You got the good screws and plates, probably titanium. Good for you.

Implants may alarm the WTMD where they would not cause an anomaly on the AIT.

The AITs (Backscatter or millimeter wave) will not cause harm to you or your implants.

Persons with hip replacements, pacemakers and such have actually sought out the AIT because if there isn't an anomaly, there isn't the need for a pat-down as there would be with a WTMD.

This doesn't mean someone will absolutely be exempt from a pat-down but the chances are greatly decreased as it would with a WTMD, which would be 100% if they normally alarm.