Shear Wave Elasticity Imaging for Monitoring Risk of Skin Breakdown Following Subcutaneous Implantation

Subcutaneous implants are widely used in craniofacial reconstruction to restore structural integrity and aesthetics; however, complications such as skin breakdown and implant exposure remain common and can significantly impact patient outcomes. These adverse events are hypothesized to be preceded by biomechanical changes in the overlying skin, including stiffness alterations resulting from increased mechanical stress and tissue remodeling. This study evaluates the feasibility of using ultrasound shear wave elasticity imaging as a non-invasive, quantitative tool to monitor skin stiffness following subcutaneous implantation and assess its potential for identifying exposure risk. 16 SKH1-elite mice were divided into four groups: three groups receiving different 3D-printed poly-ε-caprolactone implants (unimodal block, bimodal block, and unimodal dome) and a non-implanted control group. Shear wave elasticity imaging measurements were acquired prior to implantation and longitudinally over 12 weeks post-implantation to quantify temporal changes in skin shear modulus. Skin shear modulus increased significantly from pre-implantation baseline to immediately post-implantation, reflecting elevated mechanical stress and non-linear elastic behavior in the overlying skin. Subsequently, shear modulus decreased at varying rates depending on implant type and sustained stress that led to eventual exposure. Comparison of shear modulus temporal behavior between exposed (stiffer) and non-exposed groups revealed statistically significant differences at two weeks post-implantation ( p < 0.01). These findings demonstrate that shear wave elasticity imaging can quantitatively capture implant-induced changes in skin stiffness and has strong potential as an early indicator of implant-related skin complications. This approach may provide a valuable tool for guiding implant design and improving post-operative monitoring strategies.