MMP7 and osteoarthritis: To obtain direct evidence that the Wnt/β-catenin signaling pathway can trigger extracellular matrix degradation and hypertrophic chondrocyte differentiation in osteoarthritis, we activated the pathway in vitro by using LiCl in normal and osteoarthritic chondrocytes and evaluated the expression levels of basic catabolic (MMP-7, 9, 13, 14, ADAMTS-5, and 4) and hypertrophic markers (collagen X).