Patient-specific finite element modeling of bones

Abstract

Finite element modeling is an engineering tool for structural analysis that has been used for many years to assess the relationship between load transfer and bone morphology and to optimize the design and fixation of orthopedic implants. Due to recent developments in finite element model generation, for example, improved computed tomography imaging quality, improved segmentation algorithms, and faster computers, the accuracy of finite element modeling has increased vastly and finite element models simulating the anatomy and properties of an individual patient can be constructed. Such so-called patient-specific finite element models are potentially valuable tools for orthopedic surgeons in fracture risk assessment or pre- and intraoperative planning of implant placement. The aim of this article is to provide a critical overview of current themes in patient-specific finite element modeling of bones. In addition, the state-of-the-art in patient-specific modeling of bones is compared with the requirements for a clinically applicable patient-specific finite element method, and judgment is passed on the feasibility of application of patient-specific finite element modeling as a part of clinical orthopedic routine. It is concluded that further development in certain aspects of patient-specific finite element modeling are needed before finite element modeling can be used as a routine clinical tool.

Effects of densitometry, material mapping and load estimation uncertainties on the accuracy of patient-specific finite-element models of the scapula

“…The limitations of the methods used for generation of reference models are very similar to those of other FE models of bones discussed elsewhere [14,45,46]. There are, however, a few remaining points that need to be taken into account.…”

“…A typical procedure for creating patient-specific FE models of the musculoskeletal system includes the following steps [14]: (1) acquisition of images using clinical image acquisition techniques such as computer tomography (CT) or magnetic resonance imaging (MRI), (2) segmentation of images and creation of FE meshes, (3) assignment of patient-specific mechanical properties based on density values and empirical correlations between bone mineral density and Young's modulus, and (4) application of patient-specific musculoskeletal loads and boundary conditions that are estimated from patientspecific musculoskeletal models [15]. Owing to the increased availability of imaging modalities, development of efficient image processing programmes, increased computational power and new approaches in image-based modelling such as the use of statistical shape and appearance models [16], patient-specific FE modelling of the skeletal system has become feasible during the last decade and a number of researchers have investigated the different aspects of patient-specific FE modelling for different applications [17][18][19][20][21].…”

Three-Dimensional Finite Element Analysis of Maxillary Sinus Floor Augmentation with Optimal Positioning of a Bone Graft Block

“…The finite element method is a common numerical stress analysis in engineering and biomechanics, used to resolve mechanical problems [1,10,13,17]. FE models with complex geometric structures can be easily modified to accommodate various assumptions.…”

Potential for estimation of Young's modulus based on computed tomography numbers in bone: A validation study using a nano-indentation test on murine maxilla

“…BMD has been correlated with bone strength and toughness [11,12], and is often employed for diagnosis and treatment of osteoporosis and multiple osteomyelitis [13,14]. To date, conversion of the CT number to estimate BMD by means of a hydroxyapatite phantom as a reference has been widely used and accepted for clinical diagnostic purposes [15,16]. Therefore, if there is an appropriate mathematical equation that can be used to convert a BMD value to the Young's modulus, it is plausible that it would be possible to predict the modulus based on CT data.…”