Is Medical Ozone Safe when Injected Intra-articularly? A Comparative Histological Study in Rat

SUMMARY - The therapeutic use of ozone (O 2 -O 3 ) gas is controversial. Some authors claim the gas mixture is toxic and therefore out of the question, whereas, others hold that it is useful and effective when used following a certain method to treat degenerative diseases, such as knee osteoarthritis, for which the gas has been used empirically. The present work studied the effects of contact of O2-O3 with healthy knee tissues of Wistar rats and compared them to intra-articular injection of a substance known to damage the cartilage. Thirty-six Wistar rats were studied in two groups. Mono-iodoacetic acid (MIA) was injected in the first group in a single dose και, whereas O2-O3 was injected in the second group in frequent doses three times a week for three weeks. The rats were killed 40 days later and articular cartilage and surrounding tissues were studied histologically. MIA caused degenerative osteoarthritis gradually deteriorating at the knees of the first group whereas no major changes were observed in those of the second group. We conclude that following the methodology of our study medical ozone appears to be safe for use.