I wrenched my knee about a year ago. It was sudden and acute. I knew within minutes that I had injured it.

I too was frustrated that the Drs kept focusing on the arthritic aspects of my knees rather than the acute injury (I'm a 65 year old male). Fortunately the physical therapist that I worked with simply focused on making things better and, sure enough, things got better.

My knee injury came on the heals of a back injury so I decided to just forget backpacking for a year and build myself up. That's all behind me now and I'm good to go. You will be too but I don't have enough experience to guess when.