Abstract
Observations on specimens from 100 consecutive synovectomies indicate that disintegration of the menisci of rheumatoid knee joints starts at the anterior and posterior horns. The middle part may still be fairly normal. Breakdown of macromolecules takes place, which is shown by viscosimetry. The activi ties of betaglucuronidase, cathepsin, arylsulfatase B, and acid phosphatase are higher in the degenerating, soft parts of the menisci than in the still healthy parts. Vague evidence of a collagenolytic activity could be found in the fibrocartilaginous homogenates.