Amxfred, I hope your surgery went well. I was involved in many sports in the past....Football 12 yrs, softball 42yrs, tennis 51 yrs, etc......most of it in Illinois. Well eventually I got a metal knee. Have it for 16 yrs now...no problems. The best thing is that when I'm around some of my grandkids, I "detect" their knees -- no sound, then I detect my knee -- BEEP, BEEP! They really enjoy that but really don't understand 'a metal knee'.