I had my right tkr on December 11, 2012 and it went fantastic. I am pain free and able to use that knee freely. My left knee is really arthritic but hasn't been hurting very bad until February. I went to my os who gave me a cortisone injection and it felt really good up until a week ago. Now I'm in severe pain and limping when I walk. I'm unable to stand from a sitting position without it hurting and my sleep is disrupted due to pain. I have an appointment with my os next week and am wondering if I should get another cortisone injection or schedule a tkr. I'm an elementary principal and on my feet a great deal. With summer coming it probably would be a good time to get a tkr because i wouldnt miss work, but I'm unsure. What do you think I should do?