Clinical Experience With the Use of Low-Intensity Pulsed Ultrasound (LIPUS) in the Treatment of Atypical Femoral Fractures.

OBJECTIVE: The aim of this study was to report the clinical results of atypical femoral fractures (AFFs) treated with low-intensity pulsed ultrasound (LIPUS).

MATERIALS AND METHODS: The data on AFFs that were surgically treated in our hospital from 2010 to 2016 was retrospectively analyzed. AFF was diagnosed based on the criteria defined by the second report of an ASBMR task force.

RESULTS: Seven fractures in 6 cases were included in this study. Two fractures were referred to us as being nonunion. Five fractures were subtrochanteric fractures and 2 fractures were shaft fractures. Five fresh AFFs were fixed with an intramedullary nail and 2 nonunion fractures were fixed with plates. LIPUS was used in 6 fractures. Bone union was achieved in 5 fractures with the average time to union being 17 months (5-29). In 4 out of the 6 fractures treated with LIPUS, bone union was achieved after 14 months on average. In the other 2 LIPUS-treated fractures, bone union was not achieved even at 1 year after surgery.

DISCUSSION: It is known that AFF healing tends to be very slow. Some case reports indicate that AFF healing might be accelerated by LIPUS. In the current series, the subtrochanteric fracture that was not treated with LIPUS healed at 29 months after surgery, which was much longer than the average time to union in the 5 fractures that were treated with LIPUS. Although our number of cases is small, LIPUS may be a potentially useful tool for accelerating AFF repair.