Synovial fluid analysis by ferrography

Ferrography is a technique for magnetically harvesting and separating metallic particles from aqueous and non-aqueous suspensions. We have adapted this method of analysis to the study of cartilaginous and osseous wear particles, as well as fragments of soft tissue, found in the synovial fluid of human joints. As ferrography employes magnetism to harvest particles and arrange them in an orderly fashion, it is first necessary to impart a positive magnetic susceptibility to the biological materials. The trivalent paramagnetic cation of the rare earth element erbium is used for this purpose. Based on this principle, a method for the ferrographic analysis of synovial fluid has been devised, which is presently being employed in the study of human joint disease. Using this technique, improved diagnosis of arthritis may be possible. In addition, it may lead to a deeper understanding of the aetiology and pathogenesis of degenerative arthritis and other destructive joint diseases.