Research Article Design Concepts of Polycarbonate-Based Intervertebral Lumbar Cages: Finite Element Analysis and Compression Testing J. Obedt Figueroa-Cavazos, 1 Eduardo Flores-Villalba, 1 José A. Diaz-Elizondo, 2 Oscar Martínez-Romero, 1 Ciro A. Rodríguez, 1 and Héctor R. Siller 1 1 Tecnologico de Monterrey, Escuela de Ingenier´ ıa y Ciencias, 64849 Monterrey, NL, Mexico 2 Tecnologico de Monterrey, Escuela de Medicina, 64710 Monterrey, NL, Mexico Correspondence should be addressed to H´ ector R. Siller; hector.siller@itesm.mx Received 16 November 2015; Revised 29 March 2016; Accepted 18 April 2016 Academic Editor: Tadeusz Mikołajczyk Copyright © 2016 J. Obedt Figueroa-Cavazos et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Tis work explores the viability of 3D printed intervertebral lumbar cages based on biocompatible polycarbonate (PC-ISO5 material). Several design concepts are proposed for the generation of patient-specifc intervertebral lumbar cages. Te 3D printed material achieved compressive yield strength of 55 MPa under a specifc combination of manufacturing parameters. Te literature recommends a reference load of 4,000N for design of intervertebral lumbar cages. Under compression testing conditions, the proposed design concepts withstand between 7,500 and 10,000N of load before showing yielding. Although some stress concentration regions were found during analysis, the overall viability of the proposed design concepts was validated. 1. Introduction Te combination of biotechnology and 3D printing has led to the rise of 3D bioprinting, which is a processing technique that promises to solve critical issues while fnding printable biomaterials, increasing the capacity of precise position- ing and including cell sources, in order to be successfully applied in diagnosis, personalized medicine, and regenerative medicine [1]. Literature that demonstrates the disruptive- ness of this group of applications is spread out in several felds. Radenkovic et al. suggested the idea of manufacturing personalized human hollow organs with lower architectural complexity using detailed patient information, acquired by medical imaging, appropriate cell type, and 3D printing technology [2]. Other works showed the potential of medical and industrial applications of several classes of 3D printing techniques that may be useful for attending the future demand for organ transplants. For example, Yoo made a comparison among diferent 3D bioprinting technologies in order to evaluate their impact on human health and medical devices industry [3]. Visser et al. stated that the potential application of 3D bioprinting in medicine will evolve into tissue printing in the near future [4]. 3D printing of implants, prosthesis, and other medical devices can be considered an important stage of the full devel- opment of 3D bioprinting applications. Particularly, design of prosthesis and implants is nowadays embracing the use of 3D printing technologies as FDM (Fused Deposition Modeling), in order to solve the need for customization and the need for providing a fast response in surgical interventions [5]. Some previous works show that it is possible to satisfy the main features required in customized medical devices such as strength, sterility, dimensional stability, and safety. For exam- ple, Rankin et al. used a FDM machine for surgical retractors prototyping. Tis prototype was sterilized and tolerated the tangential force needed to fulfll the requirements before failure, both before and afer exposure to sterilization [6]. A specifc case of the need of customized implants is column surgery. Tis is performed in order to ease patholo- gies associated with back pain that are sometimes caused by deterioration of surrounding fbrous ring of intervertebral discs, resulting in spinal disc herniation. Te column surgery that deals with this illness is usually known as spinal fusion surgery, where the vertebrae gradually fuse into a single body with the introduction of an intervertebral cage implant. Spinal fusion is done most commonly in the lumbar region Hindawi Publishing Corporation Applied Bionics and Biomechanics Volume 2016, Article ID 7149182, 9 pages http://dx.doi.org/10.1155/2016/7149182