Progress of computational biomechanical modelling for calcaneal fracture fixation

Background

Calcaneal fractures are among the most disabling and costly orthopaedic injuries, frequently requiring surgical fixation via open reduction and internal fixation (ORIF) or minimally invasive fixation (MIF). Finite element (FE) analysis is an increasingly critical in silico tool for optimizing implant designs and comparing fixation constructs, yet the technical modelling strategies and limitations specific to calcaneal fracture biomechanics have not been systematically mapped.

Technology

The FE modelling pipeline comprises sequential technical domains: (1) medical image-based geometry reconstruction and mesh generation; (2) material assignment (elastic modulus, Poisson's ratio, constitutive laws for bone, cartilage, and ligaments); (3) virtual fracture creation (gap width specification, Sanders classification implementation); (4) implant insertion (plate/screw/nail geometry, contact definition); (5) boundary conditions (standing/gait loading protocols, constraint schemes, muscle force incorporation); (6) solver configuration (static/quasi-static analysis); and (7) outcome extraction (von Mises stress, displacement, construct stiffness, micromotion metrics, etc.). This systematic scoping review followed JBI methodology and PRISMA-ScR guidelines to identify FE studies from PubMed, Web of Science, Scopus, and IEEE Xplore. Methodological quality was evaluated using the MQSSFE instrument for computational orthopaedic models.

Results

Twenty-three studies were included, predominantly using single-subject CT models with artificially created Sanders type II–III intra-articular fractures. Most employed calcaneus-only geometries, linear elastic isotropic bone properties, tetrahedral meshes, and quasi-static stance loading. Locking plates, hybrid plate–screw constructs, screw-only MIF, and intramedullary nails were compared via stress distribution and construct stiffness. Several studies introduced topology-optimized plates and micromotion-based fracture gap metrics, demonstrating that MIF with supplementary percutaneous screws can achieve biomechanical stability comparable to ORIF. However, verification (mesh convergence) and validation procedures were inconsistently reported, dynamic loading and multi-patient cohorts were rare, and interfragmentary strain–based healing criteria were largely absent. This delineation of the current technical design space highlights priorities for more physiologically realistic and methodologically robust in silico studies.