Investigations for the development of a biochemical joint function test.

The reversible and thus potentially curable, early stage of degenerative joint diseases, so consequential for both the individual and the economy, has so far not been diagnosable objectively. Intraarticular functional tests aim at detecting latent metabolic changes in the joint in order to find out early changes in risked persons. The present animal experiments on osteoarthrosis showed early changes of the glycogen metabolism and the swelling behaviour of the articular cartilage. Therefore, the diagnostic value of intraarticular injections of depot glucose was tested in the form of metabolizable hydroxyethyl starch and the non-metabolizable dextran, which were administered as non-buffered solutions. 35 ml of 0.5% solutions of hydroxyethyl starch or dextran in isotonic saline were injected intraarticularly to unselected patients before knee operations. By means of punctures of the joint 10 min, 1 h, 5 h, and 24 h after the injection, about 3 ml fluid samples were taken for biochemical, biophysical and cytological examinations. The examination produced, for the first time, evidence on the volume and composition of the synovia of osteoarthrosis patients from whom no synovial fluid can be obtained. The analysis of the punctates after loading permits of grouping the patients according to osteoarthrotic changes and various reaction patterns of the synovial marginal tissue with regard to disposition to exudation.