[Ultrastructure of detritus synovitis ("hydroxylapatite synovitis?") (author's transl)].

Detritus synovitis is a sequel of cartilage and osseous destruction in diarthrosis. Cartilage and bone fragments are enclosed by granulation tissue. Remnants of the destroyed bone and calcified cartilage appear as defined accumulations of hydroxylapatite crystals in the granulation tissue. These hydroxylapatite tissues resemble those considered by other authors as being responsible for a "third crystal synovitis, namely, hydroxylapatite synovitis". However, the findings communicated here allow us to conclude that these crystals are the sequel of a destruction of diarthrosis, so that it is not justified to consider hydroxylapatite synovitis as a separate disease entity.