Potential Femoral Head Osteonecrosis Model Induced by High-Intensity Focused Ultrasound

Focal Bone Lesions Following Ultrasound Diathermy: Case Series

“…However, at very high energy levels, high-intensity focused ultrasound can induce bone osteonecrosis, by osteocyte damage and vascular thrombosis, with a direct relationship existing between ultrasound exposure duration, tissue temperature and bone damage for temperatures above 43°C. 11 Other than the patients presented here and the one previous report, 9 low-intensity ultrasound diathermy has not been recognised to cause bone changes. While the superficial location of the affected bone areas would have increased susceptibility to any ultrasound beam, the effect of specific technical parameters such as ultrasound duration, mode (continuous, long or short pulsed), beam intensity, and frequency is not known as these were not investigated in this study.…”

“…10 It has been found that if the osteonecrotic area is large, vascular compromise will limit repair to a degree that appreciable healing will not occur. 11 However, if the osteonecrotic area is small, the initial vascular compromise can be circumvented, provided the initial insult is discontinued, enabling small areas of osteonecrosis to heal over time with revascularisation and bone repair. 12 Such a healing response was apparent in the one case presented that underwent follow-up MRI and in three (38%) of the eight patients reported by Yeh et al 9 Therapeutic ultrasound can be low or high intensity.…”