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.
The way you wrote this was really fascinating an informative. Was disappointed not to see a link to a personal blog or anything on your profile. I could read a lot more of your stuff.
Thanks for the compliment, I just lurk here on HN and I finally came across something in my wheelhouse. Happy to contribute. With private practice and a house full of kids I imagine my blog should be ready by 2029.
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.
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:
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.
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.)
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.
> 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!).
>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.
I think we are in the same boat. Mine's in the knee and I have microfracture to "fix" it but I think if the paper is correct then it does mean hyaline naturally regrows because there is no fibrous cartilage in those joints so this result should only apply to hyaline, no?
I had an OAT procedure in my knee 6 months ago or so. After living with arthritis for almost 6 years I finally have no pain. Will it last for 30 years or more? I don’t think so, but for now it’s the best that happened to my knee in a long time.
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.
So in the 80's the BBC had a program called Tomorrow's World. They had a race horse which had worn its cartilage which would have meant retirement. Surgeon opened front knee enough to drill up into bone from where the cartilage had worn our, bone marrow (stem cells) spilled out, sealed up knee and the stem cells adopted/became the tissue it was next to which included new cartilage. Horse recovered quickly, like allowed to walk around in a day or two and was back running when stiches were removed. No visible signs of pain. Hailed as a success for worn cartilage.
I don't understand why the medical professionals use metal alloys for joint replacements considering how the metal is attacked by the immune system and deposited elsewhere in the body. Doesn't make sense.
L-ascorbic acid is vitamic c and L-Lysine is one of the essential amino acids. This doesn't seem to be particularly groundbreaking supplementation.
You get a whole bunch of L-Lysine every time you eat meat/chicken/fish/milk/legumes. Vitamin C is a common supplement.
Were you 'dosing' at extremely high levels? excess vitamin c is secreted in urine. Your body can't store excess amino acids either - they are converted to ammonia and then into urea/uric acid in the liver.
When I read the name L-Lysine, it suddenly reminded me that I used to buy it exactly for that reason.
A doctor recommended to have surgery on a joint, but I didn’t have the money or insurance. So I did some research and started taking supplements that contained L-Lysine among other things. Also started doing light exercises just to increase the blood flow to that joint. And some how it was fixed.
I think is the only supplement that has actually worked for me.
Edit : glucosamine was another of the supplements I was taking.
I do physical labor and take two supplements to keep my joints from bothering me: Glucosamine Chondroitin Complex and Instaflex Advanced.
I started the first one many years ago when I was lifting 30-80 pounds shoulder high all day at work. It noticeably reduced the joint pain I experienced after about two weeks.
The second I started using this summer and wow. I'm 50 years old and feel like I can play racquetball again.
With my business my right shoulder was deteriorating due to
raising buildings using a handyman jack. I could not lift a glass of water off the nightstand while in bed. Since taking the Instaflex, my shoulder has steadily improved and I'm confident I will soon have my full strength back.
I wonder if eating gelatin would work similarly; it's basically collagen. https://chriskresser.com/you-need-to-eat-gelatin-here-are-th... -- 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.)
All I can say is that it made an unmistakeable difference for my problem within a week, and it seems safe to try. It's my general understanding that proteins get broken down to amino acids in digestion, so the expected advantage for generally healthy people would be in getting enough of the right ones in the right proportions.
I can only hope that you'll take this story and evidence to a nearby research university/hospital/med school and convince someone that they could win fame and fabulous prizes if they found out you were correct and pursued the research successfully.
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.
Thing is daily pills and even surgery are far more scalable than finding competent rehab facilities that can take patients regularly. This is an incredible problem that I think technology is nearly on the cusp of changing. Gamification[1] of the process, externalizing the internal motivations that drove you to continue those good habits will be critical.
Will I think part of that is that a surgeon or pill tell you simple instructions and you have a good idea on what to get back. Exercise is way better but you get no guidance on whether you're doing it right or if it's working.
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.
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.
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.
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.
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.
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.
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.)
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.
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.
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.
no, those get broken down by the digestive system, and as other commenters have noted (despite the article title), there is no way for the body to use it anyway.
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.
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.
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.
I had similar, but they knew what they’d find. So they just cleaned up the shredded flaps of my TFCC and shortened the ulna ~3mm (it was abnormally long).
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!
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!
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.
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.
I learned a little about this topic recently after a bad knee injury from running [torn meniscus] --
Blood supply does have a lot to do with healing-or-not -- taking the meniscus as an example, about 30% of the meniscus has a blood supply, the rest does not, so that if the injured part is of that 30%, it can actually heal, whereas if not, they can only clean it up and stitch it together like a rag doll ---
[for the curious : I got lucky and my injury healed tolerably well on its own sans surgery]
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..
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.
I believe the prevailing thought on the audible cracking is that it is the bubbles in the fluid between cartilage and nothing to do with the cartilage itself.
That's my understanding. But the collapsing bubbles are next to the cartilage I believe, and it seems to me should therefore be causing cavitation erosion. When cavitation erodes a boat's propeller, the cavitation is occurring in the water next to the propeller, not in the propeller itself.
The cracking sound is caused by nitrogen bubbles, not by cartilage breaking. Cracking your knuckles is safe as far as we know, if anything it probably helps because you're stretching your ligaments.
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%.
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.
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.
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.