New member: misery must love company because I don’t feel so bad now. (cervical)

[TPatti]

Annapurna-I agree, If only there was such a thing as an unbiased expert

[Conan26]

Originally Posted by RP_OutWest

I just found the thread here that has several members speculating on the durability of both polycarbonate urethane and UHMWPE w.r.t. the M6L. Some seem more concerned than others.

It appears that the M6L produces less debris than ball and socket types. But it may compress more over usage. That is the first concern. It seems the study used 20M cycles and the M6L lost 1.3 +/-.6 mm of height when subjected to 1200N (per actuation I guess.) I think this relates to about 10% of a lumbar disc. I suspect the M6C won’t have anywhere near 10% compression, there is not nearly as much load at that level.

The second concern is the UHMWPE annulus wearing against the plates into which it is woven. UHMWPE has a better wear profile than Teflon, but that doesn't tell me anything in regards to its use in the M6. One member sighted a study (I think form SK) that said not one single strand of the annulus failed after whatever test they ran (possibly the 20M cycle test).


Here’s the link.
http://www.adrsupport.org/forums/f51...-million-5198/

BTW, ball and socket discs use these materials also so they are not immune to similar failure mechanisms. Also, they wear on each other via abrasion. The annulus in the M6 probably does not have compressive force pushing it against the metal plates when moving across it like the ball does against the socket.

The best advice is that there are a sufficient number of recipients that have had the M6 for 5 years or more. If there becomes a problem we should be able to here about it on forums like this one well before the ones we have fail. But hopefully that won’t happen.


TPatti, i'll have to look for your story on here. I hope your recover is going well.

Hey welcome and i do enjoy reading posts like yours, as i am a Mechanical engineer, and if i could hold out longer i would try for Cadisc L but i cant and within the next few days will be heading out to germany to get my op, but like i have said what is designed in the lab or on soildworks or rhino is so different to in the human body or building etc

As in the lab its under ideal situations and nothing can simulate how your going to twist and turn for the next few years or if it was implanted correctly and nothing compares to your natural disc.

but if i do have anything wrong with my c spine later down the road ill go for Cadisc C or please god 3D printing is a wee bit further on as that is the future

[RP_OutWest]

These are great response. Jim do you know if there were any conclusion to the 10/20/85 million cycle question? It appears every manufacture uses different definitions of what "lifetime" means. Also, what is a reasonable load? I just read a study on spine compression in long distance runners that referenced 2000N as an appropriate force at the heal (of the shoe). I would like to believe that artificial disc designed for both the lumbar and cervical spine are more robust in the c-spine. But haven't made that leap yet.

Thanks for the pointer to Cadisc Conan. That does look interesting. Do you know how long it has been in use?

-RP

[RP_OutWest]

I talked to Dr. Lauryssen this weekend. He called me from his car while on his way to the airport to fly to Switzerland. He said he is accredited for surgery there and just needs a contract with a hospital that is competitive with Germany and Spain. He indicated he is looking for pricing details of German and Spanish doctors that would allow him negotiating leverage.

As for me, he confirmed that I definitely need surgery sooner than later. This is because he sees Osteophytes at the offending levels. Neither MRI report nor my other doctor indicated that I have bone spurs.

I will now be contacting doctors in Europe to see what their schedules are.