What is ultrasound?:
Ultrasound is a sound in a frequency of a range that humans cannot hear. The sound waves are produced by a machine, and applied through a probe to the skin surface. Ultrasound is used for many medical applications including imaging (often used to image pregnancies), therapeutic (deep tissue heating), and treatment (as is the case with fracture healing).
How is ultrasound used to heal bone?:
Ultrasound has several effects of healing bone that may alter the rate at which fractures unite. Ultrasound causes effects ranging from small temperature changes is the tissue to increased gene expression. It is not known which effect of ultrasound on cells alters the healing process.
Does ultrasound make bone heal faster?:
There is good scientific evidence showing that certain fractures, specifically nonunions, can show faster healing with the use of ultrasound. There is also evidence that these devices can help in patients who have poor healing potential including diabetics, smokers, and patients taking oral steroid medications.
Ultrasound has been shown to have beneficial effects in fracture healing, but is probably only useful in situations where healing potential is limited.
Nelson, FR, et al. "Use of Physical Forces in Bone Healing" J. Am. Acad. Ortho. Surg., September/October 2003; 11: 344 - 354.