
Humans have salamander-like ability to regrow cartilage in joints - mrfusion
https://eurekalert.org/pub_releases/2019-10/dumc-hhs092719.php
======
jdmcnugent
Orthopedic surgeon here. Articular cartilage regeneration is definitely the
holy grail of my field, but for all of the promises of biologics (growth
factors, stem cells, collagen matrices) it always seems to be “another five
years away”.

The part of this article that I find most interesting was identifying a marker
that can differentiate ankle cartilage vs the hip. This is certainly a
phenomenon that we all observe clinically, hip and knee arthritis is vastly
more common than ankle arthritis despite the weight bearing surface of the
ankle being significantly smaller (meaning more force per square area). When
we do encounter ankle arthritis, it is almost always the result of prior
intra-articular fractures or instability from chronic ligamenous injuries, not
the normal osteoarthritic age related degeneration we see in hips and knees.

Let’s find out what makes ankle articular cartilage so special and sprinkle it
in our hips and knees.

~~~
ubertoop
My guess? It's actually the consistent use of the cartilage that keeps it
healthy. Just like how weight bearing exercises can promote deposition of
calcium in bone, I'd imagine there's a similar mechanism for cartilage?

Hip joints (especially in modern era) get far less weight bearing on them -
especially as a force / area, since we're sitting all the time.

~~~
jdmcnugent
Motion and loading is definitely integral to cartilage preservation. Unlike
most tissues in the body, articular cartilage does not receive oxygen and
nutrients from blood vessels, but rather directly from the oil-like synovial
fluid that helps lubricate the joint surfaces. I imagine the thin squishy
layer of cartilage behaves like a sponge, deforming compressive forces drive
synovial fluid out and removing the load (taking weight off the joint) sucks
synovial fluid back in, sort of like inhaling / exhaling.

Here is a pretty good basic science review article about articular cartilage:

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3445147/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3445147/)

------
ChrisBland
I wish this was true. I've had cartilage damage in my elbow from sports and
have gone through major surgery over it. This technology has always been '10
years away'; from mesh or paste with stem cells, to other 'new' technology to
regrow it. It simply is not there yet. I check every year, I reach out to any
doctor starting a clinical trial. Hyaline cartilage does not regenerate
naturally. The best they can do is get the body to reproduce Fibro cartilage
which is essentially scar tissue. For those wondering about what treatments
are available, check out Microfracture (breaks bone to release bone marrow
cells to generate Fibro), OATs (osteochondral autograft transfer system) which
pulls cartilage out of other areas and then places them in the damaged area.
If this were to ever be true, it would be the biggest breakthrough in quality
of life improvements for seniors as they are the most likely to experience
breakdown in cartilage in joints. It severely limits their mobility.

~~~
Xcelerate
I have an internal debate with myself over which will come first: nuclear
fusion as society’s primary energy source, solving P vs NP, or repairing
damaged cartilage. My bets are on the former two.

(Also, I had the OATS procedure 9 years ago; it didn’t really fix anything
unfortunately.)

~~~
thfuran
I'd guess they'll occur in reverse order. Or at least fusion last. There are
some _serious_ engineering concerns to work out. And even if it were to become
economical and reliable overnight, there'd still probably be a few decades
before it replaced enough existing infrastructure to be the primary energy
source.

~~~
itcrowd
> if it were to become economical and reliable overnight, there'd still
> probably be a few decades before it replaced enough existing infrastructure
> to be the primary energy source

Well, hypothetically if nuclear fusion is solved, wouldn't that be the one of
these three with the largest incentive to fix overnight?

Solving climate change for the whole world, not just a problem only some niche
groups are interested in would seem more pressing than the other two issues
(as serious as they are!).

~~~
thfuran
>hypothetically if nuclear fusion is solved, wouldn't that be the one of these
three with the largest incentive to fix overnight?

Maybe but it's the only one that'd take probably several trillion dollars in
infrastructure spending on top of just knowing how to do it. There's a huge
difference between "net positive energy fusion reactor" and "economically
viable fusion energy generation" and another huge gap between that and "fusion
reactors are the primary means of energy generation". The other items are
achieved either by a proof or by proof of concept / trial.

------
eledumb
I had a pretty horrific left knee injury wrestling. I was carted off to the
hospital, when the accident was described to the Orthopedic surgeon he
actually recoiled and was concerned I may have totally destroyed my and that
it might not be repairable, it was 1979. From the time of the accident until I
was in surgery it was less than 3 hours.

Somehow I managed to only stretch all my knee ligaments, ACL PCL,MCL,LCL, a
few small inline tears, but nothing severed, but he said they were like
overused rubber bands all stretched out. I did however shred all the
cartilage. The cartilage was a mess, so much so that when they surgically
removed all the cartilage from my knee. I have the video of the surgery, all
my knee cartilage was removed, they scraped the bones in order to give me the
smoothest ride possible, but it doesn't do much. When you don't have cartilage
in your knee it's pretty obvious.

Fast forward 22 years to mid 2001 when I start following the teachings of
Linus Pauling regarding L-Ascorbic Acid and L-Lysine for heart disease
prevention. I started taking high levels of both in divided doses during the
day. My stress levels plummeted, and my overall health significantly improved,
but after about 6 months I started to notice my knee was changing, a lot. My
pain was going away and I didn't notice the bone on bone activity, after about
9 months my knee stopped hurting completely.

In fact it felt so good that I started walking for exercise, normally after 5
minutes of walking I felt like I was gun shot in the knee, but nope I was able
to walk fine for as long as I wanted. I then started jogging and then running,
no pain, no pain at all.

I've seen my orthopedist and while he's not willing to just give me and MRI,
based on all of his examination he said my left knee is no different then my
right knee and he didn't believe me that I had all my cartridge surgically
removed 20 years before. I took the video, just in case, and I played the
video. My knee has a unique scar from when I was a child and fell on a bottle,
I had the scar when they performed the surgery and shot the video and I still
have the scar, so there is no doubt that all my cartridge in my knee was
surgically removed in 1979.

L-ascorbic acid and L-Lysine are basic building blocks for cartilage. I'm just
a sample size of one, but I know my cartilage is back, maybe not all the way
back, but more than enough back that my knee rock solid stable, it's smooth as
silk, I have no pain and my orthopedist can't find a difference in my knees.

For what it's worth.

~~~
abecedarius
I wonder if eating gelatin would work similarly; it's basically collagen.
[https://chriskresser.com/you-need-to-eat-gelatin-here-are-
th...](https://chriskresser.com/you-need-to-eat-gelatin-here-are-the-reasons-
why/) \-- or conversely I wonder if your supplements would work better for me.
(I was starting to suspect arthritis until I added this into my diet.)

~~~
ncmncm
Gelatin goes right through, undigested. Fact doesn't stop scams, though.

I used to eat a lot of Lysine to try to control cold sores. Didn't work.

~~~
abecedarius
Interesting --
[https://en.wikipedia.org/wiki/Gelatin#Digestibility](https://en.wikipedia.org/wiki/Gelatin#Digestibility)
claims otherwise.

------
tjpaudio
This is something I have long suspected. I have definitely heard of instances
where friends subsequent MRIs have shown regrown cartilage in the knee, but
years later. And it doesn't happen for everyone. The friends that regrew, they
were runners, they took their injury seriously, they kept moving but were very
serious about maintaining flexibility, diet, hydration, etc. I think if you
wear down your cartilage, but do nothing to address the tightness that caused
the wear in the first place, then you will not see regrowth. The fact that
this is an interesting research finding is reflective of somewhat a sad fact
in my eyes: people generally do not take care of themselves, instead hoping
for surgery or a pill or procedure. Few will add an hour of rehabilitative
work to their daily routine and instead just live with the issue forever and
complain. I have herniated discs, torn bicep tendons, had tendonitis nearly
everywhere at one point or another, sublexed my knees, but nearing 40 I still
am active as ever with no daily pain. Some of these injuries took me years to
recover from, but recover I did.

~~~
whoiskevin
Bull. I've had cartilage worn out in my knee for years. I remain active and
take it very seriously. You don't get "regrowth" and recover. And frankly I
don't believe MRIs have shown regrowth...this is a constant rumor I hear all
the time and yet no one shows any consistent formula for this regrowth which
means it is either false or just rare and not reproducible.

~~~
tjpaudio
My personal experience has been it's a grueling exercise in trial and error to
find what works. To have the opinion that its all bull is certainly justified,
we for sure don't know the formula, but I propose that it's there, beckoning
to be figured out. Just to stretch and keep active is not detailed enough.
It's identifying problem areas, working on them every day, but also working
them especially hard and taking time off when you have flare ups. Staying
active, but not blindly... Finding the right amount of movement that causes no
issue, and increasing ever so slowly, and backpedaling when you mess up, and
reducing the number of times you backpedal because every time you have to it
works against you. Doing this every day, being patient, being at terms with
some things take years. 4 years ago my back dr told me I should stop doing all
physical things - the pain would never go away. I said screw that. Its been 7
years now. I rock climb, I lift weights, I hike, I surf... No pain. It's
possible.

~~~
thelittleone
Your description of self treatment is very similar to what I did for a
herniated disc. I found that if I got myself into some silence and worked with
breathing I could hear my body intuitively telling me what to do.

------
phkahler
There is nothing proven in this article. They seem to have some new insights
into the process, but they have not demonstrated any capability yet.

We all have the ability to generate cartilage and limbs, that's how we got
those things. The open question remains as to why some animals can do so again
and humans dont.

~~~
ignoramous
> The open question remains as to why some animals can do so again and humans
> dont.

One of those talks that blew me away: [https://www.youtube-
nocookie.com/embed/RjD1aLm4Thg](https://www.youtube-
nocookie.com/embed/RjD1aLm4Thg)

Professor Michael Levin talks abt how certain animals regrow their body parts
and how this process can be transmuted to other species. A very nascent but
civilization altering research.

Edit: HN discussions:

[https://news.ycombinator.com/item?id=18742131](https://news.ycombinator.com/item?id=18742131)

[https://news.ycombinator.com/item?id=18736698](https://news.ycombinator.com/item?id=18736698)
(thx u/carapace)

~~~
carapace
You beat me to it. (I linked to the same talk in a sib comment.) This is
probably one of the most important lines of research today.

One thing I'd like to point out: He keeps saying "it would be cool to have
technology like this", I think it's really important to remember that _we_ are
"technology like this". For example, rather than grow organs in labs and
transplant them, maybe we can learn to (re)grow our own organs _in situ._

------
carapace
Children under the age of seven or so can regrow the severed tip of a finger.

See
[https://en.wikipedia.org/wiki/The_Body_Electric_(book)](https://en.wikipedia.org/wiki/The_Body_Electric_\(book\))
and "What Bodies Think About: Bioelectric Computation Outside the Nervous
System (youtube.com)"
[https://news.ycombinator.com/item?id=18736698](https://news.ycombinator.com/item?id=18736698)

~~~
sfink
I read that book long ago. He found regeneration happens a lot more than in
just kids' fingers. Given nerves in the right places, it sounded like the
biggest obstacles were scar tissue and infection. (The latter is most likely
why we evolved to prefer the former over regeneration. A permanently scarred
animal survives much longer than a gangrenous one.)

------
Xcelerate
As someone in my late 20s with cartilage damage in both my knees and back due
to sports, this progress can’t come soon enough. I miss running a lot (and
miss not having constant back pain), and it’s confounding to me why something
that _appears_ so simple, cartilage repair, has made almost no real progress
over decades (I know it’s not simple). I keep following the research and
hoping new discoveries will eventually lead to something tangible.

~~~
40four
Right there with you... can we please find a way to trigger this regrowth in
my knee that I had a meniscectomy on! :)

It is next to impossible to do any jogging any more without having a multi day
recovery period from the inflammation.

Doesn't seem to be any tangible methods in this article, but I've heard some
promising stories of successful stem cell treatments.

------
Nuzzerino
Link to the actual paper:
[https://advances.sciencemag.org/content/5/10/eaax3203](https://advances.sciencemag.org/content/5/10/eaax3203)

------
dajohnson89
On a somewhat-related note: would glucosamine chondroiton pill speed this
process? There's a lot of debate whether they do anything at all.

~~~
loeg
This specific process? Who knows. Evidence for efficacy of glucosamine in
general? Summary by random website[1] says strong evidence of weak effects, no
evidence of strong effects.

[1]: [https://examine.com/supplements/glucosamine/#effect-
matrix](https://examine.com/supplements/glucosamine/#effect-matrix)

~~~
mikelyons
How often does strong->weak, no->strong indicate/correlate placebo effect?

~~~
loeg
Never, as far as I know. In this particular case, there are several double-
blinded studies for the cases described as "strong evidence, weak effect."
Blinding should eliminate any placebo effect.

------
mrwebmaster
I have broken my both knee cartilages. First time when I was 23 and recently
when I was 35. Fist knee recovered successfully after some years (I'd say
about 5 years). The second injury was 2 years ago and the knee is almost 100%
recovered, I feel some little pain only after running 10K and also after
playing soccer.

Both injuries were in the outer meniscus. There is a difference in the inner
and the outer meniscus (perhaps the inner cannot recover because of less blood
flow?). I didn't go to surgery.

Things I can do without any pain whatsoever: running 5K at a fast pace,
karate, barbell squat.

------
ineedasername
I had to have surgery for a minor tear in my wrist a few years ago. They
didn't know going in precisely what they'd find, but knew that if it was a
portion that had blood flow, they could repair and thing would grow back. If
there was no blood flow, they most they could do was clean the tear area,
stitch things back a bit, but they'd always be a little weak and I'd always
have to be careful not to reinjure.

~~~
npongratz
Don't keep us in suspense :) What did they find in your case?

~~~
ineedasername
Hah, sure: They found there was still some minimal blood flow, so it was kind
of an in-between case. It means that with physical therapy, I mostly
recovered, and if I strain it a bit I don't have to worry too much about
tearing it again, I just end up in a bit of pain, wearing a brace for a few
days. Of course I'm still overly careful, so that helps too.

------
elcritch
One interesting tidbit that this article doesn’t mention is that fiber
orientation of cartilage is fundamental to the functionality of different
cartilaginous tissues. It’s similar to how fiber orientation in carbon fiber
parts will be adjusted to provide strength and durability in specific
directions. Articular cartilages likely is somewhat more evenly oriented, but
tendons are highly aligned to length and meniscus aligned in a hoop like
direction. New or repaired cartilage in different tissues need exercise and
other forms of mechanical agitation to align properly. Even if we could repair
all cartilage readily we’d still need lots of physical therapy and to regrow
damaged tissue at a slow pace. So no miracle sir on the couch cures even if
this works.

On another the meniscus (and vertebrae discs?) loose blood flow after mid-30
or thereabouts and might make effective delivery or healing more difficult.
It’ll be interesting to see what happens in the next decade or two!

------
JoeAltmaier
My son lost a chunk of his thumb joint to a router accident. The doctor saw
the mess, and bandaged it up for 6 days to let the bleeding/soft tissue damage
resolve some.

When unbandaged 6 days later, the thumb cartilage in that joint was back, and
the thumb worked fine. No surgery; no more attention needed. Still working 10
years later!

~~~
mikelyons
Did he just rub some dirt on it? How do you explain this?

~~~
JoeAltmaier
Related to Wolverine I guess.

------
catalogia
I've suspected that cartilage regenerates ever since I learned that long term
knuckle cracking doesn't cause long term damage, despite the audible crack
coming from cavitation (which can be very destructive to things like ship
propellers, eroding the metal over time.)

If it didn't, my hands would probably be crippled by now.

~~~
hanniabu
I thought it was known that cartilage can regrow but it's just at such an
incredibly slow pace due to lack of circulation that you can effectively say
it doesn't grow?

Edit: after some googling I found this result

> age 15 or 16 would be about the average age for bones to stop growing, so
> from that point on, there is no collagen regeneration in the cartilage. Your
> body, on its own, cannot regenerate the cartilage it loses in its adult
> years.

[https://regenexx.com/blog/does-cartilage-heal-on-its-
own/](https://regenexx.com/blog/does-cartilage-heal-on-its-own/)

~~~
convery
That does sound weird considering how many athletes develop issues later in
life due to build up of cartilage. My friend, 66, for example did boxing in
his late 20's and started getting issues in his 50's due to nasal-blockages,
to the point where he now needs to drill away some of the cartilage to get rid
of migraines and such..

~~~
joncrane
True hyaline cartilage cannot "build up." The good stuff (intra articular) is
a precious resource that you can only lose, not gain.

The cartilage in your nose and ear are different, and besides, the stuff
that's blocking your boxer friend's nose, and causing cauliflower ear is not
really cartilage. It's fibrous growth which has a blood supply. It's your body
trying to replace real cartilage with a poor substitute.

~~~
ChrisBland
Exactly, not all cartilage is the same. The good stuff doesn't come back
unfortunately.

------
ajcarpy2005
I recently read _The Body Electric_ and it gives insights into the body
regenerating limbs.

------
DanTien
Has anyone any experience with stem cells? I believe the efficacy of PRP pales
by comparison although I'm pleased to hear others success with it.

~~~
padpnut
I’ve had multiple PRP injections on my ankle and it helped dramatically. I had
chronic ankle pain and found it painful just walking. After 2-3 PRP injections
it helped reduce the pain by 80%.

------
throwaway123x2
I have stage 3 chondromalacia + flat feet + loose joint, an incredibly unholy
trinity. Nothing amount of PT seems to work and the arthsocopy didn't help
much either. If anyone's got any tips, I'd love to hear them.

------
rpmisms
So, this would seem to open up possibilities for transplants and/or gene
therapy?

~~~
djohnston
i hope so. my spine is 30 going on 95 :(

~~~
pfrench42
You should consider looking into Prolotherapy. I had increasing levels of
lower back pain since I was twelve. It had gotten so bad I couldn't roll over
in bed without sharp pain.

My neighbor was a naturopath, I helped him photograph some before/after xrays
of a 70 year old woman's knee (before was bone on bone; she regrew her
meniscus and bone spurs disappeared)

I did three prolotherapy sessions (they're painful) with him over a few months
and I have been pain free for over fifteen years now. I actually started
playing rugby after my first session.

~~~
dajohnson89
this is fascinating. who could i talk to, with more questionS?

~~~
pfrench42
This is his website. Be warned, naturopaths are a little odd and opinionated.
:) [http://www.arizonaprolotherapy.com/](http://www.arizonaprolotherapy.com/)

