This review systematically reviews the structural characteristics and signal transduction pathways of different PDGF isoforms and their receptors (PDGFR-α and PDGFR-β), focusing on their biological roles at the cellular level, including the regulation of mesenchymal stem cell migration and expansion, the impact on chondrocyte survival and metabolic activity, and their bidirectional regulatory effects in the synovium-cartilage axis and osteoarthritis-related microenvironment. The gene discussed is PDGFRA; the disease is osteoarthritis.