Abstract： Objective Combined with the anatomical and histopathological observation of human specimens,this paper prelimi-narily reveals the histological and pathological similarities and differences between lower limb tendon foci and tendon nodes of dif-ferent ages,so as to lay a foundation for the establishment of differential criteria between tendon foci and tendon nodes and explore its possible pathological mechanism.Methods Twelve voluntarily donated cadaver specimens were selected as experimental sub-jects,including 2 cases of knee osteoarthritis(KOA)in young,middle-aged and elderly specimens,and 2 normal cadavers in young,middle-aged and old age.Eight knee joints of KOA cadavers and 12 knee joints of normal cadavers were taken out and observed under pathological microscope.Results The histopathology of tendon nodes in KOA cadavers was different from that in normal cadavers.Compared with the tendon nodes in normal cadavers,the soft tissues in KOA cadavers showed interstitial vascular dilatation and hyperemia,inflammatory cell infiltration,widening of muscle fiber septum and thickening of cyst wall.There was a significant difference between the two groups(P＜0.05),but not at a significant level.Conclusion The histopathological features of KOA cadaver specimens under microscope may be related to the structural characteristics of tendon lesions,and the histopatho-logical difference between tendon foci and tendon nodes may be one of the main reasons for their difficulties in clinical differential diagnosis,which provides an idea for further exploration of the differential diagnosis criteria between tendon foci and tendon nodes.