In 2008, a paper by A.J. Hart et al. was published in the medical journal Hip International that explains “A cup inclination angle greater than 45 degrees is associated with increased wear rates of metal on polyethylene (MOP) hip replacements,” but that “The same maybe true for metal on metal (MOM) hips yet this has not been clearly shown.”
Determining specific orientations of metal-on-metal hip replacement components that contribute to wear or can lead to lower rates of wear are important because metal particles can wear off from metal-on-metal implants and lead to kidney and liver damage, severe skin irritation (hypersensitivity), pseudotumors, and increased cancer mortality.
And in fact, this team did find orientations of metal-on-metal hip replacement components observed to lead to less wear: “We identified a threshold level of 50 degrees cup inclination. Below this threshold, the mean whole blood cobalt and chromium were 1.6 ppb and 1.88 ppb respectively; above this threshold, the mean blood cobalt and chromium were 4.45 ppb and 4.3 ppb respectively.” (For clarity, “ppb” means parts per billion, and is one of many ways to measure the concentration of metal ions in blood. This method is also used to determine the concentration of pollutants in water and the air.)
Finding that, “All patients above the threshold had metal levels greater than any of the patients below the threshold”, Hart et al. write “Additionally, our new analytical methods may allow blood metal levels to be used as a realistic biomarker of in vivo wear rate of MOM hips” and “The implication is that metal levels can be minimised with optimal orientation of the acetabular component.”
Due to the fact that DePuy Orthopaedics, Inc., the manufacturer of the popular ASR / ASR XL metal-on-metal hip replacement systems, has failed time and again to adequately warn users of the risk of elevated blood metal ion levels and premature device failure associated with the ASR, a number of DePuy ASR hip replacement lawsuits are currently being filed.
If you or a loved one used a DePuy ASR hip replacement system that failed or resulted in complications, you may be entitled to significant financial compensation. For a free, no-obligation case consultation, contact our team of DePuy ASR lawyers at the information provided below. We have the skills, resources, and experience required to win the justice you deserve.
(855) 452 – 5529
Our DePuy ASR™ / ASR™ XL Hip Replacement Lawsuit Information page is a great place to start if you have any questions about DePuy ASR metal-on-metal hip replacements.