The medical industry in the US is well known for its often crippling high costs. The Orthopedic Implant Company in Reno, Nevada joined the medical device market in 2010 with the aim of lowering the cost of trauma-based implants. While The Orthopedic Implant Company has developed an array of systems for bone fractures, they have yet to develop soft-tissue injury solutions. Rotator cuff tears are the most common soft tissue injury requiring surgical repair. Working with design inputs from local surgeons and under strict FDA regulatory requirements, Team 16 aims to develop a system that can be integrated into the team’s existing business model. By providing reusable tools and quick loading, resterilizeable anchors, Team 16 will attack the market by providing a competitive quality suture anchor system that reduces both cost and waste without sacrificing efficiency. Creating an innovative, high-value suture anchor system without infringing on existing patents is the top priority for the team.
Proof of Concept
Team 16’s proof of concept (PoC) will test the ability to easily load a suture anchor with three sutures. The PoC will test the viability of the team’s innovative design concept. Each team member will test the various hole diameters with a set of sutures using a simulated suture threader. All time and ease of use data will be recorded to help quantify the feasibility of the team’s chosen design concept.
The suture anchor system (SAS) is designed to reduce the cost and waste associated with rotator cuff surgery. By allowing the system to be re-sterilized after each surgery, the design dramatically cuts the costs related to the sterile packaging process. The following items will be included in the team’s SAS resterilizable kit: a set of threaded suture anchors, two anchor drivers, a bone punch, and a easy to use suture threading device. Each component will follow the design inputs and specifications dictated by local surgeons and industry standards.
The major specification that Team 16 needed to fulfill is creating an anchor that has the ability to be manually loaded with up to three sutures under operating room conditions. After a successful proof of concept (PoC) test, the team determined a final anchor hole diameter which helped lead the team to the completion of a prototype design.
The SAS kit will allow the user to quickly load anchors with #2 sutures of their choice using a unique suture threader design. The anchor will then be fitted to the end of the anchor driver and the loose suture ends managed on the handle, ready for the surgeon’s use. Upon completion of the surgery, the entire system is rewashed and refilled with anchors from the hospital’s backstock. The sterilization process can then be repeated time and time again saving both patients and hospitals money and reducing waste.
All individual components of the Suture Anchor System were machined and fabricated between the manufacturing lab at the University of Nevada, the Innevation Center, and team member Petr’s family machine shop. Images of the components and machines used for the fabrication process are shown below.
Figure 1: PEEK anchor threads being machined on the CNC lathe at the University of Nevada, Reno’s machine shop.
Figure 2: Ten PEEK anchors prepared on a CNC lathe before going to the mill to receive eyelet holes and the driver interface.
Figure 3: Finalized PEEK anchor and driver interface designed for quick loading and easy suture management.
Figure 4: Driver handle in the process of fabrication here at UNR’s machine shop.
Figure 4: Driver handle in the process of fabrication here at UNR’s machine shop.
Figure 6: Finished anchor caddy with nine 5.5mm suture anchors.
Figure 7: Assembled bone punch with a machined adapter and a simulated laser marking.
Figure 8: Sterilization tray and 3D printed instrument holders.
Testing and Results
Test Plan Each team member loaded and inserted ten anchors into industry standard 10 pcf (pounds per cubic foot) foam using the instruments designed and fabricated by Team 16. Along with the 40 tests performed by the team members, 26 additional tests were performed by people at Innovation day to prove that the system is usable even by untrained passerbys. The team also determined an approximate pull-out force for the anchors by performing a simple set of tests using a luggage scale and the same 10 pcf foam.
Test Results All components of the system worked well and even exceeded expectations. The suture threading device was intuitive and easy to use by those who were completely unfamiliar with the system. Once loaded with sutures the anchor is easily interfaced with the driver and the sutures wrap conveniently around the suture manager. Even inserting the anchor to the proper depth was easily completed by users with little to no instruction.
The system did not fail at any point during the testing and was able to withstand repeated use as desired. While it was discovered that the anchors could pull out from the 10 pcf testing foam, the results only verified research which stated that “If there is a repair failure it would likely result from tendon/bone failure” as not one anchor failed under the forces applied. The failure always resulted in the 10 pcf foam.
The tables below show the average time for each team member to thread an anchor with three #2 sutures and load it onto the driver. Following initial design inputs provided by surgeons, the goal was set at two minutes. The team was happy to discover that the time required to load the sutures averaged between 20 and 30 seconds. In order to get an idea of the competitive pull-out strength, the team used a simple luggage scale and a high-speed camera. With an average pullout force of 217 N, Team 16’s SAS competes with Arthrex (185.7±4.2 N) and RoG (279.2 ±20.8 N).
Project Results The main problem that the project solves is that rotator cuff repairs are unnecessarily expensive for hospitals and patients. By eliminating both unnecessary waste of instruments, and the need for sterile packaging, the team dramatically cuts the costs associated with current systems. The system will provide a more economically and environmentally viable product to the users. Local surgeons who have provided design inputs have shown a great interest in this product and anticipate its market release as does Team 16.
Meet the Team
Born and raised in South Lake Tahoe, CA, Petr is currently a sixth year college student prepared to graduate this spring. He spent three years at Cuesta Community College taking mechanical engineering courses before transferring to the University of Nevada, Reno. Petr earned a summer engineering internship with a local medical device company called The Orthopaedic Implant Company. The company offered to sponsor Petr’s senior design project and, upon graduation, Petr plans to stay and grow with the company.
Anthony is a senior at the University of Nevada, Reno pursuing a Bachelor of Science degree in mechanical engineering. Originally born and raised in the Bay Area, he moved to Reno to attend the university. In addition to his academics at UNR, Anthony has developed his knowledge and skills through many years of hands on experience with mechanics as well as his recent project engineering internship at a highly successful company. After graduation, Anthony plans to pursue an engineering career that will match his interests and experience in project management.
Cooper is a senior at the University of Nevada, Reno pursuing a Bachelor of Science degree in Mechanical Engineering. He is also pursuing a minor in Spanish. Cooper has been qualified for the College of Engineering and College of Liberal Arts Dean’s list from 2012 through 2015. He is a native Nevadan, born and raised in Reno. After graduation, Cooper plans on securing a job in engineering renewable energies throughout South America, preferably in Colombia, Argentina, or Chile.
Brock is attending the University of Nevada Reno (UNR) as a senior level mechanical engineer and is planning on graduate with a bachelor’s of science degree in the spring of 2017. Brock is a native Nevadan, originally from the town of Genoa, and graduated from Douglas High School. After graduating from UNR Brock plans to continue working at his internship as a design engineer while exploring opportunities to work in various locations across the globe.
Team 16 We would like to give a special thanks to the following:
The Orthopaedic Implant Company For sponsorship and funding
and Dr. Uppal For critical design inputs and feedback
Tony “The Machine” Berendsen
and Rand C For fabrication assistance and support
The faculty and staff of the Innevation Center For guidance in training and use of equipmen