Hi Vix! Glad you popped in. Sorry to hear of your knee! I too am having knee problems and I know it's all due to the weight. I am trying to suck it up till I've been banded and at least get to the 150's to do something about it.
Can you exercise without doing the lower body? As in, get some 3-5lb weights, sit on a chair and lift them? Anything?
Anyways, good luck and keep in touch with us.