Right knee, ACL surgery. They used part of my Patella Tendon. That was in 2002. It's been my stronger knee ever since. Recovery took a few months. Had it back to athletic shape within the year, but I took it easy, not wanting to risk re-injury. I have played BBall and Soccer since the surgery, but not wanting to hurt my other knee, I have stopped with those sports.
Hiking the hills is good enough for me.
"Therefore, wo be unto him that is at ease in Zion!" 2 Ne. 28: 24