Prediction of torsional failure in 22 cadaver femora with and without simulated subtrochanteric metastatic defects: A CT scan-based finite element analysis

• Published in: Acta orthopaedica Vol. 77; no. 3; pp. 474 - 481
• Main Authors: Spruijt, Sander, Van Der Linden, Jacqueline C, Sander Dijkstra, P D, Wiggers, Theo, Oudkerk, Mathijs, Snijders, Chris J, Van Keulen, Fred, Verhaar, Jan A N, Weinans, Harrie, Swierstra, Bart A
• Format: Journal Article
• Language: English
• Published: Basingstoke Informa UK Ltd 01.06.2006; Taylor & Francis
• Subjects: Aged; Aged, 80 and over; Biological and medical sciences; Bone Density; Cadaver; Diseases of the osteoarticular system; Female; Femoral Fractures - diagnostic imaging; Femoral Fractures - etiology; Femoral Fractures - pathology; Femoral Fractures - prevention & control; Femoral Neoplasms - complications; Femoral Neoplasms - pathology; Femoral Neoplasms - secondary; Fracture Fixation; Fractures, Spontaneous - diagnostic imaging; Fractures, Spontaneous - etiology; Fractures, Spontaneous - pathology; Fractures, Spontaneous - prevention & control; Humans; Injuries of the limb. Injuries of the spine; Male; Medical sciences; Middle Aged; Models, Biological; Osteoporosis. Osteomalacia. Paget disease; Prognosis; Risk Factors; Tomography, X-Ray Computed; Traumas. Diseases due to physical agents; Femur; Diseases of the osteoarticular system; Fracture; Bone disease; Metastasis; Prevention; Surgery; Strain distribution; Stiffness; Long bone; Torsion; Failure; Quantitative analysis; Human; Radiodiagnosis; Malignant tumor; Trauma; Recommendation; Fixation; Treatment; Simulation; Risk factor; Medical imagery; Models; Computerized axial tomography; Predictive factor; Finite element
• ISSN: 1745-3674; 1745-3682
• DOI: 10.1080/17453670610046424

Background In metastatic bone disease, prophylactic fixation of impending long bone fracture is preferred over surgical treatment of a manifest fracture. There are no reliable guidelines for prediction of pathological fracture risk, however. We aimed to determine whether finite element (FE) models constructed from quantitative CT scans could be used for predicting pathological fracture load and location in a cadaver model of metastatic bone disease. Material and methods Subject-specific FE models were constructed from quantitative CT scans of 11 pairs of human femora. To simulate a metastatic defect, a transcortical hole was made in the subtrochanteric region in one femur of each pair. All femora were experimentally loaded in torsion until fracture. FE simulations of the experimental set-up were performed and torsional stiffness and strain energy density (SED) distribution were determined. Results In 15 of the 22 cases, locations of maximal SED fitted with the actual fracture locations. The calculated torsional stiffness of the entire femur combined with a criterion based on the local SED distribution in the FE model predicted 82% of the variance of the experimental torsional failure load. Interpretation In the future, CT scan-based FE analysis may provide a useful tool for identification of impending pathological fractures requiring prophylactic stabilization.