Study Of Imageological Assessment Of Quantitative CT On Fracture Healing

Partâ… The efficacy of fracture healed assessment byQuantitative CT (QCT)Objective: To investigate the efficacy of assessment for fracture healed byQuantitative CT (QCT)Method: Twenty healthy New Zealand rabbits was randomly divided into 2groups: group A(union model group, transverse fracture open created onmid-shaft of tibia and inter-fixed by kirschner wire) and group B(non-unionmodel group, transverse fracture with 5mm defect on mid-shaft of tibia opencreated,then sealed with bone wax on fracture site and medulla cavity,inter-fixed by kirschner wire) ,At Week 2, 4, 8 and 12, Kirschner wire werewithdrawn and plain X-ray and Quantitative CT scanning were performed onbilateral tibia, then rabbit were scarified and its bilateral tibia were desectedand histologically examinated, Regarted the result of X-ray and histologyanalysis (HE) as the "golden standard", the assessing accuracy of thequantitative CT(QCT) parameter and results were statistically investigatedwith the receiver operating charcteristic curve(ROC) ,and the developing tendency of the results of quantitative CT(QCT) parameters during thedifferent stage of the fracture healed process were observed, compared withthat of the corresponding segment of normal side.Result: group A: at Week 2 and Week 4,X-ray and histology analysisappealed the fracture line was obviese and filled with irregular callus; atWeek 8 and Week 16,X-ray and histology analysis appealed the fracture linewas vague or vanishing, irregular callus changed gradually into continuousand intact cortex; group B: at Week 2 and Week 4,X-ray and histologyanalysis appealed the fracture line was obviese and the ossifications wereinactive without nomal callus formation; at Week 8 and Week 16, the fractureline was still presented,osteocyte and bone trabecula were scarce anddistributed irregularly; the analysis of parameters and results of thequantitative CT(QCT) by the receiver operating charcteristic curve(ROC)showed the area of curve (accuracy)of material parameter-Bone MineralDensity (BMD) Vs Bone Mineral Content(BMC) were 0.781Vs0.750,structure parameter-cross-sectional area (CSA) Vs cross-sectional moment ofinertia(CSMI) were 0.781 vs0.469(p＜0.05), extending parameter regarded asBone Strength Indices(BSI),which is multiplication of material parameterand structure parameter - CSA Bone Strength Indices (BSI_CSA) Vs CSMIBone Strength Indices(BSI_CSMI) were 0.913vs0.813(p＜0.05), the results of the area of curve (accuracy) between BSI_CSA,CSA,BMD were0.905vs0.921vs 0.905( p＜0.05); All the results of quantitative CT(QCT)parameters (BSI_CSA,CSA,BMD,BMC,CSMI) presented up or downdeveloping tendency with the process of fracture union or nonunion.Conclusion: Quantitative CT(QCT) can provide quantitative evidence todistingquish fracture union model and nonunion model , of which thescreening parameter with more accuracy were BSI_CSA,CSA,BMD ,they hadsimilar assessing potential with conventional radiograph ,featuring moreefficacy and accuracy.Partâ…¡The correlation between the Quantitative CT(QCT)parameter and bone histological structure and mechanicalproperty of fracture site.Objective: To investigate the correlation between the results of measurementby Quantitative CT (QCT) and the bone histological structure and mechanicalproperty of fracture siteMethod: Sixty New Zealand rabbits (transverse fracture open created onmid-shaft of tibia and inter-fixed by kirschner wire) were randomly divided into 4 groups. At Week 2, 4, 8 and 12, Kirschner wire was withdrawn andperformed plain X-ray and Quantitative CT scanning on bilateral tibia, andthen scarified. Regarded itself normal tibia as control, 7 pairs of specimenswere analyzed by Confocal Laser Scanning Microscopy (CLSM) and Bonehistomorphometry,8 pairs of specimens were examined by the four pointbending biomechanical test; the correlation between the results ofmeasurement by Quantitative CT parameter (BSI_CSA,CSA,BM) and thecorresponding bone histological structure parameter (BFR,BV/CV,TB.N),mechanical property parameter (Load,stiffness) were statistically analysised.Result: At Week 2, 4, 8 and 12, the measurement result of the BV/CV andTB.N,the Load and stiffness significantly statistically presented the changingstatus of the fracture healed( p＜0.05 ), as well as that of Quantitative CTparameter (BSI_CSA,CSA,BMD) ( p＜0.05 );Correlation analysis showed thatQCT result of fracture site by bone mineral density (BMD),cross-sectionalarea (CSA) and cross-sectional area bone strength indices (BSI_CSA) hadsignificantly positive correlation(r=0.50～0.90,p＜0.01) with BFR,BV/CV,TB.N, had significantly positive correlation(r=0.46～0.99,p＜0.01) with boneLoad and stiffness as well, Of which the correlation between CSA,BSI_CSAand Load were the best (r= 0.90,0.82, p＜0.01).Conclusion: QCT had the potential of noninvasively assessing the mechanical property of fracture healed process with quantitative analysis ofthe micro-structural changes of fracture healing. It significantly statisticallyand logically correlated with the result of conventional experimentalquantitative solution (histology and mechanics).Partâ…¢Quantitative computed tomography (QCT) for assessment oftherapeutic efficacy of low-intensity ultrasound (LIUS)on distal radius fracture repaired.Objective: To observe the potential of quantitative CT (QCT) in assessmentof therapeutic efficacy of low-intensity ultrasound (LIUS) on distal radiusfracture repair.Methods: 20 patients with distal radius fracture (type A) were randomlydivided into ultrasound group (10 cases received ultrasound therapy aftermanipulative reduction and cast immobilization) and control group (10 casesreceived only manipulative reduction and cast immobilization). Ultrasoundgroup received ultrasound treatment, 20 min/ day, the average intensity ofultrasound was 30 mW/cm²; All patients were followed up weekly by three specified orthopedics for a period of 4 to 7 months (average 5.4months).Fracture union time,the cortical cross sectional area (CSA) and thebone mineral density (BMD) were detected by QCT (TOSHIBAAquilion/TSX-101A, with the original standard bone density scanningphantom and a condition of 120 KV, 75mAs, 0.5S and 5 mm slice thickness)on 14^th d, 42^nd d and 70^th d. After bone mass of 3 cm ranging around thefracture site and standard phantom scanned,CSA and BMD of both sidesmeasured, the average of bone strength index (BSI) (CSA×BMD) in 1CMaround fracture site (5 slices) were calculated and statistically analyzed.Results:Compared with the control group, the ultrasound group's BSI(F_group= 18.823,p＜0.01 ) and cortical BMD (F_group=3.085,p＜0.05) were allsignificantly higher, the effect of interaction between LIUS and time factorwas Eta_group^*time＞Eta_group＞Eta_time·Conclusions:The LIUPS can effectively accelerate the fracture healingprocess, CSA and BMD at the fracture site assessed by QCT may serve asquantitative indices in evaluation of distal radius fracture healing, showingthe potential diagnostic superiority of precision, substantivity and sensitivity.