What are the top causes of osteoarthritis?

Osteoarthritis is the loss of the cartilage on the end of the bone. It's not the accumulation of debris necessarily, although that can be a secondary thing, but it's the loss of the smooth surface on the end of the bone. Well, that's again a loaded question in that regards because we really don't know (who is at risk for developing osteoarthritis). People who have a genetic predisposition, maybe a family history. People that are overweight. People that overuse and are overweight, so it's kind of a combination of multifactorial things. People that have had a prior injury to their knee, whether it be an ACL injury in high school.