The Crosstalk Between Cartilage and Bone in Skeletal Growth

While the flat bones of the face, most of the cranial bones, and the clavicles are formed directly from sheets of undifferentiated mesenchymal cells, most bones in the human body are first formed as cartilage templates. Cartilage is subsequently replaced by bone via a very tightly regulated process termed endochondral ossification, which is led by chondrocytes of the growth plate (GP). This process requires continuous communication between chondrocytes and invading cell populations, including osteoblasts, osteoclasts, and vascular cells. A deeper understanding of these signaling pathways is crucial not only for normal skeletal growth and maturation but also for their potential relevance to pathophysiological processes in bones and joints. Due to limited information on the communication between chondrocytes and other cell types in developing bones, this review examines the current knowledge of how interactions between chondrocytes and bone-forming cells modulate bone growth.