I just had screws placed in my ankles after surgery. will it set off the metal detector at the airport?

Unlikely...: That you will set off the metal detectors. My group did the largest study on this and found that no implants set off the gate type detectors, but depending on the size of the hardware they could be detected in some cases by wand-type detectors. The reference is: bluman et al(2006): detectability of commonly used foot and ankle implants by security screening devices. Foot ankle int 26:1096-1102.