For continuous ultrasound in wound healing, a frequency around 1 to 1.5 MHz for about 5 minutes daily is associated with which outcome?

• A. Increased breaking strength of incision
• B. Decreased wound tensile strength
• C. Delayed epithelialization
• D. Infection risk

Answer: (A)

Continuous therapeutic ultrasound applied to wounds can stimulate healing by increasing tissue heating, which boosts cellular activity involved in repair. Using a frequency around 1 to 1.5 MHz targets the tissue depth relevant for skin and subcutaneous layers, and applying it in continuous mode for about 5 minutes daily creates a thermal effect that enhances collagen synthesis and fibroblast activity. As collagen is laid down and reorganized, the wound gains tensile strength, resulting in an increased breaking strength of the incision. This is the outcome most aligned with those parameters.

Decreased wound tensile strength, delayed epithelialization, and higher infection risk don’t fit this effect profile; properly applied continuous ultrasound tends to promote healing and strength, rather than impairing it or increasing infection risk.