Prediction of mechanical strength of distal femur following GCT surgery using quantitative computed tomography based finite element method

Distal femur is the most frequently affected site by giant cell tumor (GCT). Surgery including tumor curettage and defect reconstruction with bone cement is a widely-used treatment. While post-operative fracture is a common complication, no criteria and/or biomechanical data are available to identify patients at high risk of fracture.  Since there is a strong correlation between bone strength and its fracture risk, in this study, bone strength following GCT surgery was predicted using quantitative computed tomography (QCT)-based finite element method (FEM). Mechanical properties of bone-cement interface, along with non-linear and non-homogeneous, as well as post-yield properties of bone were taken into account in the FE models. The accuracy and precision of FE models in predicting bone strength were evaluated using statistical tests by comparing the FE results with the results obtained using in-vitro mechanical tests on 14 cadaveric specimens and an independent data set. According to paired t-test analysis, no significant difference was observed between the bone strengths predicted by FEM   and those calculated by in-vitro tests  . In addition, based on the results of regression analysis, there was a linear relationship between  and with a slope not different from 1. The obtained results show the capability of QCT-based FEM in predicting bone strength in distal femur following GCT surgery, and thus they can be employed to investigate various features of the bone-cement construct with the hope of shedding light on the obscure aspects of the problem.