Horses for courses of course, but I went through a long bad patch with my knees many years ago, back in my 50s and 60s. Sharp needle pains, especially on stairs, until out of curiosity and with no other immediate avenue forwards I started taking glucosamine and chondroitin pills manufactured by various different companies. Not cheap, and not really expecting much, but to my own surprise they worked! Now I take occasionally, whenever I feel twinges approaching again.