STABILITY & MOTION VS. THE PERSONA KNEE SYSTEM. The Zimmer Persona Knee

Transcription

1 STABILITY & MOTION VS. THE PERSONA KNEE SYSTEM The Zimmer Persona Knee

2 The ATTUNE Knee System was designed to deliver stability and motion while the Zimmer Persona Knee System emphasizes the number of implant sizes (and shape) to provide personalized patient fit. Before deciding which system may provide your patients improved results, a quick review of peer reviewed literature on implant design and how it impacts patient satisfaction may help answer the question. 1 DePuy Synthes Joint Reconstruction ATTUNE Knee System Stability & Motion vs. the Persona Knee System

3 WHAT IMPACTS PATIENT SATISFACTION: 1 Instability: Instability causes pain in many patients. 28% of patients are not satisfied with the stability of their knee when going up or down stairs. 1 Instability is also one of the main causes (10 22%) of knee failure. 2 2 Implant Fit: Mahoney and Kinsey showed that femoral component overhang of 3 mm was associated with an almost twofold increased risk of knee pain, more severe than occasional or mild at 2 years after surgery. It was shown 57% of patients have at least one area of the implant with this overhang. 3

4 INSTABILITY: Improved implant stability can be achieved 2 ways: 1. Increasing the conformity between the femoral component and insert can help improve implant stability Reduced implant conformity in flexion is necessary to allow the knee to rotate in flexion. However, it has been shown that abrupt changes in conformity may allow the femoral component to slide forward on the tibial insert. A gradual reduction in conformity has been shown to improve implant stability while allowing the freedom to move. 5 While walking down stairs, high anterior forces are placed on the knee When an abrupt change in conformity occurs, the knee becomes unstable and slides forward The chart below shows the ATTUNE Knee provides more stability while still allowing rotational freedom in deeper flexion. This is accomplished through a gradually reducing radius, ATTUNE GRADIUS Curve, on the femoral component paired with a mating tibial insert. The result is a balanced level of motion and stability that more closely matches that found in the native knee. 4 The ATTUNE GRADIUS Curve aids in patient performance during dynamic activities such as going up and down the stairs. 5 FLEXION ANGLE 0º 15º 30º 60º 90º 120º ATTUNE CR FB Abrupt Change None ATTUNE PS FB ATTUNE CR RP ATTUNE PS RP Zimmer NexGen CR FB Zimmer NexGen PS FB None None None º º 5 DePuy Synthes Joint Reconstruction ATTUNE Knee System Stability & Motion vs. the Persona Knee System

5 IMPLANT FIT: The ATTUNE Knee System provides an extensive range of sizes to help address challenges associated with implant fit. 6 Based upon the many shapes and sizes of the body types analyzed, DePuy Synthes Joint Reconstruction* created a sizing portfolio to meet the needs of the diverse worldwide patient population. The ATTUNE Knee System provides 10 standard sizes of femoral and tibial components and 4 additional narrow femoral component sizes as well as 1 mm increments in the tibial inserts to achieve a well balanced knee. Femoral Sizes Tibial Sizes Insert Thickness Increments ATTUNE Knee mm Increments Zimmer Persona mm increments Number of Patients Tibial Asymmetry Figure 1. The native tibia does have slight asymmetry. However, due to wide variations in patient anatomy, asymmetric designs may result in increased overhang for a number of patients. Average Persona It is important in total knee arthroplasty to have a tibial base design that covers as much proximal tibial bone without overhang. Proper coverage without overhang is necessary to reduce the risk of subsidence and to avoid excessive overhang, which may lead to soft tissue irritation and patella tracking complications. While Zimmer promotes the benefits of asymmetry to accomplish optimal coverage and rotation, data has shown that having more tibial base sizes is most important in achieving tibial plateau coverage. 7 In the graph below, when the Persona tibial base was assessed for bone coverage in a database of more than 14,000 patients, the level of asymmetry designed into the Persona tibial base resulted in increased overhang for a number of patients (figure 1). 8 The ATTUNE Knee System was designed with 10 symmetric tibial base sizes to address proper tibial coverage without overhang. Figure 2. The colors represent the average amount of bone each tray does not cover on the tibia. Blue is 0 1 mm and Red is 4 5 mm. When proper rotation (medial third of tibial tubericle) is set for the tibial base placement, the symmetric design of the ATTUNE Tibial Bases (Fixed Bearing and Rotating Platform) and the system s comprehensive size offering provide better coverage (84 86%) without overhang as compared to the asymmetric Persona tibial base design (figure 2). 7 Stability & Motion vs. the Persona Knee System ATTUNE Knee System DePuy Synthes Joint Reconstruction 6

6 The ATTUNE Knee System delivers stability and motion by combining conformity through the patented ATTUNE GRADIUS Curve and mating tibial insert, matched with a comprehensive size offering to help achieve a patient s optimum performance. For more information on the ATTUNE Knee System and its unique design advantages, contact your local DePuy Synthes Joint Reconstruction Sales Consultant. References: 1. Bourne RB, Chesworth B, Davis A, Mahomed N, Charron K. (2010) Comparing patient outcomes after THA and TKA: is there a difference? Clin Orthop Relat Res. 468(2): Noble PC, Gordon MJ, Weiss JM, Reddix RN, Conditt MA, Mathis KB. (2005). Does total knee replacement restore normal knee function? 431: Mahoney OM, Kinsey T. (2010) Overhang of the femoral component in total knee arthroplasty: risk factors and clinical consequences. J Bone Joint Surg Am. 92(5): Sathasivam S, Walker PS, (1999) The conflicting requirements of laxity and conformity in total knee replacement, J Biomechanics;1999;32: Clary CW, Fitzpatrick CK, Maletsky LP, Rullkoetter PJ. (2012) Improving dynamic mid-stance stability: an experimental and finite element study. Presented at the Orthopaedic Research Society 2012 Annual Meeting; San Francisco, CA. 6. University of College Dublin. Fitzpatrick. Data on File. 7. Mahfouz M, Scuderi GR, Fatah, EA, Bowers LN. (2013) Evaluation of Tibial Component Coverage in Total Knee Arthroplasty. Presentation 189; 80th AAOS Meeting. Chicago, IL. 8. Clary, C. W., Deffenbaugh, D., Leszko, F., Courtis, P. (2013). Tibial tray design factors affecting tibial coverage after total knee arthroplasty. Presented at the International Society of Technology in Arthroplasty 26th Annual Congress, Palm Beach, United States. Limited Warranty and Disclaimer: DePuy Synthes Joint Reconstruction products are sold with a limited warranty to the original purchaser against defects in workmanship and materials. Any other express or implied warranties, including warranties of merchantability or fitness, are hereby disclaimed. WARNING: In the USA, this product has labeling limitations. See package insert for complete information. CAUTION: USA Law restricts these devices to sale by or on the order of a physician. Not all products are currently available in all markets. The third party trademarks used herein are the trademarks of their respective owners. *DePuy Synthes Joint Reconstruction, a division of DePuy Orthopaedics, Inc. DePuy Orthopaedics, Inc. 700 Orthopaedic Drive Warsaw, IN T. +1 (800) DePuy Synthes Joint Reconstruction, a division of DOI All rights reserved. DSUS/JRC/0814/0358