I've been making saw dust in a serious manner for 30 years and have been playing at it since high school in 1958.   
Well I let my guard down this afternoon for just a mili-second and believe me, that's all it takes.  I know exactly how I did it, it was stupid - just dumb a$$ STUPID  -     
Fortunately, it'll just require reconstructive surgery, an out patient thing I'm told, but none the less, I'll be NOT riding the bike for a week or so - maybe longer.   
I just knicked the bone but obliterated the tendon  - the Dr. said that can be fixed.  That's a good thing, the down side is I don't know how involved it will be.   
BTW - I was working on furniture for a show this fall.