Good morning thank you Dr. I'm 45 years old. Two years ago I suffered from bad Sciatica and thank goodness I have been painlessly mobile since last July 2013, however now, for the past 3-4 weeks my knee from the same leg sporadically swells up for no reason at all, and although it doesn't work, it is uncomfortable when it cracks a few hours before it swells and of course during the swelled period, its hard to walk on it. I know it can be many things but I'd like to narrow down the possibilities of what it might be causing it. thank you