What has finite element analysis taught us about diabetic foot disease and its management?:a systematic review

Over the past two decades finite element (FE) analysis has become a popular tool for researchers seeking to simulate the biomechanics of the healthy and diabetic foot. The primary aims of these simulations have been to improve our understanding of the foot's complicated mechanical loading in health and disease and to inform interventions designed to prevent plantar ulceration, a major complication of diabetes. This article provides a systematic review and summary of the findings from FE analysis-based computational simulations of the diabetic foot.A systematic literature search was carried out and 31 relevant articles were identified covering three primary themes: methodological aspects relevant to modelling the diabetic foot; investigations of the pathomechanics of the diabetic foot; and simulation-based design of interventions to reduce ulceration risk.Methodological studies illustrated appropriate use of FE analysis for simulation of foot mechanics, incorporating nonlinear tissue mechanics, contact and rigid body movements. FE studies of pathomechanics have provided estimates of internal soft tissue stresses, and suggest that such stresses may often be considerably larger than those measured at the plantar surface and are proportionally greater in the diabetic foot compared to controls. FE analysis allowed evaluation of insole performance and development of new insole designs, footwear and corrective surgery to effectively provide intervention strategies. The technique also presents the opportunity to simulate the effect of changes associated with the diabetic foot on non-mechanical factors such as blood supply to local tissues.While significant advancement in diabetic foot research has been made possible by the use of FE analysis, translational utility of this powerful tool for routine clinical care at the patient level requires adoption of cost-effective (both in terms of labour and computation) and reliable approaches with clear clinical validity for decision making

Toward the Development of Virtual Surgical Tools to Aid Orthopaedic FE Analyses

Computational models of joint anatomy and function provide a means for biomechanists, physicians, and physical therapists to understand the effects of repetitive motion, acute injury, and degenerative diseases. Finite element models, for example, may be used to predict the outcome of a surgical intervention or to improve the design of prosthetic implants. Countless models have been developed over the years to address a myriad of orthopaedic procedures. Unfortunately, few studies have incorporated patient-specific models. Historically, baseline anatomic models have been used due to the demands associated with model development. Moreover, surgical simulations impose additional modeling challenges. Current meshing practices do not readily accommodate the inclusion of implants. Our goal is to develop a suite of tools (virtual instruments and guides) which enable surgical procedures to be readily simulated and to facilitate the development of all-hexahedral finite element mesh definitions

Fuzzy tissue classification for non-linear patient-specific biomechanical models for whole-body image registration

Comparison of whole-body medical images acquired for a given patient at different times is important for diagnosis, treatment assessment and surgery planning. Prior to comparison, the images need to be registered (aligned) as changes in the patient’s posture and other factors associated with skeletal motion and deformations of organs/tissues lead to differences between the images. For whole-body images, such differences are large, which poses challenges for traditionally used registration methods that rely solely on image processing techniques. Therefore, in our previous studies, we successfully applied image registration using patient-specific biomechanical models in which predicting deformations of organs/tissues is treated as a non-linear problem of computational mechanics. Constructing such models tends to be time-consuming as it involves tedious image segmentation which divides images into non-overlapping constituents with different material properties. To eliminate segmentation, we propose Fuzzy C-Means (FCM) classification to assign material properties at the integration points of a finite element mesh. In this study, we present an application of the FCM tissue classification algorithm and analyse sensitivity of the accuracy of whole-body image registration using non-linear patient-specific finite models to the FCM classification parameters. We show that accurate registration (within two times of the image voxel size) can be achieved