Human and bovine articular cartilage loading measured with a new resistive sensor: effects of protease degradation and osteoarthritis.

This report describes the use of a new micro-thin resistive-based sensor to measure dynamic vertical loading of normal and osteoarthritic (OA) human knee cartilage repetitively under conditions of simulated knee joint loading. Articular cartilage discs were cultured in 3 DMEM +/- IL-1, lipopolysacharide (LPS) and trypsin over 7 days. Loading force, force distribution and peak pressure were evaluated. The sensor detected early stiffness and dynamic loading changes due to IL-1, LPS and trypsin treatment, and differences between normal and early OA human cartilages showing decreased cartilage stiffness due to enzyme treatment and osteoarthritis.