No Patella.

Hi everyone, about 23 years ago I had my Patella smashed through a sporting injury, This resulted in first having half of my Patella removed and then the rest when that wasn't successful, thereafter I had further surgery to repair a torn Quad muscle which was torn shortly after I had the previous surgery to remove the the other half of my Patella. Since then my knee joint has been unstable with me having to wear supports to add some stability, just recently though this instability as become more common resulting in me having a bad fall and injurying an ongoing neck problem. Now what I would like to know is would I be better off insisting on a knee replacement to give me more stability, I am 47 years of age, and the Doctors always seem to say I'm too young, is this still the case or would I benefit fron a knee replacement.