ABSTRACT
Objective To evaluate the application value of ultrasound in vascularization of different artificial bones . Methods A total of 15 New Zealand rabbits were utilized for model establishment of classic segmental bone defect in bilateral radius . Recombinant human bonemorphogenic protein-2 ( rhBMP-2 ) coralline hydroxyapatite(CHA) and CHA were implanted into left and right limbs . Each CHA was divided into 4 equal parts which were examined with conventional ultrasonography and contrast-enhanced ultrasonography( CEUS ) on 3 d ,7 d ,11 d ,15 d ,30 d and 45 d respectively . CEUS quantitative was performed by time-intensity curve(TIC) ,which parameters including the basic intensity(BI) ,peak intensity (PI) ,increased signal intensity ( ΔSI) and time to peak ( TTP) . Then the results were analyzed and compared to pathology . Results Within the same duration ,the vascularization degree in rhBMP-2 group was stronger than that in the ordinary group with advanced vascularization time . Positive correlation was detected between ΔSI and time of both groups ( r =0 .938 ,0 .890 ;P =0 .000) ,and negative correlation was found between BI/PI or TTP and time ( BI/PI: r = -0 .798 ,-0 .899 ; P = 0 .000 ;TTP= r -0 .874 ,-0 .868 ;P = 0 .000 ) . No statistical significance was observed among four observation points of both CHA ,which indicated no obvious difference in vascularization degree of each observation point . Conclusions The structure of bone graft can be clearly displayed by conventional ultrasound ,and CEUS is able to show the early blood perfusion in two CHA grafts and to accurately evaluate the difference of CHA microvascular growth before and after rhBMP-2 application . The combination of these two techniques is a promising approach of evaluating bone graft vascularization in clinical practice .