Limb Lengthening Forum
Limb Lengthening Surgery => Limb Lengthening Discussions => Topic started by: Michael J. Assayag, MD on March 13, 2021, 06:29:38 PM
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Hey Everyone,
I have been monitoring the posts about this topic for weeks now, and tried to avoid commenting too much about the topic, Now I think it is time to set the record straight officially and talk about the Stryde recall, its causes and the future. Let it be known that I am in no way shape or form a NuVasive consultant, that except for using some of their implants in my limb lengthening clinical practice, I have no financial affiliation with them. This post comes from my own initiative.
(If you do not want to read this long post, go straight to the end for the conclusions )
Let's start by generally talking about orthopedic implants. Most orthopedic implants, whether used in joint replacement, fracture fixation, or deformity correction, have mechanical as well as chemical properties. None is completely inert and they all interact with the human body it is in contact with. The body is a very complex machine with chemical properties, also submitted to mechanicals principles. Our body is quite corrosive in itself! we are like a big saline water container.
Here are a few examples of corrosion in orthopedic implants:
- Junction between head and neck of a Hip Replacement
- Metal on Metal hip replacement coupling (more surface wear than corrosion)
- junction between screws and metal plates/nails in fracture fixation
- Spine fusion rods
I am sure there are 100 more examples i'm forgetting, but you get the point. All those mechanical implants achieve their objective, the task for which they have been conceived, with a small compromise of corrosion. Corrosion that is mostly asymptomatic , that is noted during implant removal surgery, and is likely to never cause any further issue. It is a known fact and none of those devices are pulled from the market. During orthopedic training, material properties is part of the standard curriculum.
So what causes corrosion? When metal has tiny microscopic scratches, and body fluids are pumped into these scratches, 2 pieces of metal touching will start transferring ions .That reaction transforms a refined piece of metal(stainless) into a ''more chemically stable metal'' (that reddish residue we call rust, or corrosion). It is typical of stainless steel and can be accelerated by other materials such as silicon. The nail is literally bathing in a bucket of salt water when it is sitting inside of the bone. Patients want weight bearing implants, and stainless steels are, for now, the only good material that can provide weight bearing.
Even if we venture in the world of other stainless steel internal lengthening rods, we know that STRYDE is not the only one to create corrosion! There are other nails that have been around for literally decades, with the same problem. But because it does not create any significant issue, (no cancer, no metal toxicity, no adverse effects), they have remained on the market and deemed effective and safe. Corrosion at the same male-female junction has been found upon removal of other internal lengthening rods.
So what is the status with the Stryde recall?
The recall of all stainless steel implants was done COMPLETELY VOLUNTARILY by NuVasive to address physican and patient concerns, investigate the reaction, its significance, and improve the product to eliminate de problem. I have read all kind of ominous threads out there and it is time to demystify them:
What is the underlying issue?
An inflammatory reaction in the bone at the male-female junction (where the small piece comes out of the bigger piece) was noticed that in 10-15% of patients with stryde, 6 to 9 months after the initial surgery. This seems to occur slowly enough that the bone has time to repair itself faster without breaking. This reaction completely disappears when the nail is removed. To be completely clear, Dr. Herzenberg who was part of the design team for the PRECICE nail, has always advocated for implant removal, even when he was using ISKD! So the concept that nail removal is pushed by surgeons due to this reaction with completely ridiculous. Any reasonable surgeon should consider removing lengthening implants.
What is that reaction?
From taking biopsies of the bone reaction after nail removal in our center, the current most likely working hypothesis is that the reaction seen on xray is just a manifestation of the body's defense mechanisms (white blood cells) against the corrosion. Remember, the body is a complex machine that always interacts with metal implants, so this is not entirely abnormal.
Can I suffer from Metal poisoning with a lengthening rod?
We have also been drawing Chromium and Cobalt levels in our patients with Stryde nails. Normal levels of Chromium are below 1ng/ml (there is chromium in your drinking water !) The levels of cobalt were normal in our patients and chromium levels never rose beyond 1.5ng/ml (highest safest concentration is 15ng/ml, which is 10folds those levels).
Would you still implant a Stryde nail in your family member if it were necessary?
Yes. Understand me well here: I am not minimizing the fact that Stainless lengthening nails create some amount of corrosion. I believe this needs to be investigated further and that actions should be taken to solve the issue. As a rule of thumb we should always try to improve our technology. But I believe the implant to be safe and reliable, and that it is only a matter of time before we can start using weight bearing implants again.
CONCLUSIONS?
all orthopedic implants have mechanical and chemical properties.
They all interact with the corrosive and alive human body.
Stainless steel lengthening nails may create corrosion where 2 pieces of metal rub against each other. Stryde is not the only one.
The body tries to protect itself by creating a healing reaction around it. It seems to be benign and self limiting, but we are all actively researching this.
NuVasive is doing its due dilligence and addressing the problem to find solutions. We should all be happy and encouraged about that.
Engineers are smart. We are all confident that Nuvasive will find a fix and that Stryde will be back on the market soon.
Bottom line is: Whether we like it or not, the world is made of compromises. Any implant designed to defy nature and lengthen a limb, replace an articulation, fix a fracture, enhance bodily features (i'm including all cosmetic fillers, neurotoxins and prosthetics AND medications) , has the potential to create some problems. If one is not willing to risk complications or problems, one should avoid any kind of surgery altogether.
"For every action, there is an equal and opposite reaction"
- my main man Sir Isaac Newton
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Thanks for your detailed and thorough perspective. I think the most important unknown most of us are wondering currently is, "When will this be an option again?" and the most critical part of your reply would then be:
The recall of all stainless steel implants was done COMPLETELY VOLUNTARILY by NuVasive to address physician and patient concerns, investigate the reaction, its significance, and improve the product to eliminate the problem.
This is the key point from my perspective. NuVasive reps have been trying to sell the line that they are just doing the recall for "testing and review" which would allow it to come back in just a few months. I doubt that same as you do. I think they are recalling to try to fix the problem, and fixing the problem may take longer. Re-engineering anything in the span of just a few months might be doable but if they intend to perform re-testing or make multiple designs to attempt different approaches to fixing it that will all obviously take some work.
Without insider info from NuVasive though we're all guessing about that.
I did see one x-ray on the forum from someone with a Stryde who had what looks to me like some pretty significant heterotopic ossification around the distraction point and was told by his surgeon to "push it back towards the bone" and try to massage it to break it up. I'm sure that's been rare, but there was then definitely something a bit unusual about the Stryde and this issue, as I've never seen or heard of that with the Betz/Guichet steel nails.
Here you can see his x-rays:
http://www.limblengtheningforum.com/index.php?topic=64978.msg187526#msg187526
(https://s7d2.turboimg.net/t/51825147_sideviewbone.jpg) (https://www.turboimagehost.com/p/51825147/sideviewbone.jpg.html)
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Thank you doctor, that was really useful.
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I did see one x-ray on the forum from someone with a Stryde who had what looks to me like some pretty significant heterotopic ossification around the distraction point and was told by his surgeon to "push it back towards the bone" and try to massage it to break it up. I'm sure that's been rare, but there was then definitely something a bit unusual about the Stryde and this issue, as I've never seen or heard of that with the Betz/Guichet steel nails.
Here you can see his x-rays:
http://www.limblengtheningforum.com/index.php?topic=64978.msg187526#msg187526
(https://s7d2.turboimg.net/t/51825147_sideviewbone.jpg) (https://www.turboimagehost.com/p/51825147/sideviewbone.jpg.html)
You are very welcome.
What you see on that xray is not related to the implant itself. It is a possible complication of limb lengthening surgery. I lack detail of the surgical technique, do not know about the patient nor have I seen any other xray (in orthopedics we tend to say "1 view is no view") to reliably comment on that out of control bone formation.
however I can guarantee that the comment made in the thread that
i mark. The issue you experienced with the tumour-like outgrowth of the bone onto the side of the nail is now a reason why Stryde has been suspended in the UK for now.
is completely false.
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You are very welcome.
What you see on that xray is not related to the implant itself. It is a possible complication of limb lengthening surgery. I lack detail of the surgical technique, do not know about the patient nor have I seen any other xray (in orthopedics we tend to say "1 view is no view") to reliably comment on that out of control bone formation.
however I can guarantee that the comment made in the thread that
is completely false.
Right. Fair enough. I suppose the theoretical concern is if the device is chewing itself up and corroding from poor mechanics shedding metal into the soft tissue this could trigger inflammation which would then lead to increased risk for heterotopic ossification like this. In which case there could be a link. Or as you said it could have nothing to do with the Stryde and be a patient factor that he would have had in his case either way (or a surgeon factor).
With an N of 1 obviously no way to know that for sure. Maybe NuVasive has more info on this. If they're seeing it in a higher number of cases than the Precice it might suggest a link. Someone on here claims Paley has seen more cases of this with Stryde but that is hearsay and I don't know if he really did:
Paley has announced that 60% of people have had odd bone formation possibly due to corrosion.
The other example of concern on this forum I have seen was this case, where his chromium levels were 2-3 times the norm, suggesting there likely was a significant amount of flaking/breakdown/leaching/corrosion:
http://www.limblengtheningforum.com/index.php?topic=66149.msg189943#msg189943
I agree entirely there's no reason for anyone to automatically worry for people who already had the Stryde. Maybe just check your chromium levels and as long as you're healing well you're probably fine. For my own benefit, I wish they didn't pull it at all. The abnormal ossification is the only thing I would worry about as that can cause chronic pain after. If you dodge that or there's truly no connection it's probably still the best device even with these flaws.
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Very helpful doc!
The body tries to protect itself by creating a healing reaction around it. It seems to be benign and self limiting, but we are all actively researching this.
Is this something to research specifically with limb lengthening and Stryde? If corrosion is a common phenomenon with many implants, then the healing reaction should have happened with other implants too isn't it? And the benignity of such healing reactions should have also been researched, right?
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Thank you very much for the detailed response Dr. This kind of information is very helpful to us all.
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Excellent post doctor, as always from you.
Thank you with all the knowledge you offer to us.
I have a question though. Could the corrosion of steel (or any metal in orthopaedic nails, plates etc), except from poisoning which you mentioned that is not the case, increase the possibilities of a tumor in bone or other organs?
This is the most important thing for me and I would like a clear answer if you can.
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Excellent post doctor, as always from you.
Thank you with all the knowledge you offer to us.
I have a question though. Could the corrosion of steel (or any metal in orthopaedic nails, plates etc), except from poisoning which you mentioned that is not the case, increase the possibilities of a tumor in bone or other organs?
This is the most important thing for me and I would like a clear answer if you can.
This is highly unlikely.
The only orthopedic implants known to have precipitated what we call Pseudotumor (which is not cancer) are certain types of Metal on Metal coupling hip replacements. However hip replacements move constantly and were creating more than a thousandfold the amount of metal debris.
as for the bone formation reaction i mentioned before, everyone please note that it is not reported at the regenerate site, but at the telescopic junction of the nails.
As for corrosion in orthopedic implants , it is very well documented and has been extensively studied .
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How does corrosion affect health in general
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I have a question though. Could the corrosion of steel (or any metal in orthopaedic nails, plates etc), except from poisoning which you mentioned that is not the case, increase the possibilities of a tumor in bone or other organs?
This is the most important thing for me and I would like a clear answer if you can.
How does corrosion affect health in general
I'm not him of course but I was interested by this question so I tried to find some literature on it to get an evidence-based answer. Here is a very long article summarizing the expected toxicity potentials for metal implants:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6384782/
Their table 3 summarizes different materials' expected toxicities, which vary of course depending on the metal type.
It seems though we don't actually know what metals are going into these LL devices publicly because they just describe the Stryde as "stainless steel" and yet a user had elevated chromium from it. The rep said that was normal as chromium was also part of the design. What other metals are part of the design? Who knows. Will they tell us if we ask?
I guess if people really want to know the theoretical toxicity the first step would be finding out from NuVasive exactly what elements are used, then referencing table 3 there.
In terms of cancer, they say: "Corrosion is an important factor in the design and selection of metals and alloys for service in vivo. Allergenic, toxic/cytotoxic or carcinogenic (e.g., Ni, Co, Cr, V, Al) species may be released to the body during corrosion processes." So they are saying for example chromium is potentially carcinogenic and we have already seen one case of leaching of chromium with high blood levels from Stryde.
They also say in a general sense regarding all implants: "metal ions that are released as degradation products are transported by body fluids to remote tissues where they may elicit an adverse biological reaction (such as cytotoxicity, allergy or even cancer)."
To get a real world sense of the potential impact from this, I found this study of metal-on-metal hip implants which would be expected to grind and leach their metallic elements over time:
https://www.bmj.com/content/344/bmj.e2383
They found in the first 7 years after getting these hip replacement units, there was no increased rate of cancer, but also state: "These data are reassuring, but the findings are observational with short follow-up. The use of hospital episode statistics data might underestimate cancer diagnoses, and there is the possibility of confounding by indication. Furthermore, as some cancers have a long latency period it is important that we study the longer term outcomes and continue to investigate the effects of exposure to orthopaedic metals."
If we're sure chromium is the main leaching risk then we can discuss that in more detail. Chromium exists as Chromium III or Chromium VI. Chromium III is the natural form which we all need in our diet and is nontoxic. Chromium VI is usually the form that is used in metal plating (I believe). It would be really important to clarify if they are using chromium-3 or chromium-6 if you want a clear answer. The risks of chromium-6 exposure which include cancer are detailed here:
https://www.epa.gov/sites/production/files/2016-09/documents/chromium-compounds.pdf
In reality, whether chromium-3 or chromium-6, either way, I would guess cancer risk from one of these devices to be near zero. Potato chips are carcinogenic as well but it doesn't mean most people who have potato chips will develop cancer from them. Just because something is theoretically carcinogenic (or carcinogenic in very high levels) doesn't mean of course it will actually be carcinogenic (or carcinogenic in low levels).
If the levels are not very high or not very high for very long, then the body can usually tolerate things and have no harm done. It would be interesting and helpful perhaps if some current Stryde users could post their chromium levels as they lengthen to see how widespread/universal the issue is, how severe, and whether it lasts the full 2 years or if it's just temporary during distraction. Or ask NuVasive whether it is chromium-3 or chromium-6. Or what other elements are in the device so people know what else to have checked.
This sounds flippant but remember that even the act of living and existing is carcinogenic, as we will almost all develop cancer no matter what we do if we live long enough. We are all exposed to carcinogens every day in the smoggy air or in our food or water. It is somewhat a part of normal life and the big question is more about the severity and exact nature of the exposure, as for most of us, all carcinogens cannot be totally avoided even in normal daily life.
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Biodur 108 (the stainless steel alloy used for Stryde) is made up of 19 to 23% chromium
https://www.fwmetals.com/materials/stainless-steel/biodur-108/
Chromium is the anti rusting property added to most or all stainless steel in the world in general I believe, don't think nuvasive is hiding anything tho 😳
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Biodur 108 (the stainless steel alloy used for Stryde) is made up of 19 to 23% chromium
https://www.fwmetals.com/materials/stainless-steel/biodur-108/
Chromium is the anti rusting property of most or all stainless steel in the world in general I believe, don't think nuvasive is hiding anything tho 😳
Oh great. That's very helpful. I didn't realize the alloy type was public or so easy to find. I didn't mean to imply they were hiding anything either way in a sinister sense. I just thought maybe it would be a "proprietary trade secret."
So if you want to be sure you'd need a blood test for:
Iron, Manganese, Chromium, Nickel, Copper, Molybdenum, Cobalt
Looks like the device is almost purely iron, manganese, and chromium so those would be the most important to watch if you wanted to get checked periodically through the process.
And again it would be important to clarify if it's chromium-3 or chromium-6, as chromium-3 is mostly harmless. Someone could email Fort Wayne Metals and I'm sure they'd let us know.
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Hopefully after the biocompatibility testing, we will get our Stryde back and that Dr. A is right. If Dr. A has confidence in it's quick return then I have some hope. If not, I think I would be willing to sign a waiver for this surgery. Obviously the limitation is Nuvasive themselves now making a decision. Stryde has just changed so many people's lives, not even for CLL for just regular limb discrepancy and such. Positives heavily outweigh the negative- assuming if it's true that it leaks chromium but only at a small enough rate that is still considered only slightly elevated and not toxic.
Really want this back by summer 2022.
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thanks Dr Assayag!
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Hopefully after the biocompatibility testing, we will get our Stryde back and that Dr. A is right. If Dr. A has confidence in it's quick return then I have some hope. If not, I think I would be willing to sign a waiver for this surgery. Obviously the limitation is Nuvasive themselves now making a decision. Stryde has just changed so many people's lives, not even for CLL for just regular limb discrepancy and such. Positives heavily outweigh the negative- assuming if it's true that it leaks chromium but only at a small enough rate that is still considered only slightly elevated and not toxic.
Really want this back by summer 2022.
2022 could be possible. also, sorry to bother you but your claim in your signature, do you have any proof or how did you come up with this?
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2022 could be possible. also, sorry to bother you but your claim in your signature, do you have any proof or how did you come up with this?
I read it on the news. Some countries have banned this AZ vaccine due to it.
It is a small amount of people that get these side effects. But I don't see why anyone would even bother taking that risk at all. Just get the Moderna or Pfizer.
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How does corrosion affect health in general
Thanks Dr. A - another valuable contribution to this forum. Much appreciated!
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I read it on the news. Some countries have banned this AZ vaccine due to it.
It is a small amount of people that get these side effects. But I don't see why anyone would even bother taking that risk at all. Just get the Moderna or Pfizer.
bruh it's just speculations. as of now it seems like there is no causal correlation as a control group has as many cases of thromboembolic events as the EU group of people who got that side effect after the vaccine had. I doubt it really is a side effect since there is no real evidence supporting it.
Also idk where you live but usually you cannot choose which type of vaccine you get. It's decided by your field (and age maybe).
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It's a speculation that can potentially kill you. No harm no foul. I'm just trying to help people. Feel free to take AZ vaccine. I respect your choice. Even if it's 1% chance or 0.01% chance, I want to help people. All we know that it has more blood clots than OTHER vaccines. So if you had the choice- then pick a non AZ is my suggestion. Free world of course, so pick AZ if one decides it's fine, free will. I don't know about you but, if I was offered AZ, I would take it of course, if I wasn't doing a procedure where I break my legs and blood clotting is going to happen and is one of the major causes of death... potentially kill me. Then I would not take it. I am not anti-vaxx. I hate anti-vaxx people.
Vaccine is not decided by field or age in America in my state. It's just what's availible or offered. Moderna and Pfizer is most popular here. No choice either, but they preemptively tell you what they have.
Imagine I did not say this despite seeing the news and someone actually dies to DVT after taking this vaccine and getting LL. That would be a big regret by myself.
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And it might be speculation- a speculation that warranted Italy, Denmark, Iceland, Norway, Bulgaria, Austria, Estonia, Lithuania, Luxemborg, Latvia to temporarily suspend it enough to investigate. Seems important enough to add to my signature- no?
I am not trying to be a liar. I literally have no gain from this. I truly want to just give people the info, and they can decide what to do with it. My personal recommendation is wait and let them investigate it. Of course you can proceed with it- free will.
When they investigate and find it clear of any blood clot risk or remove certain batches that are bad- I'll happily be willing to take the AZ before LL (not that it's going to happen, I'm not doing LL anytime soon). And like I've said in my signature- it's PROBABLY safe.
Please I am not anti-vaxx or fear mongering. I love vaccines actually. I always get the flu shot every year like a good boy. This is a real issue guys! Please do your own research! My opinion is just my opinion!
You also have free will guys! You can take it if you want! I am not stopping you- just warning of potential issues.
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Thanks for the informative post. When do you estimate Stryde returning to the market?
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Can you comment on the partial weight bearing of Precise 2? Am I required to be on wheelchair during the consolidation phase? I'm around 150 lbs and I'm hoping to use the largest size Precise 2.
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Thank you for the clarification!
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It's a speculation that can potentially kill you. No harm no foul. I'm just trying to help people. Feel free to take AZ vaccine. I respect your choice. Even if it's 1% chance or 0.01% chance, I want to help people. All we know that it has more blood clots than OTHER vaccines. So if you had the choice- then pick a non AZ is my suggestion. Free world of course, so pick AZ if one decides it's fine, free will. I don't know about you but, if I was offered AZ, I would take it of course, if I wasn't doing a procedure where I break my legs and blood clotting is going to happen and is one of the major causes of death... potentially kill me. Then I would not take it. I am not anti-vaxx. I hate anti-vaxx people.
Vaccine is not decided by field or age in America in my state. It's just what's availible or offered. Moderna and Pfizer is most popular here. No choice either, but they preemptively tell you what they have.
Imagine I did not say this despite seeing the news and someone actually dies to DVT after taking this vaccine and getting LL. That would be a big regret by myself.
Okay I understand you are concerned but please offer some evidence-based proof because from what I have read is that the WHO investigates it and as for now it just seems like it is a bias in terms of causality (confounding). I respect you wanting to maximize safety though, in my opinion not getting vaccinated is a way bigger risk, catching covid during LL would be terrible too, especially if your one of the unlucky ones that got a severe course. Also, you are given anti-coagulation medicine during lengthening so I don't know, even if you would have had a bigger risk of blood clots the medication would possibly prevent it.
It is not your fault if some unfortunate complications happen to a person that does LL because if they choose to do it, it is their decision to endure all possible risks.
And it might be speculation- a speculation that warranted Italy, Denmark, Iceland, Norway, Bulgaria, Austria, Estonia, Lithuania, Luxemborg, Latvia to temporarily suspend it enough to investigate. Seems important enough to add to my signature- no?
I am not trying to be a liar. I literally have no gain from this. I truly want to just give people the info, and they can decide what to do with it. My personal recommendation is wait and let them investigate it. Of course you can proceed with it- free will.
When they investigate and find it clear of any blood clot risk or remove certain batches that are bad- I'll happily be willing to take the AZ before LL (not that it's going to happen, I'm not doing LL anytime soon). And like I've said in my signature- it's PROBABLY safe.
Please I am not anti-vaxx or fear mongering. I love vaccines actually. I always get the flu shot every year like a good boy. This is a real issue guys! Please do your own research! My opinion is just my opinion!
You also have free will guys! You can take it if you want! I am not stopping you- just warning of potential issues.
I am from one of these listed countries and we (med students) are scheduled to get AZ in a couple of weeks or so, so it's not suspended, idk about other countries though.
if it really is a risk, then I think I can agree on not taking it beforehand, or at least take it a couple of weeks or months before LL and not right before.
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Okay I understand you are concerned but please offer some evidence-based proof because from what I have read is that the WHO investigates it and as for now it just seems like it is a bias in terms of causality (confounding). I respect you wanting to maximize safety though, in my opinion not getting vaccinated is a way bigger risk, catching covid during LL would be terrible too, especially if your one of the unlucky ones that got a severe course. Also, you are given anti-coagulation medicine during lengthening so I don't know, even if you would have had a bigger risk of blood clots the medication would possibly prevent it.
It is not your fault if some unfortunate complications happen to a person that does LL because if they choose to do it, it is their decision to endure all possible risks.
I am from one of these listed countries and we (med students) are scheduled to get AZ in a couple of weeks or so, so it's not suspended, idk about other countries though.
if it really is a risk, then I think I can agree on not taking it beforehand, or at least take it a couple of weeks or months before LL and not right before.
I understand, I agree that it's most likely nothing and sure there are probably confounding variables not accounted for. I just am going to warn about this for the slim chance that AZ is actually no bueno.
I agree getting covid during LL is very bad.
My recommendation:
For privileged people: If two vaccine sites are availible, one offers a Moderna, other offers a AZ, I would go to Moderna (assuming you can go to both). Like for example a local university offers AZ but all the government health facilities offer Moderna (Not a real situation for me, USA has not approved AZ yet). Both have open appointments available. Thus, I would go to the Moderna IF I had the choice. Of course most areas are limited appointments and stock, and health officials recommend to get what ever is available. Covid is riskier than the low chance of getting this side effect. I understand that idea also, so I am saving my recommendation for privileged people who can "choose".
I agree, it may be a smart idea to take it a few weeks before hand and then do LL.
You are "more" right in a sense though, that COVID is more dangerous than any of the potential side effects of a AZ vaccine, so I agree and think we are on the same page
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I understand, I agree that it's most likely nothing and sure there are probably confounding variables not accounted for. I just am going to warn about this for the slim chance that AZ is actually no bueno.
I agree getting covid during LL is very bad.
My recommendation:
For privileged people: If two vaccine sites are availible, one offers a Moderna, other offers a AZ, I would go to Moderna (assuming you can go to both). Like for example a local university offers AZ but all the government health facilities offer Moderna (Not a real situation for me, USA has not approved AZ yet). Both have open appointments available. Thus, I would go to the Moderna IF I had the choice. Of course most areas are limited appointments and stock, and health officials recommend to get what ever is available. Covid is riskier than the low chance of getting this side effect. I understand that idea also, so I am saving my recommendation for privileged people who can "choose".
I agree, it may be a smart idea to take it a few weeks before hand and then do LL.
You are "more" right in a sense though, that COVID is more dangerous than any of the potential side effects of a AZ vaccine, so I agree and think we are on the same page
Yes, I agree with this. If you can choose -> take moderna. If not but you can get AZ weeks or months before your surgery, take it.
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Can you comment on the partial weight bearing of Precise 2? Am I required to be on wheelchair during the consolidation phase? I'm around 150 lbs and I'm hoping to use the largest size Precise 2.
The 12.5mm precice allows for up to 70lbs of weight bearing, which would really only allow standing with arm assistance.
Walking unassisted should really only be allowed when 2 solid full cortices are seen on xray. meaning that 1 bone side are viewed on each xray (front and side view)
weight bearing more than that puts you at risk of implant breakage. try at your own risk.
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Thanks for the informative post. When do you estimate Stryde returning to the market?
Hard to tell for sure.
July to September
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The 12.5mm precice allows for up to 70lbs of weight bearing, which would really only allow standing with arm assistance.
Walking unassisted should really only be allowed when 2 solid full cortices are seen on xray. meaning that 1 bone side are viewed on each xray (front and side view)
weight bearing more than that puts you at risk of implant breakage. try at your own risk.
Dr. what about screws ? can they bear too that much weight?
we all are concerns about nail but in this forum I didn't see any patient who bend or break his nail? just saw screws are bent or break
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Thanks for the response. Another quick question - how long can a Precice patient expect to be using a wheelchair/assistance?
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How do Precise 2 patients get in and out of a vehicle? Since they have to use wheelchair and have to get in a car to go to a physical therapy place.
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How do Precise 2 patients get in and out of a vehicle? Since they have to use wheelchair and have to get in a car to go to a physical therapy place.
I used Precice 2.2 in my femurs. The femur rods can handle at least a combined 150lbs (75lbs times 2 legs), so unless you are heavy you can probably stand up on both feet. As such, you can essentially rotate your feet out of the car, put both on the ground, and stand up, and then use the walker from there. Similar procedure to get back in. You can hold onto the car if needed.
Note that the tibia nails have a lower weight bearing capacity, so that might differ.
Thanks for the response. Another quick question - how long can a Precice patient expect to be using a wheelchair/assistance?
I never used my wheelchair, but I did have to use the walker for several months.
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Thanks for the response. How many cm's did you gain and how long was "several months"? How long was it until you could was unassisted?
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Thank @FomerKidd. I'm planning to do Precise 2 with Dr. Depiparshad this June. Do you have any pro tips for the surgery & recovery? How long did it take you to walk without assistance? How long did it take you to recover to normal walking gait? There aren't as many Precise 2 diaries out there comparing to Stryde. I appreciate your response.
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I forget the exact time, but maybe 5-6 months until I was cleared to walk unassisted. The rule of thumb they give is that, however long you spend lengthening, you probably need about the same of time to be consolidated. You cannot walk unassisted until that time.
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Dr Paley... recall of Stryde interview
https://youtu.be/qBQKYz2gFqw
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Dr Paley... recall of Stryde interview
https://youtu.be/qBQKYz2gFqw
Thanks for posting. The main point is at 14:30. He says of 122 implants that they followed up in a year on:
- 36% of the bones were totally normal
- 64% total of the bones had abnormal changes
Of those 64% with abnormal bone reactions, it was broken down into:
- 40% had extra bone thickening (hypertrophy)
- 3% bone breakdown (lysis).
- 21% had combination of hypertrophy and lysis.
The issue seems to develop at 6-12 months once the distraction is done. There have been no fractures so far from lysis, but that would be the main threat. He didn't talk about what you'd need to do if you got bad lysis (as none have had it so far that bad), but I presume you might need a permanent nail or grafting if it fractured and wouldn't thicken back up.
Then at ~51 min he talks about two possible solutions NuVasive is working on:
- Coat the junction in polyethylene (plastic)
- Add a sleeve over it to seal it the junction
He guesses if they try to fix the problem (rather than just re-release it) it will most likely happen by 10 months from now and maybe longer.
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Very well summarized maximize!
It also wasn't clear what the actual cause of lysis was, and whether it happens with other nails like Precice as well.
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Very well summarized maximize!
It also wasn't clear what the actual cause of lysis was, and whether it happens with other nails like Precice as well.
He's saying the lysis is occurring due to the corrosion (rusting), same as the hypertrophy. The corrosion (rust) is irritating the bone and it is reacting either with overgrowth (hypertrophy), breakdown (lysis) or some combo thereof. It's not happening with Precice because Precice is titanium which won't corrode. Stryde is steel (which is mostly iron) and steel/iron can more easily rust.
The only significant issue that has been raised on the forum he did not address is whether NuVasive is testing people's blood for chromium or other metal levels. We had one person post here saying he had 2-3 times the chromium of normal and the NuVasive rep was in the room when he was told (so they are aware).
He said there are no cases of proven cancer from a corroded implant, but realistically that would almost be impossible to prove causality on, unless it was happening in massive numbers. I agree it's unlikely to be an issue for anyone. You've only got the device for 1-2 years and it's probably a minimal amount. But if you want to be technically correct, chromium-6 is defined by government agencies as a potential carcinogen (if that's the type of chromium used in the alloy). I would expect NuVasive to want to do blood tests on people as well, and maybe they are, and those numbers will be reassuring. Or maybe they don't want to stir that potential hornet's nest of "technicalities" so they're just ignoring it.
Either way if they can coat or seal the joint that should solve it, but as he said that's probably going to take about a year.
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He's saying the lysis is occurring due to the corrosion (rusting), same as the hypertrophy. The corrosion (rust) is irritating the bone and it is reacting either with overgrowth (hypertrophy), breakdown (lysis) or some combo thereof. It's not happening with Precice because Precice is titanium which won't corrode. Stryde is steel (which is mostly iron) and steel/iron can more easily rust.
The only significant issue that has been raised on the forum he did not address is whether NuVasive is testing people's blood for chromium or other metal levels. We had one person post here saying he had 2-3 times the chromium of normal and the NuVasive rep was in the room when he was told (so they are aware).
He said there are no cases of proven cancer from a corroded implant, but realistically that would almost be impossible to prove causality on, unless it was happening in massive numbers. I agree it's unlikely to be an issue for anyone. You've only got the device for 1-2 years and it's probably a minimal amount. But if you want to be technically correct, chromium-6 is defined by government agencies as a potential carcinogen (if that's the type of chromium used in the alloy). I would expect NuVasive to want to do blood tests on people as well, and maybe they are, and those numbers will be reassuring. Or maybe they don't want to stir that potential hornet's nest of "technicalities" so they're just ignoring it.
Either way if they can coat or seal the joint that should solve it, but as he said that's probably going to take about a year.
Well the part I don't get is how the same corrosion can have completely opposite effects of hypertrophy and lysis. I think it's just a hypothesis at this point.
One more scary thing from the interview was the rare Earth magnet which is sealed but the seal can theoretically break as time passes. No one knows the impact of that event. I hope that the seal is a tried and tested thing in implants and that there is no debate about that.
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Well the part I don't get is how the same corrosion can have completely opposite effects of hypertrophy and lysis. I think it's just a hypothesis at this point.
One more scary thing from the interview was the rare Earth magnet which is sealed but the seal can theoretically break as time passes. No one knows the impact of that event. I hope that the seal is a tried and tested thing in implants and that there is no debate about that.
I don't think anyone could give you a good answer for that. The body can react to damage in varied and unpredictable ways. An example would be skin scarring. Some people are prone to hypertrophic scars (big overgrown scars). Some people are prone to atrophic scars (underdeveloped scars). Often it has nothing to do with the skin cut or how it was stitched. It's just how that person reacts as an individual.
Probably in the cases of combined lysis and hypertrophy you could theoretically find that there is a difference between whether those spots are being differentially loaded by standing or in different contact with the rust itself vs. the metal leaching from the rusted spots. But this would be very hard to verify and no one is going to bother because it doesn't really matter except for curiosity. Either way they need to stop the rust or seal it off so that's what they're doing.
I doubt the magnet is an issue at all. He was just pointing out that sealing something off as a solution works in principle and using that as an example.
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64% with abnormal bone reactions? That's a high number. Would the hypertrophy or lysis show up in an x-ray?
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The best part of interview is cyborg put lipstick and dr. Paley had background of his Institute. LOL . too much hypocrisy
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Paley said that he doesn't want to "downplay" the whole thing etc, but to compare 5months in a wheelchair with going back to using iphone6 is the definition of downplaying imo.
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Paley has an incentive to downplay the precise experience and it’s easy for him to say it’s no big deal as he isn’t the one in a wheelchair for months. He is acting like there isn’t a major difference between stryde and precise when he and other surgeons have been on record multiple times saying how much better stryde is. But now all of a sudden it’s “almost the same”. Paley is obviously at the top of his field but it’s not fair to patients when a doctor downplays just how tough of a recovery experience it will be. There is a significant difference and Paley knows this. But I can understand as he is running and business but at the same time he should be more transparent about the differences and not just say “oh the only difference is that it’s not fully weight bearing” when that is literally what made stryde such a revolutionary device for LL. At least Dr. Assayag is up front with the lack of weight bearing.
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Looks like dr. Assayag and Giotkas (judging from the text on his website) are more optimistic about a swift return.
I was planning to do surgery end of year.
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Paley has an incentive to downplay the precise experience and it’s easy for him to say it’s no big deal as he isn’t the one in a wheelchair for months.
You may not be able to walk but you're not wheelchair bound. I used a walker for the duration of my Precice lengthening and consolidation (on femurs), but I had to essentially had to hop around -- both feet on the ground at the same time, or neither of them.
Obviously, being able to walk is better, but moving around with a walker is far better than a wheelchair.
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Would the hypertrophy or lysis show up in an x-ray?
Yeah, x-ray should show it. That's how they were assessing it.
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Thanks maximize. I've just looked again at my last x-ray and the bones are swollen at the points where the corrosion is occurring. I wonder does this go away after the rods are removed or is it permanent?
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You may not be able to walk but you're not wheelchair bound. I used a walker for the duration of my Precice lengthening and consolidation (on femurs), but I had to essentially had to hop around -- both feet on the ground at the same time, or neither of them.
Obviously, being able to walk is better, but moving around with a walker is far better than a wheelchair.
I am interested in doing precice as well. How much did you lengthen, how much did you weight and when where you able to use crutches?
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Thanks maximize. I've just looked again at my last x-ray and the bones are swollen at the points where the corrosion is occurring. I wonder does this go away after the rods are removed or is it permanent?
I would expect it's likely permanent. Once the bones heal that is just the way they are. Sometimes bones can remodel a bit after healing. Like if you fixate a bone with a slight misalignment and there is a jagged point sticking out at either end usually that will smooth over with time. But generally the way it heals is the way it remains.
If Paley is right, as long as you aren't showing obvious lysis or weak points that thickening will do you no harm. He says he believes this hypertrophic bone should be stronger than normal bone.
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Definitely not permanent. Bones always remodel.
Remodeling is always going to happen. A hole from corrosion will be filled in. hypertrophy will go back to normal. Lysis will go back to normal.
Active corrosion from the nail is what causes this to occur. Once it is removed, remodeling happens
Email Paley if you don't believe me. Also emailed giotikas and he confirmed, removal causes this to eventually remodel and go away
If it's permanent, what's the point of removal then? You're already screwed for forever? Our bones are amazing. They remodel everything.
It will go back to normal. Bones are amazing.
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Thanks guys. I've just had time to watch the whole thing there. I think at 25 mins Paley mentions that the thickening goes away after a couple of years, hope this is true.
What I don't understand is why the bone is thickening at the corrosion sites. I get why it would thicken at the screw sites due to adapting to stress load but I'm confused as to why it thickens in an area where there is no direct load placed on the bone. It seems like the bone is almost reacting to the rust in the same way a tissue would to inflammation caused by an infection or likes, I hope I'm completely wrong about this.
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It seems like the bone is almost reacting to the rust in the same way a tissue would to inflammation caused by an infection or likes, I hope I'm completely wrong about this.
You're absolutely right. He even said it in the video. I recommend watching the whole video in detail. Paley specifically acknowledges this. He's not hiding anything, and he tells us that this corrosion is directly causing the bone adjacent to react. He concurs everything you said, in the video.
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update ...
https://youtu.be/AC-fkgM59mI
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I am interested in doing precice as well. How much did you lengthen, how much did you weight and when where you able to use crutches?
My experience was very similar to Purushrottam's. I do recommend giving his diary a read.
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You're absolutely right. He even said it in the video. I recommend watching the whole video in detail. Paley specifically acknowledges this. He's not hiding anything, and he tells us that this corrosion is directly causing the bone adjacent to react. He concurs everything you said, in the video.
My only worry is that, although Paley says the bones are thicker and stronger, it's the reason why they became thicker that worries me. If the hypertrophy occurred due to load bearing exercise or similar then in all probability the bone will be healthy, if it enlarges due to inflammation caused by corrosion then surely it's reasonable to assume there might be something wrong. I'm just curious if a sample of the bone tissue was examined at a cellular level would it be as healthy as normal bone?
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My only worry is that, although Paley says the bones are thicker and stronger, it's the reason why they became thicker that worries me. If the hypertrophy occurred due to load bearing exercise or similar then in all probability the bone will be healthy, if it enlarges due to inflammation caused by corrosion then surely it's reasonable to assume there might be something wrong. I'm just curious if a sample of the bone tissue was examined at a cellular level would it be as healthy as normal bone?
Yes, it's not ideal obviously and they are going to find a solution to this to prevent corrosion from affecting the bone. It can and has burned holes through the bone so it's not a good thing and hopefully Nuvasive fixed this soon so people can do CLL!
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Yes, it's not ideal obviously and they are going to find a solution to this to prevent corrosion from affecting the bone. It can and has burned holes through the bone so it's not a good thing and hopefully Nuvasive fixed this soon so people can do CLL!
Not ideal, little bit of an understatement ;D If there was some clarification as to whether or not the thickened bone at the corrosion site is normal, healthy bone then I think it would put a lot of people's minds at ease. The only way they could test that though is by taking a sample and analyzing it.
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My only worry is that, although Paley says the bones are thicker and stronger, it's the reason why they became thicker that worries me. If the hypertrophy occurred due to load bearing exercise or similar then in all probability the bone will be healthy, if it enlarges due to inflammation caused by corrosion then surely it's reasonable to assume there might be something wrong. I'm just curious if a sample of the bone tissue was examined at a cellular level would it be as healthy as normal bone?
Does the thicker bone not develop in some external patients?
Personally I have seen some thicker bones on LON femur patients using titanium rods which do not corrode as far as I am aware, well they do not corrode as easily anyway.
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Not ideal, little bit of an understatement ;D If there was some clarification as to whether or not the thickened bone at the corrosion site is normal, healthy bone then I think it would put a lot of people's minds at ease. The only way they could test that though is by taking a sample and analyzing it.
They are doing biocompatibility test. If you even watched a second of the Victor and Paley video you would know. Just watch it. It's not long. All your questions are quite literally answered by the video.
And yes, it quite literally burned a goddamn hole in the bone. It's not ideal to have a hole in your bone.
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64% with abnormal bone reactions? That's a high number. Would the hypertrophy or lysis show up in an x-ray?
Dude, watch the video. He shows X-rays with about a dozen examples of how the corrosion affects the bone one year after op.
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Dude, watch the video. He shows X-rays with about a dozen examples of how the corrosion affects the bone one year after op.
Why are you replying to an old message? ;D I saw the corrosion effects x-rays, I watched the entire video a couple of days ago. Don't recall him saying anything about testing, I'll need to watch it again.
So they're doing a biocompatibility test AFTER they've fitted hundreds of people with the device? Well that's reassuring.
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They are doing biocompatibility test. If you even watched a second of the Victor and Paley video you would know. Just watch it. It's not long. All your questions are quite literally answered by the video.
And yes, it quite literally burned a goddamn hole in the bone. It's not ideal to have a hole in your bone.
He said that they're doing a bunch of biocompatibility testing on the nail and metallurgical studies on nails that have been removed. That's it. He didn't mention anything about taking samples from current patients to see if whether or not the thickened bone at the corrosion site is healthy.