FINE-STRUCTURE AND DISTRIBUTION OF LYMPHATICS IN THE SYNOVIAL-MEMBRANE OF MONKEY AND HUMAN KNEE JOINTS - A STUDY USING AN ENZYME-HISTOCHEMICAL METHOD

The fine structure and distribution of lymphatics in the synovial memb rane of monkey knee joints, and human knees with osteoarthritis and rh eumatoid arthritis, were studied by light and electron microscopy usin g an enzyme-histochemical method. Whole mount preparations and tissue sections were doubly stained for 5'-nucleotidase and alkaline phosphat ase. The 5'-nucleotidase positive lymphatics could be distinguished fr om the alkaline phosphatase positive blood vessels. In monkey specimen s the 5'-nucleotidase lymphatics were densely distributed in the media l and lateral parts of the suprapatellar pouch and infrapatellar fat p ad, in both the superficial and deep of the sublining cell layers. Col lecting lymphatics were well developed in the deep fibrous layer and i n the merging epimysium. In the knees with both types of arthritis, th e patterns of distribution were the same as in the monkey. No lymphati cs were found in well developed villi in rheumatoid arthritis, but man y blood vessels were present.