Outline · [ Standard ] · Linear+ Does Ultrasound effect metal implants?, ultrasound over metal

[jweb]

I believe Michelle Cameron's text "Physical Agents in Rehabilitation" will have some information on this. I don't have any actual journal references for you but perhaps that text cites some...

j

[moni]

Ultrasound should always be used with precaution. There are different opinions around that. It's said that Therapeutic ultrasound can be used over metal implants with precaution. However a person should consider the contraindication where sensible areas such as eye, pregnancy, brain, heart are exposed to ultrasound. Just my two cents.

[honey86]

I can not find research on the effect of ultrasound over metal implants.some say "NO!" Some say ultrasound will not heat up the metal. I need documentation.
Clark

[AussiePhysio]

The basic physiology of therapeutic ultrasound tells you that the sound energy will be completely reflected (instead of absorbed) by a metalic surface. So the soft tissues near the metal will get a double dose of the ultrasound energy as it passes through the tissue the first time, and then again on its way back from around the metal.

So NO the metal doesn't heat up, but YES the soft tissues around the metal can be burned and permanantly damaged around the metal. remember that your thermal receptors are generally in the skin so patients don't percieve the heat internally until it reaches the point of tissue breakdown or the increase temperature reaches the skin (and the damage is done).

however - dosage of US energy is important to consider: pulsed / continuous? intesnsity?, frequency? it's possible to use us around metal carefully and not burn tissue- but do you really need to and is it worth the risk? And if one doesn't understand the phyisiology and rationale behind the use of US then i would advise against it's use.

diagnositc ultrasound (RTUS) uses a much lower intensity of energy and would not generally have as pronounced a heating effect though it would give you lots of artefact on the image. I assume you meant therapeutic us though.

maybe a better question is why are physios still using a modality that has such poor evidence base behind it?
We have so many better options.

U/S is not how i would want my physio to spend my time with me!
Cheers,
PK