| Objective To establish a Mongolian sheep-pushed osteogenesis model,use conventional ultrasound,color doppler ultrasound,and contrast-enhanced ultrasound imaging techniques to monitor the stretch-stretching period and analyze the images of new bone formation by contrast x-ray.The characteristics of the study,to assess the degree of new bone vascularization,to explore the clinical value of multimodal ultrasound in the early monitoring of bone lengthening,in order to improve the success rate of bone extension treatment.Methods Ten kinds of the same species,the same month,the weight of 18-20 kg,the same condition of the Mongolian sheep,the right hind limb tibia was pulled into the osteogenesis model.On the third day after surgery,the elongation was started at a rate of 1 mm/d,and it was pulled once every 4hours,6 times/d,and pulled for 27 days,and mineralized for 4 weeks.X-ray,conventional ultrasound,color Doppler ultrasound,and contrast-enhanced ultrasound were performed on the 3rd,9th,15 th,21st,and 27 th days of the traction.X-ray was used to observe the contralateral alignment of the fracture,to evaluate the mineralization of the new bone,and to measure the length of the bone extension.Color Doppler ultrasonography was used to observe the blood flow signal in the bone extension zone.Contrast imaging was used to observe the contrast agent perfusion process.The basic intensity(BI),peak intensity(PI),peak time(TTP)and area under curve(AUC),were measured by contrast-enhanced TIC-Analysis software.Calculate the intensity value(EI,the difference between PI and BI),BI/PI value,compare the statistical difference of PI,EI,BI/PI,TTP values in different time periods,with P<0.05 as the difference Statistically significant,the characteristics of neovascular blood flow formation and the degree of vascularization were analyzed.Results(1)X-ray examination revealed that there was a blurred sacral shadow in the prolonged area on the 27 th day of the traction.(2)Conventional ultrasound observed that the evoked hypoechoic area was observed in the extended area on the 3th day of the traction,and then a large piece of high echo was formed.Color doppler shows that theblood flow signal is developed from a sparse point signal into a denser and directional blood flow signal,the resistance index is from high to low,and the spectrum shape is changed from high resistance to low resistance blood flow spectrum.The length of the osteotomy fissure at each time period was measured on the sonogram,which was consistent with the adjustment of the length of the external fixator and the length measured by the x-ray.(3)Contrast-enhanced ultrasonography showed that the contrast agent perfusion area ratio gradually increased with the passage of time,the density of contrast agent microbubble perfusion gradually increased,contrast agent perfusion imaging was more obvious,and the perfusion direction moved from the center of the medullary cavity like the new cortical bone.Gradually,there is a tendency to slow forward from the inside to the outside.There were significant differences in AUC,TTP,EI,and BI/PI between the groups.Correlation analysis between each time group and each quantitative quantitative analysis showed that EI increased with time and showed a significant positive correlation(P<0.05);BI/PI decreased with time,showing a significant negative correlation(P<0.05).TTP decreased with time and showed a significant negative correlation(P<0.05).Conclusion(1)Ultrasound multimodal imaging technology can detect the morphology of new bone tissue earlier than x-ray,and can clearly show the morphological structure of early new osteophytes during bone elongation.(2)It is sensitive to the detection of osteophytes less than5 mm in diameter.(2)Ultrasound contrast can quantitatively evaluate the degree of internal vascularization of the epiphysis during the osteogenesis process.It is an effective method to evaluate the speed and quality of bone formation in the early stage of bone extension.(3)Ultrasonography has certain limitations for the monitoring of epiphyseal mineralization.(3)Combined with x-ray,it has broad application prospects for the evaluation and prediction of the development and prognosis of bone prolongation. |
