Well, with knee problems myself and being mid-30s I can tell you so much a person does can affect them starting when I was about 28. From shoe squishiness, to walking up house stairs with a normal gait throughout the day, to how much massage/PT you do on your knees and IT band. Most don't know (except PT guys), but the IT band acts as a spring, so it can get hella tight and put pressure on your knee. (Surprisingly, well formed squats and biking in moderation with knee braces on strengthen them up quite a bit.) If you can dig into it and the muscles surrounding the knee including where the IT inserts into your hip, it can totally rehab sh*te knees. Hurts like hell though. Any massage will help rehab, I did it on my hands too with some cheapo clamp I got from the store wrapped in tape that completely changed them after 1-2 months. So maybe CR has better massage/PT practice. I wouldn't compare anything they did before 19-25 or 30 because stem cells and such still hanging around in the body ready to grow back tissue that doesnt grow back in the later years.
Edit: oops thought you said CR played basketball. Yeah basketball can be hell on the knees.