3-D Printed Pelvis Holding Up After 3 Years 82
An anonymous reader writes "Here's a neat story out of Britain, with good news about long-term success for the patient involved, and for others who might benefit from similar procedures: three years ago, surgeon Craig Gerrand successfully printed and implanted an artificial pelvis (actually, about half of one) into a patient suffering from a rare form of cancer. Other techniques were ruled out, because the patient would be losing so much bone. So, after careful scanning, additive printing with titanium was used to create the replacement: 'In order to create the 3-D printed pelvis, the surgeons took scans of the man's pelvis to take exact measurements of how much 3-D printed bone needed to be produced and passed it along to Stanmore Implants. The company used the scans to create a titanium 3-D replacement, by fusing layers of titanium together and then coating it with a mineral that would allow the remaining bone cells to attach.' Now, three years after the procedure, the printed pelvis is holding up just fine, and the patient is able to walk with a cane."
Not plastic, titanium (Score:4, Informative)
There is not much difference with respect to physical properties between printed and sintered metal or ceramics. Sintering is a very well established fabrication process combining endurance, flexibility in design and low weight. However, laser-powered, layered construction a.k.a printing allows for even greater flexibility and most importantly one-off fabrication. This is ideally suited to medical applications like this one. However do not expect to be able to do this at home anytime soon.
Re:Not plastic, titanium (Score:4, Insightful)
Selective Laser Sintering metal printing although much stronger than typical Fused Deposition Modeling is nowhere near as strong or tough as cast and treated metal components. It has it's place and this is one, but SLS is not great everywhere.
Re:Not plastic, titanium (Score:4, Insightful)
Wiki quote: "Unlike some metal sintering techniques, the parts are fully dense, void-free, and extremely strong."
Bah. Sintered metal parts are usually both of those first two things. But the parts have an inferior failure mode (and are more likely to fail) when compared to forged due to the fine grain structure, as opposed to a large interlocking grain structure. Large grains are like legos and small grains are like sand. The large grains interlock, the small grains don't.
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Far from an expert on the subject: is there any reason why something that was built with sintering can't be brought up to near-melting and cooled, to restructure the lattice?
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I've often wondered if you could create a permanent magnet by sintering in a strong magnetic field, but I don't know why you'd get any other results.
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This is titanium, not a ferrous metal. It can't be magnetized.
Re:Not plastic, titanium (Score:4, Insightful)
Forging is what creates the large, interlocking grain structure. No forging, no large interlocking grains. You do get some benefits from sintering, like extreme regularity. Thus, even though the failure mode is less desirable, you can more reasonably engineer out failure because you have a better expectation of how the part will behave. The only problem is that ounce for ounce it won't behave as well as forged+machined, so you're either going to throw more material at the problem, or you're going to have to do more design work and then use more costly manufacturing processes. There are inexpensive sintering processes which are not substantially different in most ways from casting plastic, and even without incremental deposition techniques you get secondary benefits which also reduce cost like being able to crack the caps off conn rods instead of machining them to match. By combining deposition modeling you can also create shapes which you can't reasonably cast, which makes using sintered metal practical; you can throw more metal at the problem where necessary to increase durability and strength lost by using sintered metal as opposed to forged, but you can also reduce metal in places you couldn't with casting, without machining it away.
I am also not an expert on this subject, but I've been doing a lot of reading on it recently.
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This is all well and good, but don't forget the application here: an artificial pelvis. It doesn't have to be super-strong, it only has to be as strong as something made out of living cells and a bunch of calcium. An artificial titanium pelvis taking up the exact same volume as a natural one should easily be stronger, no matter what kind of process is used to make it. It's not like our human bones have strength-to-weight ratios challenging forged titanium.
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This is all well and good, but don't forget the application here: an artificial pelvis. It doesn't have to be super-strong, it only has to be as strong as something made out of living cells and a bunch of calcium.
I was answering the question posed, not pondering the ramifications of sintering as it relates to medical prosthetics.
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I had thought quenching (I think is the term) was specifically intended to fix the crystallization. I've seen it done after forgework - before tempering, the metal is uniformly heated to a quite-high temperature and cooled a couple of times. This was explained in a way that made me think it was causing the crystallization to change in a way that made it less brittle. Incidentally you can demagnetize (or magnetize) things the same way, because things "loosen up" when heated like that, and as it cools they fi
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er, I should point out it was not cooled quickly, it was let to cool on it's own (the oven was on a timer to cycle it on it's own). Very distinct from heating it up and then plunging it into oil, which I believe is tempering?
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Whilst I wouldn't be 100% sure based on a press report, it does appear to be laser fused:
http://www.telegraph.co.uk/hea... [telegraph.co.uk]
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I consider bicycles to be a pretty demanding application stress wise...
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If you read the article you would know that the entire frame was printed.
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This is purely anecdotal, but the two indie framemakers I know who have worked with 3d printed lugs have both said the lugs broke very quickly and they only used them for prototypes, didn't consider them safe to ride. One said he thought he could make a 3d printed lug (this was stainless steel, through shapeways, silver-soldered to Reynolds SS tubing) that would be durable but he guessed it would weigh about 4x as much as equivalent forged columbus lugs.
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Selective Laser Sintering metal printing although much stronger than typical Fused Deposition Modeling is nowhere near as strong or tough as cast and treated metal components. It has it's place and this is one, but SLS is not great everywhere.
Of course, in this application, it only needs be be as strong as the bone it is replacing.
Sounds like 3D printing... (Score:5, Funny)
...is getting some hip new applications.
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Okay, everyone. Put down your pitchforks.
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http://instantrimshot.com/clas... [instantrimshot.com]
just remember folks this was NOT done on a MakerBot or similar (But just wait like 10 years)
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> ...is getting some hip new applications.
Shouldn't that be some new hip applications?
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Indeed, but you must remember, it's not the treatment itself that is so costly over here. It's all the tacked on state regulations and overhead associated with healthcare that drives up the cost.
The raw materials cost the same here as they do there. Same thing for the infrastructure, the buildings, the instruments, the mechanical, chemical and other associated support devices and manpower it takes to perform such an operation from end to end, etc. etc. etc. They all cost the same.
Look at it like this, ho
Re:And how much would that cost in America? (Score:4, Insightful)
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As someone who has lived & travelled across much of the world, the UK's public transport infrastructure, especially within cities, ranks very highly.
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As someone who has lived & travelled across much of the world, the UK's public transport infrastructure, especially within cities, ranks very highly.
And, given how bad the UK's 'public transport' (i.e. mostly private companies subsidized by the taxpayer) is, that just shows how much it sucks everywhere else.
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Europe has much more government than America, and far more regulation, yet healthcare there costs a fraction as much, even when they're using medical devices manufactured in America.
Explain that one.
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Stupid typical warmongering American. Fuck off and die with your shitty healthcare.
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You have no idea what you're talking about.
An artificial hip joint, made in America, costs around $15000 at an American hospital, even though it only cost a few hundred dollars to make (in America).
That exact same joint, flown to Belgium and installed at a hospital in Belgium, costs less than USD$1000.
Are you going to try to tell me that Belgium doesn't have state regulations?
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Belgium has more regulation than America. Things cost much, much less. Hence, regulation is a GOOD thing.
Are you really that fucking stupid?
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Issue is really Regulators vs Lawyers.
Titanium? (Score:3)
Personally, I would have opted for adamantium.
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You don't know that adamantium is magnetic.
Lead is most certainly non-magnetic (same with copper), yet according to the first X-Men movie, Magneto has no trouble controlling lead bullets.
In the second movie, he stopped the X-Men's airplane from crashing. Airplanes aren't made from steel, they're made usually from aluminum, another totally non-magnetic substance.
Apparently, in the X-Men universe, ALL metals are magnetic.
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Great (Score:3)
Ex-cell-ent. Can he still get an MRI with his implant?
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Yes, Titanium is not a ferrous material.
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It doesn't need to be ferrous, just conductive to prevent an MRI. However that doesn't mean that he can't get an MRI. Printed composites are not terribly conductive, so that may make it possible, but I cannot know for sure without looking at the literature/testing.
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Printed composites are not terribly conductive
Please do let us know how the conductivity of titanium is affected when it is sintered.
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Yes, Titanium is not a ferrous material.
I have a titanium plate in my neck and while it is not impacted by an MRI (ie not ripped out), the MRI is impacted by it. Images in that area are pretty much worthless
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Isn't that the study that got debunked because it turmed out the bulk of the people rating astrology as scientific had misread it as "astronomy"?
If so, it might say more about Democrats' literacy than their their belief in astrology.
It would also be what is expected, given that the consituency of the Democratic party is heavily weighted toward groups of people who have been the victims of poor public schools.
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Elvis?
A 3-d printed Elvis is exactly what I thought too!
We can rebuild him. We have the technology. (Score:3)
(...)
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Just the beginning (Score:2)
Look at this: New 3D Printer by MarkForged Can Print With Carbon Fiber [popularmechanics.com] Definitely more companies are going to develop products like these...
Imagine the possibilities it opens for elder and disabled people care. And with the current ageing of the population in developed countries, this will certainly be a huge industry.
Misread the Subject (Score:1)