Radiation effects produced by the intra-articular injection of 32P.

Colloidal forms of radioactive isotopes are being used for the treatment of some articular diseases. The radiation effects of intra-articular injection of 0.25 mCi of 32P in the form of colloidal chromic phosphate were investigated in one of the knee joints of adult Wistar rats. The contralateral knee was used as a control. The animals were sacrificed one, 7, 14, 28 and 56 days later. Destructive changes were found after 56 days. The articular cartilage was atrophied and covered by a fibrous pannus. The growth cartilage was severely disorganized and there were deleterious effects on both cells and matrix.