The main purpose of this study was to compare the altered metabolism in rheumatoid arthritis to normal hyaline cartilage by thermoanalytical methods. Further aim of this investigation was to elucidate the importance of water content and kinetic character of water loss. A limited number of papers have been published earlier on the subject of thermal analysis of degenerative and healthy human hyaline cartilage. Rheumatoid arthritis has not been studied previously by thermogravimetry. The only use of thermoanalytical techniques was the measurement of the enthalpy change during denaturation of the rheumatoid and normal cartilage. All samples for this investigation were obtained during live surgeries. According to the presented data, the water content of the hyaline cartilage is lower in patients with rheumatoid arthritis, than in the healthy donors. The reaction order turned out to be approximately 1 in all the cases, and the standard deviation was low. The TG curve's slope of the linear region showed, that the rate of water loss depends on the water amount remaining in the tissue. It can be concluded that the lower water content in the RA samples bound stronger to the matrix. The newly established compositional thermoanalytical measurement was sufficient for the study and differentiation of normal and rheumatoid human hyaline cartilage. (C) 2010 Elsevier B.V. All rights reserved.