Walking on water: revisiting the role of water in articular cartilage biomechanics in relation to tissue engineering and regenerative medicine.

The importance, and the difficulty, of generating biosynthetic articular cartilage is widely recognized. Problems arise from obtaining sufficient stiffness, toughness and longevity in the material and integration of new material into existing cartilage and bone. Much work has been done on chondrocytes and tissue macromolecular components while water, which comprises the bulk of the tissue, is largely seen as a passive component; the 'solid matrix' is believed to be the main load-bearing element most of the time.

Analysis of hydration and subchondral bone density on the viscoelastic properties of bovine articular cartilage.

Background: Articular cartilage is known to be a viscoelastic material, however little research has explored the impact of cartilage water content and bone density on its viscoelasticity. This study aimed to isolate subchondral bone density and hydration of articular cartilage and analyse their effects on the viscoelastic properties of articular cartilage.

Methods: Dynamic mechanical analysis was used to test samples at frequencies of 1, 8, 12, 29, 49, 71, and 88 Hz.

Viscoelastic properties of human and bovine articular cartilage: a comparison of frequency-dependent trends.

Background: The purpose of this study was to compare the frequency-dependent viscoelastic properties of human and bovine cartilage.

Methods: Full-depth cartilage specimens were extracted from bovine and human femoral heads. Using dynamic mechanical analysis, the viscoelastic properties of eight bovine and six human specimens were measured over the frequency range 1 Hz to 88 Hz.