Abstract
In joints with exudate in rheumatoid arthritis, intraarticular cortisone injection acts locally and is followed by:
1) a reduction of exudation probably due to a decrease of the permeability of the synovial membrane
2) an increase of the viscosity induced by hyaluronic acid
3) an increase of the activity of hyalu-ronidase inhibitors which may result in a decrease of the depolymerisation of hyaluronic acid.