Prediction of vertebral strength in vitro by spinal bone densitometry and calcaneal ultrasound
Prediction of vertebral strength in vitro by spinal bone densitometry and calcaneal ultrasound
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DOI：
10.1359/jbmr.1997.12.10.1721
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发表时间：
1997-10-01
影响因子：
6.2
通讯作者：
Dequeker, J
中科院分区：
文献类型：
--
作者：
Cheng, XG;Nicholson, PHF;Dequeker, J
用双能X线骨密度仪（DXA）测定62具（男28，女34）成人尸体的椎骨和跟骨骨密度，比较了脊柱骨密度（BMD）测量和跟骨超声对第三腰椎椎体强度的预测能力。采用定量计算机断层扫描（QCT）测定椎体骨小梁、皮质骨密度、皮质骨面积、椎体总横截面积（CSA），测量右侧跟骨骨传导速度（BV）和宽带超声衰减（BUA）。椎体极限载荷与DXA测定的椎体BMD相关性最好（r（2）= 0.64），而QCT参数与强度的相关性最好（r（2）= 0.61）的是骨小梁BMD与CSA的乘积。与QCT测量的骨小梁BMD相关性最好（r（2）= 0.51）;与DXA测定的BMD的相关性稍差（r（2）= 0.44），跟骨超声与极限载荷和应力仅弱相关，相关系数（r（2））为0.10-0.17，跟骨BMD也是如此（r（2）= 0.18），与跟骨超声或跟骨DXA相比，脊柱DXA和脊柱QCT对L3极限载荷和应力的预测效果显著（p < 0.001）。多元回归分析显示，跟骨超声并没有显著提高DXA或QCT对L3极限载荷或应力的预测能力，跟骨DXA BMD、骨速度和BUA彼此相关良好（r（2）= 0.67-0.76），但与椎骨的DXA和QCT测量值仅适度相关。这些数据表明，脊柱DXA和脊柱QCT提供了可比较的椎体强度预测，骨密度测量无法解释椎骨强度的变异性（通常为40%），跟骨超声测量是体外椎骨强度的不良预测因子，超声不能独立于骨密度增加预测信息，这些发现与新兴的临床数据形成对比，这表明跟骨超声可能是体内椎骨骨折风险的有价值的预测因子，体内和体外结果之间明显差异的一种可能解释是，目前跟骨的临床超声测量反映了与骨折风险相关但与骨脆性无关的因素。
Spinal bone mineral density (BMD) measurements and calcaneal ultrasound were compared in terms of their ability to predict the strength of the third lumbar vertebral body using specimens from 62 adult cadavers (28 females, 34 males), BMD was measured using dual X-ray absorptiometry (DXA) in both vertebra and calcaneus. Quantitative computed tomography (QCT) was used to determine trabecular BMD, cortical BMD, cortical area, and total cross-sectional area (CSA) of the vertebral body, Bone velocity (BV) and broadband ultrasonic attenuation (BUA) were measured in the right calcaneus. Vertebral strength was determined by uniaxial compressive testing, Vertebral ultimate load was best correlated with DXA-determined vertebral BMD (r(2) = 0.64), Of the QCT parameters, the best correlation with strength,vas obtained using the product of trabecular BMD and CSA (r(2) = 0.61), For vertebral ultimate stress, however, the best correlation was observed with QCT-measured trabecular BMD (r(2) = 0.51); the correlation with DXA-determined BMD was slightly poorer (r(2) = 0.44), Calcaneal ultrasound correlated only weakly with both ultimate load and stress with correlation coefficients (r(2)) of 0.10-0.17, as did calcaneal BMD (r(2) = 0.18), Both spinal DXA and spinal QCT were significantly (p < 0.001) better predictors of L3 ultimate load and stress than were either calcaneal ultrasound or calcaneal DXA. Multiple regression analysis revealed that calcaneal ultrasound did not significantly improve the predictive ability of either DXA or QCT for L3 ultimate load or stress, Calcaneal DXA BMD, bone velocity, and BUA correlated well with each other (r(2) = 0.67-0.76), but were only modestly correlated with the DXA and QCT measurements of the vertebra. These data indicate that spinal DXA and spinal QCT provide comparable prediction of vertebral strength, but that a substantial proportion (typically 40%) of the variability in vertebral strength is unaccounted for by BMD measurements, Ultrasonic measurements at the calcaneus are poor predictors of vertebral strength in vitro, and ultrasound does not add predictive information independently of BMD, These findings contrast with emerging clinical data, suggesting that calcaneal ultrasound may be a valuable predictor of vertebral fracture risk in vivo, A possible explanation for this apparent discrepancy between in vivo and in vitro findings could be that current clinical ultrasound measurements at the calcaneus reflect factors that are related to fracture risk but not associated with bone fragility.