Research That Led to Results

Our overarching goal at DePuy Synthes Joint Reconstruction is to improve the lives of patients through science-based innovation in orthopedics. Given research that showed us that 10 to 20 percent of knee replacement patients aren’t completely satisfied with their knee replacements, improving implant performance and patient satisfaction was a key focus of the Attune knee development.¹ We started with an unmet patient need: to improve range of motion and address the unstable feeling some patients experience during everyday activities, such as descending stairs and bending. To better understand the patient needs, we worked with a large group of engineers and scientists and cross-functional teams that collaborated with external research groups.

For example, over the course of several years, our research team visited the Joint Biomechanics Lab at a renowned university close to 30 times to work with their dynamic weight-bearing simulator, a novel device that is able to reproduce the kinematics that we see in total-knee patients. This technology allowed us the opportunity to test the performance of different designs in the simulator while re-creating the weight-bearing conditions of patients performing activities such as going down stairs and walking.

We also collaborated closely with another renowned university to create and validate computer models of total knee patients. These models provided the ability to test the performance of new implants on the computer and, in turn, gain a better understanding of what the optimal knee implant should look like.

Our research and development teams spent more than 10,000 hours working with surgeons in different settings as well as various institutions to get feedback and record data. This research also included ethnological research with doctors—filming them, studying movements and behaviors, and even looking for operating efficiencies. Other research activities included studying fluoroscopic X-rays of patient movement and extensive tests with cadaver knees.

From this extensive research into the functions of total knee replacements, it became clear to us that small changes to the geometry of the knee design can produce significant changes in the “feel” of the implant. In addition, many new product introductions in orthopedics represent incremental improvements or line extensions to existing systems, while the Attune knee looked at aspects of knee design with the goal to improve performance and satisfaction.

What resulted was an innovative knee system that combines the latest in design, kinematics, engineering and materials to deliver a high level of stability and motion to help patients achieve their optimum range of motion, giving them freedom to move while remaining very stable. To date, we’ve received positive anecdotal feedback from surgeons, patients and physical therapists regarding patient recovery, stability and motion.

David A. Fisher, M.D., an Indianapolis, Ind.-based orthopedic surgeon with whom we worked closely, has been using the Attune knee in his practice for 22 months, and reports good results.

“The patient results I’ve seen have been outstanding,” Fisher said. “What I’ve seen at six weeks is patients coming in at higher degrees of flexion, meaning they can bend their knee more easily and with higher flexion angle.My patients have also reported better walking or stair climbing ability.”

We realized that in addition to creating a knee that addressed patient needs, it was also important to be able to provide instrumentation for the knee that improves the efficiency of implantation and the functionality of the knee system. We did extensive research to develop a deep understanding of how instruments are used during surgery and how they may be improved. Among our goals for improved instrumentation were instruments that are easy to use, reduce surgical steps, and contribute to a more efficient procedure.

As a result, the Intuition line of instruments, which are used with the Attune knee, are designed to offer hospitals and surgeons fewer instrument trays, an intuitive user interface for ease-of-use, and a reduced learning curve, improving the operating room (O.R.) team experience. Key features include:

• Single-layer instrument cases that are lightweight with fewer instruments, reducing weight by 51 percent as compared to previously available instruments. The instruments also minimize the number of instrument cases in the O.R., which potentially can lower sterilization and hospital costs;
• Novel use of composite materials in orthopedic instruments, while at the same time maintaining instrument durability; and
• Design clarity through the use of color coding as well as clear markings, potentially reducing O.R. surgical errors.

Fisher says he finds many of the instrument improvements helpful in the operating room.

“The main difference I’ve seen in using the Attune knee in surgery has been tools that are lighter weight, making them easier to use for the staff, and for myself,” he said. “It’s easier to read the instrumentation so I know precisely what sizes and what we’re trying to accomplish, and the instruments that allow us to size and balance the knee during surgery are helpful.”

To date, more than 26,000 Attune knees have been provided for patients and we continue to receive positive clinical feedback. In fact, in our effort to continue to improve products, services, and processes, and provide innovative solutions for our customers, including patients, our team embraces the idea that we can never stop innovating as long as there are unmet needs.

Disclosure
Dr. Fisher has been involved in clinical research studies and implant development for 20 years. He is currently a paid consultant for DePuy Synthes Joint Reconstruction.

Reference

1. Baker PN, van der Meulen JH, Lewsey J, Gregg PJ. The Role of Pain and Function in Determining Patient Satisfaction After Total Knee Replacement. JBJS-Br. 2007; 89-B(7): 893-900.