Pendegrass Catherine J, Goodship Allen E, Blunn Gordon W
The Centre for Biomedical Engineering, Institute of Orthopaedics and Musculoskeletal Science, Royal National Orthopaedic Hospital Trust, Brockley Hill, Stanmore, Middlesex, and The Royal Veterinary College, Hertfordshire, UK.
Biomaterials. 2006 Aug;27(23):4183-91. doi: 10.1016/j.biomaterials.2006.03.041. Epub 2006 Apr 17.
Conventional amputation prosthetics are problematic because they rely on the stump-socket interface for attachment. Intraosseous transcutaneous amputation prostheses (ITAP) could solve these problems; however they rely on the integrity of the soft tissue-implant interface as a barrier to exogenous agents, and in the prevention of downgrowth and marsupilisation. We have used an in vivo animal model to study the soft tissue interfaces around bone-anchored transcutaneous implants. We hypothesise that by facilitating and increasing the area of dermal attachment to the implant epithelial down-growth will be reduced. A flange with a series of 24, 0.7 mm holes positioned immediately below the epithelium was used to increase dermal attachment. This significantly reduced downgrowth and optimised the integrity of the collagenous tissue-implant interface at the dermal level. We postulate that the flange reduces relative interfacial movement at the epithelium-implant interface by providing increased surface area for dermal tissue attachment. A tight seal at the dermal tissue level reduces the degree of downgrowth around ITAP, eliminating marsupilisation as a potential failure modality. Surface topography and coatings did not affect the degree of downgrowth or dermal attachment to straight or flanged implants. A significant negative correlation was observed between downgrowth and both epithelial and dermal attachment. This study shows that a soft tissue-implant interface capable of preventing downgrowth and marsupilisation can develop around a bone-anchored transcutaneous implant, given the incorporation of a porous flange positioned in the dermal tissues immediately below the epithelium. This will benefit applications where bone-anchored transcutaneous implants are used.
传统截肢假肢存在问题，因为它们依靠残肢与接受腔的接口来实现连接。骨内经皮截肢假肢（ITAP）可以解决这些问题；然而，它们依赖软组织与植入物接口的完整性作为对外源物质的屏障，并用于防止上皮向下生长和袋状化。我们使用了一种体内动物模型来研究骨锚定经皮植入物周围的软组织接口。我们假设，通过促进并增加真皮与植入物的附着面积，上皮向下生长将会减少。一个带有一系列位于上皮下方的24个0.7毫米孔的凸缘被用于增加真皮附着。这显著减少了向下生长，并在真皮层面优化了胶原组织与植入物接口的完整性。我们推测，凸缘通过为真皮组织附着提供增加的表面积，减少了上皮与植入物接口处的相对界面移动。真皮组织层面的紧密密封减少了ITAP周围的向下生长程度，消除了袋状化作为一种潜在的失败模式。表面形貌和涂层对直的或带凸缘的植入物的向下生长程度或真皮附着没有影响。在向下生长与上皮和真皮附着之间观察到显著的负相关。这项研究表明，在骨锚定经皮植入物周围，只要在紧邻上皮下方的真皮组织中加入一个多孔凸缘，就能够形成一个能够防止向下生长和袋状化的软组织与植入物接口。这将有利于骨锚定经皮植入物的应用。
