Two recent Australian studies have identified cobalt toxicity in DePuy ASR hip implant recipients. The ASR prosthesis implanted in both patients studied has recently been withdrawn from the U.S. market, after being implanted in approximately 100,000 patients worldwide. Increased cobalt levels have been reported to be associated with severe neurological, cardiac and endocrine symptoms.
DePuy Hip Update 1/23/13: Newly disclosed court documents have revealed that a 2011 internal investigation conducted by Johnson & Johnson on its much-troubled DePuy ASR hip implant estimated that the device would fail within five years in nearly 40% of recipients. For reasons still unclear, the company failed to make this information public while simultaneously downplaying the potential health complications associated with its metal-on-metal hip. Click here to learn more.
Free DePuy Hip Implant Case Evaluation: If you or a loved one has been diagnosed with cobalt toxicity after being implanted with a metal-on-metal hip implant device, you should contact our law firm immediately. You may be entitled to compensation by filing a lawsuit and we can help.
What’s the problem?
An article published in the May 2011 edition of the Medical Journal of Australia (MJA) reported on two Australian patients with cobalt toxicity related to metal-on-metal total hip replacements. Both patients were treated for arthritis with the recently recalled DePuy ASR XL Acetabular Hip System, which contains both cobalt and chromium.
The first patient was a 73-year-old woman who had undergone a total hip replacement because of osteoarthritis. The woman exhibited severe neurological symptoms including cognitive decline, memory difficulties and depression, which had been present for at least seven months following a cerebrovascular episode. The patient also complained of a perpetual metal taste in her mouth, as well as severe headaches, anorexia and weight loss. Tests later revealed that her serum cobalt level was 410 nmol/L (reference range, 0–20 nmol/L) and chromium level was 240 nmol/L (reference range, 0–100 nmol/L).
In July 2010, the woman suffered a severe cerebrovascular episode whose symptoms were similar to that of a stroke: dizziness, disorientation, nausea, vomiting, and being ‘off balance on the left side.’ The patient reported difficulty in remembering names and registering information, headaches and cerebellar signs (ataxia and dysdiadochokinesis). Hospital reports showed a hypodensity in the right anterior commissure, although it could not be confirmed whether this represented a lacunar infarct or a perivascular space.
The patient’s original hip replacement had been done in 2006 with a DePuy ASR hip device. The ASR system is composed of a large-diameter cobalt and chromium cup with a large modular metal head on a titanium Corail stem. Unfortunately, a total revision surgery had to be performed in March 2011 because of her elevated cobalt and chromium levels. In the months following the revision surgery, the patient felt much improved. She had regained a normal appetite and gained weight, the metallic taste in her mouth was gone, and she had less fatigue and greater energy. Additionally, her hip pain was gone and her cobalt levels had come back down to normal.
The second patient examined in the study was a 60-year-old male who had undergone a right total hip replacement with a DePuy ASR XL Acetabular Hip System prosthesis 4 years earlier. During a follow-up exam, an x-ray showed substantial bone loss around the acetabular component. Three years after his initial surgery, the patient developed a number of increasingly severe symptoms including:
- muscle fatigue in all limbs
- feeling faint when performing simple tasks
- the inability to climb a flight of stairs without resting
- decline in cognitive function
- problems remembering names
- poor concentration
During his follow-up, the patient’s serum cobalt levels were found to be 185 nmol/L, and subsequently remained consistently elevated at between 213 nmol/L and 258 nmol/L.
In February 2011, the patient underwent a total hip revision procedure. Eight weeks later, he reported significant improvement in his energy levels and a decrease in muscle pain. Additionally, the patient had significantly improved exercise tolerance and his serum cobalt levels had returned to normal.
The study’s authors concluded by stating that metal-on-metal hip implant devices have failed to live up to the promise of increased durability. In addition to failing at an unacceptably high rate, they tend to release a variety of metal ions (primarily cobalt and chromium) into local tissues and the general circulation.
“We believe our patients’ symptoms were related to their elevated cobalt levels, resulting from cobalt leaching out of their hip prostheses. Both patients had metal-on-metal hip prostheses, and both patients’ cobalt levels were reduced after removal of the metal-on-metal prosthesis. We are concerned that cobalt toxicity may be under-recognised, particularly if patients consult doctors who may not be aware of the details of the patient’s hip replacement and the potential for release of cobalt into the circulation.”
If you have been implanted with a metal-on-metal hip replacement device
If you’ve undergone a hip replacement procedure utilizing a metal-on-metal device, the British Hip Society recommends follow-up exams for at least five years and probably for the life of the prosthesis. Symptoms of cobalt toxicity may not manifest themselves for years, and may stay elevated for prolonged periods of time. Long-term exposure to cobalt has also been linked to cancer. Patients should therefore be extremely mindful to watch for alterations in neurological, cardiac, respiratory and endocrine function. Unfortunately, in the presence of persistently elevated cobalt levels, revision replacement surgery is the only method available to decrease metal ion levels.
Do You Have a DePuy Hip Implant Lawsuit?
The Product Liability and Defective Medical Device Litigation Group at our law firm is an experienced team of trial lawyers that focus on the representation of plaintiffs in DePuy hip implant lawsuits. We are handling individual litigation nationwide and currently accepting new cobalt toxicity cases in all 50 states.