On the Development of Adjuvant Arthritis in the Joint Intra-Articularly Irradiated by Radioactive Yttrium90Y Resin

Abstract

Radioactive yttrium (⁹⁰Y) resin was injected intra-articularly into the right hind ankle joints of adult albino rats. A number of animals were also injected at the same time with adjuvant in the left hind footpad. The remainder received this adjuvant injection either 2 or 4 weeks later. In the first group, in which both injections were administered simultaneously, adjuvant arthritis developed in a significantly larger number of rats than in the corresponding joints of the control rats. When irradiation was carried out 4 weeks before the adjuvant inoculation, there was insignificant difference between the development of arthritis in these animals and in the controls, but the difference between them and the animals irradiated simultaneously or 2 weeks before the adjuvant inoculation was statistically highly significant. The adjuvant arthritis which developed in the irradiated joint was histologically dominated by a large accumulation of fibrin and by fibrinoid degeneration as well as by relatively little cellularity, while the adjuvant arthritis in the non-irradiated joints of the same animals corresponded histologically to the description of adjuvant arthritis given in the literature.