Critically Appraised Topic
A female patient in her mid 80s was admitted to a skilled nursing facility due to a non-displaced acetabular fracture following a fall. She was referred to physical therapy to address her functional mobility deficits but was having difficulty participating in therapy due to increased left knee pain caused by osteoarthritis (OA). Diathermy is used throughout the skilled nursing facility, and it was suggested by the occupational therapist that I could use this modality to reduce our patient’s knee pain so she could better participate in therapy.
Is diathermy effective for reducing pain for a patient with knee osteoarthritis?
Clinical Bottom Line
There was conflicting evidence between the two articles analyzed. Fukada et al. revealed that PSWD used alone, especially low dose as compared to high dose, is effective for reducing pain in older adult patients with knee osteoarthritis compared to sham PSWD. A number needed to treat (NNT) of 2-3 was determined for PSWD to result in one additional person meeting the MCID for pain compared to the control or placebo groups. Atamaz et al. did not find a significant difference in pain scores between the SWD plus exercise group and a sham SWD plus exercise group. Both groups made statistically significant and clinically meaningful changes in pain. Because both groups received exercise, it is unknown if similar gains may be made with exercise alone, or if the sham SWD had a placebo effect. A comparison group that received exercise only would be needed to make this determination. They did, however, find a significant decrease in the amount of pain medication used in the SWD group compared to the sham group, which may suggest that diathermy is effective for decreasing pain. Both studies had strong internal validity, and good methodological quality, but the results should be cautiously applied to larger populations due to strict inclusion and exclusion criteria. Areas for further research include a study directly comparing an exercise control group, a placebo/sham group and a diathermy treatment group to truly assess if diathermy is more effective than activity and exercise for reducing pain caused by knee osteoarthritis.
Charbonneau, Laurel, "The efficacy of short wave diathermy in decreasing knee pain in female patients with knee osteoarthritis" (2014). PT Critically Appraised Topics. 41.