Abstract
AimsThe Intraosseous Transcutaneous Amputation Prosthesis (ITAP) may improve quality of life for amputees by avoiding soft-tissue complications associated with socket prostheses and by improving sensory feedback and function. It relies on the formation of a seal between the soft tissues and the implant and currently has a flange with drilled holes to promote dermal attachment. Despite this, infection remains a significant risk. This study explored alternative strategies to enhance soft-tissue integration.Materials and MethodsThe effect of ITAP pins with a fully porous titanium alloy flange with interconnected pores on soft-tissue integration was investigated. The flanges were coated with fibronectin-functionalised hydroxyapatite and silver coatings, which have been shown to have an antibacterial effect, while also promoting viable fibroblast growth in vitro. The ITAP pins were implanted along the length of ovine tibias, and histological assessment was undertaken four weeks post-operatively.ResultsThe porous titanium alloy flange reduced epithelial downgrowth and increased soft-tissue integration compared with the current drilled flange. The addition of coatings did not enhance these effects.ConclusionThese results indicate that a fully porous titanium alloy flange has the potential to increase the soft-tissue seal around ITAP and reduce susceptibility to infection compared with the current design.Cite this article: Bone Joint J 2017;99-B:393–400.
Highlights
Received 30 April 2016; Accepted after revision 7 October 2016. These results indicate that a fully porous titanium alloy flange has the potential to increase the soft-tissue seal around Intraosseous Transcutaneous Amputation Prosthesis (ITAP) and reduce susceptibility to infection compared with the current design
The Intraosseous Amputation Prosthesis (ITAP) (Stanmore Implants Worldwide Ltd, Elstree, United Kingdom) is an osseointegrated, transcutaneous titanium alloy implant that penetrates the skin to attach an external prosthesis. It avoids many of the common problems of conventional socket prostheses, such as discomfort, excessive perspiration, pressure sores caused by non-uniform pressure distribution over the stump and the need for repeated fittings due to poor fit.[1,2,3]
Osseointegrated transcutaneous prostheses are able to avoid these problems because the forces that would be encountered by the soft tissues of the stump with the use of a socket prosthesis are transferred directly to the skeleton
Summary
The effect of ITAP pins with a fully porous titanium alloy flange with interconnected pores on soft-tissue integration was investigated. Transcutaneous pins with a laser-sintered porous titanium alloy flange (pore size 700 μm and strut size 300 μm, porosity 18%) (Eurocoatings, Trentino, Italy) were used (Fig. 1a, Table I). The flanges were either uncoated (PT) or coated with electrochemically deposited hydroxyapatite (PT-HA), hydroxyapatite (HA) with fibronectin (PT-HAFn), HA with silver (PT-HAAg) or HA with silver and fibronectin (PT-HAAgFn). The details of the surface preparation and electrochemical deposition process is available in the supplementary material. An uncoated straight pin (SP) without a flange was included as a control for the DF design. The amount of silver released into fetal calf serum from PT-HAAg was measured over a four-week
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
