I am afraid David, I know little about a artifical knee. What I can say is that I torn my knee up bad falling like 10 feet to the ground off of a deck in construction. I had a torn meniscus ( spelling??), as well as a broken knee cap etc. I was 25. When I was 35, they had to repair this maniscus( sp?) eventhough I had not fallen etc, and didnt think I had reinjured myself. The sighs were locking knee, cramping in the knee when driving, and it would not bend..
I am not sure if any of this applies, but I feel for anyone with a knee injury..