Fig. 1

Workflow for generating 3D- and slice-based finite element (FE) models of equine limbs. (A) A standing computed tomography (CT) scan was performed on both equine thoracic limbs using a standing CT scanner. (B) The right thoracic limbs are isolated from the scans. (C) CT images were aligned and co-registered to a common coordinate system. (D) The proximal sesamoid bones (PSBs) and P1 bones were rotated around the joint centre to simulate the galloping posture (rotation of 49°). (E) Segmentation of third metacarpal (MC3), PSBs, articular cartilage (AC), and intersesamoidean ligament/flexor tendon (ISL/FT). (F) Material properties based on bone density were mapped to MC3 and the 3D finite element mesh is created. (G) A dorsal oblique CT slice was taken from the distopalmar section of the joint, the location of the extracted slice is indicated by a dashed line in D and F. (H) The selected CT slice was extruded to a thickness of 20 mm for slice-based modelling; anatomical landmarks are indicated here as sagittal ridge (SR, white arrow), lateral and medial condyles (dashed arrows) and lateral and medial parasagittal grooves (PSGs, solid arrows). These landmarks are also shown in (Fig. 2A and D). (I) A finite element mesh of the slice-based model was generated with bone, cartilage, and ligament structures. (J) Boundary conditions and loading are applied to the slice-based model for biomechanical simulations.