Zhou Hongbo, Hou Yongfu, Zhu Zhimin, Xiao Weixiong, Xu Qian, Li Lei, Li Xin, Chen Wenchuan
J Ultrasound Med. 2016 Apr;35(4):747-54. doi: 10.7863/ultra.15.01083.
To investigate the effect of low-intensity pulsed ultrasound (US) on periimplant bone healing and osseointegration under osteoporotic conditions.
Seventy-two 12-week-old female Sprague Dawley rats received bilateral ovariectomies. Twelve weeks later, titanium implants were bilaterally placed in the proximal tibial metaphysis. The right tibia was exposed to low-intensity pulsed US (40 mW/cm2, spatial and temporal average) for 20 min/d starting the 2nd day after implantation, and the left tibia served as a control without stimulation. The rats were randomly assigned to 6 groups of 12 each according to the US duration (group 1: weeks 0–2, 280 minutes; group 2: weeks 0–4, 560 minutes; group 3: weeks 0–6, 840 minutes; group 4: weeks 0–8, 1120 minutes; group 5: weeks 0–10, 1400 minutes; group 6: weeks 0–12, 1680 minutes). At the end of the 2nd, 4th, 6th, 8th, 10th, and 12th weeks, the rats were euthanized, and bilateral tibias were harvested. Peri-implant bone volume and bone-implant contact were assessed by micro–computed tomography; the implantbone interface was assessed histologically; and implant fixation strength was determined by a removal torque test.
Low-intensity pulsed US increased bone-implant contact at the 4th, 6th, 8th, 10th, and 12th weeks (P = .019, .017, <.001, <.001, and <.001, respectively) and periimplant bone volume at all times (P = <.001, .002, .012, .007, .005, and .010). Removal torque on the US side was improved at the 6th, 8th, 10th, and 12th weeks (P= .012, <.001, .006, and .009). Ultrasound evoked a favorable bone response in the histologic study.
Low-intensity pulsed US might enhance new bone formation, especially at an early stage, and improve osseointegration in osteoporotic bone as an auxiliary method. However, further studies are needed to elucidate the mechanisms underlying its action.
研究低强度脉冲超声（US）对骨质疏松条件下种植体周围骨愈合及骨结合的影响。
72只12周龄雌性Sprague Dawley大鼠接受双侧卵巢切除术。12周后，在双侧胫骨近端干骺端植入钛种植体。从植入后第2天开始，右侧胫骨暴露于低强度脉冲超声（40 mW/cm²，空间和时间平均）下，每天照射20分钟，左侧胫骨作为未受刺激的对照。根据超声照射持续时间，将大鼠随机分为6组，每组12只（第1组：0 - 2周，280分钟；第2组：0 - 4周，560分钟；第3组：0 - 6周，840分钟；第4组：0 - 8周，1120分钟；第5组：0 - 10周，1400分钟；第6组：0 - 12周，1680分钟）。在第2、4、6、8、10和12周结束时，对大鼠实施安乐死并取出双侧胫骨。通过微型计算机断层扫描评估种植体周围骨体积和骨 - 种植体接触情况；通过组织学评估种植体 - 骨界面；通过去除扭矩测试确定种植体固定强度。
低强度脉冲超声在第4、6、8、10和12周时增加了骨 - 种植体接触（P值分别为0.019、0.017、<0.001、<0.001和<0.001），并在所有时间点增加了种植体周围骨体积（P值分别为<0.001、0.002、0.012、0.007、0.005和0.010）。在第6、8、10和12周时，超声照射侧的去除扭矩得到改善（P值分别为0.012、<0.001、0.006和0.009）。在组织学研究中，超声引发了良好的骨反应。
低强度脉冲超声可能会增强新骨形成，尤其是在早期阶段，并作为一种辅助方法改善骨质疏松骨中的骨结合。然而，需要进一步研究以阐明其作用的潜在机制。
