Is low-intensity pulsed ultrasound effective for revitalizing a severely necrotic small bone? An experimental rabbit model.

Previously, we successfully applied a new method composed of drilling, bone marrow transplantation (BMT), external fixation and low-intensity pulsed ultrasound (LIPUS) for the clinical treatment of Kienböck's disease. The purpose of this study was to investigate whether bone regeneration can be induced by LIPUS and/or multiple drilling and/or BMT within a severely necrotic small-bone rabbit model. Eighteen rabbits were divided into three groups (BMT, drilling and control) and LIPUS stimulation was introduced daily for 8 weeks post-transplantation. Next, 12 additional rabbits were produced for the BMT group and LIPUS stimulation was introduced daily for 4 and 12 weeks (n = 6 for each). Histopathologically, new bone formations were rarely observed in the drilling and control groups. In the BMT group, the mineralizing surface areas of LIPUS(+) showed a significant increase compared with LIPUS(-) for 8 weeks. LIPUS treatment alone did not accelerate the revitalization of necrotic bones. However, LIPUS combined with BMT tended to promote new bone formation.