The first surgery I ever did by myself I cut a man’s legs off…
Not 1, but both freakin’ legs– yeah, I cried afterwards.
Welcome to your life as a surgeon!
There I was a newly appointed orthopaedic surgeon on a locum in Timmins, Ontario.
And I find myself in the operating room with a man who needs a double leg amputation.
Buckle up interns, today’s lesson isn’t for the faint of heart.
And before I tell you how to amputate a leg, let me give you the backstory.
Timmins is a relatively small town in Northern, Ontario.
It has very cold winters.
You know the “stay inside because it's not really suitable for a walk around the block”
kind.
Like -35 degrees.
Celsius.
Or like -31 degrees Fahren-freaking-heit for you Americans.
Everyday.
Now I am not from Timmins – and neither was my patient, a homeless man who had hitchhiked
719 km, 447 miles, all the way from Quebec up into the winding highways of northern Ontario.
The local police were very surprised to find a lone man trudging along an empty stretch
of road on an exceptionally cold day.
They took him into the cruiser and asked where he was from and where he was going…
As they drove, the man started to warm up and the police noticed an “interesting”
aroma wafting off the man in the back seat.
Well interns– Have you ever smelled rotting flesh?
Type that question into google and you’ll get an answer that belies the visceral sensual
impact of the real thing…
rotting meat with fruity undertones?
Gross– but in real life– truly barf worthy.
At the time, the police didn’t know what they were smelling, they just knew it didn’t
smell right and they decided to bring the man to the hospital to see a doctor.
I was just the newbie on a locum.
The resident orthopaedic surgeon providing coverage f Timmins Ontario (of which there
was only one at the time – it’s a small town) was away on vacation, and I had flown
in to cover his duties.
The nurses ran the typical diagnostic procedures and they too noticed the odd odour.
You see, when tissue is injured or dying, bacteria fester and begin to break down the
tissue.
In this chemical reaction, the rotten odour is released.
Our patient seemed okay from the waist up and thus our search led us down.
Like Toucan Sam hopping downstairs on Christmas morning…
We removed the man’s boots to find two entirely gangrenous feet.
Like they were entirely black.
Think mummification– Gangrene is death of body tissue due to lack of blood flow or a
serious bacterial infection.
It commonly affects the extremities where blood flow is less robust..
Due to their distance from the heart it takes blood longer to reach our hands and feet,
and this process is slowed in adverse conditions such as extreme cold.
Also in cold temperatures, these blood vessels constrict, which is a protection mechanism
that reduces overall blood flow to these areas, in favour of maintaining the amount of heat
the body loses.
Remember our vital organs are in here (point), and they’re the body’s primary priority.
So there I was faced with two blackened feet, but it seemed that the gangrenous tissue extended
up into his pant legs.
We removed his pants to find It is possible for gangrene to affect muscles of the body
as it had in this man.
The entire lower part of his leg, midway up the calf, was compromised, with the frostbitten
tissue extending slightly further up his leg.
When tissue is frostbitten, ice crystals literally form inside the cells, causing physical damage
and permanent changes in cell chemistry.
But freezing only kills a proportion of the cells, some survive.
Additional damage occurs when nearby tissue that has not itself frozen becomes anoxic
because blood vessels that have narrowed in response to the cold can’t deliver enough
oxygenated blood to the tissue.
This process can be aggravated by small clots that form in the narrowed vessels, slowing
oxygen delivery even more.
Should blood flow be restored to this tissue, damaged tissues release inflammatory compounds
that worsen the damage already present as a result of freezing and anoxia.
Sometimes cold also causes clots to form in small blood vessels in this tissue.
These clots may limit blood flow so much that the tissue dies.
When blood flow returns to the affected area, the damaged tissues release a number of chemical
substances that promote inflammation which worsens the damage caused by the cold.
These noxious substances are released locally and into the bloodstream as frozen tissue
is warmed.
This does not seem at all pleasant.
Our first order of business was to determine the degree of frostbite and if any of the
tissue was recoverable.
First degree: irritates the skin and pain.
Second degree: blisters but no major damage
Third degree: involves all layers of the skin and causes permanent tissue damage
Right, so we were dealing with severe frostbite in the fourth degree.
Everything in this man’s leg was frozen.
If there were a fifth degree, he would have it.
Typically we try to allow some time to see if the tissue will revascularize and “pink
back up” as blood flow is restored.
Other testing such as the CT angiogram helps us to determine what tissue is still viable.
This test involves injecting an intravenous dye into the body and then running a CT scan.This
combination produces pictures of blood vessels and tissues in the target part of your body.
So after we’d allowed for some time for the tissue to revascularize our CT angiogram
showed that there was only blood flow to about mid shin height.
Literally everything below that was dead.
It looked like he was mummified like black leather from the mid shin down.
Modern science can do amazing things, but not this…
Even in the event that we could do a vascular graft– taking the blood vessels from one
location in the body and transplanting them in the damaged legs and feet, the tissue in
the target site was too far gone.
Shrivelled up too much to be suitable receptor sites for the donor graft.
Amputation…
My favourite.
Not.
Amputation is a complex procedure that involves severing all the varied tissues (which heal
in their own particular manner) in strategic order so as to create the most functional
residual limb possible.
Limb loss is not only a physical and functional loss, but an extreme psychological and emotional
change for the patient.
Our limbs are how we interface with the world around us, and in the case of our legs–
our primary mode of transportation.
First, we must determine what level to cut the leg… ssss.
Legs.
We must consider what is going to be the best location in terms of making a stump for the
patient.
There are many prosthetic options available, but we aim to create the stump below the knee
whenever possible as this type of prosthesis requires less energy expenditure when walking.
It is also easier to fit a prosthesis on a lower extremity than the upper thigh.
And with a mid shin height amputation, at least our patient would have enough length
to give a good fit in his legs.
When fitting a prosthesis, approximately 20cm of length will suffice.
That’s the length at which we will cut the bone.
And no– an amputation procedure isn’t as simple as one straight cut across, flesh
bone and all.
We need to have enough soft tissue and skin to cover the end of the bone.
In our patient’s case, that means that we must amputate at a height that the surrounding
skin and muscle tissue is viable and not damaged by frostbite.
At this level there are no tendons to worry about, but the procedure must still follow
a stepwise approach that addresses each tissue involved.
First the skin, then the muscle.
And finally, the bone.
Put your hand up if you’ve heard of a fishmouth incision.
This is a type of incision commonly used in the amputation of limbs where the flesh is
cut to create a front flap and a back flap (resembling the mouth of a fish) where the
back flap is slightly longer so that it can wrap around and bone stump and be sewn to
the front flap.
Once the amputation is complete, the skin flap will be sewn onto the top of the reattached
muscle– so both skin and muscles must extend around the length of bone remaining.
Once the initial incisions are made, we’ll sew in a drain that we can pull out afterwards.
Combined with tight wrapping above the amputation site, this will help us to control bleeding
as much as possible.
The drain will be removed later on.
As the surgeon works their way through the muscle, they must tie off and ligate the blood
vessels (which is to close them up for good).
In ligation, a blood vessel is clamped with a hemostat and a suture is very literally
tied around the vessel.
They must also carefully sever the nerves in the region to help the patient avoid painful
neuromas.
A neuroma is the intertwined mass of scar and nerve tissue at the end of a severed nerve
that can be painful to pressure, stretching or physical manipulation…
Since the amputee's limb will be subject to all of these forces inside a prosthesis, it
is important to limit this as much as possible.
University of Washington’s department of Sports Medicine discusses several tactics
that have been devised in order to minimise neuroma formation (though none have proven
uniformly successful).
Nerve ends may be ”cauterised with chemicals or heat, buried in the nearby bone, encasing
the nerve in impervious material, ligatin the nerve or injecting it with a variety of
chemicals.
Other methods include sewing the sectioned nerves to other nerves or sewing them back
onto themselves, thereby creating a nerve loop and even simply dividing the nerve and
allowing it to retract.”
In my case, we ligated the nerves, sectioned them carefully and allowed them to retract
away from the outermost region where pressure would be most apparent.
If a nerve can be positioned in a well cushioned soft tissue site away from the incision and
scar tissue– that bodes well for the comfort of the amputee.
Now, once the nerves and blood vessels have been addressed, it is possible to sever the
bone.
We have different kinds of saws for this, but typically we will use an oscillating bone
saw.
Fun fact, in the old days we used to use something called a Gigli saw, which is a flexible wire
saw that you power with your hands.
Talk about an immersive experience, you can literally use a hand powered wire saw to sever
bone.
Another fun fact– in some detailed procedures where precision and control are particularly
pertinent, they are still used.
They allow for smooth even cutting especially in small sensitive areas.
Remember that we are creating a stump here, so this bone is cut shorter than the surrounding
muscle and skin flaps allowing them to be stretched around the bone and sutured together.
But before we get to that, we’ll typically bevel the front edge of the bone at approximately
a 45 degree angle to give it a little bit more of a gentle contour at its front edge
so that the tissue inside the stump is protected.
And finally with the bone severed and bevelled, it is time to put everything back together.
At this phase, the muscle is attached to the bone in a process called myodesis.
The surgeon will either drill holes through the bone and suture the muscle directly to
the bone or secure the muscle over the bone and suture it to the periosteum which is a
thick tissue that covers the bone.
Then the surgeon will close up the fishmouth incision around the end of the bone, and as
you recall we left the back flap longer than the front for just this purpose.
In our patient’s case, for a mid-tibia amputation, this means that the soleus and gastrocnemius
muscle will be attached to the front of the tibia.
When the muscles are attached in this way, they pull against each other, creating tension
and preventing the muscles from shortening or retracting further up the leg.
Either way, once the muscles and bones are secured in place, we can continue the procedure
by sewing the skin shut over the amputated limb.
And after all of that, I only had to do it one more time.
Chris: How was that?
Patient: I can’t feel my leg…
Chris: What legs?
An experienced surgeon can complete an amputation procedure in approximately 15 minutes.
The fastest I’ve ever seen it done was by a vascular surgeon during my residency.
He used a lister knife which is the tool that Jack The Ripper used to kill everyone (which
is basically a mini machete) and in a couple deft cuts, he sliced through everything except
for the bone.
Along with the other surgical assists, I clamped hemostats to the exposed blood vessels as
quickly as I could.
There was blood everywhere, before I could get 8 or so clamps hanging off the end of
his legs.
I was the snap release guy as he sequentially ligated the vessels in a whirl of surgical
expertise.
And then, can you guess?
He whips out the Gigli saw – of course – and severs the bone in approximately 30 seconds.
Suture it all up and we’re out of there in 10 minutes or less.
Unlike my patient up in Timmins, his amputee woke up with only one leg missing.
But I’ll tell you what– my guy was ecstatic.
Even though both of his legs were amputated below the knee, he was now going to be eligible
for disability from the government which would at least afford him a place to live.
To him, that was a superior option to living on the street as he had before.
After that, I cried.
And that was my first surgery working alone…
Welcome to your new life!
Let me know what you want me to discuss next.
Outro–