Numbness in both feet with a look of marbilizing on lt foot

I was wondering if anybody who has Avascular necrosis in there leg's are having problems with there feet. I've had my left hip replaced on Sept 8,2011 but even before that both of my feet are numb (Really numb) with an explanation from my ortho that it's part of the disease process. My left foot looks like a ground beef (seriously) I do not have diabetes and have had many tests to rule that out. but when you look at my left foot it just looks bad I've had 2 ultrasound tests on my legs. No blood clots. I was put on a 2 week regiment of injectable blood thinners at home with no relief. It's been 5-months since they replaced my left hip and it feels like the ceramic implant is moving around when walking for 20 min's or more or going up my stairs/ My leg also becomes slightly swollen after walking. you could push in with your finger and the indentation stays for a short time.. Or Pitting from my knee down.. I do have good pulses in both feet but they are just numb and also burn.. Any help would be appreciated..Randy