Articular cartilage calcification and matrix vesicles.

There has been much research in calcium-containing crystal deposition diseases of hereditary and sporadic type. Synovial cell-induced inflammation and secondary cartilage damage are common in these diseases. In most cases of these diseases and in primary osteoarthritis, there are mineral deposits in the cartilage, mineral crystals in the synovial fluid, and aberrations of pyrophosphate metabolism.