Cartilage damage and regeneration in osteoarthritis. Comments on pathomorphology

The pathomorphology of osteoarthritis is mainly related to the destruction of the articular cartilage. Both macroscopically visible matrix loss as well as fissuring and matrix degradation on the microscopical level occurs. Additionally, other joint structures, namely, the subchondral bone and the synovial capsule and membrane, undergo significant, mostly reactive changes. Besides these destructive processes regenerative cartilage formation is also found: mesenchymal precursor cells differentiate to chondrocytic cells mainly during osteophyte formation.Though osteophytes are of little functional help during joint destruction, they represent an interesting in vivo model for therapeutically induced cartilage repair. Processes found in osteophyte formation and degeneration might point to new innovative therapeutic targets and can help to understand processes going on in joints during neocartilage formation.