International Center for Orthopaedic Advancement, Department of Orthopaedic Surgery, The Johns Hopkins Bayview Medical Center, Baltimore, MD 21224-2780, USA.
J Orthop Trauma. 2010 Feb;24(2):95-9. doi: 10.1097/BOT.0b013e3181b5c0c6.
To test the hypotheses that, compared with controls: 1) femoroplasty (the injection of bone cement into the proximal femur in an attempt to prevent fragility fracture) increases the yield and ultimate loads, yield and ultimate energies, and stiffness of the proximal osteoporotic femur in a simulated fall model; and 2) the manner in which the cement distributes in the proximal femur affects the extent to which those mechanical properties are altered.
In 10 pairs of osteoporotic human cadaveric femora, we injected one femur of each pair with 40 to 50 mL of polymethylmethacrylate bone cement; the noninjected femur served as the control. The filling percentage was calculated in four anatomic regions of the femur: head, neck, trochanter, and subtrochanter. All specimens were biomechanically tested in a configuration that simulated a fall on the greater trochanter. Student t test, linear regression, and multinomial logistic regression statistical analyses were conducted where appropriate with significant difference defined as P < 0.05.
Femoroplasty significantly increased yield load (22.0%), ultimate load (37.3%), yield energy (79.6%), and ultimate energy (154%) relative to matched controls but did not significantly change stiffness (-10.9%). There was a strong (r = 0.7) correlation between yield load and filling percentage in the femoral neck.
This study showed that 1) femoroplasty significantly increased fracture load and energy to fracture when osteoporotic femora were loaded in simulated fall conditions, and 2) cement filling in the femoral neck may have an important role in the extent to which femoroplasty affects mechanical strength of the proximal femur.
验证以下假设：与对照组相比：1）股骨成形术（将骨水泥注入股骨近端以试图预防脆性骨折）增加了模拟跌倒模型中骨质疏松性股骨近端的屈服和极限载荷、屈服和极限能量以及刚度；2）骨水泥在股骨近端的分布方式影响改变这些机械性能的程度。
在 10 对骨质疏松的人体尸体股骨中，我们将每对股骨中的一根股骨注射 40 至 50 毫升聚甲基丙烯酸甲酯骨水泥；未注射的股骨作为对照。在股骨的四个解剖区域（头部、颈部、转子和转子下）计算填充百分比。所有标本均在模拟大转子跌倒的配置中进行生物力学测试。在适当的情况下进行学生 t 检验、线性回归和多项逻辑回归统计分析，显著差异定义为 P < 0.05。
与匹配的对照组相比，股骨成形术显著增加了屈服载荷（22.0%）、极限载荷（37.3%）、屈服能量（79.6%）和极限能量（154%），但刚度无显著变化（-10.9%）。在股骨颈中，屈服载荷与填充百分比之间存在很强的相关性（r = 0.7）。
本研究表明：1）在模拟跌倒条件下加载骨质疏松性股骨时，股骨成形术显著增加了骨折载荷和断裂能量；2）股骨颈中的水泥填充可能在股骨成形术影响股骨近端机械强度的程度方面发挥重要作用。
