Biomechanical model of a high risk impending pathologic fracture of the femur: Lesion creation based on clinically implemented scoring systems

Autor: Brandon G. Santoni, G. Douglas Letson, Brian T. Palumbo, David Cheong, Gerald E. Alexander, Aniruddh N. Nayak, Sergio Gutiérrez
Rok vydání: 2013
Předmět:
Zdroj: Clinical Biomechanics. 28:408-414
ISSN: 0268-0033
DOI: 10.1016/j.clinbiomech.2013.02.011
Popis: article i nfo Article history: Received 9 October 2012 Accepted 26 February 2013 Background: Multiple classifications combine objective and subjective measures to predict fracture risk through a metastatic lesion. In our literature review, no studies have attempted to validate this predicted fracture risk from a biomechanical perspective. The study goal was to evaluate proximal femur strength after creating osteolytic defects. We report a standardized technique to re-create a metastatic lesion. Methods: Eight femoral matched pairs were procured and a standardized technique was used to create an osteolytic femoral neck defect in one femur with the contralateral specimen serving as the control. Femurs were loaded to failure in a material testing machine at 2 mm/s. Failure load (N) and location of failure were documented. 3D finiteelement(FE)femurmodelswithandwithoutthelesionsweredevelopedtopredict von Mises stresses in the femoral neck and compare between the two models. Findings: Femurs containing theosteolyticdefect failedat significantlylowerloads than theintact specimens ina reproducible manner (intact: 10.69 kN (3.09 SD); lesion: 5.56 kN (2.03 SD), pb0.001). The average reduction in failure load was 48%, and the fracture pattern was consistent in all specimens. FE model comparison similarly predicted significantly higher von Mises stress at the lesion. Interpretation: Our methods and pathologic fracture model represent the clinical parameters of metastatic bone disease and suggest a significant reduction in structural integrity of the lesion-containing femur. Prophylactic surgical fixation may be warranted clinically to reduce the risk of pathologic fracture. Our model technique is reproducible and may be used in future studies.
Databáze: OpenAIRE