采用实验设计方法对有限元下颌骨骨折固定模型进行参数优化。

Parameter optimization in a finite element mandibular fracture fixation model using the design of experiments approach.

作者信息

Maintz Michaela, Msallem Bilal, de Wild Michael, Seiler Daniel, Herrmann Sven, Feiler Stefanie, Sharma Neha, Dalcanale Federico, Cattin Philippe, Thieringer Florian Markus

机构信息

Medical Additive Manufacturing Research Group (Swiss MAM), Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland; Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Basel, Basel, Switzerland; Institute for Medical Engineering and Medical Informatics IM(2), University of Applied Sciences and Arts Northwestern Switzerland FHNW, Muttenz, Switzerland.

出版信息

J Mech Behav Biomed Mater. 2023 Aug;144:105948. doi: 10.1016/j.jmbbm.2023.105948. Epub 2023 Jun 7.

DOI:10.1016/j.jmbbm.2023.105948

PMID:37348171

Abstract

Only a few mandibular bone finite element (FE) models have been validated in literature, making it difficult to assess the credibility of the models. In a comparative study between FE models and biomechanical experiments using a synthetic polyamide 12 (PA12) mandible model, we investigate how material properties and boundary conditions affect the FE model's accuracy using the design of experiments approach. Multiple FE parameters, such as contact definitions and the materials' elastic and plastic deformation characteristics, were systematically analyzed for an intact mandibular model and transferred to the fracture fixation model. In a second step, the contact definitions for the titanium screw and implant (S-I), implant and PA12 mandible (I-M), and interfragmentary (IF) PA12 segments were optimized. Comparing simulated deformations (from 0 to -5 mm) and reaction forces (from 10 to 1'415 N) with experimental results showed a strong sensitivity to FE mechanical properties and contact definitions. The results suggest that using the bonded definition for the screw-implant contact of the fracture plate is ineffective. The contact friction parameter set with the highest agreement was identified: titanium screw and implant μ = 0.2, implant and PA12 mandible μ = 0.2, interfragmentary PA12 mandible μ = 0.1. The simulated reaction force (RMSE = 26.60 N) and surface displacement data (RMSE = 0.19 mm) of the FE analysis showed a strong agreement with the experimental biomechanical data. The results were generated through parameter optimization which means that our findings need to be validated in the event of a new dataset with deviating anatomy. Conclusively, the predictive capability of the FE model can be improved by FE model calibration through experimental testing. Validated preoperative quasi-static FE analysis could allow engineers and surgeons to accurately estimate how the implant's choice and placement suit the patient's biomechanical needs.

摘要

文献中仅有少数下颌骨有限元（FE）模型得到验证，这使得评估这些模型的可信度变得困难。在一项使用合成聚酰胺12（PA12）下颌骨模型进行的有限元模型与生物力学实验的对比研究中，我们采用实验设计方法研究材料特性和边界条件如何影响有限元模型的准确性。针对完整下颌骨模型，系统分析了多个有限元参数，如接触定义以及材料的弹性和塑性变形特性，并将其应用于骨折固定模型。第二步，对钛螺钉与植入物（S-I）、植入物与PA12下颌骨（I-M）以及骨折段间（IF）PA12节段的接触定义进行了优化。将模拟变形（从0至-5毫米）和反作用力（从10至1415牛）与实验结果进行比较，结果表明其对有限元力学性能和接触定义具有很强的敏感性。结果表明，将粘结定义用于骨折板的螺钉-植入物接触是无效的。确定了一致性最高的接触摩擦参数集：钛螺钉与植入物μ = 0.2，植入物与PA12下颌骨μ = 0.2，骨折段间PA12下颌骨μ = 0.1。有限元分析的模拟反作用力（均方根误差RMSE = 26.60牛）和表面位移数据（RMSE = 0.19毫米）与实验生物力学数据高度吻合。这些结果是通过参数优化得出的，这意味着在遇到解剖结构不同的新数据集时，我们的研究结果需要进行验证。总之，通过实验测试对有限元模型进行校准可以提高有限元模型的预测能力。经过验证的术前准静态有限元分析可以让工程师和外科医生准确估计植入物的选择和放置如何满足患者的生物力学需求。