LOWER LIMBEffect of Low-Intensity Ultrasound Stimulation on Consolidation of the Regenerate Zone in a Rat Model of Distraction OsteogenesisEberson, Craig P. M.D.*; Hogan, Kathleen A. M.D.†; Moore, Douglas C. M.S.†; Ehrlich, Michael G. M.D.*Author Information Study conducted at Brown University School of Medicine/Rhode Island Hospital, Providence, Rhode Island, U.S.A. From the *Department of Orthopaedics and the †Orthopaedic Research Laboratories, Department of Orthopaedics, Brown Medical School/Rhode Island Hospital, Providence, Rhode Island, U.S.A. Address correspondence and reprint requests to Craig P. Eberson, M.D., University Orthopedics, 2 Dudley Street, Suite 200 Providence, RI 02905, U.S.A. (e-mail: [email protected]). Funded by the RIH Orthopaedic Foundation and University Orthopedics. None of the authors received financial support for this study. Journal of Pediatric Orthopaedics: January 2003 - Volume 23 - Issue 1 - p 46-51 Buy Abstract This study was performed to explore the tissue-level changes in mineralization caused by low-intensity ultrasound stimulation after distraction osteogenesis. Unilateral femoral lengthenings (7 mm) were performed on 34 male Sprague-Dawley rats. Half of the animals received daily ultrasound stimulation for 5 weeks; the remaining animals received sham treatments. Healing was assessed with serial radiographs, quantitative micro-computed tomography, and biomechanical testing. Twenty-one animals were evaluated at the conclusion of the study (9 experimental, 12 control). Radiographically, healing of the ultrasound-treated bones preceded that of the sham-treated bones by approximately 1 week. Bone volume fraction and trabecular bone pattern factor were significantly higher in the ultrasound-treated animals, but there were no significant differences in bone mineral content or bone mineral density. The ultrasound-treated femurs were 20% stiffer and 33% stronger than the control femurs, but the differences were not statistically significant. These findings suggest that pulsed, low-intensity ultrasound matures the regenerate by altering the microarchitecture of the newly formed bone. © 2003 Lippincott Williams & Wilkins, Inc.