Detecting Broken Bones with Tuning Forks

One of our readers found an interesting medical article, but it was written in nearly-incomprehensible jargon and another reader asked for a translation. We do take requests, so I'll take a shot at translating it into common English.

The article was about a field-expedient method of determining if a bone was broken when there wasn't an X-ray machine handy, or if it was necessary to reduce the number and costs of X-rays. A study was done to see if using a tuning fork and a stethoscope can find fractures in bones by going to a clinic where people with suspected broken bones would show up, and checking them with the tuning fork/stethoscope before they got an X-ray. The results were good.

The tuning fork method breaks down like this:

1. Identify the possible break. Talking to the patient is the easiest way to do this.
   
2. Check the similar bone on the other side of the body for normal sound conduction. This will give you a reference point for the volume of sound in an unbroken bone.
   
3. Check the possibly broken bone. If there is a break, the sound will be diminished or absent since sound waves travel through solid bone much better than through soft tissue. A break in the bone will interrupt the conduction of the sound waves.
   

The researcher used a common 128 Hz tuning fork applied to a point on the distal portion of the bone (further from the torso) and listened with a stethoscope applied to the proximal end (closer to the torso). Applying the fork and scope to the portion of bone closest to the surface will give the best results. 128 Hz tuning forks are used in several medical procedures and can be found easily. No batteries are needed; just tapping it against the ball of your hand will provide 20-30 seconds of a pure tone. Unfortunately, 128 Hz seems to be in the range of my mild hearing loss. I can't find a sample that I can hear, but here's a site that will let you generate any audible tone so you can hear what 128 Hz should sound like. 

The researcher had the best results finding breaks that went across the bone (transverse) and poor results with breaks that flaked off a portion of the bone (avulsion) or where two bones are jammed into each other (buckle fracture). The sample size was rather small (less that 40 patients), but it was enough to show that the test works.

From a prepper's point of view, this is a painless test that requires no power or expensive machines and it gives good results, which makes it something to think about adding to your trauma kit.