When I was 18 years old, I dislocated my left knee. I have since accidently bumped it, accidently fallen on?

it, accidently smashed it into a metal pole. When I had first dislocated it at 18, I had gone to the doctor to have water taken out of it twice. It don't know if my patella is misaligned now or not. To the left of my knee my leg has been swollen for quite awhile now. I don't know what this is. My knee for the most part is functional. I can walk, Thank God. I just wanted to ask, how do I know if my patella is misaligned or not? And what could that swelling be? Could it just be muscle and tendon that is misplaced, because my right knee has never been injured and it isn't swollen-looking on the outside of it like my left knee is. My right knee looks fine, but they don't look alike. Is there anyway to have this swelling go away or removed, so that both knees look alike?