If further studies confirm that chondroitin prevents progressive damage to the joints, it would make chondroitin distinctly better than any conventional option. Unfortunately, this study was too small to prove anything on its own. Another, larger study examined the progression of osteoarthritis in 119 people for 3 full years. This suggests that chondroitin was slowing the progression of osteoarthritis. Unfortunately, the researchers did not report whether this difference was statistically significant.
Additional evidence comes from animal studies.
The effect of both oral and injected chondroitin was assessed in rabbits with damaged cartilage in the knee. After 84 days of treatment, the rabbits that were given chondroitin had significantly more healthy cartilage remaining in the damaged knee than the untreated animals. Receiving chondroitin by mouth was as effective as taking it through an injection. Putting all this information together, it appears quite likely that chondroitin can slow the progression of osteoarthritis. However, more studies are needed to confirm this very exciting possibility.