You could look up the details, but a couple of little known guys (Peter Sagan, Julian Alaphillipe, Tyler Phinney, et al) have successfully raced after knee surgery.
FWIW, I absolutely would not rely on strangers on a bike forum, and I wouldn't depend on a doctor who doesn't understand the difference between crit racing and a coffee ride. At the very least, get a second opinion from a doctor who does sports medicine and understands both the demands you put on your knee and the level at which you're racing.
Good luck!
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Formerly fastest rider in the grupetto, currently slowest guy in the peloton
