A few years ago Zoee was diagnosed with a "possible" torn ACL. I found a site that told about recovery without surgery. With the help of my amazing mother, Zoee went on basically no activity for a few months. Then she began to take slow walks a couple of times each day. Along with some water therapy (my mom has a pool and Zoee loves to swim). Eventually she was allowed to be more active with close supervision.
Zoee spent the entire year of 2012 at my moms house. She'd have good days where she wouldn't limp at all then she'd have bad days. We brought her home this last Xmas and I thought we had wasted a year with her at my moms because she was still limping pretty bad again. Then for about a week she was actually having a hard time getting up and was limping on BOTH back legs. I upped her cosequin tablets to two a day and now she hardly ever limps!
At our last vet visit the vet said she was too skinny. I told her about her leg and how well she's doing on it now and the vet said maybe the weight loss has also helped. So she is fine with the weight but we don't want her to lose anymore.
Zoee is 8 1/2 years old, but she is back to playing and sounding like she's tearing her brother apart in the backyard. We still have days where she limps a little. But nothing like it was. She used to sometimes not even use the leg at all.

So, it is possible, but does take time, patience and consistency.

Here is the site we used for info and ideas: http://tiggerpoz.com/