Osteoarthritis Risk May be in Your Genes

In the news todaysteoarthritis Risk May be in Your GenesI have oa of both knees. I hav had Fulkersons osteotomy done to both. I am only 30yrs old. how long before total knee replacement will be needed? I am adopted so don't know anythink about family history (parents) little contact with brothers and sisters. Should I notiffy them of this? Please let me know