2 years, 4 months post op: I finally got up the nerve to run on my knee on the treadmill. I finally felt like my knee was ready for it. I am taking it easy, walking for a few minutes and running for a few minutes (at a slow pace). My knee is doing great! I have NO pain when running and I ran almost a mile yesterday. I have just a little pain when I get off the treadmill, but I am able to walk it off within a few minutes. I am so excited to be able to run again! I'm not sure how far I will push it in regards to running because I have little lesions on my non-ACI knee that I want to be cautious about. I must say that even at 2 years out I am still seeing improvements in my knee. I now find myself running up and down stairs, skipping steps, without even giving a thought to the knee. The knee is not perfect and I doubt that it will ever be perfect but I am willing to accept a little bit of pain here and there. I had an incident a couple of months ago where I aggravated it but a little celebrex calmed it down and it has been great ever since. The farther out I am from the operation, the happier I am that I went through with it. I really doubted that I would continue to see improvements beyond 1 year, let alone 2 years but yet I'm still seeing improvements. All the pain and hard work of rehab was worth it.