Cobalt knee replacement appliance and metal poisoning

Metal shedding usually occurs from metal-on-metal appliances - chromium cup & cobalt ball. These materials were used together for a while in the early 2000's on the theory that the implant would last longer -especially in younger, more active people. It turns out younger, more active people cause more metal on metal friction, with very fine debris being deposited. If the cup is plastic or ceramic, it doesn't seem to be problematic.

I had chromium cobalt hip implants, which had to be replaced after just 5 years due to shedding & metallosis. This is now considered old technology, and if I were the patient I would be asking many questions before I would consent to metal on metal.
Do you know what the other component would be used by your surgeon?
Sue

Yes sue. He uses some type of ( for lack of better word) plastic material or some type or polymer. Is there any concern regarding reaction to glue used? I now hear that is problematic? Thank you for the feedback

A few people react to bone cement, I don't have any experience with that in spite of numerous ortho surgeries and a history of allergies.
Anyone else here who knows?
Sue

Yesterday I had a partial knee replacement- and today I watched The Bleeding Edge…& ran to my booklet to check and I do indeed have a cobalt chromium implant. I had thought I had done my research but of course relying on the FDA approval is SO stupid and I know they’ve really lost a lot of credibility over the past few decades. Should I start freaking out now or wait until I show symptoms? Now I’m going to have to have my blood checked yearly for cobalt….

Hello Gabette, Welcome to Mayo Connect, where patients and caregivers come to share experiences.

I have seen the Bleeding Edge, and it was scary. In fact, I the metal-on-metal hip implants and all the side effects. They were removed 12 years ago, and I am fine now.

One of the things we must remember is that no surgical intervention is completely risk free, and we make the choice to improve our quality of life. Even after the issues I had, I would do it again - my quality of life these past 17 years is far superior to what I would have had without surgery.

While there are a few examples of problems with the chromium cobalt knee prosthetics, they are far more rare than with the hips (which are now off the market.) As rare as they are, I suspect extensive research would show that the risks of all types of knee implants would be roughly similar.

I looked for about a half hour, and it does not seem that the incidence of heavy metal deposits and the attendant problems is as prevalent in knees as it was in hips. Probably because the mechanics are very different.

In the metal-on-metal hips, the acetabular cup and the femur implant fitted together directly, with no cushioning lining or wear layer between the two. Friction between the two metal surfaces caused a great deal of metal to be shed into the surrounding tissue.

In chromium-cobalt knee prosthetics, the femur implant and tibia implant are made of metal. Between the two is a cushion, that emulates our cartilage. It is made of a cros-linked polymer, and being softer than the metals, it is the part that compresses and wears. Hence in a fully successful implant, there is very little or no wear on the metal. It seems if problems with metal occur, it is because one or more components fail - they may remain loose within the bone, or glue may break down and cause loosening. This can happen with any knee implant, whether chromium & cobalt, titanium, or another metal.

So, if I were you, I would breathe a sigh of relief, and remain vigilant for any sign that the implant is not fully secure in the bone after it heals. Full healing and in growth takes several months, and can be confirmed with x-rays after 6 months or a year as recommended by your doctor. Then I would spend the next several months working to get that new knee in shape so I could get back to my life.

Sorry this is so long. Congratulations on your new knee. You will find many people here to coach you through recovery. Just remember the first few weeks are the worst. Ice, elevation and pain control are your best friends. And PT will hurt, but is critical to full recovery.
Sue

I know this is dramatic but I LOVE YOU!!!! Thank you so much for your incredibly insightful reply!!!! I feel so much better- but yes, vigilance is key. & even before I watched the documentary I had wondered how long that polymer cushion would last-I’m a very active person. Or I was a very active person and I hope to be that again.
Thank you so much. I’m so happy I posted that.
Gabby

Oh Gabby - with your attitude, you will be very active again. Just remember your body has been assaulted. My sister-in-law had 2 partial knees almost 6 years ago now, and is going strong - she is a Master Naturalist, state park volunteer, grandma of 9...

I will give you one heads up - as you begin to heal, you may feel like you have burning or zapping sensations - anywhere from above the knee to the toes. This is your nerves, which were insulted by the surgery, waking up and healing. It can be quite unpleasant, but it is temporary - a few weeks or so. I found motion - walking, pedalling, or kicking in the pool to help when my hips were healing. She went with ice packs, heat packs & Icy Hot gel.

Please be kind to yourself and do your therapy so you will be your best new self...
Sue