Metal on Metal warning (old but ongoing news)

The paper from the British edition of the Journal of Bone and Joint Surgery gives some details comparing metal on ceramic and metal on metal bearings:

A prospective, randomised controlled trial comparing ceramic-on-metal and metal-on-metal bearing surfaces in total hip replacement
  1. R. Schouten, FRACS, MBChB, BSc, Orthopaedic Surgeon Christchurch Hospital, Department of Orthopaedic Surgery and Musculoskeletal Medicine, University of Otago, Christchurch, PO Box 4345, Christchurch, New Zealand.
  2. A. A. Malone, FRCS (Tr&Orth), FRACS, Orthopaedic Surgeon Pacific Radiology, PO Box 1195, Buddina 4575, Queensland, Australia.
  3. C. Tiffen, FRANZCR, Radiologist
  4. C. M. Frampton, PhD, Statistician and G. Hooper, FRACS, Associate Professor Christchurch Hospital, Department of Medicine, Riccarton Avenue, Private Bag 4710, Christchurch, New Zealand.
Abstract
In a double-blinded randomised controlled trial, 83 patients with primary osteoarthritis of the hip received either a ceramic-on-metal (CoM) or metal-on-metal (MoM) total hip replacement (THR). The implants differed only in the bearing surfaces used. The serum levels of cobalt and chromium and functional outcome scores were compared pre-operatively and at six and 12 months post-operatively.

Data were available for 41 CoM and 36 MoM THRs (four patients were lost to follow-up, two received incorrect implants). The baseline characteristics of both cohorts were similar. Femoral head size measured 36 mm in all but two patients who had 28 mm heads. The mean serum cobalt and chromium levels increased in both groups, with no difference noted between groups at six months (cobalt p = 0.67, chromium p = 0.87) and 12 months (cobalt p = 0.76, chromium p = 0.76) post-operatively. Similarly, the mean Oxford hip scores, Western Ontario and McMaster Universities Osteoarthritis index and University of California, Los Angeles activity scores showed comparable improvement at 12 months.

Our findings indicate that CoM and MoM couplings are associated with an equivalent increase in serum cobalt and chromium levels, and comparable functional outcome scores at six and 12-months follow-up.
 
Just another nail on this subject - perhaps we put the thread to bed now! Note the DePuy reference at the end.

Complication rate increased with metal-on-metal THA
Voleti P. J Arthroplasty. 2012. doi: 10.1016/j.arth.2012.05.023.
  • November 19, 2012
Due to lack of demonstrated superiority, increased complication rate, greater cost and the potential for adverse medical consequences, researchers caution against using metal-on-metal bearing surfaces during total hip arthroplasty, according to recent study results.

Researchers performed a systematic review of literature published between January 1980 and July 2011. They compared metal-on-metal (MOM) and conventional primary total hip arthroplasty (THA) functional outcomes, radiographic outcomes and complication rates. Data were extracted and aggregated using a Mantel-Haenszel cumulative fixed effects meta-analysis.

There were no significant differences between MOM and conventional THA Harris Hip Scores, according to the abstract. Researchers also found no significant difference in radiographic radiolucent lines between either group.

However, researchers noted patients who underwent MOM THA experienced a significantly increased complication rate as well as greater erythrocyte, serum and urine metal ion concentrations.

Disclosure: The researchers report being on the speaker’s bureau for Salient Surgical and being a paid consultant for DePuy.
 
You know that feeling, when you wished you never started something :eeeuw:
:iagree: Bumpa
 
Well, I'm pleased you started it, @Dingbat7 It's been a great resource!.
 
Hey all,

Haven't been on the site in a few years (2010, I think), but I am back due to this particular topic. I'll post a recovery thread that will detail my experience with complications of MoM as a resource for others.
 
UTdave, thanks I look forward to reading your story. One of my friends has a six monthly blood test to check the level of metal ions in the blood.
 
This paper compares metallic ions between, ceramic on metal and metal on metal hip replacements:
A prospective, randomised controlled trial comparing ceramic-on-metal and metal-on-metal bearing surfaces in total hip replacement
R. Schouten, FRACS, MBChB, BSc, Orthopaedic Surgeon Christchurch Hospital, New Zealand
A. A. Malone, FRCS (Tr&Orth), FRACS, Orthopaedic Surgeon Christchurch Hospital, New Zealand
C. Tiffen, FRANZCR, Radiologist Pacific Radiology, Queensland, Australia.
C. M. Frampton, PhD, Statistician Christchurch Hospital, New Zealand
G. Hooper, FRACS, Associate Professor Christchurch Hospital, New Zealand​

Abstract
In a double-blinded randomised controlled trial, 83 patients with primary osteoarthritis of the hip received either a ceramic-on-metal (CoM) or metal-on-metal (MoM) total hip replacement (THR). The implants differed only in the bearing surfaces used. The serum levels of cobalt and chromium and functional outcome scores were compared pre-operatively and at six and 12 months post-operatively.

Data were available for 41 CoM and 36 MoM THRs (four patients were lost to follow-up, two received incorrect implants). The baseline characteristics of both cohorts were similar. Femoral head size measured 36 mm in all but two patients who had 28 mm heads. The mean serum cobalt and chromium levels increased in both groups, with no difference noted between groups at six months (cobalt p = 0.67, chromium p = 0.87) and 12 months (cobalt p = 0.76, chromium p = 0.76) post-operatively. Similarly, the mean Oxford hip scores, Western Ontario and McMaster Universities Osteoarthritis index and University of California, Los Angeles activity scores showed comparable improvement at 12 months.

Our findings indicate that CoM and MoM couplings are associated with an equivalent increase in serum cobalt and chromium levels, and comparable functional outcome scores at six and 12-months follow-up.
 
Hmmm - so metal cups are out as well then ....
 
I know this is not quite about metal-on-metal but does add something to the intelligence:

Speaker: Minimal in vivo roughening seen with scratch-resistant ceramic surface
January 16, 2013 KOHALA COAST, Hawaii
Cobalt-chromium counterface roughening can occur in vivo and increased counterface roughness can increase the wear of ultra-high molecular weight polyethylene, while minimal in vivo roughening occurs with scratch-resistant ceramic surfaces, said a presenter at Orthopedics Today here.

“This may offer an advantage, particularly in the younger patient with many years ahead of them who would be at risk for failure,” Michael D. Ries, MD, said.

He noted there have been similar mid-term in vivo clinical outcome measures of oxidized zirconium and cobalt chromium.

Ries cited a study where cobalt-chromium and oxidized zirconium femoral components were tumbled in an abrasive alumina powder before wear testing. After 5 million cycles, the components’ roughness values were within the clinically relevant range. Oxidized zirconium, however, wore 89% less than cobalt chromium, he said.

In a recent study Ries discussed, 11 retrieved oxidized zirconium femoral knee arthroplasty components and 11 retrieved cobalt-chromium femoral components were matched for patient age, time in vivo and cause for revision. Profilometry results demonstrated significantly less roughness of the oxidized zirconium components than the cobalt-chromium components.

Reference:
Ries MD. Oxinium in every knee: Affirmative. Presented at Orthopedics Today Hawaii 2013; Jan. 13-16, 2013; Kohala Coast, Hawaii.
 
Here is the latest from the FDA on this issue:
FDA issues MoM hip safety update, proposes PMA application process
January 17, 2013
The FDA updated its safety communications page for metal-on-metal (MoM) hip arthroplasty implants on January 17 and issued a proposed order that requires manufacturers of MoM systems to submit premarket approval applications.

Metal-on-metal (MoM) prostheses were originally evaluated under the 510(k) premarket notification program and designated Class III devices.

The FDA page was updated with information that guides orthopedic surgeons on patient selection and consideration of alternative hip systems. It also discussed how to educate patients about the risks of MoM hip implants and their revision and recommends that surgeons specifically monitor patients for adverse events following hip arthroplasty with these devices.

According to the communication, these recommendations were based on evaluating the risks and benefits of the implants and the literature on these devices, as well as results of the June 2012 Orthopaedic and Rehabilitation Devices Advisory Panel Meeting.

According to the FDA safety communication, the following individuals are most at risk for events such as device wear, loosening and adverse local tissue damage: patients with
  • bilateral implants;
  • resurfacing systems with small femoral heads (44 mm or smaller);
  • females;
  • receiving high doses of corticosteroids;
  • evidence of renal insufficiency;
  • suppressed immune systems;
  • suboptimal alignment of device components;
  • suspected metal sensitivity (such as cobalt, chromium or nickel);
  • severely overweight
  • high levels of physical activity.
“Presently, the FDA does not have enough scientific data to specify the concentration of metal ions in a patient’s body or blood necessary to produce adverse systemic effects,” the FDA wrote in the safety update. “In addition, the reaction seems to be specific to individual patients, with different patients having different reactions to the metal wear particles.”

The FDA stated there is no clear need for physicians to check metal ion levels in asymptomatic patients deemed to have properly functioning hips. But they did recommend the use of additional diagnostic imaging and seeking specialized radiology expertise to assess and diagnose soft tissue surrounding the implants in symptomatic patients.

For patients with MoM implants who are symptomatic, the FDA recommends an evaluation be performed every 6 months. All other patients should be evaluated every 1-2 years, based on information in the communication.

References:
http://www.fda.gov/MedicalDevices/Safety/AlertsandNotices/ucm335775.htm
http://s3.amazonaws.com/public-inspection.federalregister.gov/2013-01006.pdf
 
And here is a response from the past-President of the BOA in the UK:
Perspective
Peter R. Kay
I think overall, from the U.K. perspective, metal-on-metal has been a real problem. [For] most surgeons in the United Kingdom, our usage of metal-on-metal hip replacements has dwindled to almost nothing because we cannot really find any advantage. The patients do not do any better in terms of function. There is some evidence the patient’s reported pain levels are higher anyway and the revision rate is higher, so it is not adding much value.

In terms of metal-on-metal, we [Medicines and Healthcare products Regulatory Agency] have gone a little bit further than the FDA because we also recommend having a metal ion level test. It is very hard to find a metal ion level where you can say whether patients are likely to run into problems, but one of the reasons we chose to go down that route was that the medical literature is not absolutely clear on whether aseptic lymphocytic vasculitis associated lesion reaction is a hypersensitivity reaction or just a reaction to high metal ion levels.

Most patients will have a reaction if the level is quite high. So we chose this level of 7 parts per billion (ppb) for both cobalt and chrome. If you have a level of 7 ppb or above, chances are a fair number of people so far that have problems have levels of that or above that. So, that’s the sort of level where you start to feel more worried. If it’s below 7, what we have discovered is that low levels are rarely associated with a problem, especially levels below 3 ppb.

The difficulty is, the patients who are anxious seem to develop some of the symptoms that are put down as being due to high metal levels. They don’t feel right; maybe their eyes aren’t good; there is a buzzing in their ears. And it is very difficult to reassure that sort of patient. So we have gone a little bit further to suggest that there may be a place for doing a metal ion level test. Not that that metal ion level means you should revise at a particular level, but at a low level we feel we can reassure a patient, and at a higher level we think that can be a sign that things might be going the wrong way.

Peter R. Kay, FRCS
Past president, British Orthopaedic Association
Consultant orthopaedic surgeon
Wrightington Hospital
Wigan, England
 
Josephine, it was published in the last Orthopedics Today and was a follow-up to the preceding article referenced immediately above.
 
Pumkin, I am very grateful for your posting on J & J's MOM devices. Sadly, the organisation I worked for (1970-1998) until I retired was the world leader for fracture fixation (Straumann/Stratec/Synthes - I went through three name changes - a bit like the NHS) was bought by J & J in June last year. Do I hang my head in shame?
 
No, Thanks to the UK joint registries they had to come clean about the MOM replacements much sooner than they would have, putting additional people at risk.
 
Latest news on the ASR front - we have to watch this space for more!
ASR trial begins amid controversy over uncovered court documents
January 29, 2013
The first lawsuit for the DePuy Articular Surface Replacement (ASR) System in the United States got underway on Jan. 25 in Los Angeles.

The plaintiff, former North Dakota prison guard Loren Kransky, sought a hip replacement in 2007 to relieve arthritic pain, which physicians carried out with the DePuy ASR implant. He has since had the implant removed, according to media reports about the trial.

The ASR prosthesis was recalled in August 2010 after the National Joint Registry for England and Wales reported 12% to 13% of patients’ hips treated with the prosthesis would require revision within 5 years.

“DePuy acted in the best interests of patients in deciding to voluntarily recall the ASR Hip System and in creating a program to work with patients and their health insurers to address medical costs directly associated with the recall,” Mindy Tinsley, director of worldwide communications at DePuy Synthes Joint Reconstruction, told Orthopedics Today.

During a pretrial hearing on Dec. 3, 2012, Paul Voorhorst, MS, MBA, director of worldwide biostatistics and data management at DePuy Orthopaedics, stated that a 2011 internal investigation conducted by Johnson & Johnson, DePuy’s parent company, revealed 37% of ASR XL hips were estimated to fail within about 5 years. These projections for survivorship of the implants were reportedly never released, according to court documents from the pretrial hearing.

Commenting on the estimate, Tinsley told Orthopedics Today, “At all times the company was looking out for patient interests by analyzing data on the ASR Hip System. The internal analysis referenced was based on a small, limited set of data that could not be used to generalize the revision rate for ASR, unlike published data from national joint registries that include large numbers of patients and detailed revision information.”

To date, more than 10,000 lawsuits for failed ASR implants have been filed in state and federal courts regarding the DePuy ASR product. Approximately 93,000 patients worldwide were treated with these prostheses. One-third of the patients are located in the United States.

A Johnson & Johnson press release dated Jan. 24, 2013, stated the company set aside $922 million in 2012 to handle the ASR lawsuits and recalls.

“In the [United States], thousands of payments have been made to ASR patients for testing and treatment and other out of pocket expenses,” Tinsley stated. “We encourage ASR patients to contact the help line at 888-627-2677 to have their questions answered and to submit claims for reimbursement.”

“DePuy believes the evidence to be presented at trial will show the company acted appropriately and responsibly,” she added.

Reference:www.documentcloud.org/documents/560445-testimony-on-artificial-hips.html.
 
Wow - this reads like a spy novel. I'll watch this space. Thanks Bob!
 
Thanks Jacey, I agree and it is not finished yet. I had to check to see if J & J (DePuy) was one of our sponsors - just in case it tread on someones toes!
 

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