Figure 2.
Potential cell–matrix interactions with the soft/hypertrophic callus. Chondrocytes and chondroprogenitor cells within the fracture cartilage callus extracellular matrix (ECM) may be tethered to collagen type II and X through integrins.40 Cell to cell interactions occur through cadherins. Glycosaminoglycans are bound to the collagen structure and sequester local growth factors within the ECM. Sequestered growth factors interact with chondroprogenitors, activating cell-signalling pathways that promote chondrogenesis, which in turn promotes the expression of matrix remodelling factors.42 Figure generated using the Servier medical art database (http://www.servier.com/Powerpoint-image-bank).