It is common to have knee pain. He needs to be taking Glucosamine Sulphate, 500 mg once a day and his knee pain will go away quickly. If he is rich and can afford them, up to 3 times a day. the rest of his life. It builds up the cartilage and is fabulous. The best I have found is from Quest.
The other thing he needs if he can switch to the more natural which is what I take is grape seed. If I take grape seed religiously, 2 caps a day, I have no knee pain, but I too the Glucosamine for 3 years. He needs the whole seeds, do not buy those stupid supplements, they are useless.
After he buys the seeds, griind them and put in caps. We are so lucky Hopinso is back she has so many wonderful cures.