Formation of calcium phosphate crystals in normal and osteoarthritic cartilage

Abstract

The presence of three different types of calcium phosphate crystals and the associated increase in matrix vesicles and alkaline phosphatase activity of arthritic articular cartilage may imply a calcification abnormality and may have aetiological implications in certain forms of osteoarthritis. The discovery of cuboid (Whitlockite) crystals in human articular cartilage is quite new and requires further characterisation. Previously Whitlockite has been reported only in pathological calcification sites in soft tissues such as lung and spleen and in hard tissues such as carious dentine.