Hip replacement using metal-on-metal bearings has only been performed for a little over ten years. Clinical results have shown that the procedure is generally highly successful when performed properly, and the patient has been properly selected. One of the issues with metal-on-metal bearings is the wear of the device. Wearing down of the metal device is potentially dangerous as it may alter the natural ion concentrations in the blood.
One comparative study of the blood levels of metal ions before and after implantation of a metal-on-metal was conducted by D.J. Langton et al. and published in the Journal of Bone & Joint Surgery, the study is titled “Blood metal ion concentrations after hip resurfacing arthroplasty.” The researchers “sought to determine whether there is a significant difference in the chromium (Cr) and cobalt (Co) concentrations in the blood of patients surfaced with two common types of resurfacing arthroplasty. [And] also sought to identify the orientations of the component most strongly associated with the lowest blood metal ion levels”
The study included 90 patients with unilateral articular surface replacement (ASR) hip resurfacings. The average time of blood sampling to test metal ion concentrations after implantation of the hip resurfacing device was 26 months. These results were compared with 70 patients with unilateral Birmingham Hip Resurfacing (BHR), patients receiving this device had their blood sampling checked an average of 47 months after implantation.
The results showed that metal ion concentration after ASR resurfacing is linked to both the size of the implant and the angular orientation of the device. Similar relationships were observed in the BHR patients. Blood ion concentrations were the lowest in the larger acetabular components, as they appear to be more resistant to wear than smaller ones. The researchers concluded that the ideal BHR acetabular component positioning is between 45-55 degrees, while the ideal ASR angle is roughly 40 degrees.
If you used a metal-on-metal hip implant and suffer symptoms of metallosis as a result, or have experienced another negative side effect, you may be entitled to significant financial compensation from the manufacturer of your device. For a free, no-obligation metal-on-metal hip replacement lawsuit, contact our team of DePuy ASR hip replacement lawyers at the information provided below. We have the skills, resources, and experience required to win the justice you deserve.
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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.