So sorry to hear you have been suffering for over 2 years. My foot as well was numb and tingling after my right TKR. I keep going to different doctors until I found someone who cared and she ordered an ABI Test. It measures the pressure in your legs. When they found the pressure was .4 on my right and 1.26 on my left, I was sent to a cardiologist who ordered an angiogram which showed the popliteal artery behind by knee was totally blocked. The knee surgeon had pinched it during my TKR. I had yet another dangerous surgery where a vascular surgeon cut open the back of my knee and opened the artery. I got 1/2 the numbness and tingling gone right away and my toes were not purple and my foot was not cold. If I would of listened to my knee surgeon who kept saying give it a year or too, I would of lost my leg from my knee down. As it is I probably have cell and tissue damage to my foot from not having any blood flow for 60 days. I may or may not get full feeling back. I am taking gabapentin for the pain in my foot.
The ABI test is a simple test done by ultrasound. I wish you the best!