Hi and welcome to HCM.
Heat and ice can help but not too much if there is no swelling in this area. It sounds like knee arhritis which can be caused by trauma but also by degenerative disease or gout
. Few things can be done. First is periodically steroid
injections into knee.it can be helpful for some time. Secood is, arthroscopic so called "cleaning" but it isnt done in every institution. Ask your doctors about it. YOu should exercise when have no pain,wjen painful you should rest and keep leg elevated. WIsh you good health.