Research & Innovation

Dr. Antonio Valdevit Headed to Kyoto as NIRA Finalist

Stevens Institute of Technology Affiliate Assistant Professor Dr. Antonio Valdevit was selected as a finalist for the New Investigator Recognition Awards (NIRA) competition at the 7th Combined Meeting of the Orthopaedic Research Societies (CORS). The meeting, to be held October 16-20, 2010 in Kyoto, Japan, gathers orthopedic researchers from across the globe to discuss musculoskeletal issues.

Dr. Antonio Valdevit Stevens Institute of Technology Valdevit’s poster, “New Method for Performance Analysis of Pedicle Screw Designs” will vie with 19 other finalists for one of five cash prizes. The work stems from Valdevit’s doctoral dissertation, which was conducted at Stevens, The Innovation UniversityTM.

Approximately 200,000 spinal fusions are performed annually. The procedure results in the boney union of two vertebral bodies via rigid stabilization. The stability is achieved through the use of spacers in the front and a combination of rods and screws in the back. To firmly anchor the screws, the surgeon places them in the pedicle of the vertebra. Traditionally, pedicle screw designs have been compared using static pullout. While pullout techniques are standard, they are not clinically relevant, because such a loading condition does not occur in the body. Further, pullout tests tend to be insensitive to unique design features as the bone within the vertebral body fails in shear.

In order to better differentiate the characteristics of pedicle screw designs, Valdevit’s work has focused on the use of toggle fatigue testing to evaluate mechanical functionality of these pedicle screws. Highlighted in this study was the use of nonlinear methods in the analysis of the deformation at the screw/bone interface and work generated due to loading. What was found was that not only do these commercial pedicle screws display a similar curve patterns with respect to the cycle number, the mathematical parameters that describe the curves are unique to the screw design. In cases of spinal fusion, a rigid system is required to obtain suitable for fusion. However, overly rigid systems can induce stress shielding and predispose adjacent segments to degeneration. The next step is to correlate the performance characteristics using the methods in this study to clinical data in order to provide clinical validation for current and new designs.

“With the new age of health care that we are to undertake, data such this may become standard practice in the evaluation of spinal instrumentation” Valdevit says.

To learn more about Dr. Valdevit’s work, visit his Faculty Profile.

About Stevens Institute of Technology
Founded in 1870 and celebrating 140 Years of Innovation, Stevens Institute of Technology, The Innovation University™, lives at the intersection of industry, academics and research. The University's students, faculty and partners leverage their collective real-world experience and culture of innovation, research and entrepreneurship to confront global challenges in engineering, science, systems and technology management.
Based in Hoboken, N.J. and with a location in Washington, D.C., Stevens offers baccalaureate, master’s, certificates and doctoral degrees in engineering, the sciences and management, in addition to baccalaureate degrees in business and liberal arts. Stevens has been recognized by both the US Department of Defense and the Department of Homeland Security as a National Center of Excellence in the areas of systems engineering and port security research. The University has a total enrollment of more than 2,200 undergraduate and 3,700 graduate students with almost 450 faculty. Stevens’ graduate programs have attracted international participation from China, India, Southeast Asia, Europe and Latin America as well as strategic partnerships with industry leaders, governments and other universities around the world. Additional information may be obtained at and