A Critical Assessment of the Clinical Efficacy and Cellular Response to Low Intensity Pulsed Ultrasound for Fracture Repair

Abstract

Fracture repair continues to be widely investigated, both within the clinical realm and at the fundamental research level. Clinical application of low intensity pulsed ultrasound (LIPUS) has shown great promise as an effective, minimally invasive treatment for accelerating fracture repair and has warranted further investigation into the cellular manifestation of applied ultrasound. Toward this end much has been learned about the response of osteoblasts to LIPUS stimulation. In vitro and in vivo evaluation of cellular response to LIPUS have revealed an increase in proliferation, protein synthesis, collagen synthesis, membrane permeability, integrin expression, and increased cytosolic calcium, to name a few, further clarifying its utility and overall impact on cellular behavior. Considerable effects of LIPUS on the cells of musculoskeletal soft tissue have been reported as well. The growing body of research in this area suggests that LIPUS may be a powerful tool in the development of novel approaches to musculoskeletal repair and regeneration. Regenerative engineering-based approaches to musculoskeletal healing and regeneration that incorporate polymeric scaffolds and stem cells may be combined with LIPUS to move beyond bone repair to large scale multicomponent tissue repair.