Design of an advanced temporary hip prosthesis for an effective recovery of septic mobilizations: a preliminary study

The purpose of this study was the design and preliminary feasibility study of an advanced temporary hip prosthesis acting as an in-site drug dispensing system. An interactive device was designed to improve the recovery of bone infections compared to the mechanical spacers currently used in septic mobilizations. A commercial device was chosen and modified specifically for the purpose. First of all, the device was provided with a hydraulic multi-channel system connected via catheter to a subcutaneous valve, refillable with a drug aqueous solution from the outside. Moreover, since it allows samples of biological fluids for analyses to be drawn directly from the implantation site, this chemical dispensing system was designed to allow the course of infections to be monitored and customized therapies to be dosed. The insertion of biocompatible membranes inside the channel ends was considered essential to prevent their occlusion by fibrous tissue growth, thereby preserving the device functionality. Moreover, a biodegradable spongy ring was designed to be fixed onto the stem in distal position both to give primary stability to the implant and to act simultaneously as a scaffold for bonelike cell growth.