Effect of low-intensity ultrasound stimulation on consolidation of the regenerate zone in a rat model of distraction osteogenesis.
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.
Eberson
Craig P
CP
Brown University School of Medicine/Rhode Island Hospital, Providence, Rhode Island, USA. ceberson@lifespan.org
Hogan
Kathleen A
KA
Moore
Douglas C
DC
Ehrlich
Michael G
MG
D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density / Q000502:physiology; D001861:Bone Regeneration / Q000502:physiology*; D001842:Bone and Bones / Q000648:ultrastructure*; D008297:Male; D023421:Models, Animal; D019857:Osteogenesis, Distraction / Q000379:methods* / Q000534:rehabilitation*; D011184:Postoperative Period; D011336:Probability; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D012680:Sensitivity and Specificity; D013718:Tensile Strength; D014464:Ultrasonic Therapy / Q000379:methods*