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NexGen® RH Knee

NexGen® RH Knee
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Zimmer ® NexGen® RH Knee The next generation of rotating hinge knees

That Hinges on Innovative Design The NexGen RH Knee is designed to address the key issues that relate to many conventional rotating hinge knee designs. The design of the NexGen RH Knee features a modular hinge mechanism that results in 95% of the load being carried by the tibial condyles1, similar to the loading pattern of a primary implant design. Because the femoral condyles remain centered on the tibia throughout the range of motion and the shape of the patella groove is similar to the NexGen design, patella tracking is similar to a primary knee design. For the more challenging...

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Contact Area/Loading Analysis The test evaluated the amount of contact that occurs between the RH Knee femoral component and articular surface. The large condylar contact patches confirm that the load stays toward the central portion of the tibial articular surface throughout ROM. In many conventional rotating hinge knee designs, the hinge bears the majority of the compressive load until full extension is achieved. Designs that have the center of rotation located posteriorly can cause “booking” of the joint, which may result in stress on the cement interfaces or accelerated...

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Bone Conservation & Simple Instrumentation Many rotating hinge knee designs require significant bone removal to accommodate the bulky hinge mechanism. The NexGen RH Knee uses NexGen Primary or Revision Instrumentation Systems and standard NexGen femoral A/P bone cuts to help conserve bone. Although a variety of modular augmentation options are available for the RH Knee femoral and tibial components, none are required by the construct; therefore, good bone does not have to be removed to accommodate built-in augmentation or a bulky hinge mechanism. To further simplify the surgical technique,...

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Patellofemoral Tracking Like NexGen Femoral Components The RH Knee Femoral Component has a similar patellofemoral design as the other NexGen Femoral Components. The groove allows the patella to track deeply–similar to an anatomic patella. This maximizes the patellofemoral contact area, increases the resistance to lateral subluxation, and provides a smooth transition from flexion to extension. The central location of the hinge axis keeps the femoral condyles in a consistent sagittal plane. This allows for more normal patellar tracking since the patella does not shift posteriorly during...

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Tibial Base Plate Fatigue Test1 The strength of the Rotating Hinge Knee tibial baseplate was evaluated under extreme conditions by placing a cyclical load on the component, with no bony support under the baseplate. All samples completed the 10 million cycles without evidence of fracture or cracking. Hinge Pin Loosening Test1 The hinge construct was tested under load for 5 million cycles to determine if the hinge pin would loosen. The results showed that the hinge pin did not loosen as a result of the cyclical movement. Articular Surface Pull Off Test1 The capture mechanism was tested to...

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Surgeon Choice is the Operative Word A comprehensive offering of femoral and tibial components, combined with stem extensions and augments, provide for true interchangeability and patient specific solutions. Zimmer NexGen RH Knee Size B Size 1 Non-Modular Tibial Base Plate The Size B Femoral Component is used with the Size 1 Rotating Hinge Knee Tibial Base Plate. This base plate is only available in a non-modular design. Size B Tibial Articular Surface The Size B Tibial Articular Surfaces are used with the Size B Femoral Component. RH Knee Femoral and Hinge Post Extension Components RH Knee...

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1. Data on file at Zimmer. The results of these tests have not been shown to correlate with clinical mechanisms. Contact your Zimmer representative or visit us at www.zimmer.com

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