In knee implants, polyethylene is a very strong plastic that is highly durable, but it has the potential to oxidize over time. To help prevent oxidation, AOX Polyethylene utilizes a new antioxidant that stabilizes free radicals without affecting the mechanical properties or strength of the polyethylene.1,2 Lab tests show that the AOX material provides high material strength.3
"AOX Antioxidant Polyethylene, which was developed by DePuy, represents a next generation polyethylene material that when coupled with the design benefits of rotating platform technology offers function, wear resistance and oxidative stability," said Andrew Ekdahl, President, DePuy Orthopaedics. "AOX Polyethylene provides surgeons with another advancement from DePuy Orthopaedics to meet the needs of their patients."
The FDA approval of DePuy's rotating platform knee systems with AOX Polyethylene was based in part on mechanical, material, biocompatibility and wear testing.
SIGMA ® Knee System
The SIGMA ® Knee System, which includes fixed-bearing and rotating-platform options, is the leading knee system in the U.S. and has been provided for nearly 1.7 million patients.4 According to the National Joint Registry for England and Wales, at five years, more than 98% of the SIGMA Knees were still in use.5
One SIGMA Fixed-Bearing Study has shown that 10 years after surgery, 99.6% of patients still depend on SIGMA Knees and most reported excellent relief of pain, improved range of motion and better function of the knee.6 SIGMA Fixed-Bearing Knees are based on the clinically proven P.F.C. ® Knee.7 DePuys SIGMA Rotating Platform Knees allow more natural movement with less wear to the implant than traditional knee replacements.8
LCS COMPLETE Knee
The LCS COMPLETE ® Knee includes primary and revision implant options, and is based on the clinically proven LCS Mobile Bearing Knee System. More than one million LCS Mobile Bearing Knees have been provided worldwide since 1977.9 According to the National Joint Registry for England and Wales, at five years, more than 97% of LCS COMPLETE Knees are still in use.10 One study shows that after 20 years, more than 96% of the LCS Knee implants were still in use.11
Important Safety Information
The performance of a knee replacement depends on a patients 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. Patients should consult with an orthopaedic surgeon to determine if knee replacement surgery is appropriate for them.
About DePuy Orthopaedics
DePuy Orthopaedics, Inc., a Johnson & Johnson company, is a leading global provider of orthopaedic devices for hip, knee, and trauma and extremities as well as bone cement and operating room products. It is part of the DePuy Family of Companies, which has a rich heritage of pioneering a broad range of products and solutions across the continuum of orthopaedic and neurological care. These companies are unified under one vision – Never Stop Moving ® – to express their commitment to bring meaningful innovation, shared knowledge and quality care to patients throughout the world. Visit www.depuy.com for more information.
 Data on File at DePuy Orthopaedics, Inc. WR070300.
2 Data on File at DePuy Orthopaedics, Inc. WR070248.
3 Standard Specification for Ultra-High-Molecular-Weight Polyethylene Powder and Fabricated Form for Surgical Implants. ASTM Designation: F648-00
4 Data on file at DePuy Orthopaedics, Inc.
5 National Joint Registry for England and Wales 2011 Annual Report (Table 3.36, page 161).
6 Dalury, et al. Midterm results with the P.F.C. SIGMA Total Knee Arthroplasty System. The Journal of Arthroplasty. 2008; 23: 175-181.
7 Dixon M., et al. "Modular Fixed-Bearing Total Knee Arthroplasty with Retention of the Posterior Cruciate Ligament. A Study of Patients Followed for a Minimum of Fifteen Years." The Journal of Bone and Joint Surgery Am. 2005; 87:598-603.
8 McNulty DE, Swope SW, Auger DD, Smith T. 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).
9 Data on File at DePuy Orthopaedics, Inc.
10 National Joint Registry for England and Wales 2011 Annual Report (Table 3.36, page 161).
11 Cemented Rotating-Platform Total Knee Replacement: A Concise Follow-up, at a Minimum of Twenty Years, of a Previous Report. Callaghan JJ, Wells CW, Liu SS, Goetz DD, Johnston RC. The Journal of Bone & Joint Surgery Am. 2010; 92:1635-1639
Posted by Sean Fenske, Editor-in-Chief, MDT