School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, Australia; Medical Device Research Institute, College of Science and Engineering, Flinders University, Adelaide, Australia.
South Australian Bone & Soft Tissue Tumour Unit, Flinders Medical Centre, Adelaide, Australia; College of Medicine and Public Health, Flinders University, Adelaide, Australia.
Clin Biomech (Bristol). 2023 Apr;104:105931. doi: 10.1016/j.clinbiomech.2023.105931. Epub 2023 Mar 6.
Finite element modelling methodologies available for assessing femurs with metastases accurately predict strength and pathological fracture risk which has led them to being considered for implementation into the clinic. However, the models available use varying material models, loading conditions, and critical thresholds. The aim of this study was to determine the agreement between finite element modelling methodologies in assessing fracture risk in proximal femurs with metastases.
CT images of the proximal femur were obtained of 7 patients who presented with a pathologic femoral fracture (fracture group) and the contralateral femur of 11 patients scheduled for prophylactic surgery (non-fracture group). Fracture risk was predicted for each patient following three established finite modelling methodologies which have previously shown to accurately predict strength and determine fracture risk: non-linear isotropic -based model, strain fold ratio -based model, Hoffman failure criteria -based model.
The methodologies demonstrated good diagnostic accuracy in assessing fracture risk (AUC = 0.77, 0.73, and 0.67). There was a stronger monotonic association between the non-linear isotropic and Hoffman -based models (τ = 0.74) than with the strain fold ratio model (τ = -0.24 and - 0.37). There was moderate or low agreement between methodologies in discriminating between individuals at high or low risk of fracture (κ = 0.20, 0.39, and 0.62).
The present results suggest there may be a lack of consistency in the management of pathological fractures in the proximal femur based on the finite element modelling methodologies.
现有的评估带有转移病灶的股骨的有限元建模方法能够准确预测强度和病理性骨折风险，这使得它们被考虑应用于临床。然而，现有的模型使用不同的材料模型、加载条件和临界阈值。本研究旨在确定评估带有转移病灶的股骨近端骨折风险的有限元建模方法之间的一致性。
对 7 名出现病理性股骨骨折（骨折组）的患者和 11 名计划进行预防性手术的患者（非骨折组）的股骨近端进行 CT 扫描。采用三种已建立的有限元建模方法预测每位患者的骨折风险，这些方法之前已被证明能够准确预测强度和确定骨折风险：非线性各向同性模型、应变折叠比模型、霍夫曼失效准则模型。
这些方法在评估骨折风险方面具有良好的诊断准确性（AUC=0.77、0.73 和 0.67）。非线性各向同性和霍夫曼模型之间的相关性更强（τ=0.74），而与应变折叠比模型的相关性较弱（τ=-0.24 和-0.37）。在区分高风险和低风险骨折个体方面，不同方法之间的一致性中等或较低（κ=0.20、0.39 和 0.62）。
本研究结果表明，基于有限元建模方法，在股骨近端病理性骨折的管理上可能存在不一致性。
