I m 36 yrs. old, male, with a very physically demanding job. I recently had my third knee operation. I have torn meniscus in both knees and complete tears of both acl s, all repaired. I want to know if glucosimine and condroiton is of any benefit. I read about a product called Instaflex as well as others. Will any of these help improve and prolong joint function, if so which ones are best, if not is there anything else I can do? I have been told that I will have to have both knees replaced down the road.