A mechanical model for predicting the probability of osteoporotic hip fractures based in DXA measurements and finite element simulation
A mechanical model for predicting the probability of osteoporotic hip fractures based in DXA measurements and finite element simulation
复制标题
基于 DXA 测量和有限元模拟的预测骨质疏松性髋部骨折概率的机械模型
DOI：
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发表时间：
2012
影响因子：
3.9
通讯作者：
L. Gracia
中科院分区：
文献类型：
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作者：
E. López;E. Ibarz;A. Herrera;J. Mateo;A. Lobo;S. Puértolas;L. Gracia
背景骨质疏松性髋部骨折是老年人群残疾、生活质量下降甚至死亡的主要原因。药物治疗的决定基于 BMD 测量对骨折危险因素的评估。生物力学模型与临床研究的结合可以更好地估计骨强度并支持专家的决策。方法基于损伤和骨折力学开发了评估骨折概率的模型，通过临床 BMD 测量评估骨折过程中涉及的机械强度。该模型旨在模拟骨骼的退行性过程，随之而来的是骨量的损失，从而导致其机械阻力的降低，从而导致由于不同的创伤而导致骨折。选择了非治疗条件下和接受药物治疗的临床研究，并根据特定患者的实际 BMD 测量结果进行了拟合。该预测模型应用于股骨近端的有限元模拟。骨折区域将根据载荷情况（侧向跌落、冲击、意外载荷等），使用从对应于所考虑时间的进化模型获得的骨的力学特性来确定。结果分析了未治疗患者和接受不同治疗的患者的BMD演变。从机械损伤的演化过程中得到断裂概率的演化曲线。未经治疗组患者的进化曲线呈现出骨折概率显着增加的趋势，而接受药物治疗的患者的曲线则显示出不同程度的风险降低，具体取决于治疗类型。结论有限元模型可以获得详细的损伤和骨折概率图，识别股骨颈、转子间和转子下区域的高风险局部区域，这些区域是骨质疏松性髋部骨折的典型位置。所开发的模型适合个体化病例使用。该模型可以更好地识别骨质疏松症早期阶段的高危人群，并可能有助于治疗决策。
BackgroundOsteoporotic hip fractures represent major cause of disability, loss of quality of life and even mortality among the elderly population. Decisions on drug therapy are based on the assessment of risk factors for fracture, from BMD measurements. The combination of biomechanical models with clinical studies could better estimate bone strength and supporting the specialists in their decision.MethodsA model to assess the probability of fracture, based on the Damage and Fracture Mechanics has been developed, evaluating the mechanical magnitudes involved in the fracture process from clinical BMD measurements. The model is intended for simulating the degenerative process in the skeleton, with the consequent lost of bone mass and hence the decrease of its mechanical resistance which enables the fracture due to different traumatisms. Clinical studies were chosen, both in non-treatment conditions and receiving drug therapy, and fitted to specific patients according their actual BMD measures. The predictive model is applied in a FE simulation of the proximal femur. The fracture zone would be determined according loading scenario (sideway fall, impact, accidental loads, etc.), using the mechanical properties of bone obtained from the evolutionary model corresponding to the considered time.ResultsBMD evolution in untreated patients and in those under different treatments was analyzed. Evolutionary curves of fracture probability were obtained from the evolution of mechanical damage. The evolutionary curve of the untreated group of patients presented a marked increase of the fracture probability, while the curves of patients under drug treatment showed variable decreased risks, depending on the therapy type.ConclusionThe FE model allowed to obtain detailed maps of damage and fracture probability, identifying high-risk local zones at femoral neck and intertrochanteric and subtrochanteric areas, which are the typical locations of osteoporotic hip fractures.The developed model is suitable for being used in individualized cases. The model might better identify at-risk individuals in early stages of osteoporosis and might be helpful for treatment decisions.