Bones can be not quite enough sometimes, and for my secret military organization, every possible advantage is given to the soldiers. Including reinforcing bones. But...where do I put the metal?

Material specifics:

  • Handwavium Material X

  • Will not cause blood poisoning/other effects once in place

  • No ill effects during placement by nanites

  • At least as strong as steel

The material will be placed while the bones are shattered, so there is easy access to anywhere in/on the bones. Once the material is in place the soldier is given some Skele-Gro to fix the bones together in about five minutes. The metal as well as calluses(which remain thanks to a slight modification in the SkeleGro) make for very strong bones. In theory.

Assuming the material can be placed easily, where do I put Material X for maximum bone reinforcement? If it uses less that's great too, but I don't think it will be very easy to measure how much your method uses without actually trying it.

Below is just a bunch of information not in the original question from the comments I'm just putting here so everything is in the same spot.

  • Looking more for blunt force protection than bullet proof bones. If they can be tossed around and then get back up whereas most people would be waiting for an ambulance, that's more what I'm looking for.

  • Don't worry about ligaments, just bones at the moment.

  • Try to keep mostly bones rather than completely replace the bones. Keep at least a 50-50 bone-metal ratio. More bone is better.

  • Doesn't necessarily have to be metal, anything that strengthens will be acceptable.

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    $\begingroup$ What does "maximum bone reinforcement" mean, though? Survive falls from greater heights? Blunt force trauma (eg someone swinging a mace)? Bullet impacts? Are you just looking at the bones or the ligaments too? $\endgroup$ May 11, 2021 at 10:30
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    $\begingroup$ @KerrAvon2055, for now, more blunt force protection(i dont expect to ever get bullet proof ribs, they have vests for that) so they can be tossed around, but get back up when most people would be waiting for the ambulance. and just the bones need to be strengthened. $\endgroup$ May 11, 2021 at 10:32
  • $\begingroup$ I think I'd go with carbon reinforcement rather than metal; strong, light, holds broken bones in place. Or go repairable, not unbreakable. The guy with his leg stuck in a machine can't cut off a mangled limb (to grow a new one) if the bone is semi-indestructible. I've seen what this kind of pinning can do, and it will be more lethal than losing a limb. Anyone wants to use this as an answer, feel free. $\endgroup$
    – DWKraus
    May 11, 2021 at 11:47
  • $\begingroup$ Is reinforcement the ultimate goal or is (partial) replacement also acceptable? And what DWKraus is saying, is metal obligatory or is anything that strengthens it ok? $\endgroup$
    – Trioxidane
    May 11, 2021 at 11:52
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    $\begingroup$ Sounds like you're trying to pull off a realistic Wolverine. Should note that even canonically, the only reason Wolverine survived this process was that he has super-human healing, really his only actual superpower. The whole adamantium skeleton and retractable claws thing was only possible because of his healing abilities. $\endgroup$ May 11, 2021 at 20:17

6 Answers 6


On the outside

Of the body that is.

It's generally a bad idea to have anything in the body that the body can't repair. The metal is going to get bent and broken, it's going to need repair. It seems you have some solid medical technology going on here, but if you need to replace the bent metal in someone's leg that's a major operation you've set yourself up for. Better to let the bones be bones and give the troops power armour.

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    $\begingroup$ Good point, especially since a secret military organisation that can be easily identified every time they pass through a security checkpoint at an airport when off duty will not stay secret for very long. $\endgroup$ May 11, 2021 at 10:41
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    $\begingroup$ If something damages a person that the metal in the bones is bent or broken, they probably deserve a trip to the hospital anyway. With their nanobots it seems a relatively trivial thing to repair the damagevor replace the bent metal. And as KerrAvon correctly states, it is about a secret military. Strengthening bones seems much easier to do than somehow taking power armour all over the globe/wearing it all the time. $\endgroup$
    – Trioxidane
    May 11, 2021 at 13:22
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    $\begingroup$ If the bones are fracture-proof to the degree that the rest of the meat is irreparably harmed first, then worrying about bent or fractured metal is pointless. However, it's unclear that this is ever an issue... for any bad bone fracture, if the bone had been unbreakable would the injury have not simply transferred to the surrounding tissue? Fractured bones work the same way that crumple zones in cars work: they absorb impact. If they don't absorb the impact because they're unbreakable, then everything else suffers. The question has a premise defect. $\endgroup$
    – John O
    May 11, 2021 at 14:44
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    $\begingroup$ @Trioxidane It's well understood that you can die from organ and blood vessel damage from a shock wave or impact even if there is no damage to bones. Protecting just the bones leaves all the important delicate bits (vital organs) open to catastrophic damage. The tougher you make the bones, the more weapons will target the soft tissue trauma that kills more easily and the more extreme the weapons may become if they target the bones. $\endgroup$ May 11, 2021 at 16:10
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    $\begingroup$ @StephenG what is your point? That the OP should ask a different question for his secret military? Besides, a club to your arm, leg, chest or head can still be mitigated with a material other than bone. Not everyone has access to advanced guns and such. Not knowing the story, I would just answer the question about stronger bones. $\endgroup$
    – Trioxidane
    May 11, 2021 at 16:25

I read the question and the answers and this is what I believe that will help you:

Your soldiers already have a strong armor but you want to give them a strong skeleton. Replacing a percentage of their bones have a lot of pros and cons.

Bones are already really strong, but I believe I can help you to make them stronger:

  • Put the reinforcements on the outside - this way you don't need to shatter their bones and them use Skele-Gro - The calluses have their own pros and cons
  • The reinforcements should be something that keeps the bones in place without prejudicing them: maybe a strong elastic net:
    • That allows blood to go in and out
    • It maintains the bones in place when something breaks them
    • The net itself can elastically repel some bullets and also is easier to repair with nanobots
    • If you really want stronger bones, the net can be used to compress the bone to make it stronger (but also easier to shatter) - maybe the compression can be electronically controlled so it changes based on the situation
  • $\begingroup$ Nice. +1 for "stronger but also easier to shatter". :) $\endgroup$ May 12, 2021 at 7:42


There's two things you want to do. First you want to make the bones more like children's bones. They have competitively more cartilage than calcium in there, if my translation efforts serve me well. That means they are able to bend more, thus break less fast. Bones of older people are more strong in the sense that they keep their shape, but that means they are also more inflexible and thus break faster. So bones with more cartilage and thus more flexibility are preferred, especially as you get the strength from whatever you put inside it.

What you want to add is Graphene. With nano-tubing you can make incredibly strong and flexible materials. To support the bones, you can add a diamond or honeycomb lattice throughout the bone, most preferably a 3D version. The lattice can certainly be added to the surface of the bone as well as the attachment points for ligaments and such. Possibly it can near fully encase the bone as well, while still allowing . Depending on the area there can be many small shapes for strength, or some larger ones to just keep everything together. Made correctly they can soak up most of the energy of many common impacts, reducing the strain on the normal bones.

The lattice will let the bone still work as normal, so normal functioning for the immune system for example is unimpeded. Graphene is made from carbon, making a rejection reaction low as far as I can tell. Damage to the Graphene can likely be absorbed, just like most carbon in the body, while the bone can regrow if any Graphene goes missing. If ligaments or muscles lose their attachment it can still regrow to the Graphene or the bone underneath. Even if this would be problematic, it is likely that the soldiers are brought back in for a new treatment anyway.

One "negative" is that the nano-tubes are set in a certain way. The honeycomb lattice should reduce this, but especially with encasing the bones you have most of the nano-tubes set in a certain way. Even if you double-up or more, where the first layer is all horizontal, the second vertical, the third diagonal to the other two, etc., you will never have the full strength available. This is not an easy blanket strength thing. For example, the legs will be strengthened mostly for running and falling. Although the lattice and such will help, a club to the side of the leg can still easily break it, especially if the leg is standing or otherwise braced.

Further advantages of the nano-tube Graphene is that it isn't magnetic or otherwise detectable with normal means, allowing the soldiers to function in normal life/undercover.


This is hard

No, really, the fact that you want to "mettalize" your bones will create a few problems.

First, as @Separatrix said, the body has a bad time reacting to things that himself can't repair or are strange to the body. The metals usually used in fractures are a mixture of stainless steel and titanium, titanium might be a better option since it's stronger and withstands some strain.

Second, bones are not completely rigid. They can strain slightly. This is important because the harder a material is, the easier it is to shatter when bending or hitting it. If for example you want to protect your soldiers from blunt force, the titanium might shatter on hit, creating internal injuries each time your soldier moves that muscle.

I would follow @Separatrix answer and add protection on the outside. But not metal. Metal was used in the medieval era to protect against stabbing and slicing, being very most useless against blunt weapons (because the impact is still felt throughout the body). Use something that can absorb the hit instead, something made of fabric. Adding the advantage that will be easier for your soldiers to move around.


Drag those supersoldiers into the millenium!

Metal, schmetal. Schmetal, I tell you! What are you, patching up Steve Austin? Carbon fiber is how one reinforces bones these days.

carbon fiber augmentation


Carbon fiber technology provides strength and durability with ease of placement in comparison to stainless steel and titanium. The modulus of elasticity of the carbon fiber technology is closer to that of cortical bone than stainless steel or titanium implants, allowing the surrounding bone to function without undue stress from the internal fixation. The implants are composed of longitudinal and diagonally-oriented fibers of carbon, allowing for strength in multiple planes.

That xray is a little retro with the metal nails; those can be carbon fiber too. You don't need to shatter the bones. Slip the carbon fiber rod down the middle and sheathe the outside where you need it. The carbon fiber rod can flex like bone and if the bone breaks the rod will hold the pieces in place while your supersoldier chugs some of that Skelegro you did not need to use.

Carbon fiber rods and plates in bones is not fiction.

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    $\begingroup$ but those make the bone weaker not stronger, unless the bone is severely compromised to start with, and then you are not even bringing it up to normal bone strength. $\endgroup$
    – John
    May 12, 2021 at 0:41
  • $\begingroup$ If you ever work with pure carbon fibre in impact situations you'll find it's a pretty terrible material, then there's a heartbreaking little click and it fails spectacularly. Carbon-aramid is far better in practice, you get the same strength but higher toughness at lower weight, the aramid allows it to flex and take impact better, bones need a little flex. $\endgroup$
    – Separatrix
    May 13, 2021 at 8:58

This is the microstructure of compact bone (cortical), this is the calcium phosphate and collagen that makes up the nonliving part of bone and this is what you are replacing.

enter image description here

Your big problem, you see all those holes, those have to be there, they contain the blood and nerves that allow the spongy bone and marrow to grow. spongy bone functions to regulate your blood calcium and phosphorus.

enter image description here

How to replace it without loosing those blood vessels is the hard part. I know of no existing technology that will allow it. you may have to resort to a handwave like nanomachines.


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