Whitlockite crystals have been observed in both degenerating and normal art
icular cartilages. To determine their potential for inducing cartilage dege
neration, we studied their ability to induce mitogenesis and synthesis and
secretion of metalloproteases in vitro. Whitlockite crystals were found to
stimulate cell proliferation and to stimulate synthesis and secretion of st
romelysin and collagenase. However, they were less stimulatory than crystal
s that contained calcium (Ca) and phosphate without magnesium substitution
for Ca. Whitlockite crystals elicit biologic cellular responses that sugges
t potential pathogenicity in arthritis, but are less potent than Ca phospha
te crystals without magnesium.