Bone Mineral Density And Bone Strength Evaluation Of Femoral Neck In Postmenopausal Women

Objective Bone mineral density and bone strength of femoral neck were evaluated in postmenopausal women.Multiple parameters of bone mineral density (BMD)were determined firstly by vQCT technique in the femoral neck of postmenopausal women,to compare the differences of determined valus and the ability of vQCT and DXA in discriminating osteoporotic fracture,and to assess the effect of vertebral fracture status on volumetric BMD of proximal femur.To get the most sensitive index in discriminating osteoporotic fracture through measuring calcaneal quantitative ultrasound of postmenopausal women,and to evaluate the correlation in the parameters ofvQCT in femoral neck and QUS in calcaneals.Material and Method1.90 postmenopausal women were collected and divided into three groups based on the BMD value of femoral neck measured by DXA:T≥M-1SD,T＜M-2SD without and with osteoporotic fracture.MSCT(GE Healthcare,Light Speed 16)scans of proximal femur and the phantom(Image Analysis company)were acquired and the reconstructed image slice thickness was 1.25 mm.The MPR images of the left proximal femur were performed using Osteo CAD software(Neusoft Medical System CO Ltd)to make measurements of femoral neck,including cortical BMD (Cor),trabecular BMD(Trab),integral BMD(Int),neck length(NL)and the minimal cross-sectional area of neck(CSA).2.Bone quantitative ultrasound of bilateral calcaneuses were acquired in 60 postmenopausal women that were divided into three groups based on the BMD valuemeasured by DXA:T≥M-1SD,T＜M-2SD without and with osteoporotic fracture.It was fininshed automaticly by quantitative ultrasound apparatus (Osteospace-2000).Bilateral calcaneuses were measured in everyone.The following parameters were calculated:broad band ultrasound attenuation(BUA),spead of sound(SOS),stiffness index(STI),T-score and Z-score.3.Statistical analysis:All of the BMD and QUS parameters of every group were compared using ANOVA and covariance analysis of variance.The comparison of parameters of the bilateral calcaneal quantitative ultrasound using a paired t test.P value less than 0.05 was considered as statistical significance.The ability of discriminating osteoporotic fracture was evaluated using ROC curve with the following parameter:BUA,SOS,STI.ResultsPartⅠ1.In all the volumetric BMD indices there were statistically significant differences between nomal group and osteoporotic group,as well as,nomal group and osteoporotic fractured group,even after the correction of age,height and weight.In all the volumetric BMD indices except the index of Cort,there were statistically significant differences between osteoporotic group and osteoporotic fractured group(P value 0.000 and 0.007).The decent of Trab between group one and group two was the most as 37.4%.There was no significant difference of Neck-DXA and LS-DXA between osteoporotic group and osteoporotic fractured group.2.In general,age was negative correlated significantly with Cor,Trab,Int,Neck and LS(P=0.000),and the strongest correlation was between age and Trab.Weight, BMI had positive significant correlation with Trab,Total,Neck and LS,and had no significant correlation with Cor.There were significant correlation in Cor,Trab,Int,Neck and LS(P=0.0000), and the strongest correlation was between Int and Trab(r=0.920).3.Geometric parameters of the femoral neck were determined by 16 slice CT scans and vQCT technique in postmenopausal women.The mean value of NL in nomal group was79.7±3.62mm,and osteoporotic group was 89.8±3.66mm;The mean value of NL in nomal group was 634±67.4mm,and osteoporotic group was 563±60.8mm.4.The precision of 3D-BMD of femoral neck was between 0.159%～1.107%. NL showed the highest precision.0.159%between twice measures and 0.203% between observers were obtained All of the above parameters were useful for monitoring therapy efficacy.PartⅡ 1.In all the indices including Cor,Trab,Int,Neck,BUA,SOS,STI there were statistically significant differences between nomal group and osteoporotic group,as well as,nomal group and osteoporotic fractured group,even after the correction of age,height and weight.In all the quantitative ultrasound indices only the index of STI,there were statistically significant differences between osteoporotic group and osteoporotic fractured group.There was no significant difference of BUA and SOS.2.In general,vBMD of femoral neck was correlated significantly with BUA,SOS,STI(P=0.000),and the strongest correlation was between BUA and Trab(r=0.779,P＜0.01).3.There was significant correlation in SOS,BUA and STI between bilateral calcaneuses.SOS of the right calcaneus was higher than the other.But there was only small differerce in SOS between bilateral calcaneuses,BUA and STI had no significant differences between bilateral calcaneuses.4.The area under the ROC curve for BUA,SOS,STI was between 0.812 and 0.913.And STI was the the most sensitive index in discriminating osteoporotic fracture(sensitivity 90.0%,specificity81.2%).Conclusions1.Parameters derived from vQCT of femoral neck and calcaneuses QUS could different osteoporotic fractured vertebra from unfractured group,so they could predict fracture risk clinically.Trab was the best vQCT parameter for diagnosing fracture,and STI was the best one of QUS.2 Age was negative correlated significantly with Cor,Trab,Int,BUA,SOS and STI(P=0.0000),and weight,BMI had positive significant correlation with them.The strongest correlation was between age and Trab.3.Geometric parameters of the femoral neck were determined by 16 slice CT scans and vQCT technique in postmenopausal women.It was valuable clinically for improvement of bone strength assessment in osteoporotic diagonosis.4.The precision of 3D-BMD was high enough for monitoring therapy efficacy, and NL showed the highest precision. 5.There was significant correlation but and only small differerce between bilateral calcaneuses.It would be better to evaluate the ability of determined values in discriminating osteoporotic fracture through measuring bilateral calcaneal quantitative ultrasound than one side.6.In all the three parameters of QUS,STI was the best for diagnosing OP.But vQCT was better than QUS in discriminating osteoporotic fracture.Co-application of vQCT and QUS will offer great promise for improvement of clinical osteoporosis diagnosis,predicting fracture risk and bone strength assessment.