[The joint in algodystrophy. Joint fluid, synovium, cartilage].

The joint fluid in cases of algodystrophy was studied in 17 samples. It is poor in cells (275/mm3 with a mean of 15% polymorphs). The protein level was studied 4 times and was equal to or greater than 40 g/l, i.e. double the normal value. A detailed histological examination of 33 biopsies of synovial tissue reveals a typical appearance of the synovium in algodystrophy, defined by 6 features, 2 negative and 4 positive: absence of hyperplasia of the synovial lining, absence of any real inflammatory cell infiltrate, presence of a marked hypervascularity, an oedema of the chorion, especially marked in the first weeks of the disease, hyperplasia of the walls of some arterioles, and fibrosis of the chorion which becomes more marked as the disease progresses and which is predominantly in the deeper layers. The authors recall that articular cartilage can show superficial alterations of structure with areas of fibrosis.