Hi Natalie
I had a small one removed (it was just sucked out apparently! ) during knee arthroscopy last summer, surgeon also repaired both cartilages and debrided the knee. If it's just the cyst I think it's usually done through the back of the knee as this has the best access and requires only a few stitches.
You will be fine, it is a very minor op and after affect effects should be minimal. You will be up and about straight away. Good luck

Lyn x