Robert Frykberg, DPM, MPH discusses the risks for partial foot amputations in the diabetic foot, as well as describes the indications and techniques for performing a hallux and transmetatarsal amputation.
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TAPE STARTS – [00:00]
Male Speaker 1: So I'll be giving the first talk and I think it's hopefully a little bit useful for you to discuss some data and just a little bit about techniques, and certainly complications, morbidity, and mortality of minor amputations in the diabetic patient. Many years ago, many podiatrists weren't licensed to do amputations. Now, it's becoming increasingly more common, even in Arizona.
I'm titling this talk, Minor Amputation Principles and Techniques in Brevitis, very briefly. We can get this to go – this is not moving. Rich, can we advance that, stay under the wire, that we need a new battery on this or is this off? Okay. So, all right. Again, Steve? Okay. Good. Okay, thank you. Okay. All right. These are my disclosures. These are learning objectives as published.
I like to start out with this quote by one my favorite old papers, The Menace of Diabetic Gangrene by Elliott Joslin, published in The New England Journal in 1934. Those of you who don't know, Joslin was a leading diabetes physician in the world in his day back in Boston. He was actually in private practice but he was the founder of the Joslin Clinic, and he had a great deal of experience in managing diabetes and he is very insightful. And he practiced in the institution that I first trained in, so obviously, I had a great affinity for Dr. Joslin.
But diabetic gangrene has been increasing as a menace to my patients. I think we can all state, even now, it's increasing as a menace to my patients. Most of what I did at the VA was dealing with gangrene on a daily basis. And with that backdrop, I want to talk about things that might lead to gangrene and how we might handle such patients with the eye on limb preservation, as the modus operandi of all of us in the room here. We discussed this slide earlier today. Again, it's just a review of the multiple interrelationships between the underlying pathophysiology found in the diabetic patient that can indeed lead to infection, foot ulceration, infection, gangrene and then amputation. And so we need to be aware of all these underlying metabolic deficiencies, if you would.
We also talked about this stairway to amputation without high risk foot with neuropathy, with or without peripheral arterial disease at the bottom, sustained some type of an injury, develops a chronic wound, the wound becomes infected and gangrene sets in. And of course, once gangrene develops with full tissue necrosis, amputation at some level is going to be required. And of course, the level of amputation is predicated upon the vascularity, as well as the amount of tissue loss. But of course, as I said this morning, there are many opportunities or several opportunities here for amputation prevention. And that's our job, amputation prevention, even if it's minor amputation prevention or at least minimizing the level to which amputation is required. This is an old study from Sweden, but this is a very good data from [Bjorn Applechris] [04:00].
This is from [Sjogren‐Larsson] [04:02] in clinical orthopedics, 1998. And they found that minor amputations will take three times longer to heal than major amputations, but longevity is far more favorable as we know for patients having minor, rather than major amputations. We could see the two survival curves here. This is the minor amputation curves or people die much later, and you can see how rapidly they die off after a major lower limb amputation. So hence, a good reason for us to practice prevention of major amputations, oftentimes by practicing skilled use of minor amputations.
This paper from 2015 also came from a large cohort of diabetic patients in the UK. Here, we have another cohort of 416,000. This is different than the cohort we had this morning. There are number of deaths within this cohort. But the primary exposure variable in their data was lower extremity amputation and the primary outcome was all-caused death, which was caused from any possible causation. And the all-caused death after lower limb amputation fully adjusted for other risk factors like cardiovascular disease, cerebrovascular disease, peripheral arterial disease, was a hazard ratio of 2.37. So almost two and a half times the risk for death after a lower limb amputation compared to patients who do not have an amputation.
So again, these are stories along the same theme that we had talked about this morning. So we do know that amputations lead to a premature death, just like we talked this morning about the inherent risk for premature mortality, even in patients just with a diabetic foot ulcer.
So, Hoffstad had said, "Individual diabetes and LEA are more likely to die at any given point in time compared to patients who have diabetes but no LEA." The non-amputated person is always the reference population we're making these comparisons. So more data that supports what we've known for 50 or 60, or 70 years that people with lower limb amputations and diabetes die sooner than their counterparts who don't suffer those amputations.
This paper from [Ven Batten] [6:29] comes from a well-publicized European study called EURADIA, where the studied in 14 centers around Europe, over 1,200 patients with a new diabetic foot ulcer. And there were number of reports about the level of the ischemia, the number of infections, et cetera, in this overall study. And they followed the patients up to one year or death. And within this cohort of 1,200, 32 patients or 18% of the patients required minor amputation. Hopefully, we can see the primary risk factors; male, sex, deep ulcer, infection, and peripheral arterial disease as you would expect. But with odds ratio highest, six-fold for deep ulcers.
Now, remember, we also talked about a paper this morning that looked at ulcer, early onset, osteomyelitis and gangrene. Well, this would be equivalent to gangrene, deep ulcers, six-fold increase risk for minor amputation. Again, things that we would anticipate but here are some data to support it from our prospective study although this study is in Europe.
Another European study that comes from Sweden is 410 consecutive patients undergoing minor amputations in a Swedish population. The Swedish population is good to study because they don't lose anybody. Those are very stable populations for the most part.
And you could see the median age here is somewhat order than our population, be 73 years. But the value here is this population was studied for 25 consecutive years. Now, any 4% of the patients undergoing the minor amps had deep infection or gangrene, 61% with PAD or critical limb ischemia, and 19% of their patients died before healing. But notably, almost 80% of the surviving patients healed at or below the ankle level, but at a median healing time of 26 weeks, about six months. So this corroborates what Larsson had said about his earlier population, where minor amputations can take a lot longer to heal, but the patients do much better.
And in this regard, 21% of the patients required a re-amputation above the ankle, so about 21% of the minor amps failed, requiring higher level amputations. And they could not find any predictive parameter that excluded healing at the below ankle level. Many studies looked, investigated for important risk factors that will predict non-healing. But many times, these are highly variable, depending upon the patient population, and they could not find any in this study.
This study by Osman out of Turkey, we see a number of papers coming out of Turkey. This is also 2011, 126 minor amputation patients, again, with the mean age of 70 years old. Now, they had an overall five-year mortality of 27%, which was far different and far lower than we saw from some data even on ulcer five-year mortalities, which were up to 71% as you recall this morning. Fifty-eight percent of the deaths were the first year, but very interesting in this population. It was greater death rate in patients who are not diabetic compared to those who were diabetic. Very interesting population. So you can see the survival curve here in red, the non-diabetic patients. They died off much faster than the diabetic patients. Maybe they were older as well, so more variability.
What are the indications for our diabetic lower extremity amputation? This could be any level, whether it'd be a toe, a foot, a ray or what have you. Fulminant infection or chronic osteomyelitis, very commonly, gangrene or chronic ulceration, often with extensive tissue loss, non-reconstructible ischemia, and sever deformity or instability. Believe it or not, I've done a number of ankle disarticulation amputations for severe, unstable Charcot at the ankle. It was chronically ulcerated and those patients could do quite well. So again, your indications are very much determined by the needs of your patients, but it could be anyone or more of these different types of problems.
So what types of further leg-sparing amputations are we talking about? Well, the most common now is just going to be lesser toe, hallux first ray and lesser rays. TMA, we'll talk about a little bit more. Very, very common. That's often called the diabetic's operation from many years ago, Chopart, Boyd, Pirogoff and Syme. I have very little experience or none with Boyd or Pirogoff, but a good deal of experience with Syme, Choparts, TMAs and the rest of the operations. But these are all the most common. In this country or abroad, these are all very, very common. I say the least common are probably these three and certainly the Syme amputations is very few centers that have any great experience for the Syme amputation.
So we'll talk about this one. Richie, can we get that movie going on this one. I don't know why. Maybe you have to click it or something, Steve. There you go. It should work. I was hoping it would work. Anyway, the most common operation or amputation is going to be your lesser toe amputations of course. Of course, they're going to be either interphalangeal or a joint disc articulation, depending on the level of necrosis. I'm sorry. I don't know why this doesn't work. It worked on my computer and it should work back there. Try it again. Because we have a number of movies on this one. Okay. Well, I guess it's not going to work.
Indications again are going to be the same. Gangrene of the toe but not involving the MTP joint. Osteomyelitis, very common, recalcitrant ulcer and the presence of ischemia. The easiest amputation and my preferred amputation of the lesser toe is really at the MTP joint, leaving a medial and a lateral flap so that you can affect the primary closure, provided there's no puss at that level and that's even more for more distal gangrene or osteomyelitis. Because I don't think people do that well with amputations leaving part of the toe. I just haven't had the best luck because the flexor still functions and then people can get ulcerations on the tip of the remaining toe.
So I prefer going through a disarticulation whenever possible. It's not always possible. Real frankly, not always necessary but more of than not, I think. I think that makes more sense than not. But again, these are by far the most common amputations. These are easier to do than a hammer toe arthrodesis. Of course, it's very, very simple. You just have to have good tissue handling techniques.
Always look for primary closure whenever it's feasible, whenever it's possible, because you don't like it being an open wound that can get infected right on cartilage. Because we're leaving cartilage on the head of the metatarsal in this regard, it appears. There's been a lot of controversy over that over the years, but I really didn't find it to be of any practical significance as long as there was no obvious infection when you do your disarticulation.
I guess it's going a little slow there. The computers are slow back here, so I'm sorry about this. No videos necessary, guys, back there. So the next most common is going to be hallux amputations. Hallux amputations, a lot of people like to do interphalangeal. I also will prefer just doing a joint disarticulation because it's easier. And again, many times, those of you who have done a partial hallux amputation, you'll leave the flexor brevis intact and that will still keep plantar flexing, that stamp of the big toe. Only allowing you later on to go back and then have to do a complete resection of that. So I prefer whenever possible, as tissue allowed, to do a disarticulation at the MTP joint. Usually again, with medial or lateral flaps, or a dorsal, or plantar flaps so that can affect the primary closure. Of course, in the absence of any acute infection.
So the indications are going to be gangrene of the hallux, not involving the MTP joint. If gangrene involved the MTP joint, then you'd be relegated to doing a more proximal ray amputation. Osteomyelitis are very common reason. We have osteomyelitis such as in the case like this at the IP joint, an easy way to get around this, especially in a patient with modest degrees of ischemia would be an amputation. That would be this case for recalcitrant ulcer in the presence of ischemia. Very often, we would do that because we didn't want to allow a patient who's been revascularized, who's got residual levels of modest ischemia to go on with an open wound that can easily get infected afterwards.
So I'm sorry, the movie is just not working for some reason.
Male Speaker 1: Yeah?
Male Speaker 1: It's a good point, but I haven't found any good way to do that other than protective footwear. Remember, all these amputations, you have to follow them with protective footwear. But I'm not doing prophylactic [TMAs] [16:43]. I'm not doing prophylactic TALs, unless there's a good reason to do it.
The TMA is, well, as I said earlier, it has been called the diabetic's operation because the same hospital that Elliott P. Joslin practiced at, the New England Deaconess Hospital, is where these authors came from, and the McKittrick brothers who were Jocelyn's surgeons. Joslin was actually the first person ever to have a diabetic foot team and that team back in the '20s and early '30s, consisted of himself and another medical doctor, Howard Root, and his surgeon, the McKittrick brothers. His own foot team, nurses and his own podiatrist. So as I said in the [indecipherable] [17:31], there's nothing new under the sun. All of our focus nowadays on multidisciplinary teams are not new. They're just following up with Joslin 10 years ago.
So the McKittrick brothers, Leland and John were his surgeons. And up until recently, they had the largest series of TMAs in the literature published, 215 TMA patients. Remember, this was publish a 1949, and in those days, there was no such things as revascularization. So they would be very liberal in their application of TMA to their patients.
An ischemic, ulcerated great toe, with a level of ischemia or dependent rubor going up to the midfoot would be a TMA, because they couldn't revascularize these people. So they did probably more TMAs than we would do now because of that fact. But they got very, very adept at doing the classic transmetatarsal amputation. These are really pictures from the original 1949 paper. And I'm always trained to do TMAs there the classic way, and I still prefer to do those with a long plantar flap, we'll see some images later. But a long plantar flap and your closure on the top.
But they had long-term results about two years, 67% success. This mirrors any success from papers that you see nowadays and that means complete healing, and no limitation of activities. But they did have their failures of course, where 17% went onto proximal amputation or early death. They deemed the functional results excellent in the healed patients. They didn't require special footwear. Although, the shoes that they gave them were protective and they used a cotton roll or lambs roll in the front part of the foot as more or less a prosthesis. And remember, the success that was found at the Deaconess Hospital with McKittrick's is because they had a podiatry service and active in-patient podiatry service at Joslin's hospital that would constantly follow these people looking for prevention.
Believe it or not, many years ago, TMA was not considered to be a successful operation because people are doing it and just letting their patients go. And they weren't following them carefully like they did at the original hospital, and that was a difference between much of the failures and success.
So these are the original images from that study and it's really a remarkable paper to read. So there have been other modern studies. This is not a talk just on TMAs but I think it serves as well to review this literature. Healing rates still today are between 50% and 74%, maybe higher, maybe a little lower, depending on the series and the size of the series. Postoperative complications are high. Meaning, infections, wound healing, failures or disruption, postoperative infections as you can see on the images here. And revisions and reoperations as we'll see from other data are very, very common and you have to be prepared. If you're going to do the TMA, you must be prepared to do the revisions. And there's up to a 30% major amputation rate when these people fail, especially if they have preexisting ischemia.
From the literature, predictors for non-healing, which is really what we want to look at here, end-stage renal disease, peripheral arterial disease, A1Cs of greater than 10%. One paper was even as low as 8%. And of course, leukocytosis at the time of surgery, meaning, about 12,000 or above at the time of surgery. So if you're going to engage in the transmetatarsal amputations, you must be ready for the complications. But usually, the complications can be dealt with, with good wound care and judicious surgical technique.
Now, I wanted to put this paper and this is just a new publication this year, and it comes from the Kaiser system in Northern California. Pollard had done a paper about a decade ago on 99 or 100 patients. And they followed this up with a retrospective chart review of the TMAs done in their institution in Northern California Kaiser Center. And they looked at three-year mortality, proximal limb amputations, and lack of healing or wound healing failures. And you can see things like this would be a lack of healing, but these are the typical complications that you can easily get to heal if you just serve very careful and judicious with your wound care.
So the results that they had published in this largest series published yet to date, where the 36% of patients died within three years, 36% also required a more proximal limb amputation, which is pretty similar to what the McKittrick brothers had reported, although it's a little bit higher, and 22% of the patients healed without complications. Now, that's not overall healing rate. That's healing without complication. Many of these patients have a complication like you can see here, but you can get them to eventually heal, it just takes a long time.
So what are the predictors for non-healing and death? Primarily, with non-palpable pedal pulses as you might expect very, very important predictor for proximal limb amputation by about three-fold compared to those patients who did have palpable pulses. Failed healing after TMA, about two-and-a-half-fold compared to patients who did have palpable pulses. And also death within three years, almost two-fold the risk if patient did not have palpable pulses at the time of the TMA.
And another risk for mortality during three years of the end-stage renal disease where it was a three-fold risk. So other papers had pretty much shown these. These are just rather new data that supports everything that we had seen. And you can see numbers sometimes are different from one paper to another. But the more numbers that we have in the more modern population, the more reliable they are. So about 22% of the patients can heal without complications. But 60% somewhat patients would heal at that level, which is actually pretty good. So I think this is an important paper to keep in mind too as you're reviewing literature on TMAs.
Again, unfortunately, all my videos I spent so much time putting together are not working. Now, this seemed to be working better. These are my cases from the operating room for the most part, showing different types, different stages of the operation, different indications for TMA. Many times, you have that plantar ulcer and necrosis on the bottom of the foot that you have to actually wedge out when you're doing your plantar flap. And on the top left, you could see where we are doing that. But remember, our incision is transverse across the forefoot, the midfoot, and a long plantar flap that is raised up and sutured on the top. We do not do fish mouth TMAs. I do not like seeing fish mouth TMAs. This is not a fish mouth incision.
Over here, I think you can see – down here, you can see I like to use a Gigli saw. In Italy, we call it Agili saw, because very quick, it's fast and it cuts right across the metatarsals without having to individually go and cut through each one with a saw. And of course, we do this for severe foot ischemia, for foot sepsis, osteomyelitis, multiple gangrenous toes. Many times in the face of prior partial foot amputations of the forefoot, primary closure of a difficult wound after like a necrotizing soft tissue infection.
Healing rates again, between 50% and 74%, pretty much fits in with the latest study from Adams, and postoperative complications is high as 87%. As I said, if you're going to do this operation, just be prepared for the complications that will invariably occur. They're not always major complications but you need to be prepared for them and think about them even while you're doing the operation, think about what you're going to do the next step if they'd become a problem.
One paper by Sheyan had stated years ago, if you need revascularization, it's always better to have the revascularization first before you do the definitive TMA. Then afterwards – obviously, that's in the absence of acute infection. These come from Lee Sanders paper, showing the various types of incision. This wasn't a paper. This is actually a surgery chapter in I think [Jerifo's] [26:29] Textbook of Surgery. With the plantar flap, the curve plantar flap, the transverse incision on the top, and then just taking that flap and meeting it up on the top. This is where you have to take out that wedge because of necrosis or chronic ulcer on the bottom, and you just take that T-shaped flap and just close it over and suture it together. Actually, I like this because it works out very well because there's no redundant skin. Many times, there's scalloped edges and redundant skin on the TMA otherwise.
So in summary, minor amputations are critical components of care for the acute or chronic diabetic foot, infection, gangrene and osteomyelitis, with or without ischemia, are the most frequent indications. Frequently, they're staged procedures to control for infection. And as we've said, they often need revision and you have to be prepared for this. Expect the need for revision and just yield it as it comes up, but don't neglect the hesitancies and the problems, and treat them aggressively and early.
And then the level of minor amputation is determined by your vascular status and the tissue status. The amount of tissue lost from let's say a prior I&D or soft tissues necrotic infection. And improved survival and ambulatory status exist compared to major amputation, despite the longer healing times. Remember, these patients will take longer to heal, but it's worth the effort because you'll spare them their limb. And as we've said, major amputations are going to have a far earlier mortality rate than will the minor amputations and we saw that going way back to the Larsson paper that I showed you before.
So in summary, getting back to Joslin's paper, it has been forced upon me that gangrene is no heaven-sent but it's earthborn. Gangrene, Joslin understood very well that there were reasons for it, vascular disease, infection, neglect and poor glucose control. And so, he made a serious point about cleanliness, early intervention, multidisciplinary teams working to save the limbs on these patients. So with that, thank you very much.
Male Speaker 2: Okay.
TAPE ENDS - [28:53]