Update -
It has been about two and a half years since my Patellofemoral PKR. The recovery really exceeded my expectation. While my surgical knee still has some limitations, I have no problems at all in biking, skiing, hiking and rock climbing. From mid-July to early Oct, I rode my fully loaded touring bike across the country, from Seattle to Astoria, OR, then to Yorktown, VA, totaling 4570 miles, without walking the bike a single step. The surgical knee held up extremely well and was oftentimes the stronger knee. (My other knee started to have the early symptoms of the surgical knee before the surgery so I am not sure how long it can last.)