13. AMPUTATION OSTEOPLASTY
• Stops tib/fib motion - may lead to less pain
• Provides broader distal bone surface - may increase
end bearing
• Periosteal Flap used to cover end of tib and fib -
more normal intra-osseous pressure
• Improved outcomes have not been proven
14. ISCHEMIC LIMBS
• Blood supply better on the posterior and medial
aspects
• Performed at a higher level
• Procedure of Ertl is contraindicated
• Tourniquet
There are two most common types of all amputations: Transtibial (below-knee) amputations and transfemoral (above-knee) amputations
Transtibial (below-knee) amputations can be divided into three levels The appropriate level must be determined for each individual patient.
It accounted for 36% of all amputations.
There are variety techniques, all procedures may be divided into those for nonischemic limbs and those for ischemic limbs.
With the non-ischemic limb, the optimal level of amputation must be chosen with the consideration between the lever arm for the prosthesis and the sufficiency of “circulation” for healing soft tissue. The amputation level also is governed by the cause (e.g., clean end margins for tumor, level of trauma, and congenital abnormalities).
In adults, the ideal bone length for a below-knee amputation stump is 12.5 to 17.5 cm, depending on body height
There is a rule of thumb for selecting the level of bone section is to allow 2.5 cm of bone length for each 30 cm of body height.
Place the patient supine on the operating table, and use a tourniquet for control bleeding.
Use the anteromedial joint line to measure the desired length of bone and mark that level over the tibial crest
Outline the anterior and posterior skin flaps with the same length, the length of each flap is one half the anteroposterior diameter of the leg at the level of bone section.
Begin the anterior incision at the level of bone section and swing it distal to the previously determined level of the flap. When crossing the tibial crest, deepen the incision and mark the periosteum with a cut to establish a point for future measurement, continue proximally to end at a similar position on the opposite side
We do the same with the posterior incision
Reflect the anterior flap the deep fascia and the periosteum in a single layer
Right here on the anterior aspect of the fiula in the interval between the extensor digitorum longus and peroneus brevis, we can identify and isolate the superfiial peroneal nerve, the nerve is pulled down gently, divided and allowed it retract to the muscle
Divide the muscles in the anterior compartment of the leg at a point 0.6 cm distal to the level of bone section so that they retract flush with the end of the bone.
As these muscles are sectioned, we can identify the anterior tibial vessels and deep peroneal nerve, ligate and divide the vessels at a level just proximal to the level of intended bone section.
we bevel the tibial crest with: begin 1.9 cm proximal to the level of the bone section, and cut obliquely distalward
Section the tibia transversely, and section the fibula 1.2 cm proximally.
Divide the muscles in the deep posterior compartment 0.6 cm distal to the level of bone section. That expose the posterior tibial and peroneal vessels and the tibial nerve. Divide them, bevel the gastrocnemiussoleus muscle to forms a myofascial flap long enough to cover the end of the tibia to the anterior fascia.
Smoothly round the ends of the tibia and fibula with a rasp, and irrigate the wound to remove all bone dust.
Release the tourniquet, hemostatis all bleeding points.
Bring the gastrocnemius-soleus muscle flap over the ends of the bones, and suture it to the deep fascia and the periosteum anteriorly
Place a drainage tube deep to the muscle flap and fascia, and bring it out laterally through the skin 10 to 12 cm proximal to the end of the stump.
Fashion the skin flaps for closure without tension.
POSTOPERATIVE CARE Rehabilitation after transtibial amputation in a nonischemic limb is fairly aggressive.
An immediate postoperative rigid dressing helps control edema, limits knee flexion contracture, and protects the limb from external trauma.
This technique is called amputation osteoplasty which transforms the typical transosseous amputation site into an end-bearing limb.
This procedure seal the medullary canal and form a bone bridge between the tibia and fibula, by sutured a periosteal sleeve over the osseous transections.
Theoretically, pain, better proprioception, preservation of tissue quality and prevention of tibiofibular instability.
The results were not significantly different from those with normal technique.
With the ischemic limb, one thing we should remember is the blood supply is much better on the posterior and medial aspects than on the anterior or anterolateral sides. So the amputation techniques for the ischemic limb are characterized by skin flaps that favor the posterior and medial side of the leg.
The amputation is performed at a higher level
Traditionally, a tourniquets is avoided
For ischemic limbs, Burgess recommended amputation 8.8 to 12.5 cm distal to the knee joint line.
Outline a short anterior flap and a long posterior one. The posterior flap should be 1 cm longer more than the diameter at the level of bone section.
And the other step is similar with the non-ischemic technique.
After transtibial amputation, a soft dressing can be applied but it has two main disadvantage, some areas may be tighter than others, become loose quickly.
So a rigid dressing is preferred.
In short, a couple of things we should note with the below knee amputation, there are 5 nerve, saphenous, superficial peroneal, deep peroneal, tibial, sural.
Nerves should be drawn distally, cleanly, divided and allowed to retract back away from areas of scar.
Three Major Vascular Bundles Anterior Tibial Vessels, Posterior Tibial Vessels, Posterior Tibial Vessels, Peroneal Vessels
The second part I want to mention is TRANSFEMORAL (ABOVE-KNEE) AMPUTATIONS
This level is second in frequency only to transtibial amputation. Normally, It can be classified as short transfemoral, medial transfemoral, long transfemoral.
Position the patient supine, and apply a tourniquet.
Outline equal anterior and posterior skin flaps.
The length of each flap should be one half the anteroposterior diameter of the thigh.
Incision that starts at the midpoint on the medial aspect of the thigh at the level of anticipated bone section. The incision passes in a gentle curve distally and laterally, crosses the anterior aspect of the thigh at the level determined as noted earlier, and curves proximally to end on the lateral aspect of the thigh opposite the starting point
Fashion the posterior flap in a similar manner
reflect the flaps proximally, divide the quadriceps muscle and reflect it proximally to the level of intended bone section.
Identify, ligate, and transect the femoral vessal in the femoral canal. Incise the periosteum and divide the bone with a saw
Identify the sciatic nerve and divide it.
Divide the posterior muscles transversely so that their ends retract to the level of bone section, and remove the leg (Fig. 16-8B). Isolate and section all cutaneous nerves
Drill several small holes just proximal to the end of the femur, attach the adductor and hamstring muscles to the bone with nonabsorbable or absorbable sutures (Fig. 16-8C). The muscles should be attached under slight tension.
Suture the quadriceps over the end of the bone, to the posterior fascia of the thigh
Insert drainage close the skin with interrupted non-absorbable sutures
In my first talk I’ve mentioned this problem. Now more than ever it is important that amputations be performed by surgeons who have a complete understanding of amputation surgical principles, postoperative care, and prosthetic design.
But I believe that not all of us pay a lots attention in the two former issues
I take this picture right in our center. This is not a good not a right way to dressing the stump.
The purpose of the bandage is shaping a stump,
Use diagonal not circular turns, because this will restrict blood flow to your stump and could cause pressure areas or other more serious problems.
Pressure should graduate from very firm at the end of your stump to moderate at the top of the bandaging
Bring in the stump edges to promote a conical stump shape
Anchor the bandage above the proximal joint to prevent it from sliding off the stump
If the bandage becomes loose or too tight, take it off, re-roll the bandage and re-apply it
There are one more thing I want to share with you today. It’s about the prosthetic design.
This is a conventional prosthetic. At the top you have a socket, that fits over the residual limb, And then you have the knee, and then a pylon, and then a foot.
More than 3000000 amputees need a new knee every years
And what are their options? This is a high-end. This is what we'd call a "smart knee." It's got a microprocessor inside. It can pretty do anything, but it's 20,000 dollars
This is a low-end titanium knee. It's a polycentric knee that mimics a natural human knee. But at 1,400 dollars, it's still too expensive for people like in this country.
And lastly, here you see a low-end knee. This is a knee that's been designed specifically for poor people. The mechanism here is a single axis, and a single axis is like a door hinge. So you can think about how unstable that would be.
This woman and her team have created a knee that has ability of a low-end titanium knee, but with only 80. They call it re-motion knee.
I'm going to show you a video now. You can see him walking. He's wearing the a single axis knee. And he's doing a 10-meter walk test. And you'll notice that he's struggling with stability as he's walking. Now this is a man that wearing one of the earlier versions of remotion knee, and he's doing that same 10-meter walk test. And you can see his stability is much better.
This is a commercial product, and for more information you can access this site.
There is the truth that even with the most modern industry product like this, just over 35% of the amputees do not not use their prostheses. What is the reason?
Normally, we mold and cast the stump to create prosthetic sockets with a single-material.
Such sockets often leave intolerable amounts of pressure on the limbs of the patient, causing the pressure sores and blisters. These sockets were painful because they did not fit well
If your socket is uncomfortable, you will not use your leg.
This man and his college in MIT have used MRI (magnetic resonance imaging) to capture the actual shape of the patient stump.
Then use finite element modeling (mô hình phần tử hữu hạn) to predict the internal stresses and strains on the normal forces, and then create a prosthetic socket for manufacture.
They use a 3D printer to create a multi-material prosthetic socket which relieves pressure where needed on the anatomy of the patient. By this way, they can make sockets quickly and cheaply.
One of their patients, who has been an amputee for about 20 years and worn dozens of legs, said, "It's so soft, it's like walking on pillows, and it's sexy"
Look at this part of the prosthesis.
And this man, he look normal. Now you can see, his legs are bionic. This concept is used to describe the integration between the body and the prosthesis, that attached to the the body to bridge the gap between disability and ability.
I hope I could understand this circuit diagram, but I did not
I know it technology behind, but This bionic work similiar to how muscles work in the calf region. This bionic propulsion is very important clinically to patients.
Now on the left you see the bionic device worn by a lady -- on the right a passive device worn by the same lady. bionic device emulate normal muscle function -- enable her to do something everyone should be able to do, go up and down their steps at home.
To conclusion, One thing I’ve learned that every person should have the right to live life without disability if they so choose -- the right to live life without severe depression; the right to walk or to dance, in the case of limb paralysis or limb amputation.
it's time to stop treating our patients like this or like this. He deserves to go on his feet and not on his hands.
Finally, please allow me to invite you to watch a touching video, that inspire me, and me the motivation to talk about this problem today.
Adrianne is a dancer, she lost her limb in the terrorist attack. In 3.5 seconds, the criminals took her off the dance floor. In 200 days, they put her back.
