Intramedullary Balloon Catheter Stent For Tubular Fractures

Abstract

Trauma remains one of the leading causes of mortality, with fractures accounting for the majority of trauma; therefore novel therapies are desperately needed to optimize patient outcomes. The fixation device, intramedullary nailing has a long history, which dates back to the 16th century and has evolved in various aspects. Intramedullary nailing has had a good success rate, and it has now become a gold standard for the treatment for diaphyseal fractures, however drawbacks related to the technique still exist, but continued research regarding new mechanisms and internal fracture fixation devices can overcome these drawbacks. New “biological osteosynthetic devices”, which are minimally invasive, with shorter healing times, have the potential to transform future orthopedic treatment. Internal fixation methods have showed significant advancement in the treatment of fractures. The advantages of biological internal fixation lower severe risks and complications, on the expense of less important mechanical drawbacks. New osteosynthetic devices, such as intramedullary bone stents can be superior to current internal fracture fixation devices, as they have a modulus of elasticity closer to that of bone, cause minimum trauma and soft tissue damage. Additionally, they can overcome both major and minor complications posed by conventional devices, such as stress shielding, infections and an inadequate blood supply. The present research study was inspired by the Auxetic (‘rotating-triangles’) geometry proposed by Grima et al. The main objective of this study was to adopt a novel manufacturing technique for the fabrication of Auxetic films and Auxetic intramedullary stents, with uniform rotating triangle geometry. In order to easily deploy the Auxetic stent orally into the intramedullary canal, a commercial balloon dilatational catheter was used, which was cost effective. Polyurethane (PU) was selected as the material of choice for the design and manufacture of an Auxetic film (rotating triangles), as it is one of the most widely used bio-compatible and blood compatible materials used in biomedical applications, and has played a major role in the development of a variety of medical devices. Both seamed and seamless Auxetic stents were manufactured and tested. Tensile testing of the Auxetic films (rotating-triangles) was performed in order to characterize their deformation behavior and mechanical properties. The tensile test was also used to calculate the Poisson’s ratio of the Auxetic films. The stent expansion test was performed on both the manufactured seamed and seamless stents in order to analyze the transverse and axial expansion of the stents