I actually like it from a story PoV that Kara didn't just magically get fixed by a few days in sickbay, our girl might have achieved the impossible and flown an enemy ship home after everyone thought she was dead, but she broke her knee too.

I think she just REALLY dislikes feeling helpless, and being stuck in a hospital bed is pretty helpless in every way (though I love the Galactica sickbay and Doc Cottle).