Fun fact: Diamonds are virtually invisible on medical x-ray images


Welcome to Five Fun Facts, a curated list of orthopedic-related trivia (although sometimes we stray a little off-topic), published monthly.


1. Is it possible for diamonds, one of the hardest substances on Earth, to be virtually invisible on a medical x-ray?


The properties that determine if an object appears in an x-ray are density, thickness, and atomic mass (learn about attenuation coefficient). As it turns out, diamonds, which are pure carbon, have an atomic mass of just 12 and are therefore radiolucent (transparent) on medical x-ray.


Cubic zirconia crystals, which contain zirconium, will attenuate the x-ray beam by a factor of approximately 35 times more than a diamond of the same size.


2. If a fully-grown Tyrannosaurus rex were to stand on a one-inch cube of bone, would the bone crumble from the weight?


Amazingly, no. Topping out at an estimated 15,500 pounds, a T. rex falls short of the compressive weight a cubic inch of bone can support, which is 19,000 pounds.


While our bones have excellent compressive strength, their ability to absorb shear force is not quite as impressive, especially if delivered quickly (in other words, don’t let a T. rex thwack you with its tail).


3. How much weight do our feet absorb on a daily basis?


With every step, the force absorbed by your foot is the equivalent of 1.2 times your body weight. So, if you weigh 130 pounds and take between 8,000 and 10,000 steps a day, that adds up to about 1.5 million pounds.


4. My child is a pitcher. Should I be concerned about rotator cuff injuries?


Rotator cuff injuries are commonly associated with softball and baseball players (pitchers, especially), so you might assume we see sudden spike in rotator cuff patients during the spring sports season. But, in reality, that’s not the case, mainly because we see these types of injuries throughout the year (our surgeons perform a total of about 150 rotator cuff repairs a year). Truth is, this type of injury can happen to anyone at any time of the year, especially those over the age of 40. Also, we think our local athletes are generally well coached and train properly, which helps them avoid sports-related injuries.


So, when it comes to your young athlete, don’t agonize about potential injuries, but simply remain observant. If your young athlete experiences any pain or discomfort — in their shoulder or elsewhere — consult an athletic trainer or see a sports medicine doctor before a more serious injury occurs.


5. Does my risk of a musculoskeletal injury or condition increase with age?


There’s no sugar coating this. Yes, people age 65 or older are about 50% more likely to seek treatment for trauma, back pain, arthritis, or another types of musculoskeletal conditions than adults under the age of 65. The good news is that your doctor can advise you on preventative measures so you can beat the odds.


Image source: https://www.minnisjournals.com.au/articles/Radapr07_pp3.pdf

The information on this page is for your education and should not be considered medical advice regarding diagnosis or treatment recommendations.