Use of Pulsed Shortwave Diathermy and Joint Mobilization to Increase Ankle Range of Motion in the Presence of Surgical Implanted Metal: A Case Series

Abstract

STUDY DESIGN: Case series. BACKGROUND: Traditionally, all forms of diathermy have been contraindicated over metal implants. There is a lack of research-based evidence for harm regarding the use of pulsed shortwave diathermy (PSWD) over orthopedic metal implants. Because PSWD is an effective modality for deep heating, we investigated whether ankle range of motion (ROM) could improve with the cautious use of PSWD and joint mobilizations, despite orthopedic metal implants being in the treatment field. CASE DESCRIPTIONS: Four subjects presented with decreased ankle ROM due to extensive fractures from traumatic injuries. All subjects were postsurgical, with several internal fixation devices. Subjects previously received rehabilitation therapy involving joint mobilizations, therapeutic exercises, moist heat, and ice, but continued to lack 15 degrees to 23 degrees of ankle dorsiflexion. The Human Subjects Review Board of Brigham Young University approved the methods of this case series. Subjects gave written informed consent. Initial dorsiflexion active ROM for each patient was -3 degrees, 0 degrees, 8 degrees, and 5 degrees, respectively. Treatment regime consisted of PSWD to the ankle for 20 minutes at 27.12 MHz, 800 pps, 400 microseconds (48 W). Immediately after PSWD, mobilizations were administered to the joints of the ankle and foot. Ice was applied posttreatment. OUTCOMES: Dorsiflexion improved 15 degrees, 15 degrees, 10 degrees, and 14 degrees, respectively, after 8 or 13 visits. All patients returned to normal activities with functional ROM in all planes. Follow-up 4 to 6 weeks later indicated that the subjects maintained 78% to 100% of their dorsiflexion. No discomfort, pain, or burning was reported during or after treatment. No negative effects were reported during the short-term follow-up. DISCUSSION: When applied with appropriate caution, we propose PSWD (48 W) may be an appropriate adjunct to joint mobilizations to increase ROM in peripheral joints, despite implanted metal. We continue to advise caution when applying diathermy with machines other than the Megapulse II. Further research is needed to determine the safety parameters of other diathermy machines. As a final caution, we advise that diathermy not be used in the presence of a cardiac pacemaker or neurostimulator.