Should I be asking for metal ion tests?

[jakemn]

Reading some of the posts here, it seems a lot of folks who received either HR or THR are being tested regularly for metal ions.  I have a 1-year-old BHR implant, and I'm feeling great.  But it makes me wonder, is this something I need to request of my PCP as a standard part of checkups, or is regular ion monitoring only required for "problematic" implants ?  I'm not even sure how to go about requesting it, or if it has to be done by a THR/HR surgeon's office ?

Jake in MN

[Baby Barista]

Dr. Pritchett says getting ion testing without symptoms, is like taking your car to a mechanic when there's nothing wrong.

[Dannywayoflife]

If your device is properly implanted its pointless!

[obxpelican]

Some docs are doing the tests @ 2- 3 years to get a baseline and for studies.

Remember guys, the MOMs are being attacked right now and metal ions are the big issue so what better way to disprove them by giving them hard stats.


Chuck

[hernanu]

I had mine at two years, more like Chuck said as a baseline. My doctor is doing them pretty regularly at two years.

[fenceman]

My Dr. also said that they are not needed unless there is a problem. 

[Arrojo]

Dr. Su requires it every year.  I had my one year test two days ago.  And for the record, I also brought my old car in for a 120,000 mile check up two days ago even though everything seemed fine and my mechanic (who I have trusted for many years) said I needed new front brakes.

[hippy hippy shake]

Getting my bilat BHRs real soon, but can add that  there are recent guidelines (1/17/2013) from the FDA on metal-on-metal hip devices.  That included the following:

Follow-up of asymptomatic patients with metal-on-metal hip implants, including physical examinations and routine radiographs, should occur periodically (typically every 1 to 2 years). 

If the hip is functioning properly, the FDA does not believe there is a clear need to routinely perform additional soft tissue imaging or assess metal ion levels in the blood.
Be aware that there are certain patients who are at risk for increased device wear and/or adverse local tissue reactions (ALTR) and should be followed more closely. They may include:

    -Patients with bilateral implants
    -Patients with resurfacing systems with small femoral heads (44mm or smaller)
    -Female patients
    -Patients receiving high doses of corticosteroids
    -Patients with evidence of renal insufficiency
     -Patients with suppressed immune systems
    -Patients with suboptimal alignment of device components
    -Patients with suspected metal sensitivity (e.g. cobalt, chromium, nickel)
    -Patients who are severely overweight
    -Patients with high levels of physical activity.

I think Dr. Su just has been doing it for years as standard practice anyhow.
Seems to make sense to me, but I'm not a doctor.

[johnny_canuck]

I'll put in my 2 cents (thats 3 cents Canadian).

1\ I had a right-hip resurfacing ~1 year ago (this week, in fact). Every radiological exam I've had since the procedure said perfect positioning of both parts of the appliance. Recovery went very smoothly.

2\ 2 weeks or so ago, developed a 'squeak'. Many posts on this forum suggest that this is like a simple 'hydration issue'. Maybe - but 'squeak' = direct MoM contact, without the synovium cushioning the two pieces of metal. Result -- perhaps more ion release.

3\ my surgeon agreed that it might be worth sending out blood for tests for cobalt and chromium. Glad I/we did -- both came back 10-12 range, way above where they should be. This has several obvious implications, but the larger point I'd like to make is this: I don't think there is any reason not to have regular testing for metal ions. You have (or might be considering) a MoM appliance. Some people have no problems, but as with all statistical distributions, there are those fall in the 'bad tail' -- meaning, you might have problems (I might, it seem, be one of them).

But, you have no way a priori of knowing where you are in the distribution. So, I'd say, get the test, annually or semi-annually. Especially if you fall into the groups where there is some prior reason for concern (in my case, hyper-active exercise schedule, and small diameter appliance -- 44 mm). And, if you start squeaking, then I'd say do it sooner than later, and don't simply assume that upping your hydration solves the problem. It might reduce -- or even eliminate -- the squeak, but might also mask something else.

[johnny_canuck]

For completeness, there is a direct inverse relationship between device diamter and probability of increased ion release: smaller the diameter, more likely you might have ion issues. Some light reading of some slightly older but still relevant literature about the issue below. To some degree, this is why some national health services, and some surgeons, will now no longer work with 'small diameter' patients. I knew the risks going in to my surgery, and rolled the dice. But, we must remember that there is some probability that said roll will come up craps:

Langton DJ, et al. The effect of component size and orientation on the concentrations of metal ions after resurfacing arthroplasty of the hip. J Bone Joint Surg (Br) 2008;90(9):1143–51. doi: 10.1302/0301-620X.90B9.20785.

Amstutz HC, Wisk LE, Le Duff MJ. Sex as a patient selection criterion for metal-on-metal hip resurfacing arthroplasty. J Arthroplasty. 2011;26(2):198–208. doi: 10.1016/j.arth.2010.03.033.

McBryde CW, et al. The influence of head size and sex on the outcome of Birmingham hip resurfacing. J Bone Joint Surg Am. 2010;92(1):105–12. doi: 10.2106/JBJS.I.00197.