Background and objective

Degenerative diseases of the musculoskeletal system significantly reduce the quality of human life. Hip resurfacing is used to treat degenerative diseases in the later stages. After surgery, there is a risk of endoprosthesis loosening and low-energy fracture during daily physical activity. Computer modeling is a promising way to predict the optimal low-energy loads that do not lead to bone destruction. This paper aims to study numerically the mechanical behavior of the proximal femur, amenable to degenerative changes and subjected to hip resurfacing under low-energy impact equivalent to physiological loads.

Methods

A numerical model of the mechanical behavior of the femur after hip resurfacing arthroplasty under low-energy impacts equivalent to physiological loads is presented. The model is based on the movable cellular automaton method (discrete elements), where the mechanical behavior of bone tissue is described using the Biot poroelasticity accounting for the presence and transfer of interstitial biological fluid.

Results

For the first time, it is shown that a poroelastic model allows predicting the service life of endoprostheses, taking into account the individual characteristics of the bone tissues amenable to various degenerative diseases. The obtained results indicate that the changes in the bone properties have a significant influence on the critical forces corresponding to the first appearance of microcracks and the fracture formation. At the same time, their effect on the type of fracture is negligible. A much more impact on the type of fracture has the kinematic and dynamic conditions of the exposure.

Conclusions

The obtained results show the promise of using the proposed model for predicting the operational resource of resurfacing endoprostheses, taking into account the physiological features of the structure of the patient's bone tissues.

中文翻译：

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考虑到骨组织的退行性变化，在低能量影响下重铺种植体松动和股骨骨折的风险评估。计算机模拟

背景和目标

肌肉骨骼系统的退行性疾病大大降低了人们的生活质量。髋关节表面重整用于后期阶段的退行性疾病。手术后，在日常体育锻炼中可能会出现假体松动和低能量骨折的风险。计算机建模是预测不会导致骨骼破坏的最佳低能量负荷的一种有前途的方法。本文旨在从数值上研究股骨近端的力学行为，该行为适合于退行性改变并在相当于生理负荷的低能量冲击下进行髋关节表面重修。

方法

提出了在等效于生理负荷的低能量冲击下髋关节表面置换术后股骨力学行为的数值模型。该模型基于可移动细胞自动机方法（离散元素），其中使用Biot多孔弹性描述了骨组织的机械行为，考虑了组织间生物液的存在和转移。

结果

首次显示，多孔弹性模型可以预测假体的使用寿命，同时考虑到各种退行性疾病的骨组织的个体特征。获得的结果表明，骨性质的变化对与微裂纹的首次出现和断裂形成相对应的临界力具有显着影响。同时，它们对骨折类型的影响可以忽略不计。暴露的运动和动态条件对骨折类型的影响更大。

结论

考虑到患者骨组织结构的生理特征，获得的结果显示了使用所提出的模型来预测覆膜内修复术的操作资源的希望。