Background: Tumor curettage and cementation is a widely-used treatment of benign bone tumors in the distal femur. While postoperative fracture is a common complication, no criterion or biomechanical data is available to identify patients at high risk of fracture. Given the strong correlation between bone strength and its fracture risk, this study aimed to develop a non-invasive method to predict distal femoral strength following the surgery.

Methods: 14 cadaveric human distal femora in which tumor surgery was mimicked by curettage and cementation (similar to the treatment of giant cell tumor in this region) were tested under compression force to measure bone strength. In addition, the 3D models of the specimens were created using quantitative computed tomography (QCT) images. Bone strength was measured with finite element analysis (FEA) in ABAQUS by applying loading conditions similar to the mechanical tests on the models. The accuracy and precision of the models in predicting bone strength were evaluated using paired t-tests and linear regression analyses.

Results: No significant difference was observed between bone strengths predicted using FEA and the values measured in the laboratory via mechanical tests based on paired t-tests results (P> 0.05). Moreover, regression analyses indicated a linear relationship between experimentally measured and FEA predicted bone strengths with a slope not different from 1.

Conclusion: The results demonstrated the capability of QCT-based FEA in predicting bone strength in distal femur following tumor surgery. Therefore, the method can be employed to assess various features of bone-cement constructs with the hope of shedding light on the obscure aspects of the problem.