The application of laser therapy to sites containing surgical implants is perfectly safe. These implants will not heat up or be affected in any negative way when the treatment is carried out appropriately. Laser therapy is used to decrease postoperative pain while enabling the patient to experience a shorter convalescence period before returning to function.
Let’s consider what happens with tissue sites that have metal hardware. The laser light will be reflected from the implant and sent back through the tissues. Thus, if a bone surface has a metal implant over it, the tissues between the surface of the implant and the surface of the tissues will be exposed to more photons than the rest of the target site. To account for this, the laser operator simply needs to 1) increase their scanning speed when they are treating over an implant overlaying a bone and 2) treat 360° around the limb to ensure light penetrates to underlying fracture lines or osteotomy sites.
Target sites with cerclage wire and IM pins can certainly be treated as well. Because cerclage wire will cause minimal reflection, there is no need to increase scanning speed with these sites. The same is true for IM pins since they are located inside the bone itself, not on its surface.
Regardless of the specific case, the laser operator will constantly monitor the patient for any signs of discomfort and may possibly adjust the power settings down and/or increase scanning speed accordingly, as some very superficial implants (or very small patients with little soft tissue overlying the implant) may be uncomfortable.
The conscientious laser operator will be mindful when treating any patient with surgical implants, as these sites often develop arthritic changes as time goes on. In this manner, the presence of surgical implants actually predisposes patients for laser therapy in their later years.