Musings of a Cancer Doctor

Wide-ranging views and perspective from George W. Sledge, Jr., MD

Monday, March 18, 2013

The Bicyclist With the Artificial Leg

The other day I was walking to work when a bicyclist with an artificial leg went by. It caught my eye. I stopped and stared, quite rudely. He was relatively young, in his mid-20s, I would guess -- perhaps one of Stanford’s legions of graduate students or post-docs. Trousers (trouser?) covered one leg; the other was a carbon fiber or titanium rod. There were shoes on both “feet.” In seconds he was gone down the road, traveling on at a decent speed, unaware of my interest.


There was so much the doctor in me wanted to know. How did he lose his leg: some childhood trauma? A war wound? An osteosarcoma? How long had he had the artificial leg? Certainly the trauma, whatever it was, had affected his life, but did it still do so? Was he as functional as ever? Or perhaps – as the claim has been made for the South African runner Oliver Pistorius -- even more functional than ever?


This brief incident got me thinking about replacement parts, the technologic enhancements that have transformed orthopedics and rehabilitation medicine in recent decades. I am an oncologist, and know practically nothing of either specialty, but it is clear that a prosthetic revolution took place while I wasn’t watching.


And indeed, Wikipedia assures me, this is the case.


A generation ago the thought of an amputee bicyclist would have been, if not preposterous, at least unlikely. The older prosthetics (from the Greek prósthesis, "addition, application, attachment") were heavy, ugly, minimally functional affairs. Starting in the 1980s the field has seen continuous advances: CATCAM (Contoured Adducted Trochanteric-Controlled Alignment Method), microprocessor-controlled prosthetic knees, hydraulic and pneumatic controls, carbon fiber, myoelectric limbs, computer-aided design, lithium-ion batteries, robotic controls, targeted muscle reinnervation.  The list goes on and on.


The modern lower extremity prosthesis is a technologic wonder. With myoelectric controls it is close to being a direct extension of the human nervous system. And even more wonderful technology is on the way, with neural interfacing technology implanting chips in the brain capable of controlling prosthetic devices: to date only in monkeys, but coming soon to an OR near you.


That the bicyclist with the artificial leg caught my eye no doubt says more about me than him, or the times we live in. The average person sees nothing strange about a man riding a bike: enhancing performance is what human technology has done since Olduvai Gorge, after all.


Internal enhancements are, by comparison, quite new, and still have something of the strange, the unnatural, about them. Consider the shoe at the end of the bicyclist’s artificial leg. Why was it there? Pistorius  ran on blades -- no shoes to be seen -- so were these shoes to enhance function, or just to make those watching more comfortable?


Probably the former: perhaps artificial legs don’t meld seamlessly with bike pedals yet. And if not for function, why did he care? He did not cover the artificial leg, after all. Which implies that he is not only reliant on the technology, but also comfortable with it, considering it essentially normal and unexceptional.


Artificial legs are part of a long list of prosthetics. Hips, knees, arms, jaw -- you name a bone and someone has probably replaced it. And of course bones are only the beginning, the low-hanging fruit of internal enhancements, largely a matter of physics rather than biology. Does anyone doubt that we are on the edge of functioning livers, kidneys, pancreases, hearts, and whatever else stem cell technology will allow in the coming years?


By and large these prosthetics have been implanted in response to some medical problem. But this too is beginning to change: prosthetic enhancements for the healthy are on the way. We can make you better than Mother Nature did!


Perhaps you’ve heard of an intellectual movement called transhumanism, its goal to fundamentally alter the human condition by enhancing our physical and intellectual properties. Max More, one of its founders, describes transhumanism as “a class of philosophies that seek to guide us towards a posthuman condition. Transhumanism shares many elements of humanism, including a respect for reason and science, a commitment to progress, and a valuing of human (or transhuman) existence in this life. … Transhumanism differs from humanism in recognizing and anticipating the radical alterations in the nature and possibilities of our lives resulting from various sciences and technologies .”


Well, radically altering nature and human life is nothing new. Anyone alive today lives in a radically different world than did his or her grandparents. But the transhumanist movement, at least in its own eyes, represents something different, something transformative, pointed at an unimaginable future.


Maybe they are right. I have my doubts, skeptic that I am, oncologist that I am, firmly wedded to the reality of our mortality and the flaws inherent in human nature.


What will it mean to be human a hundred years from now, assuming the human race hasn’t erased itself from this sadly abused globe? Prosthetic legs, whether for osteosarcoma or performance enhancement, hardly alter what it means to be human, after all. That bicyclist was off to work, and next year’s patient with a replacement liver will go back to the coffee shop (or perhaps the bar), none the wiser for the experience.


None of these enhancements change what it means to be human, because technologic enhancement is what we have always done. It defines us as a species, probably has done so for as long as we have walked upright and had opposable thumbs, but certainly for as long as we have drunk coffee for its attention-enhancing benefits. Starbucks is full of transhumanists at 8:00 AM. See if your life isn’t radically altered without caffeine.


What I do know is that the technologic enhancements won’t make us better people. I mentioned the runner Oliver Pistorius, the first amputee to run in the Summer Olympics. Leaving aside whether his “blade runner“ prosthetics were kinetic advantage or disadvantage, the story fascinated exactly because of the promise both for repair of our defects (Pistorius was born without his lower legs) and for the future improvement in the human condition.


Will the 2024 Olympics see a field of 4x400 runners on carbon fiber blades controlled by neural-interfaced chips? Will teenagers trying out for the high school track team demand enhancements from their parents? “Come on, Mom, everyone’s doing it. How am I expected to compete?” Who need steroids or EPO in this brave new world?


But the other side of the Pistorius story must give us pause. Oliver Pistorius is now charged with murdering his beautiful 29-year-old girlfriend. Carbon fiber lower limbs are not a solution for the human condition, nor do they represent a form of anger management. Until we are capable of moral enhancement, transhumanism will just be more of the same old killer ape story.


Having said that, if I need a new pancreas in the next few years, I trust the technology will be sufficiently developed. We are all bicyclists, trying to get somewhere, regardless of our defects.