Oden Z M, Selvitelli D M, Bouxsein M L
Department of Orthopedic Surgery, Charles A. Dana Research Institute, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA.
J Orthop Res. 1999 Sep;17(5):661-7. doi: 10.1002/jor.1100170507.
Hip fracture among the elderly is a large and growing public health issue. Presently, all therapies approved for treatment and prevention of osteoporosis involve pharmacological agents that act systemically. In this study, we evaluated the feasibility of preventing osteoporotic hip fractures with local, rather than systemic, therapy. Our hypothesis is that local therapy to increase bone density may be as effective as systemic therapy in reducing fracture risk. Thus, the goal of this investigation was to use finite element analyses to study the effect of a localized increase in bone density on the strength of an osteopenic, human femur. Finite element predictions of the failure load were made after increasing the bone density within small regions in the proximal femur. The outcome variable from these analyses was the predicted load required to break a femur in a simulated fall to the side with impact on the greater trochanter. Increasing the density by 25% relative to baseline values in a small region (0.86 cm3) of the femoral neck increased the predicted failure load by 6.2%. The same density increase in a much larger region (4.92 cm3) increased the failure load by 15%. Inclusion of more than one region of increased density provided little additional benefit. In comparison, when the density of the entire femur was increased by 5% relative to baseline values, the predicted failure load increased by 5.4%. These findings suggest that agents capable of inducing increased bone density in small regions of the proximal femur have the potential to reduce the risk of hip fracture.
老年人髋部骨折是一个规模庞大且不断加剧的公共卫生问题。目前，所有获批用于治疗和预防骨质疏松症的疗法均涉及全身作用的药物制剂。在本研究中，我们评估了采用局部而非全身疗法预防骨质疏松性髋部骨折的可行性。我们的假设是，增加骨密度的局部疗法在降低骨折风险方面可能与全身疗法同样有效。因此，本研究的目的是使用有限元分析来研究股骨近端局部骨密度增加对骨质减少的人体股骨强度的影响。在股骨近端的小区域内增加骨密度后，对破坏载荷进行了有限元预测。这些分析的结果变量是在模拟向一侧跌倒并撞击大转子的情况下使股骨骨折所需的预测载荷。相对于股骨颈小区域（0.86立方厘米）的基线值，骨密度增加25%可使预测的破坏载荷增加6.2%。在大得多的区域（4.92立方厘米）内同样增加骨密度可使破坏载荷增加15%。包含多个骨密度增加区域几乎没有额外益处。相比之下，当整个股骨的骨密度相对于基线值增加5%时，预测的破坏载荷增加5.4%。这些发现表明，能够在股骨近端小区域诱导骨密度增加的药物制剂有可能降低髋部骨折风险。
