In Silico Finite Element Analysis of the Foot Ankle Complex Biomechanics: A Literature Review

Computational approaches, especially Finite Element Analysis (FEA), have been rapidly growing in both academia and industry during the last few decades. FEA serves as a powerful and efficient approach for simulating real-life experiments, including industrial product development, machine design, and biomedical research, particularly in biomechanics and biomaterials. Accordingly, FEA has been a "go-to" high biofidelic software tool to simulate and quantify the biomechanics of the foot-ankle complex, as well as to predict the risk of foot and ankle injuries, which are one of the most common musculoskeletal injuries among physically active individuals. This paper provides a review of the in silico FEA of the foot-ankle complex. First, a brief history of computational modeling methods and Finite Element (FE) simulations for foot-ankle models is introduced. Second, a general approach to build a FE foot and ankle model is presented, including a detailed procedure to accurately construct, calibrate, verify, and validate a FE model in its appropriate simulation environment. Third, current applications, as well as future improvements of the foot and ankle FE models, especially in the biomedical field, are discussed. Lastly, a conclusion is made on the efficiency and development of FEA as a computational approach in investigating the biomechanics of the foot-ankle complex. Overall, this review integrates insightful information for biomedical engineers, medical professionals, and researchers to conduct more accurate research on the foot-ankle FE models in the future.

Contributions regarding 3D modelling of biomechanics of the foot

Within this paper, a detailed study is elaborated regarding the human foot during both orthostatic and gait, the main goal being to develop 3D models which are very useful in the foot motion and loading state research. In order to elaborate the accurate 3D modelling of the human foot assembly, a thorough biomechanical study is done. Such a study was required due to the fact of the high anatomical complexity of the motions within the foot, taking into consideration the 26 bones and 33 joints consisting it. The research aims the CAD modelling of the biomechanics of the healthy subjects alongside with predisposed pathological conditions. The resulting models will have important utility in both educational field and for further CAE approaches and studies.

Maximally Disfiguring Surgery for Forefoot Osteomyelitis: Time for a Rethink?

The treatment of choice for diabetic foot osteomyelitis is surgical debridement and targeted antibiotics with or without revascularization, depending on vascular status. In our society, debridement is done by either a vascular or orthopedic surgeon, and the common teaching is that generous amputation of bone with the accompanying soft tissue envelope is essential for adequate source control and to prevent recurrence (which remains as high as 30% even with this approach). Most of our patients undergo formal ray amputation through the metatarsal neck, while a few get digital amputations through the interphalangeal joints. Many of the resultant wounds cannot be closed and are left to heal by secondary intention. These amputations invariably alter the biomechanics of the foot and leave large and slow-healing open wounds, which have associated adverse psychosocial impacts. We describe 2 cases of patients who had osteomyelitis in the region of the forefoot who underwent complete bony resections of the osteomyelitis but with sparing of the soft tissue envelopes with good outcomes, and we challenge the dogma that maximal debridement of soft tissue must accompany debridement of necrotic and infected bone.

Prevalence of Proximal Tarsal Disruption in Lisfranc Fracture-Dislocations

Category: Midfoot/Forefoot Introduction/Purpose: Lisfranc fracture/dislocations comprise of spectrum of injury including simple disruption of the lisfranc articulation to more complex tarsometatarsal fracture/dislocations. A further known variant of lisfranc injuries involves proximal tarsal disruption, specifically through the articulation of the medial and middle cuneiform. In the absence of polytrauma and high energy injury it is unknown what proportion of patients with sport or primary axial loading injury have proximal medial column variants of the lisfranc fracture. Recognizing and stabilizing this disruption is critical to establishing a stable medial column and restoring appropriate biomechanics of the foot. Methods: After IRB approval a retrospective cohort of patients was established at a single instutition utilizing CPT codes consistent with fixation of lisfranc/tarsometatarsal fracture-dislocations. Surgical encounters over a 3 year period were identified and retrospective chart review of operative reports and independent evaluation of imaging was used to determine medial column/proximal variants within the included subset of patients. Low energy fracture mechanisms with adequate imaging and operative reports were included in the study. Results: A total of 52 low energy lisfranc fracture-dislocations were included in the study for evaluation of injury patter. Based on imaging studies, intra-operative findings and fixation modalities 30 medial column variants (58%) were identified in this cohort. This subset of patients showed instability through the medial ray extending proximal to the lisfranc articulation and requiring intercuneiform fixation. Conclusion: Tarsometatarsal fracture-dislocations represent a spectrum of injury from disruption of the lisfranc joint to multiple midfoot dislocations. A proximal variant of this injury pattern with intercuneiform disruption is often noted, but prevalence has not been established. In low energy tarsometatarsal fracture-dislocations this study notes a 58% prevalence of medial column disruption requiring additional proximal fixation. Recognizing this injury pattern and appropriately addressing the pathology is critical for obtaining a stable foot and favorable outcome.

Application of magnetorheological fluids in the design of a leg prosthesis with active damping

The article is about of research of the behavior of magnetorheological materials (MR), later it will be implemented in a prototype leg prosthesis with active damping for people who have suffered amputations in lower extremities, which considers the use of an actuator with Magnetorheological Fluids (MRF) LORD MRF – 140 CG, whose control is based on the adjustment of the magnetic field applied to the MRF using in its design the main parameters of anatomy and biomechanics of the foot-leg system, so that the force applied in the course of the gait cycle it can be absorbed by the prosthesis, reducing the impact on the user's column thus allowing the prosthesis to be subjected to tests for emulation in different positions according to the applied load.