The involvement of the synovium is common in phlogistic processes of various joint diseases. Apart from synoviocytes and the other cells in the synovial tissue, circulating cells recruited from peripheral blood also participate in the phlogistic process. The increased expression of adhesion molecules on both circulating and endothelial cell surface may further this recruitment. We studied 15 patients affected by serious gonarthrosis requiring a prosthetic implant (GPI) and 7 with knee prosthesis aseptic loosening (KPL) to evaluate adhesion molecule expression and phlogistic infiltration in the synovium using immunohistochemistry and microscopic analysis. As control we studied 10 subjects affected by degenerative meniscopathies undergoing a selective arthroscopic surgical meniscectomy. Analysis with Kruskal-Wallis test showed no statistical significant differences in the expression of CD54, CD11a, CD11b and CD18 in three groups examined. The model of variance analysis (Friedman test), showed that CD54 expression is greater in patients with GPI and KPL in comparison with the other molecules. Adhesion molecules and their functions are important in arthropathies not only because their evaluation can allow us to identify the degree of inflammation and to predict its evolution, but also because pharmacological control of their expression could have important therapeutic implications.