Hi quickster,
Thank you for posting your question.
Our BFST products are safe to use whenever there are medical pins or plates present. You shouldn't have any concerns when treating your knee. The BFST uses energy that only works on soft tissue, in your case this would be the soft tissues in and around your pin(s). This will speed the recovery by promoting blood flow to your knee.
If you would like to speak to us about this matter further, please feel free to contact us toll free 7 days per week.
Regards,
Stew