Edmondston S J, Singer K P, Day R E, Price R I, Breidahl P D
School of Physiotherapy, Curtin University, Western Australia.
Osteoporos Int. 1997;7(2):142-8. doi: 10.1007/BF01623690.
The estimation of vertebral fracture risk in individuals with suspected osteopenia is commonly based on measurements of lumbar spine bone density. The efficacy of vertebral size and deformity, as assessed by vertebral morphometry, in the prediction of fractures has been less studied. In an ex vivo investigation the regional relationships between vertebral size, vertebral deformity, bone density and compressive strength throughout the thoracolumbar spine were examined. In 16 vertebral columns (T1-L5) the bone mineral content (BMC) and bone mineral density (BMD) of each segment were measured using lateral projection dual-energy X-ray absorptiometry, and the vertebral cancellous density (VCD) and mid-vertebral cross-sectional area (CSA) measured using quantitative computed tomography. Vertebral body heights were determined from mid-sagittal CT scans, and vertical height ratios calculated for each segment. The failure load and failure stress of the isolated vertebral bodies were determined using a material testing device. Separate analyses were performed for the upper (T1-4), middle (T5-8) and lower (T9-12) thoracic, and lumbar (L1-5) segments. In all regions, failure load was strongly correlated with BMD (r = 0.82-0.86), moderately correlated with VCD (r = 0.60-0.71) and vertebral height (r = 0.22-0.49), and poorly correlated with the height ratios (r = 0.04-0.33). Failure stress was best predicted by BMD (r = 0.73-0.78) and VCD (r = 0.70-0.78) but was poorly correlated with all morphometric variables (r = 0.01-0.33). The segmental correlations between BMD and VCD ranged form r = 0.49 to r = 0.79. For all regions, BMD and VCD were included in the stepwise regression models for predicting failure load and failure stress. Either the mid-vertebral height or CSA were included in all the failure load models, while mid-vertebral height was included in only one of the failure stress models. The results suggest that vertebral deformity and size (as assessed by vertebral morphometry) make only a minor contribution to the prediction of vertebral strength additional to that provided by bone densitometry alone. The consistent regional relationships between variables appear to support the practice of global fracture risk assessment based on lumbar spine densitometry.
疑似骨质减少个体的椎体骨折风险评估通常基于腰椎骨密度测量。通过椎体形态测量法评估的椎体大小和畸形在骨折预测中的效能研究较少。在一项体外研究中，检查了整个胸腰椎椎体大小、椎体畸形、骨密度和抗压强度之间的区域关系。对16个椎体柱（T1-L5），使用侧位投影双能X线吸收法测量每个节段的骨矿物质含量（BMC）和骨矿物质密度（BMD），使用定量计算机断层扫描测量椎体松质骨密度（VCD）和椎体中部横截面积（CSA）。从矢状面CT扫描确定椎体高度，并计算每个节段的垂直高度比。使用材料测试装置确定分离椎体的破坏载荷和破坏应力。对胸段上部（T1-4）、中部（T5-8）和下部（T9-12）以及腰段（L1-5）节段进行单独分析。在所有区域，破坏载荷与BMD密切相关（r = 0.82-0.86），与VCD中度相关（r = 0.60-0.71）和椎体高度中度相关（r = 0.22-0.49），与高度比相关性较差（r = 0.04-0.33）。BMD对破坏应力的预测最佳（r = 0.73-0.78），VCD次之（r = 0.70-0.78），但与所有形态测量变量相关性较差（r = 0.01-0.33）。BMD和VCD之间的节段相关性范围为r = 0.49至r = 0.79。对于所有区域，BMD和VCD被纳入预测破坏载荷和破坏应力的逐步回归模型。椎体中部高度或CSA被纳入所有破坏载荷模型中，但椎体中部高度仅被纳入一个破坏应力模型中。结果表明，椎体畸形和大小（通过椎体形态测量法评估）对椎体强度预测的贡献仅略高于单独骨密度测量法所提供的贡献。变量之间一致的区域关系似乎支持基于腰椎骨密度测量进行整体骨折风险评估的做法。
