FEM analysis of expandable intramedullary nails in healthy and osteoporotic femur

• Autorzy: Kajzer W. , Kajzer A. , Marciniak J.
• Języki publikacji: EN

Abstrakty

EN

Purpose: The paper presents the results of numerical analysis of expandable intramedullary nail – femur system in different states of healing. The aim of the research was to determine displacements, deformations and stresses occurring in a bone depending on the age of the patient and the extent level of osteoporosis. Design/methodology/approach: A femur was selected to numerical analysis. The analysis concerned the influence of the load and torsion of the system on the obtained results of displacements, deformations and reduced stresses. In order to make calculations, four models with different mechanical properties were chosen: model 1: femur with mechanical properties corresponding with a femur of a patient at the age of 16, model 2: with mechanical properties corresponding with a femur of a patient at the age of about 28, model 3: with mechanical properties corresponding with a femur of a patient at the age of about 20 and at the age of 50 to 65 years old and model 4: with mechanical properties corresponding with a femur of a patient at the age above 70 or with osteoporosis. For the chosen model of intramedullary nail, mechanical properties of titan alloy Ti-6Al-4V were used. Two load steps were analyzed: load step 1 in which simple axial load with a value ranging from 250 up to 1000 N simulating patient standing on one leg was used, and load step 2 – a torsion analyzing loads that the nail is exposed to while walking. Findings: Conducted analysis of the system showed the difference in displacements, deformations and reduced stresses depending on assumed mechanical properties of femur and load step of the system. Research limitations/implications: The limitations were connected with the necessity of simplifying the assumptions, which were associated with limitations caused by boundary conditions. In researches 4 forces loading the femur axially were used: 1: force F = 250N, 2: with force F = 500N, 3: with force F= 750N and 4: with force F = 1000N and 5 values of angle displacement of the femur head were assumed: 1: angle displacement ö = 1°, 2: ö = 5°, 3: ö = 10°, 4: ö = 15°, 5: ö = 20°. Practical implications: Obtained results can be applied in selection of stabilization methods of bone fragments and in forecasting biomechanical conditions depending on the age of patient and the state of his general conditions of bones. Originality/value: The paper presents the displacement-deformation-stress characteristics of femur - expandable intramedullary nail system, using the Finite Elements Method (FEM) in the analysis.

Słowa kluczowe

EN

numerical analysis; biomechanical analysis; biomaterials; mechanical properties; bone

PL

analiza numeryczna; analiza biomechaniczna; biomateriał; właściwości mechaniczne; kość

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2009
• Tom: Vol. 37, nr 2
• Strony: 563--570
• Opis fizyczny: Bibliogr. 18 poz., rys., tabl.

Twórcy

autor

Kajzer W.

autor

Kajzer A.

autor

Marciniak J.

• Division of Biomedical Engineering, Institute of Engineering Materials and Biomaterials, Silesian University of Technology, ul. Konarskiego 18a, 44-100 Gliwice, Poland,

Bibliografia

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