The Approximation Principle: A Novel Mechanobiological Approach to Chronic Wound Management

Abstract

Chronic wounds represent a pathological disruption of the canonical wound healing cascade, often arrested in a pro-inflammatory phase due to cellular senescence, biofilm presence, and altered mechanotransduction signaling. Approximation in wound care refers to the process of bringing the wound's opposing tissue surfaces, either edges or walls, closer together to facilitate faster healing. Though common in acute wound closure, the approximation principle is rarely used in chronic wounds due to concerns about cavity formation and infection. This paper redefines approximation as a biomechanical intervention targeting wound wall convergence to converge wound walls through controlled compression. Unlike edge-based suturing or closure, wall approximation modifies the wound's 3D architecture and microenvironment, thus stimulating tissue regeneration. Mechanical compression influences fibroblast behavior and matrix remodeling through core mechanotransduction pathways involving integrins, cytoskeletal dynamics, and focal adhesion signaling. This study investigates the influence of skin anisotropy and Langer's lines on modulating mechanical tension and healing outcome. Integrating clinical observations with mechanistic insights, this article presents approximation as a practical, evidence-based strategy to promote healing in chronic wounds, including those not amenable to surgical closure.

Keywords: approximation; chronic wounds; mechanobiology; skin tension lines; wound edges; wound pocket; wound undermining; wound walls.