Harvey,
Sounds kind of odd to come on that quickly, arthritis is usually a slow and progressive thing that accumulates over several years, at least that's my case. I have considerable arthritis in my neck and back, and first thing in the morning I feel like somebody poured concrete around my spine. A hot shower gets me loosened up and as I move around during the morning I get better. Sitting in one place for very long or standing for long periods gets that concrete setting up again. Pretty much everybody gets at least a little arthritis as we grow older because our joints degenerate as the cartilidge wears out from use and age. Some get it faster or worse than others for various or no good reasons. I'm no arthritis expert, but osteoarthritis is the kind of arthritis I'm describing here. Rheumatoid arthritis is the real crippling kind that deforms joints and bones, and I believe is thought to be an immune system deficiency. My mom has had it since she was in her late 20's and has suffered terribly through countless operations and procedures. The doctors told her that arthritis is not hereditary, but tends to run in families. What the ??
It could be in your case that you had some arthritis prior to your operation that nobody mentioned because they just assumed you had already known about it. Hey, you are an old guy you know (you being 46 and me being only 45 for 7 more days at least). I would highly doubt that it was something that came on suddenly, that would be about as likely as me winning a gold medal in the olympics.

Keith