Key Considerations With Digital Amputations And Biomechanics
“By God, sir. I will not abide another toe!”
— The Big Lebowski to the Dude
If you are a fan of the Coen brothers’ cult comedy classic, The Big Lebowski, you already know that the loss of a toe is central to the plot of the story. If you haven't seen the film once, I will not play the spoiler. For the rest of us who have watched the movie at least five or 10 times, grab yourself a Sioux City Sarsaparilla and read on.
This month’s topic revolves around the topic of digital amputation and something that has become one of my pet peeves. Specifically, it is the serial amputation of toes that often leads to a diabetic foot left with one or two toes.
A hallux minus its four accomplices (since we’ve already broken out the movie references, let’s call this the “Sgt. Hulka” sign, a homage to another comedy classic, Stripes), the “Texas longhorn sign” (hallux and fifth toe only remaining) or the “bird” (only the middle toe remaining) presenting during an initial evaluation always leaves me wondering. In regard to taking all five toes but leaving “nubs” (i.e. the metatarsal heads remain and reek of the work of nihilists), this is equally disconcerting. All are surgical curiosities that beg the question “Why?”
Let us look at the most seemingly logical explanation for these iatrogenic foot types. They are typically the result of the need to surgically resect infected or gangrenous toes that had outlived their usefulness. Taking one toe is okay. Take another and it certainly causes more concerns. “Abide” anything beyond two toes and now additional questions arise.
Hopefully, an absence of biomechanical appreciation versus financial gain is the root cause of these anomalies. That being said, five separate digital amputations add up to greater total reimbursement than one or two digital amputations, followed by a transmetatarsal amputation at a later date. Sorry to have to raise the issue but it is the 800 lb. gorilla in this room.
Consider the scenario leading to the solo hallux. Certainly, the hallux is important in propulsion as well as in balance in a normally functioning and otherwise healthy foot. We need to question and debunk the myth that preserving the hallux is essential to balance and gait, especially in neuropathic feet. The person with decreased proprioception and a wider base of gait is inherently compensating for diminished propulsion and balance, and is hardly relying on the hallux during gait. Is the hallux important? Of course it is. Is it essential? No. Will preserving a lone hallux provide any real benefit? Doubtful. Will preserving a solo hallux create the potential for further ulceration? Quite possibly.
When chronic osteomyelitis or gangrene make digital amputation the only real option, one must always consider the biomechanics and gait of the patient. Your goal should be attaining the best possible functioning foot that will provide the least chance for additional ulcer formation at the remaining toes or foot.
I can still remember a lecture by Michael Downey, DPM, when I was a student and his surgical pearl concerning digital amputation. To summarize, he stated that a transmetatarsal amputation provides a better functioning foot than leaving a foot with one or two toes. I have followed this advice throughout my career and it has served my patients well.
Sometimes less truly is more. A well-planned transmetatarsal amputation is certainly the better option and the net result is superior in comparison to a foot with one or two toes remaining.
Until we meet again next month, try to enjoy a little some summer fun. May I suggest some bowling, a white Russian or another favorite beverage, and perhaps shopping for a carpet that really ties a room together? The Dude abides.