DESIGN, VALIDATION AND NAVIGATION OF ANATOMIC POPULATION- BASED AND PATIENT-SPECIFIC RADIAL HEAD IMPLANTS

Radial head replacement for fractures and arthritis are commonly performed; however, most available implants do not accurately replicate the complex native anatomy. This work examines the creation and surgical implantation of an anatomic implant system. Radial head morphology was parameterized using ellipse fitting to allow reverse engineering of the shape (n=50). Using the derived parameters, anatomic implants were generated for both a population “average” and patient-specific designs. Mean surface mismatch between these implant models and the native morphology was compared to an existing axisymmetric implant (n=34). Anatomic designs showed reduced mismatch relative to the existing implant with the anatomic patient-specific design performing best. A surgical navigation system was developed and tested for implant alignment. The mean placement accuracy and standard deviation was 1.5±0.5mm in translation and 1.2±1.0°, 1.4±1.8°and 5.5±3.2° in rotation about the lateral, anterior and proximal axes respectively (n=7). These studies demonstrate the feasibility of anatomic radial head implant designs; however, further work is required to improve placement accuracy

Radiological Society of North America (RSNA) 3D printing Special Interest Group (SIG): Guidelines for medical 3D printing and appropriateness for clinical scenarios

Este número da revista Cadernos de Estudos Sociais estava em organização quando fomos colhidos pela morte do sociólogo Ernesto Laclau. Seu falecimento em 13 de abril de 2014 surpreendeu a todos, e particularmente ao editor Joanildo Burity, que foi seu orientando de doutorado na University of Essex, Inglaterra, e que recentemente o trouxe à Fundação Joaquim Nabuco para uma palestra, permitindo que muitos pudessem dialogar com um dos grandes intelectuais latinoamericanos contemporâneos. Assim, buscamos fazer uma homenagem ao sociólogo argentino publicando uma entrevista inédita concedida durante a sua passagem pelo Recife, em 2013, encerrando essa revista com uma sessão especial sobre a sua trajetória

Development of an Active Elbow Motion Simulator and Coordinate Systems to Evaluate Kinematics in Multiple Positions

Elbow disorders are common as a consequence of both traumatic and degenerative conditions. Relative to disorders of the lower limb, there is comparatively little evidence to direct the treatment of many elbow disorders. Biomechanical studies are required to develop and validate the optimal treatment of elbow disorders prior to their application in patients. Clinically relevant simulation of elbow motion in the laboratory can be a powerful tool to advance our knowledge of elbow disorders. This work was undertaken with the rationale that simulation and quantification of elbow motion could be improved significantly. This treatise includes the development and evaluation of an in-vitro elbow motion simulator which, with the humerus horizontally positioned, is the first to achieve active flexion and extension in a vertical plane. Additionally, it is capable of operating in the vertical, varus and valgus positions, and while maintaining full forearm pronation or supination. The simulator controller employs a Cascade PID configuration with feedforward transfer functions, which achieves unified control of flexion angle and muscle tension for multiple muscles. Feedback of the elbow joint angle and muscle tension is utilized to achieve closed-loop control. A performance evaluation in a full series of specimens clearly demonstrated that the actual joint angle is not more than 5 degrees removed from the desired setpoint during flexion or extension in any position. Also, a new method for creating upper extremity bone segment coordinate systems which are derived from elbow flexion and forearm rotation was developed and tested. This produced joint kinematics with significantly less inter-subject variability than traditional anatomy-derived coordinate systems. This minimally-invasive method also provides increased statistical power for laboratory based studies and may prove useful for clinical applications. The new simulation techniques developed herein were applied to an in-vitro investigation of olecranon fracture repair with clinical significance. This study revealed valuable insights into a common repair procedure. This was made possible by the previously unattainable measurements that these new techniques now provide. These developments will assist surgeons and other investigators in the design and evaluation of treatments for elbow disorders, and contribute to the betterment of patient care

The Possibilities of Personalized 3D Printed Implants—A Case Series Study

Background and Objectives: Following the most recent software and 3D printing developments, the use of personalized 3D printed orthopedic implants for treatment of complicated surgical cases has gained more popularity. Today, orthopedic problems that cannot be solved with standard implants may be effectively addressed using personalized prostheses. The aim of this study is to present the designing, modeling and production stages of four different personalized 3D printed prostheses and their application in clinical cases of patients who underwent treatment in various anatomical locations with a precisely specified indication for implantation. Materials and Methods: Based on computed tomography scanning, personalized 3D printed prostheses were designed, produced and used in four patients within a period of three to five days after injury or admission. Results: Early term follow-ups demonstrated good to excellent results. Conclusions: Personalized 3D printed prostheses offer an opportunity for a treatment of choice and provide good anatomical and functional results, shortened surgical time, less complications, and high satisfaction in patients with appropriate indications. The method should be considered primarily for patients with large bone defects, or such indicated for resection. Personalized 3D printed prostheses have the potential to become more common and beneficial in the future

Towards the Evolution of Novel Vertical-Axis Wind Turbines

Renewable and sustainable energy is one of the most important challenges currently facing mankind. Wind has made an increasing contribution to the world's energy supply mix, but still remains a long way from reaching its full potential. In this paper, we investigate the use of artificial evolution to design vertical-axis wind turbine prototypes that are physically instantiated and evaluated under approximated wind tunnel conditions. An artificial neural network is used as a surrogate model to assist learning and found to reduce the number of fabrications required to reach a higher aerodynamic efficiency, resulting in an important cost reduction. Unlike in other approaches, such as computational fluid dynamics simulations, no mathematical formulations are used and no model assumptions are made.Comment: 14 pages, 11 figure

Recent trends, technical concepts and components of computer-assisted orthopedic surgery systems: A comprehensive review

Computer-assisted orthopedic surgery (CAOS) systems have become one of the most important and challenging types of system in clinical orthopedics, as they enable precise treatment of musculoskeletal diseases, employing modern clinical navigation systems and surgical tools. This paper brings a comprehensive review of recent trends and possibilities of CAOS systems. There are three types of the surgical planning systems, including: systems based on the volumetric images (computer tomography (CT), magnetic resonance imaging (MRI) or ultrasound images), further systems utilize either 2D or 3D fluoroscopic images, and the last one utilizes the kinetic information about the joints and morphological information about the target bones. This complex review is focused on three fundamental aspects of CAOS systems: their essential components, types of CAOS systems, and mechanical tools used in CAOS systems. In this review, we also outline the possibilities for using ultrasound computer-assisted orthopedic surgery (UCAOS) systems as an alternative to conventionally used CAOS systems.Web of Science1923art. no. 519