Lee Taeyong
Division of Bioengineering, National University of Singapore, Block E1 #08-03, 9 Engineering Drive 1, Singapore, 117576, Singapore.
Ann Biomed Eng. 2007 Apr;35(4):642-50. doi: 10.1007/s10439-006-9237-y. Epub 2007 Feb 8.
Currently, there is no proven sensitive or specific method for predicting pathological fracture of the femur. The clinical management of lytic femoral metastases is based on geometric measurement of the bone, of the defect, or both. However, the mechanical behavior of a structure depends on both its material and geometric properties. Our hypothesis is that a change in bone structural properties as the result of tumor induced osteolysis determines the fracture risk in bones with skeletal metastases. We developed a method of QCT (Quantitative Computed Tomography) combined with engineering beam analysis as a noninvasive tool for measuring the material and geometric properties of the femur with simulated lytic defects in the intertrochanteric region. In this ex-vivo study we prove that engineering beam structural analysis applied to serial transaxial QCT scans through human femora with simulated lytic defects at the proximal femur predicts the load at failure and location of fracture better than current clinical guidelines. Structural rigidity measured by QCT in this study may be used to predict the load carrying capacity of femurs with metastatic defects and, furthermore, may be used when the tumor has weakened the bone sufficiently such that pathological fracture is imminent and prophylactic stabilization is necessary.
目前，尚无经证实的敏感或特异方法可用于预测股骨病理性骨折。溶骨性股骨转移瘤的临床管理基于对骨、骨缺损或两者的几何测量。然而，结构的力学行为取决于其材料和几何特性。我们的假设是，肿瘤诱导的骨质溶解导致的骨结构特性变化决定了骨转移瘤患者骨骼发生骨折的风险。我们开发了一种定量计算机断层扫描（QCT）结合工程梁分析的方法，作为一种非侵入性工具，用于测量股骨转子间区域存在模拟溶骨性缺损时股骨的材料和几何特性。在这项离体研究中，我们证明，对于近端股骨存在模拟溶骨性缺损的人体股骨，应用于连续轴向QCT扫描的工程梁结构分析比当前临床指南能更好地预测失效载荷和骨折位置。本研究中通过QCT测量的结构刚度可用于预测有转移瘤缺损的股骨的承载能力，此外，当肿瘤使骨骼充分弱化以至于即将发生病理性骨折且需要进行预防性固定时，该方法也可使用。
