Charting a finite element, mechanical atlas of dermatologic wound closure

Wound geometry and the mechanical properties of human skin govern the failure modes of partially healed or scarred tissue. Though dermatologists and surgeons develop an intuitive understanding of the mechanical characteristics of skin through clinical practice, finite element models of wounds can aid in formalizing intuition. In this work, we explore the effect of wound geometry and primary intention closure on the propagation of mechanical stresses through skin. We use a two-layer, orthotropic, hyperelastic model of the epidermis, dermis, and subcutis to accurately capture the mechanical and geometric effects at work. We highlight the key assumptions which must be made when modeling closure of wounds by primary intention, clearly delineating promising areas for model improvement. Models are implemented in DOLFINx, an open-source finite element framework, and reference code is provided for reproducible and extensible science. We provide a framework for modeling the mechanical properties of skin wounds, reporting on the results of extensive finite element simulations of the skin. We perform sanity checks on the results and highlight the problems which remain in enabling clinical use of such modeling. We present finite element methods and reference code for modeling skin wounds and skin wound closure by primary intention, with a focus on reproducibility and critical examination of underlying assumptions.