"In need of surgery "

I am trying to find out when my surgery will be. Two years ago I was turning fifty and taking off the list? I was turned down because I had a slightly low iron count! Last November I was referred again by my doctor. I was told that I needed knee replacement and given a time off eight months to a year. Now after making an inquiry I have been told 15months to 18 months? Is this from last November or from today’s date? I wish that they would keep me updated. Now I can’t walk. These delays are horrendous.