MD/PhD student honored at international engineering conference

A paper authored by an MD/PhD candidate at Washington University in St. Louis recently took first prize at the American Society of Mechanical Engineers International Mechanical Engineering Congress and Exhibition.

Stephen Linderman

Stephen Linderman's paper, presenting technology for improving surgical suturing for better tendon repairs, won the top honor in the biomedical engineering and technology track at the exhibition — the world's largest, cross-disciplinary mechanical engineering conference. Linderman's research is conducted through the university's Department of Orthopaedic Surgery in the School of Medicine, and the Department of Biomedical Engineering in the School of Engineering & Applied Science.

"Surgical suturing is a crude mechanical solution," said Linderman, the paper's first author. "Sutures are in tension along their length, but the load is predominantly transferred to the surrounding tissue where sutures bend at anchor points, and this leads to failed surgeries. We found a simple way to improve repair schemes by minimizing stress concentrations, without complicating the surgeon's workflow."

The paper identified the combination of strength and stiffness needed for an adhesive on the sutures to improve a surgical repair.

"An adhesive layer that is too stiff will make things worse by concentrating stresses, and an adhesive that is too weak will fail without improving the repair," said the paper's senior author, Guy M. Genin, a professor of mechanical engineering and materials science at the School of Engineering & Applied Science. "Steve's breakthroughs were to identify the 'sweet spot' and then identify the classes of materials whose properties land in that spot. It was exciting to present this at a venue like the IMECE, where we could get feedback on our ideas from researchers with depth in a broad range of disciplines."

Linderman's team presented a set of preliminary results that show the idea will work, and it is working to commercialize the technology.

"The preliminary data are promising and exciting, and the next round of adhesives we are working on show great promise for clinical application," said one of the co-authors, Stavros Thomopoulos, a former Washington University medical and engineering faculty member now Vice Chair of Orthopedic Surgery at Columbia University.

"IMECE is the place for researchers to present breakthroughs across the entire range of mechanical engineering disciplines," said Christine M. Reilley, director of business development in the Engineering Sciences Segment at ASME. "We are thrilled to recognize Linderman and his colleagues on their contributions to the field and look forward to hearing the impact of their work on humankind."

Other Washington University authors on the paper include: Ioannis Kormpakis, a clinical and research fellow in orthopedic surgery; and Richard H. Gelberman, MD, former head of the Department of Orthopaedic Surgery. Ulrike Wegst, of Dartmouth College, and Victor Birman, of the Missouri University of Science and Technology are also authors.

The School of Engineering & Applied Science at Washington University in St. Louis focuses intellectual efforts through a new convergence paradigm and builds on strengths, particularly as applied to medicine and health, energy and environment, entrepreneurship and security. With 90 tenured/tenure-track and 40 additional full-time faculty, 1,200 undergraduate students, 1,200 graduate students and 21,000 alumni, we are working to leverage our partnerships with academic and industry partners — across disciplines and across the world — to contribute to solving the greatest global challenges of the 21st century.

The research was funded by Washington University through a Musculoskeletal Research Center Translational Grant and through the National Center for Advancing Translational Sciences of the National Institutes of Health (NIH), grant number UL1 TR000448.

Linderman SW, Kormpakis I, Gelberman RH, Birman V, Wegst UGK, Thomopoulos S, Genin GM. (2016). IMECE2016-67522: Shear lag sutures: Improved suture repair through the use of adhesives. ASME International Mechanical Engineering Conference & Exhibition, Phoenix, AZ, November 11-17, 2016.