Multiple members of my family have need to have full knee and/or hip replacements in their 60's. These surgeries have had significant impacts on their mobility and therefore quality of life as they get older. Personally, I had 2 surgeons (each of which had performed an ACL replacement on me) tell me I was likely going to need a knee replacement in my early 40's due to the condition of my cartilage, not from injury, but from regular wear and tear. Is there any research around why certain people are prone to cartilage depletion and/or osteoarthritis earlier in life than others? Are there any preventative steps that can be taken to mitigate these risks?