Answers to Metal-on-Metal Hip Questions Come Slowly but Surely

In many ways, the rise and fall of metal-on-metal hips has been like an uncontrolled experiment. Manufacturers performed minimal testing on the devices prior to releasing them into the marketplace. As metal-on-metal hips began to fail in patients, manufacturers took measures to delay – or avoid altogether – any acknowledgement that there was a problem with the metal-on-metal design. Doctors had little information to rely on and were forced to put the pieces together based on their experiences with patients. As a result, patients and doctors alike have been waiting for answers to their questions regarding the effects of metal-on-metal hip implants.

A recent information statement released by The American Academy of Orthopaedic Surgeons (AAOS) helps answer some of those questions and provides up-to-date recommendations on how to monitor these devices. The document is not intended to dictate the exact method of treatment, but it serves as a guideline that is based on the state of the published literature available.

In it, the authors discuss the intrinsic (caused by the implant) and extrinsic (something outside of the implant) causes of painful total hip arthoplasty (THA). In any case of painful THA, a thorough clinical history, a detailed physical examination, and select radiographic and laboratory tests are all essential to determining the cause(s) of pain.

The statement also provides a systemic risk stratification recommendation, which can be used to determine if a certain patient is at high-, medium-, or low-risk for hip failure. The data is consistent with some other studies in the past, which have reported trends such as a higher risk for females with metal-on-metal devices that have large-diameter femoral heads. However, this statement goes into more detail on what doctors should look for in determining a patient’s risk level and treatment options.

Having a metal-on-metal device in you can cause significant anxiety.  At GoldenbergLaw, we understand that the most important thing to anyone who has been affected by metal-on-metal hip failure is feeling better and getting back to normal life. We will continue to update our clients and others about important developments in litigation and in treatment of metal-on-metal hip failures.

FDA Publishes Guidelines for Chromium and Cobalt Testing

It is very important that patients with metal-on-metal implants are monitored and receive the appropriate chromium and cobalt testing. As we pointed out in a post last fall, definitive answers to metal-on-metal questions are difficult to come by:

Since the manufacturers of MoM devices did not study the effects of metal wear, people have likened the advent of metal-on-metal hips to a large, uncontrolled experiment. Thus, the studies that are now underway are reactive in nature and have minimal foundation to build from.”

The problems that have been reported relating to metal-on-metal wear can undoubtedly generate anxiety and worry for hip recipients and their families. Recently, the FDA released a set of guidelines to help establish uniform chromium and cobalt testing and diagnostic procedures for orthopedic doctors who are treating metal-on-metal hip recipients. This is a step in the right direction, as doctors have been forced to work off of little to no official guidelines when it comes to monitoring metal-on-metal hip recipients and interpreting results of various diagnostic methods.

FDA Guidelines for Chromium and Cobalt Testing

Soft Tissue Imaging

The first method discussed in the FDA report is soft tissue imaging. Depending on the individual circumstances, the FDA recommends one of the following:

  • Magnetic Resonance Imaging (MRI) with metal artifact reduction (MAR)

This technology offers the best visualization of soft tissue surrounding a metal-on-metal hip implant and uses non-ionizaing radiation. Panel members at the June 2012 Orthopaedic and Rehabilitation Devices Advisory Panel Meeting recommended this method over others that were discussed. However, this method is contraindicated for some patients with implants.

  • Computed Tomography Scan (CT) Scan

CT scans offer the best visualization of implant positioning and bony tissue. However, they use ionizing radiation and provide lower soft tissue visualization. Image artifacts from the implant may distort the images.

  • Ultrasound

Ultrasound allows soft tissue visualization without metal artifacts and uses non-ionizing radiation. However, it provides a lower resolution soft tissue image and has a limited depth penetration.

These tests will show the tissue surrounding the implant and any distortions in the imaging will alert your doctor to metal artifacts (particles of metal) around the implant. Your doctor can determine which test is most appropriate for your situation. Keep in mind that his or her decision may also be based on what types of tests insurance will cover.

Chromium and Cobalt Ion Tests

As you likely know, elevated metal ion levels (e.g. chromium and/or cobalt) are a concern for anyone who has a metal-on-metal hip. Ions are not visible on the imaging tests listed above, so a blood sample must be tested in order to detect them.

The FDA says that anyone who develops symptoms should be tested. However, a recent study provided evidence that blood metal ion tests can be used to measure the risk of early joint failure. The study also suggested that elevated metal ion levels, regardless of symptoms, warrant concern. This means that even symptomless patients who have undergone metal-on-metal hip replacement surgery could still have increased ion levels that predict implant failure. For this reason, we recommend that metal-on-metal hip recipients undergo chromium and cobalt testing regardless.

The FDA specifies blood test methods they believe will produce the most accurate results. These tests are rarely done in your doctor’s office; he or she will most likely send you to a lab to have them done. The FDA also specifies the criteria a lab should meet to generate the most accurate results. Many doctors have already been using labs that meet these criteria, but some may be using testing labs that are outside of the FDA’s new guidelines. Before you get tested at a lab, we recommend checking with your doctor to make sure the lab meets the FDA’s criteria for accurate chromium and cobalt testing.

Talk to your doctor

If you have any concerns or questions about your implant, do not hesitate to talk to your doctor. The FDA guidelines are not meant to replace the need to see your doctor; it is important that you keep he or she in the loop when it comes to your condition.

Do you have a Case?

If you have a metal-on-metal hip and have not yet spoken with an attorney, we recommend that you do as soon as possible. There are statutes of limitations that can bar your claim if it is not filed by a certain date. There could also be additional cut-off dates to file your claim based on settlements. Contact us for a free consultation.

Have you been told you need revision surgery?

The explanted device can be a crucial piece of evidence and it should be preserved with the surrounding tissue. We do this for our clients using a company that specializes in device preservation. If you have been told you need a revision surgery, it is best to contact us as soon as possible so that we have time to preserve the device.

Most Metal-on-Metal Hips Banned in United Kingdom

Almost all metal-on-metal hips have unacceptably high failure rates, according to UK regulators:

The United Kingdom’s National Health Service (NHS) has recently decided to ban most metal-on-metal hips in UK hospitals. The National Institute for Health and Care Excellence (NICE), the non-departmental public body that publishes guidelines for the use of health technologies within the NHS, made the recommendation to do so based on an audit of all hip surgery in England and other parts of the UK.

According to The Telegraph, NICE advised the NHS to discontinue use of all hip devices that have failed at rates higher than 5% after five years. According to NICE, the new standard will preclude future use of most metal-on-metal hips, as almost all of them failed at rates higher than that.

Metal-on-metal hips banned in UK

Photo Cred: The Telegraph http://www.telegraph.co.uk/health/nhs/10406198/NHS-hospitals-to-be-banned-from-fitting-metal-on-metal-hip-replacements-after-high-failure-rate.html

According to the report, even metal-on-metal resurfacing procedures had unacceptably high failure rates. Resurfacing hip replacements include the Adept, Durom, Recap Magnum, Conserve Plus and Cormet 2000.

Only two metal-on-metal hips managed to meet the new standards. According to The Telegraph, those devices’ failure rates were still considerably higher than those of traditional implants. Predictably, the DePuy ASR had a particularly high failure rate, which was estimated to be as high as 43% after nine years.

Although the United States has not taken the same measures, many surgeons have stopped using metal-on-metal hips of their own accord. Many manufacturers have discontinued or recalled their metal-on-metal devices, although they do not readily cite problems with metal-on-metal hips as reasons for doing so.

The age of manufacturers profiting off of these dangerous devices may be ending, but thousands of people have been left with the consequences. Many recipients have already undergone dangerous revision surgeries, and many more are left wondering if they will need to do so within the next few years.

If you believe you or a loved one are experiencing problems due to a metal-on-metal hip device, contact our office for a free consultation.

What Does it Mean to Have Elevated Metal Levels?

Hip devices containing cobalt-chromium parts have been used successfully in orthopedics for years and have been known to produce slightly elevated metal levels in patients who receive them1. Over the past decade, however, the profit-driven flurry of new metal-on-metal hip devices has left thousands of patients with much higher levels than previously observed.

Specifically, the inherent design of metal-on-metal devices often results in metal wear, which releases metal ions into the body and causes elevated metal levels. An unacceptable proportion of metal-on-metal hip recipients have needed revision surgery due to implant loosening, tissue necrosis, and pseudotumors – all of which have been attributed to elevated metal levels.

Since the DePuy ASR recall in August 2010, surgeons have been moving away from metal-on-metal implants. Many device makers have taken their metal-on-metal implants off of the market, either by issuing a recall or by “phasing them out.” It is apparent that the metal-on-metal design is causing high failure rates.

However, in relation to how widespread a problem this is, experts have come up with few definitive answers as to how interpret elevated metal levels found in patients.

Elevated metal levels can lead to hip necrosisWhy Don’t We Know More by Now?

Most metal-on-metal devices gained FDA approval through a regulatory shortcut known as the 510(k) approval process. This process requires the manufacturer to prove that the device is “substantially equivalent” to another that is already on the market. They are not required to conduct pre-market studies to prove safety and efficacy.

Since the manufacturers of MoM devices did not study the effects of metal wear, people have likened the advent of metal-on-metal hips to a large, uncontrolled experiment. Thus, the studies that are now underway are reactive in nature and have minimal foundation to build from.

As Nick Freemantle, professor of clinical epidemiology and biostatistics at University College London, pointed out, the studies should have been done before the product is used – not after.

“We shouldn’t be in this position where we don’t know and there’s so much uncertainty. The stability of a compound should have been ascertained before it was used widely in people. As yet, we don’t know the consequences of this.”

What do we know about elevated metal levels?

According to the Medicines and Healthcare products Regulatory Agency (MHRA), patients whose levels are above a threshold level of 7 μg/L should be further monitored and tested. However, it is unclear where they got this number, or if it is reliable.

Earlier this year, BMJ published a study that examined the association between elevated metal ion concentrations and early failure of hip devices. They did so by documenting the clinical course of patients who had elevated cobalt and chromium concentrations but were not experiencing symptoms of a failed device.

The results of the study provided the first real evidence that blood metal ion tests can be used to measure the risk of early joint failure. They also suggested that elevated metal levels, regardless of symptoms, warrant concern.

The study also noted differences in failure rates between men and women. Of men and women who had the same metal ion levels, women appeared to be at greater risk of joint failure than their male counterparts. This is not the first time that higher failure rates have been observed in female patients. Previously, however, the theory was that women were more prone to elevated metal levels due to heavier wear of smaller implants.

However, since the failure rates were still higher in women than men who had the same metal levels, the differences must also have a biological explanation. That is, females may be more likely to have an adverse immune response to the ions. Indeed, the prevalence of a number of immune conditions is higher in women, which, according to the study, further suggests that woman may be more likely to have problems than men.

An important conclusion to the BMJ study is that metal ion concentration levels are a useful clinical tool in predicting device failure. The data presented in the study will help doctors to develop standards and guidelines for future treatment and evaluation of metal-on-metal patients. The data also strengthens the link between the metal-on-metal design of a device and device failure, which manufacturers have contested by pointing to other potential reasons for failure.

If you have questions or would like to speak with an attorney about a potential case, contact us for a free consultation.

 

1BMJ

 

http://www.medpagetoday.com/MeetingCoverage/AAOS/37997

http://www.bmj.com/content/344/bmj.e1410#xref-ref-4-1

http://bmjopen.bmj.com/content/3/3/e001541.full

Experts Urge Metal-on-Metal Hip Recipients to Follow up with Surgeon

As the DePuy ASR litigation develops, the broader category of Metal-on-Metal hip devices is gaining more attention. According to USA Today, an estimated 500,000 people have a metal-on-metal hip implant in the United States. About 40,000 of them were used in the 12-month period from 2005-2006, when MoM implants accounted for about 32% of those used, according to the American Society of Hip and Knee Surgeons.

The use of these devices has decrease drastically since the discovery of higher failure rates and the danger of high metal levels in the bloodstream due to metallic wear. Experts like Mathias Bostrom, an orthopedic surgeon at the Hospital for Special Surgery in New York City, are now saying that “almost all metal-on-metal implants have issues.” It is important that everyone with a MoM hip device follow up with his or her surgeon

Click here to read the full USA Today article