Doctor of Philosophy

dissertationPercutaneous osseointegrated devices are being implemented and developed worldwide to improve the quality of life of amputee patients. Unfortunately, these devices disrupt the skin barrier and illicit wound healing responses which can increase the risk of infection. Unable to attach to, or integrate with, the device, the epidermis migrates alongside the device in an attempt to re-establish continuity. This phenomenon is known as epidermal downgrowth and leads to sinus tract formation, creating a portal for bacterial colonization and subsequent infection. In order to reduce the incidence of infection and improve the long-term success of percutaneous devices, there is a need to limit epidermal downgrowth by establishing a robust and stable skin-device seal. One strategy to limit epidermal downgrowth around percutaneous devices involves the application of negative pressure wound therapy (NPWT). However, it is unknown if epidermal downgrowth will remain limited once NPWT is discontinued. Additionally, the influence of NPWT on soft-tissue characteristics around percutaneous devices that exhibit limited downgrowth is unknown. Another strategy which has shown potential to improve soft-tissue outcomes around percutaneous devices involves the modification of device surface topography. Two commonly used topographies are porous and smooth. However, these topographies are unable to prevent epidermal downgrowth which can increase the risk of infection. The goal of this iv dissertation is to: 1) determine the ability of NPWT to prevent the progression of epidermal downgrowth after its discontinuation; 2) evaluate the ability of a microgrooved topography to limit epidermal downgrowth around percutaneous devices; 3) characterize soft-tissue responses, including vascularity and inflammation, to NPWT application which may play a role in limiting downgrowth. The purpose of this work is to contribute to the establishment of a robust skin-device seal with limited downgrowth for improved clinical adoption and effectiveness of percutaneous osseointegrated devices