[Early detection of arthrotic changes in animal experiments and clinical medicine]

With arthroscopy cartilage changes are being detected more and more frequently which must be classified as early arthrosis. Similar changes (stage II) could be induced in 17 rabbits 6 weeks after lateral meniscectomy. Extraction (4M-GuHcl) and gel chromatography (Sepharose 2B) of 35S-proteoglycans resulted in typical elution profiles. Aggregates were remarkably, monomers slightly reduced, and a third population of nonaggregated proteoglycans increased. In 81 patients undergoing knee arthroscopy 98 small cartilage biopsies were taken from standardized regions and analysed biochemically. Elution profiles were correlated to anamnestic and clinical data (Wilcoxon-test, cluster analyses). Irrespective of the grade of osteoarthrosis (OA) the ratio of aggregated and nonaggregated 35S-proteoglycans varied. Almost half of the samples from macroscopically "normal" cartilage revealed a depression of aggregates. No correlation to anamnestic or clinical data was found. The profiles probably represent different metabolic stages in developing OA. By analysis of 35S-proteoglycans in cartilage biopsies it seems possible to detect early metabolic changes at the onset of osteoarthrosis.