A modified method for assigning material properties to FE models of bones

Helgason, Benedikt; Taddei, Fulvia; Pálsson, Halldór; Schileo, Enrico; Cristofolini, Luca; Viceconti, Marco; Brynjólfsson, Sigurður

doi:10.1016/j.medengphy.2007.05.006

Cited by 131 publications

(98 citation statements)

References 33 publications

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“…[15][16][17][18] As we already mentioned above, an accurate density-elasticity correlation concerning the pelvic bone is not known yet, it has only been determined with indirect methods. [10,15] Nevertheless, our mean elastic modulus values (sacrum 3710 MPa, pelvic bone 4900 MPa) calculated from the cortical-cancellous bone ratio nears those, that can be found in the literature.…”

Section: Discussionmentioning

confidence: 99%

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Further development of our finite element pelvic model to compare fixation methods for pelvic fractures

Sztrinkai¹,

Bodzay²,

Pajor³

et al. 2014

Eklem Hastalik Cerrahisi

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Amaç: Bu çalışmada her türlü kırığın bilgisayarlı simülas-yonuna uygun olan ve güvenilir sonuçlar veren gerçekçi bir model yaratıldı. Hastalar ve yöntemler: İleri numune elde edebilmek için plastik bir pelvis modeli kullanıldı. Veriler sağlıklı bir pelvisin bilgisayarlı tomografi taramasından elde edildi. Üç boyutlu plastik pelvis taraması ile geometrik olarak kesin bir model oluşturuldu. Bilgisayarlı tomografi taramalarından elde edilen verilere göre kemikli kısımların materyal özellikleri modifiye edildi. Pelvis farklı segmentlere ayrıldı ve materyal özelliklerinin doğru olması için her segmentte kortikal ve kansellöz kemik maddesinin oranı tayin edildi. Pelvis modelinin doğrulanmasında, tip C pelvis hasarının simülasyonu yapıldı ve sakrum kırığı ve semfizyoliz plaklar ile stabilize edildi. Bu veriler daha önceki kadavra deneylerinden elde edilen veriler ile karşılaştırıldı. Bulgular: Yeni model üzerinde yapılan simülasyona göre, sakrum kırığının fragmanları arasındaki kayma değerleri, kadavra deneylerinde bildirilen değerlere yakındı ve artan gerilme tolere edilebilir aralıkta kaldı. Sonuç: Yeni sonlu eleman pelvis modelimiz, eski modele göre, pelvisi daha doğru yansıtmaktadır. Modelin doğ-rulaması başarılı olduğundan, güvenilir sonuçlar ile bu yöntem her türlü kırığın bilgisayarlı simülasyonu için uygundur.Anahtar sözcükler: Sonlu eleman analizi; kırık tespiti; pelvis kemiği. Objectives:In this study, we aimed to create a realistic model which is suitable for computerized simulation of any kind of fractures and provides reliable results. Patients and methods: We used a plastic pelvic model to construct advanced specimens. The data were retrieved from the computed tomography scans of a healthy pelvis. A geometrically exact model by the means of three-dimensional scanning of the plastic pelvis was obtained. The material properties of the bony parts based on the data retrieved from the computed tomography scans were modified. The pelvis was divided into distinct segments and the proportion of the cortical and cancellous bone substance in each segment were determined to make the material properties accurate. In the validation of the pelvic model, a type C pelvic injury was simulated and the fracture of the sacrum and the symphyseolysis were stabilized with plates. These data were compared with those of previously performed cadaver experiments. Results: Based on the simulation performed on the new model, the shift values between the fragments of the broken sacrum approximated the reported values of our cadaver experiments and also arising strains remained in the tolerable interval. Conclusion: Our new finite element pelvic model represents the pelvis more accurately than the former one. As the validation of the model was successful, it is suitable for computerized simulation of any kind of fractures offering reliable results.

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Section: Discussionmentioning

confidence: 99%

“…The most commonly used method is determination of the elasticity from the density, [10,[15][16][17][18] although such a value explicitly for the pelvis bone has not been determined to date. Recommendations for the most feasible density-elasticity relationship are already available.…”

Section: Objectivesmentioning

confidence: 99%

Further development of our finite element pelvic model to compare fixation methods for pelvic fractures

Sztrinkai¹,

Bodzay²,

Pajor³

et al. 2014

Eklem Hastalik Cerrahisi

View full text Add to dashboard Cite

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“…Material properties that vary spatially inside each finite element cannot be simply defined in FEA codes. Thus they have not been used very much, although they are reported to yield more accurate strain results [14]. The constant values assignment approach has many variations, depending on how the average value of a material property is calculated from CT numbers.…”

Section: Bone Materials Characterizationmentioning

confidence: 99%

“…The main difference between those variations is reflected in the av-eraging technique used. According to the simplest one, density values are assigned to every finite element node, based on the nearest value on CT sampling grid, and then a weighted average of nodal values is assigned to the element [14]. According to another technique, average element density is calculated from eight points surrounding element centroid [14].…”

Section: Bone Materials Characterizationmentioning

confidence: 99%

Material Characterization Issues in Fea of Long Bones

Korunović¹,

Trajanović²,

Stevanovic³

et al. 2014

Proceedings of the 3rd South-East European Conference on Computational Mechanics (SEECCM III)

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“…It should be noted that the modulus distribution in the male model was likely to be more accurate than that in the female model because the slice distance (0.5 mm) of the male CT images was just half of that of the female images and the unknown modulus values between the CT images were determined by averaging the known values. This is well known as the partial volume effects in the field of CT image analysis (51,52) .…”

Section: Distribution Of Young's Modulusmentioning

confidence: 99%

Biomechanical Analysis of Implant Treatment for Fully Edentulous Maxillas

Arahira

Todo

Matsushita

et al. 2010

JBSE

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Three-dimensional maxillary bone models of a male and a female patient were constructed using their CT-images. The distributions of Young's modulus were estimated from their bone mineral density distributions. Total six implants were embedded into each of the maxillary models. Finite element analysis of the maxilla models was then performed in order to assess the concentrations of strain energy density especially in the vicinities of the embedded implants. It was found that in both models, strain energy density was concentrated especially around the right-molar implant, suggesting outbreak of damage and subsequent absorption of bone tissue in this region. The female model with smaller size and lower bone density exhibited much higher localized concentration of strain energy density than the male model. Therefore, a modified placement of the right-molar implant was then introduced into the female model and such high concentration was effectively reduced by using the inclined and longer implant. It is thus concluded that this kind of three-dimensional modeling can clinically be used to predict the optimal implant treatment for each of dental patients.

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A modified method for assigning material properties to FE models of bones

Cited by 131 publications

References 33 publications

Further development of our finite element pelvic model to compare fixation methods for pelvic fractures

Further development of our finite element pelvic model to compare fixation methods for pelvic fractures

Material Characterization Issues in Fea of Long Bones

Biomechanical Analysis of Implant Treatment for Fully Edentulous Maxillas

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