Why?-pain and lack of mobility.
Good for 15-25 years. How quick do I heal?- as soon as you get out of bed (the next morning you need to be on a chair and possibly walkiing a bit). Your physcial therapy is important, is all you. If you are not proactive then you'll have problem. It takes about a year to completely feel comforatable with the new joint. The first 3 months are critical. Up up.