This website is dedicated to providing public information regarding DePuy Hip recall and other related information to the recall. None of the information on this site is intended to be formal legal or medical advice, nor should any information on this site be construed as advice that should be used in lieu of information from your attorney or physician.
Tuesday, April 12, 2011
Polyethylene (poly) materials reviewed for use in revised Depuy hips: the risk and rewards (2 of 3).
The bearing component most commonly used for total hip replacement in the United States is a metal femoral head (ball) made of either stainless steel, cast or wrought cobalt, a metal-base alloy against a polyethylene (plastic)-lined acetabular cup.
Durable and versatile
Long, successful clinical history
Not toxic to the human body
Adequate toughness for most lifestyles
May wear down over time, which can lead to inflammation, bone loss, and/or a revision procedure
What do the studies say?
Please refer to the chart in part one of three of this series for other risks and rewards.
I chose to print out a few conclusions from 2008-2010.
Distribution of polyethylene wear particles and bone fragments in periprosthetic tissue around total hip joint replacements.
Ultra-high molecular weight polyethylene (UHMWPE) wear particles play a significant role in failures of total joint replacements (TJRs). In this work, we investigated the distribution of these wear particles in periprosthetic tissues from 9 revisions and found that the there is a statistically significant relationship between the numbers of wear particles in the individual zones and the extent of tissue damage in these zones.It can be concluded with certainty that wear particles associated with this ulta-high molecular weight poly are one of the main causes of aseptic joint implant failure
Reduction of osteolysis with use of Marathon cross-linked polyethylene. A concise follow-up, at a minimum of five years, of a previous report.
We previously reported wear data at a minimum of two years following thirty-four total hip replacements with a Marathon cross-linked polyethylene liner and twenty-four replacements with a conventional (gamma-sterilized-in-air) Enduron polyethylene liner. In this current study, with sequential five-year radiographs, wear rates were determined with use of linear regression analysis. The Marathon polyethylene had average wear rates of 15.4 mm(3)/yr and 8.0 mm(3)/million cycles. The Enduron polyethylene had average wear rates of 55.5 mm(3)/yr and 29.9 mm(3)/million cycles. The adjusted volumetric wear rate of the Marathon polyethylene was 73% lower than that of the Enduron polyethylene (p = 0.001). Osteolysis developed in eight of the twenty-four hips with an Enduron liner but was not apparent in any hip with a Marathon liner.
Why did I choose to show you these studies?All of these materials have issues and you should have a conversation with your ortho surgeon to determine why he/she has chosen this new material for you.Lots of options.Risk/ reward is an appropriate consideration.There is no perfect implant which has no risks.You as a patient should be informed on your choices.