I Am Having A Total Knee Replacement On October 10.

I am having a total knee replacement on October 10. I have had a Bakers Cyst in this knee, which has been aspirated 3 times, and most recently filled again quickly with bits of cartilage and coagulated blood as well as the fluid. My surgeon is aware of this and hesitates to confirm that the knee replacement will take care of the cyst. What risks do I have and what questions should I ask him before going into surgery?