TO INVESTIGATE THE ROLE OF CARTILAGE ALTERATIONS IN THE PATHOGENESIS OF THE IDIOPATHIC FEMORAL HEAD NECROSIS, 3 COMPONENTS OF GLYCOSAMINOGLYCANS(GAG) IN PATHOLOGICAL AND HEALTH CARTILAGE, LEVELS OF HYALURONIC ACID(HA) IN SYNOVIAL FLUID AND SERUM WERE DETECTED. THE CORRELATIONS AMONG HA LEVEL IN SYNOVIAL FLUID, SERUM AND GAG CONTENT IN CARTILAGE WERE ANALYZED. THE RESULTS SHOWED THAT ①THE THREE COMPONENTS OF CARTILAGE GAG IN NORMAL ADULTS AND CHILDREN SHOWED LITTLE DIFFERENCE; ②COMPARED WITH THE NORMAL AUT...“,”To investigate the role of cartilage alterations in the pathogenesis of the idiopathic femoral head necrosis, 3 components of glycosaminoglycans(GAG) in pathological and health cartilage, levels of hyaluronic acid(HA) in synovial fluid and serum were detected. The correlations among HA level in synovial fluid, serum and GAG content in cartilage were analyzed. The results showed that ①the three components of cartilage GAG in normal adults and children showed little difference; ②Compared with the normal autopsy specimens, steroid induced ANFH and Perthes disease specimens had significantly decreased GAG contents (P0 05), but it decreased significantly (P<0 05) in Ficat Ⅲ, while hexosamine decreased sharply in Ficat Ⅱ and had no marked alternation in Ficat Ⅲ. And hexuronic acid fell sharply during Ficat Ⅱ and Ficat Ⅲ (P<0 05). Serum level of HA did not have obvious changes until Ficat Ⅲ. HA level in synovial fluid decreased extremely in Ficat Ⅲ in contrast to Ficat Ⅱ and normal controls (P0 05); ③Children suffered from Perthes disease had a much higher level of HA in serum than the controls (P<0 01). HA level in serum led an inverse correlation with that in synovial fluid. (r=-0 663,P<0 05);④There was a positive correlation between HA level in synovial fluid and GAG content in both steroid induced ANFH and Perthes disease. GAG content was positive correlated with HA level in serum of Perthes disease, whereas, there was no correlation between them in steroid induced ANFH. The results suggest that:①GAG content in affected hip decreased significantly in the early stage. It provides clinical theory basis for auxiliary treatment to cartilage in early stage; ②Sulfate radical depletion is the most conspicuous one of GAG changes in middle and late stage. It suggests that the sulfate radical glycoaminoglycans should be replenished in these stages; ③Measurement of the serum HA level is of no value in early diagnosis of steroid induced ANFH. To some extent serum levels of HA reflect biochemical changes in cartilage in Perthes disease.