Senior Design Team Tackles Precision in Hip Replacement Surgery

Hip replacement surgery is one of the most common orthopedic procedures performed in the United States. While it is highly successful, one critical step requires remarkable precision: securing the femoral stem. The femoral stem is a metal post inserted into the hollow center of the thigh bone that must fit securely to provide long-term stability. Surgeons typically use either an impactor gun or a mallet to drive the implant into place, relying largely on experience and what they can feel and hear to determine when the stem is properly seated. There is no precise measurement that confirms the implant has reached the ideal position.

As part of their senior design project, Rose-Hulman mechanical engineering students Colby Sanders, Ian Bowman, Tyler Cariola, and Trong Pham set out to measure the exact moment the implant is properly seated, replacing subjective judgment with objective data. Enovis, a medical technology company specializing in orthopedic devices, challenged the team to develop a solution that could improve surgical consistency, implant performance, and patient outcomes. 

Rebecca Bercich, PhD, associate professor of mechanical engineering, served as the team’s faculty advisor. She noted that the project presented interesting challenges that the student team had to overcome in the areas of engineering mechanics, signal processing, and fabrication. Yet with those challenges came unique benefits. 

“The students got to work alongside practicing engineers at Enovis as well as an experienced orthopedic surgeon, Dr. Michael Meneghini, as they designed tool attachments, wrote data processing scripts, and crafted an experimental protocol,” Bercich said.

Meneghini—founder and CEO of Indiana Orthopedic Institute and a 1995 civil engineering alumnus—served as the team’s clinical adviser, helping the students understand how surgeons use these instruments in the operating room. Indiana Orthopedic Institute will have a future location at Innovation Grove, which is scheduled to open in early 2027.

“Dr. Meneghini helped us understand how engineering and medicine intersect,” Sanders said.

The team proposed integrating sensors into the surgical instrument itself to detect when the implant had reached a stable, properly seated position. Although little prior research existed on this type of technology, Sanders said that uncertainty made the project even more rewarding. He enjoyed tackling a problem outside his usual coursework while helping develop an entirely new approach.

“After my senior design project, I feel like I can take on any challenge,” Sanders said. “I loved digging into this project and learning something completely new. It also showed me how much I can contribute as part of a team. Combined with my Rose education, that gives me confidence to pursue almost any engineering opportunity.” 

The team divided the project into two parts. Half designed and built a physical prototype that simulated the surgical environment. The experimental rig featured a steel outer frame with foam material representing human bone, allowing the team to recreate the conditions surgeons encounter during hip replacement procedures. The other half designed custom housings for high-precision sensors that could be mounted to the surgical instruments. Once manufactured, the prototype underwent testing while the students developed software in Rose-Hulman's materials laboratory to collect and analyze data from each simulated procedure. Enovis was encouraged by the results and is continuing to refine, manufacture and test the technology.

Sanders said he’s especially proud that the project could continue beyond graduation and eventually benefit patients. 

“I love the idea that, at the end of the day, our work will help a lot of people and further an industry that is trying to relieve pain from people,” he said. “Whenever things got hard, I reminded myself of that.”