Osteoarthrosis induced by intra‐articular hydrogen peroxide injection and running load

Osteoarthrosis of the rat knee joint was induced successfully by intra‐articular injection of 2% hydrogen peroxide (H 2 O 2 ) and running load. In the group receiving two injections of physiological saline with running load, no histological osteoarthrotic knees were developed up to 8 weeks after the injection. In the group receiving two 2% H 2 O 2 injections and running load, advanced osteoarthrosis occurred in all knees 8 weeks after the first injection, and the Mankin's score of osteoarthrotic knees appeared to be higher than the group receiving two 2% H 2 O 2 injections without running load ( p < 0.004, Kruskal‐Wallis H test). In the rats receiving a single 2% H 2 O 2 injection with running load and a vitamin E‐enriched diet, the inhibitory effect of vitamin E on the development of osteoarthrosis was statistically significant compared to the regular diet group ( p < 0.05, Wilcoxon rank test).