Low intensity pulsed ultrasound accelerated bone remodeling during consolidation stage of distraction osteogenesis

Abstract

Bone regeneration in distraction osteogenesis occurs under tensile stress with axial rhythmic distraction after osteotomy. In this study, we evaluated if the low intensity pulsed ultrasound (LIPUS) was also effective on enhancement of bone remodeling during consolidation stage of distraction osteogenesis. Open osteotomy of seventeen 18-week-old female New Zealand rabbit tibiae were performed. The distraction was applied with the rate of 1 mm per day. LIPUS (30 mW/cm 2 , 1.5 MHz) was delivered for 20 min per day during 4-week consolidation stage (n ¼ 10). The animals without treatment served as sham group (n ¼ 7). Plain X-ray, peripheral quantitative computational tomography (pQCT), and torsional test were performed. Results showed that smaller radiolucent interzone of LIPUS treatment group was gradually occupied by calcified tissue in plain X-ray at week 2. The bone mineral density (BMD) measured on radiographs increased by 9.18% in the LIPUS group. Bone mineral content (BMC), hard callus volume, and bone strength index (BSI) measured by pQCT were 83%, 116%, and 94%, respectively, in LIPUS group that were significantly greater than those of the controls. At the 4th week, LIPUS-treated callus showed the development of neocorticalization in the proximal and distal region. The BMC, hard callus volume, and BSI of LIPUS group decreased and was not significantly different from control. This was also confirmed by the maximum torque of LIPUS-treated callus (1424.2 AE 457.3 N Á mm) obtained at week 4, which did not differ from that of the sham group (1968.8 AE 895.1 N Á mm). In conclusion, the effective period of LIPUS treatment was at the initial stage of consolidation, with accelerated bone formation and remodeling. ß

A preliminary study of the effect of low intensity pulsed ultrasound on new bone formation during mandibular distraction osteogenesis in rabbits

“…EL-BIALY et al evaluated the effect of LIPUS on mandibular DO in rabbits and found a positive effect from LIPUS 8 . Compared with animal studies of LIPUS on long bone DO, the present findings are consistent with SHIMAZAKI et al 19 , SAKURAKICHI et al 17 , CHAN et al 2 and CHAN et al 1 in their conclusion of the effective timing of LIPUS, and similar to MAYR et al 14 , MACHEN et al 13 , EBERSON et al 7 and CLAES et al 5 , which demonstrated the positive effect of LIPUS.…”

“…Several authors have reported the positive effects of LIPUS on long bone DO 2,17,19 . Few studies have evaluated the effect of LIPUS on membranous bone DO.…”

Locally applied nerve growth factor enhances bone consolidation in a rabbit model of mandibular distraction osteogenesis

“…Many attempts have been made to shorten the bone consolidation period during DO, including low-intensity pulsed ultrasound, 25 recombinant growth hormone, 26 intermittent parathyroid hormone, 27 calcitonin and alendronate, 28 calcium sulfate, 29 and growth factors such as BMPs and IGF. 30,31 In the present study, locally applied hNGFb accelerated callus maturation of a distraction gap in a rabbit mandibular distraction model.…”

Low-Intensity Pulsed Ultrasound Modulates Shear Stress Induced PGHS-2 Expression and PGE2 Synthesis in MLO-Y4 Osteocyte-Like Cells

“…13,14,21,23,31,33,50,57,65,72,75,85 Pulsed US treatment also increases the rate of bone formation in distractions. 11,24,25,68,79 Exposure to low-intensity pulsed US (1.5 MHz, 30 mW/cm 2 ) for 20 min a day resulted in a 36% acceleration in the healing rate of distal radial fractures 44 and a reduction in the healing time of tibia fractures from 154 to 96 days. 35 Despite such well documented examples of accelerated and augmented fracture healing associated with low-intensity pulsed US treatment, the physical and biological process through which pulsed US interacts with living tissue remains unknown.…”