrocytes in osteoarthritic cartilage can be restored close to their normal state.

Topographical investigation of changes in depth-wise proteoglycan distribution in rabbit femoral articular cartilage at 4 weeks after transection of the anterior cruciate ligament.

In this study, we explore topographical changes in proteoglycan distribution from femoral condylar cartilage in early osteoarthritis, acquired from both the lateral and medial condyles of anterior cruciate ligament transected (ACLT) and contralateral (CNTRL) rabbit knee joints, at 4 weeks post operation. Four sites across the cartilage surface in a parasagittal plane were defined across tissue sections taken from femoral condyles, and proteoglycan (PG) content was quantified using digital densitometry. The greatest depth-wise change in PG content due to an ACLT (compared to the CNTRL group) was observed anteriorly (site C) from the most weight-bearing location within the lateral compartment.

How the structural integrity of the matrix can influence the microstructural response of articular cartilage to compression.

This study investigated how the structural integrity of healthy, surface-removed (healthy), and degenerate matrices can modify the response of cartilage to compression. Six groups of specimens were loaded up to the onset of consolidation or at full consolidation (N = 30, 5 per group, respectively) and then subsequently chemically fixed to capture the deformed state of the tissues. Creep compression was applied through an 8 mm flat-ended indenter containing a 450 μm diameter central pore, providing a region of high stress that also allowed the tissue samples to deform freely around the indenter pore during compression.

Articular cartilage surface failure: an investigation of the rupture rate and morphology in relation to tissue health and hydration.

This study investigates the rupture rate and morphology of articular cartilage by altering the bathing environments of healthy and degenerate bovine cartilage. Soaking tissues in either distilled water or 1.5 M NaCI saline was performed in order to render the tissues into a swollen or dehydrated state, respectively.

Articular cartilage surface rupture during compression: investigating the effects of tissue hydration in relation to matrix health.

This study aimed at investigating articular cartilage rupture by investigating the response of healthy and degenerate cartilage through altering the osmotic swelling environment of surface-intact, cartilage-on-bone specimens. The osmotic environment in healthy and degenerate bovine cartilage was varied by soaking tissues in either distilled water or 1.5 M NaCl saline to render the tissues into a swollen or dehydrated state (respectively).

Articular cartilage compression: how microstructural response influences pore pressure in relation to matrix health.

Our research investigated the influence of degeneration on both the pore-pressure development and microstructural response of cartilage during indentation with a flat-porous-indenter. Experiments were conducted to link the mechanical and structural responses of normal and degenerate articular cartilage. We found that from the instant of loading the degenerate matrix generated a higher peak hydrostatic excess pore pressure in a shorter period of time than the normal matrix.