低强度脉冲超声波辐照与泡沫TiC/Ti对犬节段性骨缺修复的促进作用

目的探讨低强度脉冲超声波辐照对节段性骨缺损修复效果的影响。方法将直径12 mm长20mm泡沫TiC/Ti植入6只Beagle犬的左侧胫骨节段性骨缺损区。随机分为超声组和对照组,超声组采用低强度脉冲超声波辐照（频率1.5 MHz、强度30 mW/cm2、脉冲宽度200μs、脉冲周期1 kHz、20 min/次、1次/d）,对照组为不开功率源的假辐照,术后4、8周后分别行X线检查及骨密度测定,观察及分析材料周围骨愈合情况。结果 6只beagle犬均进入结果分析。术后4周超声组骨早期成熟度优于对照组,表现在材料周围骨痂影密度增高,骨痂影由两端向中央生长;对照组仅见骨痂区密度低,还可见部分骨痂缺如。术后8周超声组新生骨痂面积优于对照组,骨干结构相对稳定;对照组骨缺损区未闭合,在骨干两侧看到少量骨痂,愈合较差。骨密度测定结果显示,4周时超声组高于对照组,两组间存在统计学差异;8周时超声组略高于对照组,但两组间没有统计学差异。结论通过联合应用低强度脉冲超声波辐照与人工骨材料修复可提高新骨形成速度及骨组织密度,缩短节段性骨缺损的骨愈合时间。

Enhancing effect of low intensity pulse ultrasound stimulation combined with TiC/Ti foam implantation on the healing of segmental bone defect in Beagle dogs

Objective The aim of this study was to investigates the influence of low-intensity pulsed ultrasound stimulation （LIPUS） on the healing of segmental bone defect. Methods To insert 12 mm diameter and 20 ram long TiC/ Ti foam material into the segmental bone defect of left tibia in six Beagle dogs. These 6 dogs were randomly divided into two groups： the experiment group with LIPUS （1.5 MHz, ISATA 30 mW/cm2, pulsed width 200 μs, pulse repetition frequency 1 kHz, once/d） , and control group without LIPUS. To observe and analyze the healing process around the TiC/ Ti foam material by X-ray imaging and to measure the hone density at 4 w and 8 w after treatment. Results Six Beagle dogs were included in the final analysis. At week 4, the maturation of newly formed bone in the LIPUS-treatcd dogs appeared earlier than that of the control group, showing an increased bone density around the implanted TiC/Ti foam material and bone callus growing from both ends towards the central portion. Such changes were absent in the control group. At week 8, the bone structure stability of the LIPUS treatment group was higher than that of the control group. The bone mineral density measurement showed that the bone density of the experiment group at week 4 was significantly higher than that of the control group （ P 〈 0.05）, but not significantly higher at week 8. Couclusions Combined application of low-intensity pulsed ultrasound stimulation and artificial bone material TiC/Ti foam can accelerate the neo-ossifieation, bone callus formation, and bone mineral density, and shorten the healing time of the segmental bone defect.