The Effects of Low-Intensity Pulsed Ultrasound Upon Diabetic Fracture Healing

In the United States, over 17 million people are diagnosed with type 1 diabetes mellitus (DM) with its inherent morbidity of delayed bone healing and nonunion. Recent studies demonstrate the utility of pulsed low-intensity ultrasound (LIPUS) to facilitate fracture healing. The current study evaluated the effects of daily application of LIPUS on mid-diaphyseal femoral fracture growth factor expression, cartilage formation, and neovascularization in DM and non-DM BB Wistar rats. Polymerase chain reaction (PCR) and ELISA assays were used to measure and quantify growth factor expression. Histomorphometry assessed cartilage formation while immunohistochemical staining for PECAM evaluated neovascularization at the fracture site. In accordance with previous studies, LIPUS was shown to increase growth factor expression and cartilage formation. Our study also demonstrated an increase in fracture callus neovascularization with the addition of LIPUS. The DM group showed impaired growth factor expression, cartilage formation, and neovascularization. However, the addition of LIPUS significantly increased all parameters so that the DM group resembled that of the non-DM group. These findings suggest a potential role of LIPUS as an adjunct for DM fracture treatment. (C) 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29: 181-188, 2011