Giusto Elena, Blunn Gordon, de Godoy Roberta Ferro, Liu Chaozong, Pendegrass Catherine
Institute of Orthopaedic & Musculoskeletal Science, University College London, Royal National Orthopaedic Hospital, Stanmore, UK.
Barts and the London School of Medicine and Dentistry, Queen Mary University London, London, UK.
Biomater Transl. 2022 Dec 28;3(4):243-249. doi: 10.12336/biomatertransl.2022.04.004. eCollection 2022.
Osseointegrated transcutaneous implants could provide an alternative and improved means of attaching artificial limbs for amputees, however epithelial down growth, inflammation, and infections are common failure modalities associated with their use. To overcome these problems, a tight seal associated with the epidermal and dermal adhesion to the implant is crucial. This could be achieved with specific biomaterials (that mimic the surrounding tissue), or a tissue-specific design to enhance the proliferation and attachment of dermal fibroblasts and keratinocytes. The intraosseous transcutaneous amputation prosthesis is a new device with a pylon and a flange, which is specifically designed for optimising soft tissue attachment. Previously the flange has been fabricated using traditional machining techniques, however, the advent of additive layer manufacturing (ALM) has enabled 3-dimensional porous flanges with specific pore sizes to be used to optimise soft tissue integration and reduce failure of osseointegrated transcutaneous implants. The study aimed to investigate the effect of ALM-manufactured porous flanges on soft tissue ingrowth and attachment in an in vivo ovine model that replicates an osseointegrated percutaneous implant. At 12 and 24 weeks, epithelial downgrowth, dermal attachment and revascularisation into ALM-manufactured flanges with three different pore sizes were compared with machined controls where the pores were made using conventional drilling. The pore sizes of the ALM flanges were 700, 1000 and 1250 μm. We hypothesised that ALM porous flanges would reduce downgrowth, improve soft tissue integration and revascularisation compared with machined controls. The results supported our hypothesis with significantly greater soft tissue integration and revascularisation in ALM porous flanges compared with machined controls.
骨整合式经皮植入物可为截肢者提供一种替代且改良的假肢连接方式，然而上皮细胞向下生长、炎症和感染是与其使用相关的常见失败模式。为克服这些问题，实现表皮和真皮与植入物紧密粘连的密封至关重要。这可以通过特定的生物材料（模仿周围组织）或组织特异性设计来实现，以增强真皮成纤维细胞和角质形成细胞的增殖和附着。骨内经皮截肢假体是一种带有支柱和凸缘的新装置，专门设计用于优化软组织附着。此前，凸缘是使用传统加工技术制造的，然而，增材制造（ALM）的出现使得具有特定孔径的三维多孔凸缘得以用于优化软组织整合并减少骨整合式经皮植入物的失败。该研究旨在调查在复制骨整合式经皮植入物的体内绵羊模型中，ALM制造的多孔凸缘对软组织向内生长和附着的影响。在12周和24周时，将三种不同孔径的ALM制造的凸缘的上皮细胞向下生长、真皮附着和血管再生情况与使用传统钻孔制造孔隙的加工对照进行比较。ALM凸缘的孔径分别为700、1000和1250μm。我们假设，与加工对照相比，ALM多孔凸缘将减少上皮细胞向下生长，改善软组织整合和血管再生。结果支持了我们的假设，与加工对照相比，ALM多孔凸缘的软组织整合和血管再生明显更好。
