Let’s start this blog with a question you probably weren’t expecting to find here…
How much do you know about salamanders?
Before you reply “absolutely nothing” or (more likely) “why on earth are you asking me this?” consider that you probably do know one thing about salamanders. Which is this: that they have the power to re-grow their tails. For example, after a predator bites them off. (You see, you did know.)
In fact they don’t merely do this with their tails, either. They can also grow completely new limbs, as this fascinating YouTube video from an American reptile centre demonstrates. (Nor are salamanders the only creatures with remarkable powers of regeneration: here are four more.)
To the next question, then: what on earth does this have to do with arthritis? Well, the answer is that it links into a very interesting study, released last year, which seemed to indicate that human limbs have the “salamander-like” power to re-grow cartilage after it gets damaged. Let’s look at the details and why it might be important.
What did the study find?
The researchers looked at tissue samples from people with osteoarthritis. If you suffer from osteoarthritis, or know someone who does, you’ll know that it’s a degenerative condition where the protective cartilage on bones begins to wear away, causing them to rub painfully against each other. Traditionally, doctors have argued that our bodies can’t produce new cartilage when it wears away; once it’s gone, it’s gone. But the study made two interesting discoveries. 1) that cartilage proteins in more arthritis-resistant joints – like our ankles – appear to be ‘younger’ than those in more susceptible joints such as hips and knees: this suggests they are in fact capable of some regeneration. 2) that the molecules responsible for controlling these proteins (microRNA) are the same as the more active ones found in critters like salamanders.
Is this completely new science?
In some ways, no. We know the body is capable of self-repair – just think about what happens when you cut yourself. We’ve seen similar things happening in knee surgery too. After performing microfracture repair on a joint that has been damaged in an accident, for example, we often observe new cartilage around the bone six months later. But that’s limited and somewhat unpredictable, and it’s happening after trauma rather than following years of wear and tear, as in osteoarthritis.
Do the findings give hope to arthritis sufferers?
The best news about the study is that it raises the possibility we could harness those key regulator-molecules to repair and reverse arthritic damage. As one of the scientists put it, “We believe we could boost these regulators to fully regenerate degenerated cartilage of an arthritic joint.” That’s a very exciting thought! But there are several challenges. One is that where regenerative stem-cell-style treatments have been used in the past, it can be hard to make them ‘take’ and produce the right kind of repair. Another is that wear-and-tear arthritis is a “biomechanical” problem, not merely a biological one. For instance, let’s imagine you have bowed legs. If that bowing is channelling a lot of weight into one part of your knee joint, the misalignment could be causing arthritic damage. In theory, injecting more ‘salamander-cells’ into that joint wouldn’t help – they’d either struggle to ‘take’, or they’d simply wear away again. The hope, perhaps, is that we might be able to combine the new treatment – if scientists can develop it fully – with a corrective operation to unload the joint and give the cells a better chance of doing their work.
Truthfully, we’re a long way from that right now. But there’s no doubt that doctors and scientists have been taking real notice of this study. It suggests the body has greater powers of regeneration than we thought. And that’s very good news: we might not have the salamander’s repair superpowers quite yet, but the outlook for arthritis treatments is becoming more positive by the year.
(Please note that Chris Bailey Orthopaedics does not endorse, and is not responsible for, the content of external websites.)