Incorporating pathological gait into patient-specific finite element models of the haemophilic ankle

Haemarthrosis is an inherent clinical feature of haemophilia, a disease characterised by an absence or reduction in clotting proteins. Patients with severe haemophilia experience joint bleeding leading to blood-induced ankle arthropathy (haemarthropathy). Altered biomechanics of the ankle have been reported in people with haemophilia; however, the consequence of this on joint health is little understood. The aim of this study was to assess the changes in joint contact due to haemophilia disease-specific gait features using patient-specific modelling, to better understand the link between biomechanics and joint outcomes. Four, image-based, finite element models of haemophilic ankles were simulated through consecutive events in the stance phase of gait, using both patient-specific and healthy control group (n = 36) biomechanical inputs. One healthy control FE model was simulated through the healthy control stance phase of the gait cycle for a point of comparison. The method developed allowed cartilage contact mechanics to be assessed throughout the loading phase of the gait cycle. This showed areas of increased contact pressure in the medial and lateral regions of the talar dome, which may be linked to collapse in these regions. This method may allow the relationship between structure and function in the tibiotalar joint to be better understood

Three subject-specific human tibiofemoral joint finite element models: complete three-dimensional imaging (CT & MR), experimental validation and modelling dataset.

This dataset includes the experimental data, three-dimensional imaging, computational models and study data from work validating three subject-specific human tibiofemoral joint finite element models. This work forms part of a wider project developing in vitro and in silico pre-clinical testing methods for tissue preserving treatments of the knee joint. The aim of the related study was to provide validation of contact mechanics outputs for specimen-specific tibiofemoral joint models and specifically investigate the need for subject-specific shape representation for the cartilage and meniscus tissues. The dataset provides a complete set of imaging, experimental and computational data for replication of the study. To maximum the potential for re-use the dataset includes imaging and experimental data, which was collected alongside the immediate study data, but not used in that work. Magnetic resonance imaging of the knee joints in their intact state is included, using eight different imaging sequences. Micro computed tomography imaging of the distal femur and proximal tibia after dissection and testing are also provided for all three knee joints. The experimental data includes pressure sensor measurements taken from the tibial cartilage surface at multiple knee joint flexion angles and photographs taken during dissection, potting and loading of the joints. The computational models are provided for all cases performed for the validation and sensitivity testing study, along with the associated results

Prediction of the mechanical response of canine humerus to three-point bending using subject-specific finite element modelling

Subject-specific finite element models could improve decision making in canine long-bone fracture repair. However, it preliminary requires that finite element models predicting the mechanical response of canine long bone are proposed and validated. We present here a combined experimental–numerical approach to test the ability of subject-specific finite element models to predict the bending response of seven pairs of canine humeri directly from medical images. Our results show that bending stiffness and yield load are predicted with a mean absolute error of 10.1% (±5.2%) for the 14 samples. This study constitutes a basis for the forthcoming optimization of canine long-bone fracture repair

A pressure dependent bone remodeling model for application in orthodontics

peer reviewe

Bovine intervertebral disc mechanical characterisation dataset

Combined experimental and computational study of mechanical behaviour of bovine intervertebral disc. Experimental data: photographic evidence of pre-strain in the disc (+ geometrical measurements); computational data: FE input models of bovine osteodiscs and reverse engineering script, model outputs; associated R, Python and matlab script

A damage/repair model for alveolar bone remodeling

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A Continuum Damage Mechanics based bone remodelling model in a finite strain framework

peer reviewe

On the periodontal ligament representation in orthodontic tooth movement modelisation

Orthodontic tooth movement (OTM) is the result of bone remodeling at the interface with the periodontal ligament (PDL) around a mechanically loaded tooth in response to a biomechanical stimulus. Modeling of the PDL therefore plays an important role in the process of modeling OTM. However when producing a finite element model from clinical computer tomography data, the PDL cannot be segmented and its geometry is approximated by many authors from the root geometry. The aim of this study is to propose alternatives to a geometrical representation of the PDL using either simple spring elements between the teeth and alveolar bone or bilateral sticking contact conditions. Results consist in a comparison of the hydrostatic and Von-Mises stresses in the bone along the root as well as the strain energy used in a bone remodeling algorithm when a 1N force is applied to a single rooted tooth crown. While both models can well represent the pressure (hydrostatic stress) transfer from the tooth to the bone, the bilateral sticking contact conditions show better results to transfer the shear stress as well as the strain energy