Tuesday, August 29, 2017

Tech Breakthrough for Those Needing Bone Transplants

Here's a story I've never told in the 7 years of this blog.  To set the time, remember Y2K?  There was massively hyped fear that computer systems everywhere were going to shut down because of a problem in the way they handled the date?  Many people were on edge waiting to see what happened on New Years and some people thought a massive disaster was going to happen. 

Two days before New Year's Day of 2000, so December 30, 1999, Mrs. Graybeard and I left the house for a morning bike ride, as we did every morning over the Christmas break.  It was a beautiful, clear morning; I don't recall the temperatures, but I don't recall wearing much in the way of cold weather clothing either.  About 4 miles from home, so just far enough to be warmed up and settling in for a long ride, I looked in my rear view mirror.  I saw a small pickup truck drifting into the bike lane and approaching behind us.  As we usually rode, Mrs. Graybeard was behind me and I was in the lead to reduce the wind she'd get.  I think I screamed something back at her but the next sensation I had was flying and tumbling onto the shoulder of the road, rolling over and coming to rest in the sparse grass.  I looked toward the road and saw her lying in the street.  In minutes, people were pulling their cars over to get out and help us.

There's no point in getting into too much detail here about a bike accident well over 17 years ago.  I was lucky enough to walk out of the ER about four hours later, with a referral to see an orthopedic surgeon as soon as I could get in, because I had a broken vertebra in my back - L1.  Mrs. Graybeard was not so lucky and while she also broke L1, hers was shattered.  The problem was Y2K - the hospital wouldn't do anything except the most urgent of emergency procedures.  She had to wait until January 2nd for surgery, which involved rebuilding the front part of the vertebra with donor cadaver bone.  The massive surgery involved going in through her abdomen, repairing that bone and fastening it in place, then going in through her back and reinforcing her broken spine, adding (as we say) a pound of stainless steel in her back.  Donor bone was made into a paste and used to cover and reinforce hardware, a paste that surgeons said would grow into a solid bone. 

The point of this is to identify with the need for an improvement in how we do bone transplants. What if a compatible bone hadn't been available?  A researcher at the University of British Columbia Okanagan's School of Engineering, Hossein Montazerian, has discovered a way to model and create artificial bone grafts that can be custom 3D printed.
“We have shown how porous bone replacements can be designed with the nature-inspired geometries and structures so that we provide cells strong, spacious and safe enough support to let them grow efficiently,” Montazerian said. “This technology allows the doctors and surgeons to design the patient-specific replacements so that they fit very well into the damaged bone area, instead of doing a secondary surgery and harvesting bone from other sites of the body for taking that replacement.”
An interesting part of this story is that Montazerian analyzed the strength of 240 different ways of making these "biologically inspired" matrices to build bone out of.
In this study, numerical procedures were performed for a library of 240 TPMS-based unit cells (comprised of 10 volume fractions of 24 selected architectures) to explore the role of pore characteristics in determining normalized values stiffness, strength, and permeability. The associated design maps were developed based on which highly porous architectures with extreme properties were selected for experimental evaluations. Calcium sulfate scaffolds were designed based on the critical designs and 3D-printed (using a powder-based technique) in different cell sizes and size effects were addressed. The scaffolds were subjected to mechanical compression tests and the results were correlated with the computational data.  [Note: TPMS = triply periodic minimal surfaces]

Besides the possibility of making bone available that the body won't reject and not waiting for a compatible donor, the ability to print bones on demand can help reduce the number of painful surgeries that some patients have to endure.
"When designing artificial bone scaffolds it's a fine balance between something that is porous enough to mix with natural bone and connective tissue, but at the same time strong enough for patients to lead a normal life," he said. "We've identified a design that strikes that balance and can be custom built using a 3D printer."

Of those he printed, Montazerian tested them to determine how they would perform physically under real-world tension and weight loads.

"A few of the structures really stood out," he said. "The best designs were up to 10 times stronger than the others and since they have properties that are much more similar to natural bone, they're less likely to cause problems over the long term."
I can anticipate doctors and old patients telling stories in 20 years or so about back when we used to actually use bone from a cadaver, or take bone from elsewhere in a person's body.  What a bunch of savages!


13 comments:

  1. I remember the incident well. And, the retrieval of the 2 bikes back to your house. You and Mrs. GB were lucky to survive the accident. Glad it ended well.

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    1. Yes, we were. Of course, I remember your help vividly.

      The thing that stayed sore for the longest time was my broken tailbone. When I got back to work after a month, a guy I worked with said, "that's going to be sore for 9 months". Son of gun was right. At least 9 full months.

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  2. Very sorry to hear about that (I've only been following your blog for about a year). I wish there was some kind of system that would just smack people upside the head with something hard if they drifted out of their lanes. I see it too often. Sheer incompetence (unless they're dying, of course).

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    1. We were back on our bikes by Easter of 2000, and rode for another decade. We kept finding a repeating story: guys would ride for some number of years, and then decide the risk wasn't worth it, usually after they got hit once - sometimes after the second time they got hit. We met a guy who was deliberately hit - the car opened a door into him while passing at 45. I think it's not out impossible to get killed that way.

      As phones started spreading widely and "texting while driving" became a thing, we just thought it was too risky.

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  4. What's weird is that I know more people who have been hurt riding bikes than riding motorcycles.

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    1. That's probably because motorcycles are part of the traffic, instead of adjacent to. A motorcycle can maneuver out of the way of a problem, but a bicycle can't do much except watch it happen.

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    2. And motorcycles also can be somewhat noisier than bicycles, if one wishes to go that route. Hear and avoid. Although bicycles CAN get pretty noisy rather quickly if you come up behind them, slam on the brakes hard enough to skid the tires slightly, and then hit the horn.

      You can also generally create a brown stripe that way...
      }:-]

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    3. There's a traffic engineer from MIT, John Forester, who has studied the topic of bicycles in traffic and has written a big book called, "Effective Cycling" His data is pretty clear that cyclists do best when they ride in the road, with traffic and behave like traffic to the best of their abilities. Obviously, no bicyclist is going to go 45, the speed limit where we here hit, or the 55 that most drivers go. Heck, 99.99% are not going to go 25. That's where motorcycles have the advantage. They really can flow with the traffic.

      Bicyclists have that disadvantage plus the disadvantage of being small to invisible in traffic. I've seen drivers appear to look directly at me at a stop sign and then pull in front of me. Did they not see me or not care? In terms of fragility, it's human flesh against around a ton of moving metal. Chances of being OK are 0% to a few significant digits.

      People have driven their cars into fire trucks running all their lights. If they're so distracted they don't notice something like that, a cyclist (or motorcyclist) doesn't have a chance.

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    4. People will slam me for this opinion, but I don't think bicycles have any business using roads designed for cars, except in rural areas and small towns where cars are few and far between. It isn't fair to the drivers to impede the flow of traffic, and it isn't fair to the bicycles to make them use travel paths that will get them killed.

      If cities want bicycle traffic, they need to allocate space for and build dedicated bicycle paths.

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  5. If cities want bicycle traffic, they need to allocate space for and build dedicated bicycle paths. ... but that just ain't gonna happen. Nobody's got the money to build a parallel traffic infrastructure. If it isn't parallel infrastructure, then you have the problem of "I need to ride my bike to that place and there's no bike path." Bike lanes on a roadway are a good alternative and not that expensive (if the lane is 20% wider, it ought to cost ... actually less than 20% more)

    Plus there's the set of problems that infrastructure brings. If accidents are more common at intersections than in straightaways (as they are) and you drastically increase the number of intersections by adding this parallel infrastructure, what happens to the number of accidents?

    I'm not going to say cyclists don't ride like total A-holes at times, but a group of cyclists is far easier to get around than a piece of construction equipment that's going slow. If you're on a two lane road behind a front end loader loaded on a truck that does 0-45 in about an hour, you're delayed. Delays in traffic happen all the time. In my mind, riding like total A-holes includes riding into traffic instead of with it, not obeying all traffic signs and lights, and not staying as far right as practical. If I saw traffic backing up behind me, I'd wave people around or even turn off the road to get out of the way. That said, there were always stretches a mile or so long with no way off the road.

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    1. Told you I would be slammed :-)

      I know all those things. What I'm saying is that bicycles have no place in the modern urban setting unless specifically allowed for. Yet another thing the modern Utopia has screwed up.

      I have seen traffic jams in the NW that added hours to traffic, just because of some group of cyclists taking a popular road. This is unconscionable. Some people will die waiting to get to a hospital due to it, and others will die at the hands of frustrated psychopaths who can't get where they're going.

      Roads are for cars. Period.

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    2. Just for completeness and in case you come back to see this, I didn't think I was slamming you. I just think what you want is essentially impossible. Nobody has the money to do it.

      The only things I've ever heard of that cause delays of hours are organized protests and activist things, not ordinary cycling. The biggest organized rides probably affect traffic, much like the Boston Marathon or other big city running events do. Around here, worst case is that they hold up Sunday morning traffic at 7AM for a minute. I agree that roads are no place for activist protests of any kind, be it Antifa or bike riders.

      I don't have any skin in this game. I don't ride in the streets any more and I can't recall the last time a cyclist bugged me while I was driving ('97?).

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