Experience of an isolated use of low-intensity pulsed ultrasound therapy on fracture healing in established non-unions: a prospective case series.

Fracture non-unions are responsible for approximately 5% of cases, with low expectation of spontaneous healing thereafter. The fractures that heal without complications can take months to heal completely. An ultrasound, typically at low intensities (0.5-50 mW/cm2), serves a diagnostic purpose, whereas at higher intensities (0.2-100 W/cm2), its role becomes more therapeutic by generating heat energy. Low-intensity pulsed ultrasound (LIPUS) is frequently used to stimulate or to accelerate fracture healing. We present a prospective review of fracture non-unions treated with low-intensity pulsed ultrasound (LIPUS). We enrolled 66 patients during August 2016 and December 2018, 38 males and 28 females; age range 19-85 years (average 49.2 years). All these patients were followed up to minimum 6 months. The average time of referral post-treatment for fractures was 8.2 months (range 6-18 months). Four patients were excluded due to various reasons. 39 out of 62 fractures showed successful healing with symptom improvement and callus formation with 67% success rate. In this case series, we noted LIPUS therapy failure in the post-ORIF scaphoid fracture and post-ankle joint fusion non-union. We did not observe any influence of a medical condition such as diabetes mellitus, osteoporosis or personal habits like smoking. The LIPUS therapy appears to have influence on bone healing, depending on the onset of therapy, fracture type and the approach to fracture care. In this case series, the compliant group showed 67% successful outcome.