I'm Trying To Figure Out Which Set Cell Theory Is

I'm trying to figure out which set cell theory is right for me, Adult meaning my own from adipose, or umbilical? I have 2 painful knees, and 2 very arthritic thumbs due to osteoarthritis. I was a NY Firefighter or 26 years and always been an athlete. I have had to stop running due to my knees even though I still swim and cycle. I'm 65 and I don't want to stop and want to run again.