Monday, January 3, 2022, Charlottesville, VA—It is snowing in Charlottesville this morning, the first snowfall of the new year. It is a heavy, wet snow and the trees in my yard are bowing down to the ground, groaning under the weight of it. Later a hard freeze is expected.
But my kitchen is warm and I am safe and dry, and there is nothing to do today but wait. The pandemic has made me good at this. I am savoring the quiet and enjoying the lack of activity on the roads. Traffic accidents are the bane of ER doctors during inclement weather and we can be inundated with multiple fender benders and fatal catastrophes alike, so I habitually pay attention to the traffic even when I am not scheduled to work.
A snow day in the ER has certain charms, though. Generally, the pace slows down a bit, especially in a heavy storm. Because the hospital has generators, we always have power and heat. And because the hospital has beds, the staff may even sleep there for days on end in a really big storm. When was the last time you went to a slumber party? (It is not as much fun as you remember after the first night or two)
One thing we will see over the next few days are the consequences of the many slip-n-falls of the unwary on icy surfaces. Some will break hips or ankles or bang their heads, but most will be FOOSHes.
FOOSH is an acronym for a Fall On Out-Stretched Hand. This is what people do instinctively when they fall. They reach out to break their fall and end up with a characteristic wrist fracture called a dinner fork deformity. Yup, your wrist is bent up like the swept-up portion of a fork, your fingers the tines of the fork. Ouch.
We reduce these fractures in the ER and then splint them. They usually heal very nicely with minimal disability. Occasionally they need an operation later, but not often.
It is commonly believed that bones heal back more strongly at the sites of fractures, but this is not accurate. Bones do get stronger, though, at the sites of chronic stress. This is called bone remodeling and it is a fascinating process.
Your bones are constantly remaking themselves throughout your lifetime. Tiny bone cells called osteoclasts are continually gnawing at your bones, destroying them and releasing their calcium into your bloodstream. Other tiny bone cells called osteoblasts are continuously laying down new bone, using the calcium in your bloodstream. A newborn baby will destroy and replace 100% of her bones in the first year of life and a healthy middle-aged adult will destroy and replace 10% of her bones every year.
There are two reasons for all of this bone turnover. First, calcium is vital not just to bone growth but most cellular processes in your body, and the blood levels of calcium are tightly regulated by hormones that stimulate the osteoclasts and osteoblasts to balance the level up or down. High or low calcium levels can be rapidly fatal, and the bones serve as a vast reservoir of total body calcium. Calcium can be quickly extracted or stored in the bones as needed.
Second, bones need to respond to vectors of stress and lay down new bone where it is needed most. Avid tennis players need stronger bones in the arm that holds the racquet for example. Olympic downhill skiers develop dense thigh bones to withstand the demands placed on them. Anthropologists examining ancient bones can sometimes determine the occupation of the deceased based on characteristic bony overgrowth. For example, a company of elite archers who drowned aboard the English warship Mary Rose when she sank in 1545 have been identified by researchers who analyzed their skeletons and found repetitive strain injuries on their shoulders and backs.
The archers were among 92 skeletons of those who died aboard Henry VIII’s flagship, which was raised from the Solent in 1982, over 400 years after her sinking.
How did those archer’s bones detect the stress of flexing heavy longbows and direct shoulder remodeling?
Bones are piezoelectric crystals. Piezoelectric crystals develop a small electrical current when deformed (bent). This tiny electric current attracts osteoblasts to lay down new bone. As long as the bone is being bent, however microscopically small the bend is, the bone will continue to generate current and lay down new bone at the site of the bending stress until the bending (and thus the current) stops. This is how the bone becomes stronger at the site of the stress.
The opposite is true as well. Applying an electric current to a piezoelectric crystal will make it bend or deform. This is happening all around you in common ordinary devices that you use but don’t really notice such as cellphones and computers, microphones, earbuds and inkjet printers.
Disposable cigarette lighters and gas grill igniters use a spring loaded hammer to bend a piezoelectric crystal to generate an electric charge across an igniter gap, sparking the fuel to ignite. This is the clicking sound you hear when you press the igniter for your grill or gas stove; a tiny hammer banging on a quartz crystal to create an electrical spark.
Well, it looks like the snow has stopped. Time to get out there and bend my bones, shoveling the driveway. What an electrifying prospect to start the new year off right.