Thank you for your question. It seems that she has got a meniscus tear (knee) along with muscle injury as ligaments become loose with use and are prone to tear. If it is from many years her recovery may be a slow process. You can try with hot fomentation (warm cotton cloth application) on affected area and consult an orthopedic for arthroscopy. He can examine her in person and prescribe proper pain-reliever with muscle-relaxants, if required. Hope this helps.
I think she was feeling a pinched nerve type sensation. When the nerves get irritated, they'll tend to tingle and feel numb...with RLS people, it's a neuromuscular problem, you can see the muscle fibers ripple when it gets bad and the nerves are misfiring all over the place, and some describe it as ants crawling on their legs, so that's what I think was going on. It's just the way she's wired. But maybe when they do the operation on her knee, could be they'll straighten out anything they see that is abnormal in her knee, and with some luck, she won't feel that anymore. But I do think it was a nerve sensation she was feeling all those years, and by popping the joint, it released the nerve that was firing off sensations going nowhere.