Abstract：
Bone mineral density (BMD) is widely used for assessment of fracture risk. For the lumbar spine, BMD is typically measured from L1-L4 as it provides the largest area for assessment with the best measurement precision. Structural artifact often confounds spine BMD in clinical practice, and the International Society for Clinical Densitometry (ISCD) recommends removing vertebrae with artifact when reporting spine BMD. In its most recent position statements, the ISCD recommended against the use of a single vertebra when reporting spine BMD but stated that further studies should be done. The current analysis was performed to compare the performance of BMD from different numbers and combination of vertebral levels on fracture prediction in a large clinical registry of DXA tests for the Province of Manitoba, Canada. The study population comprised 39,727 individuals aged 40 years and older (mean age 62.7 years, 91.0 % female) with baseline DXA after excluding those with evidence of structural artifact. Mean follow-up for ascertaining fracture outcomes was 8.7 years. Area under the curve (AUC) for incident fracture risk stratification was statistically significant regardless of the BMD measurement site or fracture outcome. AUC differences with the various numbers and combinations of vertebral levels including a single vertebral body were small (less than or equal to 0.01). More substantial AUC differences were seen for femoral neck and total hip BMD versus L1-L4 BMD, approaching 0.1 for hip fracture stratification. In summary, we found that using combinations of fewer than 4 vertebrae including individual lumbar vertebrae predicted incident fractures. Importantly, differences between these different combinations were small when compared with L1-L4. Spine BMD was a better predictor of incident spine fracture compared to the hip, whereas the hip was better for hip fracture and overall fracture prediction.
摘要：
骨矿物质密度（BMD）广泛用于评估骨折风险。对于腰椎，BMD通常从L1-L4测量，因为它提供了具有最佳测量精度的最大评估区域。在临床实践中，结构伪影经常混淆脊柱BMD，国际临床密度测定学会（ISCD）建议在报告脊柱BMD时移除带有伪影的椎骨。在最近的立场声明中，ISCD在报告脊柱BMD时建议不使用单个椎骨,但指出应进行进一步研究.在马尼托巴省DXA测试的大型临床注册表中，进行了当前分析，以比较不同数量和组合的椎体水平对骨折预测的BMD表现。加拿大。研究人群包括39,727名40岁及以上的个体(平均年龄62.7岁，91.0%女性)排除有结构伪影证据的患者后，使用基线DXA。确定骨折结局的平均随访时间为8.7年。无论BMD测量部位或骨折结果如何，发生骨折风险分层的曲线下面积（AUC）均具有统计学意义。包括单个椎体在内的椎体水平的各种数量和组合的AUC差异很小（小于或等于0.01）。股骨颈和全髋部BMD与L1-L4BMD的AUC差异更大，髋部骨折分层接近0.1。总之,我们发现，使用少于4个椎骨的组合，包括单个腰椎，可以预测发生骨折。重要的是,与L1-L4相比，这些不同组合之间的差异很小。与髋部相比，脊柱BMD更好地预测了脊柱骨折的发生。而髋部骨折和整体骨折预测效果更好。
