Abstract: ［Abstract］ Objective〖HTSS〗〓To perform ferrography analysis of wear debris in synovial fluid of patients with knee osteoarthritis and to make an early evaluation of the condition of osteoarthritis.
〖HTH〗〖WTHZ〗Methods〖HTSS〗〓Three hundreds and sixtyeight patients with suspected knee osteoarthritis were collected and divided into the normal group(46 cases) and the osteoarthritis group(322 cases) according to KellgrenLawrence（KL） classification. After aseptically extracting the joint fluid and magnetizing its sediment, the morphology of the abrasive particles was observed under the ferrography microscope. The length, area, elongation and entropy of abrasive particles were compared between normal group and osteoarthritis group.
〖HTH〗〖WTHZ〗Results〖HTSS〗〓The length, area, elongation and entropy of abrasive particles in the osteoarthritis group were significantly higher than those in the normal control group, and the difference was statistically significant(P＜005). The abrasive particle length was positively correlated with the grading and entropy, the abrasive particle length was negatively correlated with the abrasive particle area and elongation rate(P＜005).
〖HTH〗〖WTHZ〗Conclusion〖HTSS〗〓The shape and quantity of abrasive particles are related to the rate and mechanism of joint wear.The study of abrasive particles has high sensitivity and objectivity, which provides a reliable choice for the early diagnosis of osteoarthritis.

Key words: osteoarthritis； ferrography, wear particles, synovial fluid