General Knee Replacement Information

Early diagnosis and proper treatment of knee osteoarthritis is important for your long-term mobility.¹ If your doctor has recommended a knee replacement, it's important to understand that delaying surgery may further lower your quality of life, both before and for up to two years after surgery!² There is no cure for osteoarthritis and it is degenerative, which means that your pain and limited mobility is likely to get worse over time.³

One of the most effective ways to reduce severe knee pain and restore mobility is knee replacement surgery. More than 600,000 knee replacements are performed each year in the United States to replace worn and arthritic knee joints.⁴

This section explains how you can take the next step toward no longer being limited by your knee pain and finding the knee that fits your life.

Knee Replacement Implant Design

Knee replacement surgery resurfaces the bones at the top of your shin (tibia) and the bottom of your thigh (femur) with an implant made of metal and plastic parts.

The top of your shinbone is resurfaced with a metal tray topped with a medical-grade plastic spacer. This plastic replaces the cartilage, providing a smooth surface for your new knee.

An area at the bottom of your thighbone is resurfaced with a rounded metal part. This piece is designed to mimic the curve of your natural bone. The undersurface of the kneecap is also replaced with a medical-grade plastic.

Compare the Two Types of Knee Replacement Options

There are two types of knee replacements: Fixed-Bearing and Mobile-Bearing Knees. DePuy Orthopaedics has developed a unique Mobile-Bearing Knee, called the Rotating Platform knee. DePuy was the first company to receive FDA approval on mobile-bearing knee technology. The main difference between a Rotating Platform (mobile-bearing) knee replacement implant and a traditional (Fixed-Bearing) implant lies in the design of the tibial (shin) component of the implant:

• With a Rotating Platform (mobile-bearing) knee implant, the plastic spacer can rotate. This rotation can reduce the stress and wear on the implant.
• In a Fixed-Bearing implant, the shinbone is topped with a flat metal piece that securely holds the plastic spacer, also called a bearing, securely in place.
  

The blue area in this top-down view of knee replacement bearing components illustrates the amount of rotation allowed by the Rotating Platform Knee.

Both Rotating Platform, a Mobile-Bearing knee, and Fixed-Bearing designs have distinct advantages. Watch the following video to learn more about how Rotating Platform and Fixed-Bearing knee replacement implants work:

Sigma^® Knees come in a wide range of sizes, shapes, and materials, which means that there may be one that's suited for you. Your surgeon can choose the best knee replacement design for you based on your age, weight, activity level and medical condition. Learn more about Sigma^® Knees in the following sections Rotating Platform Knee and Fixed-Bearing Knee.

Important Safety Information

The performance of knee replacements depends on age, weight, activity level, and other factors. There are potential risks and recovery takes time. People with conditions limiting rehabilitation should not have this surgery. Only an orthopaedic surgeon can tell if knee replacement is right for you. Use our Surgeon Locator to find a surgeon near you who can discuss your options with Sigma^® Knee Replacement solutions.

Last Updated: 03/06/2008