Toes Are Numb On Both Feet, The Right Knee Is

Toes are numb on both feet, the right knee is numb, temperature on right knee is way colder than the left knee, can't stand very long due to pain in the right knee. Had x-rays done on right hip, it is in rough shape, had total left hip replacement done in Oct of 2010. Have had MRI's done on the brain, neck, middle back and lower back. The back surgeon doesn't think back surgery will do anything.