1. This was not published in The Lancet (a prestigious medical journal) but in the Lancet Digital Health a similar sounding spin-off journal without an impact factor that uses a pay to publish model (pay around $5000 and you get published)
This is pretty awesome. And sure, right now it's limited to high end tech at the bleeding edge of medicine, but I fully hope this will inspire the current gen owners of glowforges, makerbots, xcarves, and all of their off-brand alternatives to begin making over-engineered, novel, and interesting finger splints or Band-Aids or other diy-friendly med tech.
I have a friend whose son was born with a partial hand. They were able to use 3D printing to make a prosthetic that was cheap enough they could make new ones as he grew. IIRC, they could do themes such as iron man for the prosthetic.
I love it! In some ways these printers are only begining to exit the novelty phase (I mean the consumer versions) and already there's a minor explosion in exiting uses for them. An exciting time!
There's a common issue with slipped discs and terrible long term pain. If the day comes when we can print and install new vertebrae easily, I'm signing up. I imagine in this world of phone and PC usage, there'll be many customers in the years to come.
Me too. I suffer from degenerative discs, bone spurs and arthritis in all of my cervical and thoracic vertebrae. I'm in constant pain and if there was a realistic spinal replacement procedure, I would seriously consider it.
I don't know what caused my problems, but arthritis and bonr spurs definitely run in my family and 3 decades of poor posture haven't helped and ive had too numerous bicycle falls and car crashes over the years to even count (I was in a car accident just last week! Not my fault).
Not a doctor, haven't read the paper, but had many ASIA assessments before, during and after nerve damage in my spine that was rectified by draining a load of Step B that had formed a little pool party in there (yeah, I know...)
My short take on this, is that even a tiny amount of impingement can have a massive impact on ASIA scores.
The nerves running through your spinal cord are incredibly delicate, and it doesn't take that much to cause them to start going quite wrong.
A relatively small amount of abnormality in my case around T6-T7 area caused me to lose sensation and motor control below the abdomen. You can see before/after MRIs here: https://medium.com/@p7r/one-year-on-2b624075b0bc
Whilst the "object" is some 20mm-30mm long, the impingment into the nerves is perhaps 3mm deep at its maximum, but is pushing the nerves into my spine itself causing two pinch points on the left hand side.
That was all it took to not being able to walk or feel almost anything in my legs, or feet.
My ASIA scores were mostly 0 (no sensation), with some 1 scores (impaired sensation). A month after surgery I was scoring 1 almost everywhere.
Nerve regrowth is magical in that it just works, but it is very slow - around 0.1mm per week is what I was told - and it took me six months to not need a walking stick and have close to normal proprioception below the abdomen. Today - two years later - I still have slight numbness around the ball of my right foot (strangely it's temporal - it definitely has bad days), but am able to walk, drive and do so on without issue.
My ASIA scores now would be 2s everywhere with a single 1 on a specific point of my foot, but even then it's close to being a 2.
So, it is definitely possible that even a tiny, tiny amount of impairment into the nerves would lead to 0 and 1 scores that after 6 months move to a 2, even with pretty minor impingements.
3D-printing ranges from fragile resin pieces to metal durable enough to use as rocket nozzles. This article was about 3D printed titanium, so the resulting piece is likely stronger than bone but weaker than machined titanium would be.
It is most likely made of welded titanium particles as others point out.
Imagine a thin layer of titanium dust. Then shine a laser on the points where you want to weld. When done, add another layer over it and repeat.
Or imagine a nozzle which sprays titanium dust. Directly after the nozzle there is a focused laser point. When the dust goes through the laser it welds together. So when you do this close to a titanium surface you can add more titanium to it.
And there are other methods for 3D printing metal. But most of them are just advanced welding techniques.
Turbine blades in modern aircraft are gamma-TiAl, which is a single crystal. These are not 3d printed and the process for making them is similar but more advanced than making silicon wafers.
This is a decent documentary on Rolls Royce that discusses the single crystal blade. I think each one has 18 tons of centrifugal force, and uses a few micron layer of air to cool it, so running an engine too slow will melt them. Fascinating stuff.
It's made of titanium (though almost certainly some alloy) so they probably used a DMLS (direct metal laser sintering), SLM (selective laser melting) or DMLM (direct metal laser melting) process. All will result in fairly strong material structure. Probably not as strong as tempering/quenching would make it though. Either way, this is not something you can do with a hobby 3D printer :-)
Some components with complex overhangs and voids can be impossible to mill with a CNC. A sintering 3D printer isn't constrained in that regard, and can make arbitrarily complex geometry without sacrificing precision.
It should be noted that – contrarily to my first thoughts when reading the title – the implant won't work if the spinal cord was cut. It only serves as a sophisticated 3D printed titanium splint for the spine, which is already a big achievement by itself.
I imagine you would sorely miss having an immune function (and blood) if you replaced them all. Bone marrow is where both red and white blood cells are made.
Forged Titanium Parts & Components
The price of commercially pure titanium (CP) has risen sharply since 2003 to 2014, from $15.00 per lb to $30.00 per lb. It is an extremely light weight and high strength material.
Titanium Forgings - Forged Titanium - Commercially Pure Alloys ...
1. This was not published in The Lancet (a prestigious medical journal) but in the Lancet Digital Health a similar sounding spin-off journal without an impact factor that uses a pay to publish model (pay around $5000 and you get published)
2. No bones or anatomic parts were printed. What was printed is this: https://els-jbs-prod-cdn.literatumonline.com/cms/attachment/...