DePuy offers two Sigma^® Rotating Platform Knee Systems: Sigma RP Knee System and the Sigma RP-F Knee System. The Rotating Platform Knee is based on a revolutionary technology, the mobile-bearing knee, which DePuy Orthopaedics pioneered 30 years ago.

When the knee rotates, more stress is placed on the joint. This may accelerate the aging of a knee replacement implant. However, Sigma Rotating Platform Knees are designed to accommodate these stresses and help increase the implant's longevity. Rotating Platform Knees have been proven to reduce implant wear by 94% over traditional knee implants.¹ Studies show that even after 20 years, more than 97% of these implants are still in use.² More than one million Rotating Platform Knees have been implanted worldwide.³

Sigma RP® Knee DePuy Orthopaedics, a leader in rotating platform technology, offers both a rich history of innovation in knee replacement and a long history of clinical success in knee replacement. DePuy Orthopaedics’ Sigma Rotating Platform Knees are unique because they are designed to bend and rotate. Unlike a hinge, the surfaces of your knee joint roll and glide against each other as you bend. In other words, your knee naturally rotates as it bends.The Sigma Rotating Platform Knee provides flexibility for patients who want their knee replacement to accommodate normal movement, while minimizing implant wear, when compared to traditional knee replacements.1

Sigma RP-F Knee Much like DePuy's other Rotating Platform Knee replacement systems where the implant allows the knee to bend and rotate, move back and forth, and flex and extend, the Sigma RP-F also allows for deep knee flexion. Deep knee flexion is the movement needed for kneeling, squatting or sitting cross-legged. It may allow you to participate in social, cultural, religious or leisure activities that are important to you.

LCS® Complete™ Knee In addition to the Sigma Rotating Platform Knee and Sigma RP-F Knee, DePuy Orthopaedics also offers the LCS® Complete™ Knee. DePuy Orthopaedics pioneered this technology, and studies show that even after 20 years, more than 97% of these implants are still in use.2

Rotating Platform Knee Technology: What You Should Know

Rotating Platform (Mobile-Bearing) Knee replacements bring technological advancement to a proven design in knee implants. The Rotating Platform Knee is designed to bend and rotate, move back and forth, flex and extend, helping to accommodate more normal movement.

Benefits of the Sigma^® Rotating Platform Knee

Some people may think it's better to delay surgery until they're older because they believe that knee implants don't last. Rotating Platform Knees are designed for patients who want their knee replacement to accommodate normal movement while significantly minimizing implant wear (as compared to traditional knees).¹ Minimizing implant wear can help your knee replacement last longer.

"Many people suffer needlessly and give up the activities they enjoy," said Wayne M. Goldstein, M.D., founder of the Illinois Bone & Joint Institute. "New innovations like the Rotating Platform Knee can restore their ability to enjoy an active life."

Women may be especially interested in this technology since their knees rotate more than those of a man during normal movement.⁴ The Sigma Rotating Platform Knee accommodates for this.

NOTE:  This page comes from a Depuy web page.  Their page has some dynamic content that I can not copy that illustrates the motion of the knee as well as other highlights.  Follow this link to the actual Depuy webpage that this was partially taken from.

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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.

References:
1. McNulty, D. et al. "The Effect of Crosslinking UHMWPE on In Vitro Wear Rates of Fixed and Mobile Bearing Knees." ASTM STP 1445. Gsell, R. et al. American Society for Testing and Materials, West Conshohocken, PA. Available online at www.astm.org (2004).
2. Buechel, F.F.: et al. "Twenty-Year Evaluation of Meniscal Bearing and Rotating Platform Knee Replacements." Clinical Orthopaedics and Related Research, July 2001, pp. 41-50.
3. Data on file at DePuy Orthopaedics, Inc., 2007.
4. Hsu, Wei-Hsu, et al. "Differences in Torsional Joint Stiffness of the Knee Between Genders." The American Journal of Sports Medicine. 34 (5) May 2006:765-770