PBMT (photobiomodulation) will have no effect on implants that are compliant with current medical regulations as Curavi has passed all current requirements for EMC/EMF per IEC 60601-1-2. If you have a metal plate in your body, depending on the placement and thickness (the metal plate will block the light), the PBMT device should still be effective.
Joint replacements are placed deep under the dermal layer, and should not affect operation of the pain management device. The CuraviTM pain management belt will not mitigate disease or heal/cure any injury – its purpose is to target inflammatory tissue and rejuvenate cells to mitigate pain. It is most effective for chronic pain when used routinely and on a schedule (e.g., every morning, evening, etc., regardless if pain is present).