Mad about Science: Broken bones

By Brenden Bobby
Reader Columnist

Trigger warning: If you’re squeamish, turn the page. I love telling this story for its gross-out effect, but it’s pretty graphic. You’ve been warned. — BB

I’ll never forget what my grandfather told me as a child: “A broken bone doesn’t really hurt.”

I found out he was lying when I was 19 and suffered a compound open fracture of my tibia and fibula.

To be fair, I also impaled my leg from the inside out with the bone, so I probably hit a few nerves in the process. Regardless, it was the most extreme and indescribable pain I’ve ever suffered in my life.

The most curious thing about the entire process was that in fewer than 90 days I was back to work and walking normally.

An adult human possesses 206 bones in their body, and every single one of them can suffer breakage. In my case, a six-foot drop with forward angular momentum onto an uneven surface was the cause of the shearing force that snapped the two bones. My heel hit first, but the rest of my body kept moving at a forward and downward angle, which put an amount of shear force equal to just about my entire body weight and then some on the weakest point of the bones. I suffered an open compound fracture, where the bone was broken in two and emerged through the skin. Believe it or not, this was actually the best case scenario, considering the forces involved.

Compound fractures are extremely jarring and require medical attention to properly heal. The bone needs to be set back into place and will require surgical assistance. A doctor is likely to fuse your bones back together and hold them in place with titanium plates and screws to keep the bone from moving around during the healing process. In the case of an open fracture, a doctor may also need to repair damaged blood vessels, muscle tissue and skin.

The truly wild part is what happens when you begin healing. Bones are calcium structures that act as anchor points for our muscles, like bedrock beneath a thick layer of soil. After a fracture, your body identifies the damage and begins to clot blood around the broken parts of the bone, and if the two pieces are where they should be, these clots will bridge the gap between them. Your body will then begin fusing the two broken bones together with a flood of fibrous cells and cartilage, which is a flexible tissue that acts like a shock absorber in your joints and can also be found forming the structure of your ears. This structure is called a soft callus, and it’s markedly different from the calluses that may appear on your feet. The soft callus replaces the blood clot and appears between two and six weeks after the initial fracture. Over the course of the next two to three months the cells of this callus are replaced with cells matching the rest of your bones to create a hard callus, and what is effectively new bone growth.

Throughout the rest of your life, these cells — along with the rest of the cells of your skeleton — will be replaced by a process called remodeling.

There are numerous types of bone fracture, which can then be subcategorized by how the bone has or has not shifted because of the break. We’ve already discussed compound fractures, which don’t always pierce the skin, but when they do are referred to as an open compound fracture or an open fracture. A transverse fracture is when the bone fractures horizontally and can be categorized as a non-displaced fracture, where the bone hasn’t moved at all, or a displaced transverse fracture where the bone has shifted or off-set.

An oblique fracture is similar to a transverse fracture, except that the break is diagonal rather than horizontal. This is likely to happen when angular pressure is involved in the break, similar to mine. A comminuted fracture is when the bone breaks into three pieces. A great deal of force is required to break a bone in this way, and it’s commonly associated with things like car accidents or falling from a roof, where the downward force of impact may allow the top of the bone to act like an ax head slamming down into the lower portion of the bone.

Greenstick fractures are partial fractures and more common in children with developing bones. These are common injuries from sports, where a leg may flex just a little too far, but not far enough to cause a transverse fracture in the bone.

Hairline fractures can take the form of transverse or oblique fractures. These are generally very thin cracks in the bone that may compromise the bone’s effectiveness in maintaining your body’s structure and counteracting external forces. If left untreated, it’s possible for this kind of break to become a more serious injury.

You may be wondering why it hurts so badly when you break a bone. It turns out that our bones actually have quite a few nerves traveling through them in addition to blood vessels. These nerves are important sensors for our brain that let us know when something isn’t right — if your bone is being stressed by a lot of running, these nerves send pain signals to your brain that are telling you to ease up before something bad really happens. During a critical break, like the one I had, multiple nerves in numerous places were severely compromised. The nerves within the bones themselves sent critical signals to my brain when they were sheared, which were heightened by the nerves in my calf saying they had been compromised by something very sharp. The nerves in my skin were quick to remind me that I was an idiot for hurting myself in such a way. The pain signals continued for several days because of the swelling involved in the break — this was essentially my body saying: “Hey doofus, stay off this thing for a while, we’re trying to fix it.”

Despite permanently losing some feeling in my ankle, I got better; and, now I have a cool story to share over drinks. Now if you ever manage to catch me in shorts, I’ve got some awesome scars to prove it. And, no, I don’t set off metal detectors at the airport.

Stay curious, 7B.