Had the scope to the right knee six years ago, early 40s. Doc said he even had to scrape some of the femur (but overall, not a big job). He said he was in there 12 minutes.
Rehab will help immensely, but don't overdo the comeback too soon. Mine feels better each year, it seems. I attribute that to the Michael Jordan low-mileage theory. Doc told me road running was definitely out so now it's treadmills, ellipticals, exer bikes -- and (doc-recommended) glucosamin chondroitin.