FAI September 2024 Podcast: Painful Nonunion in Patients With Clinically Plantigrade Diabetes-Associated Charcot Foot Arthropathy

Summary

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Episode Overview

Podcast: Foot & Ankle International
Episode: Painful Nonunion in Patients With Clinically Plantigrade Diabetes-Associated Charcot Foot Arthropathy
Release Date: September 17, 2024
Host: Dr. Charlie Saltzman
Guest: Dr. Michael Pinzur, Professor of Orthopedic Surgery, Loyola University Health System

Main Theme:
This episode provides a deep dive into Dr. Pinzur’s highly impactful study on the occurrence and management of painful nonunion in clinically plantigrade patients with diabetes-associated Charcot foot arthropathy. Dr. Pinzur shares both the scientific basis and practical pearls from his decades of pioneering work, challenging traditional beliefs and emphasizing an evidence-driven, patient-centered approach to surgical care in this vulnerable population.

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Key Discussion Points & Insights

1. Redefining Painful Charcot Nonunions

• Pain as a Key Symptom: Classical teaching suggests pain is absent in Charcot foot due to neuropathy. Dr. Pinzur’s series found a subset of patients who, despite appearing healed and plantigrade on radiographs, reported significant pain, which corresponded to unhealed, nonunited fractures.
  • “When you have somebody that appears to be well controlled but they're complaining of pain, you need to be a little more vigilant...their pain is from the non union and then it's a relatively simple thing to solve.” (Dr. Pinzur, [02:28])
• Clinical Implication: Surgeons must not dismiss pain in diabetic neuropathic foot; it deserves further investigation, often with CT scanning.

2. Study Design: Patient Selection & Historical Context

• Inclusion Criteria: Patients were plantigrade, both clinically and radiographically, and had been managed conservatively but continued to experience life-altering pain.
• Exclusion Criteria: No surgery if pain was mild or absent, or if function was acceptable with accommodation footwear.
• Historical Reflection: Earlier studies that formed the bedrock of Charcot knowledge (e.g., Eichenholtz) were based on small, limited samples.
  • “All of our thinking is based on this. 50 patients...A lot of the things that we were taught turned out to be wrong. We have to look at this population differently.” (Dr. Pinzur, [07:54])

3. Revisiting Classic Theories of Charcot Foot Pathogenesis

• Dr. Pinzur posits the neurovascular and neurotraumatic theories are not mutually exclusive, but both contribute to disease:
  • Diabetic patients with neuropathy are likely to have systemic osteopenia and fragility fractures that may fail to heal, particularly in higher BMI patients who load their feet more.
  • “We've asked for years, do we believe in the neurotraumatic or the neurovascular theories of Charcot foot?...I think both theories are correct.” (Dr. Pinzur, [05:15])

4. Preoperative Medical Optimization

• Four "Hard Stops" for Elective Surgery:
  • Hemoglobin A1C < 8.0
  • Control of hypertension
  • Adequate hemoglobin (no anemia)
  • Cardiac optimization
• Patient Safety Emphasis:
  • Always aim for patients to be in best possible health pre-op.
  • Prefer regional anesthesia to reduce complications and costs.
  • “We care for these patients at half the projected cost...it's because we don't have medical complications...” (Dr. Pinzur, [10:48])

5. Surgical Techniques & Pearls

• Circular External Fixation Preference:
  • Allows minimally invasive approaches and preservation of motion segments.
  • Enables controlled compression and enhances primary bone healing.
  • “We can use the modern approach of MIS surgery...my incision might be a centimeter...the reason I like to use frames...I lose no more motion segments.” (Dr. Pinzur, [13:04])
• Bone Grafting:
  • Rarely uses bone grafts/biologics unless autologous; data does not show marked added benefit.
• Technical Tips:
  • Closed rings always (never two-thirds).
  • Olive wires in heel and forefoot at 30° angles; tensioned for compression.
  • Tension always to 120 mm (never with squeeze tensioner due to inadequate force).
  • “Always use closed rings. Never ever use a two thirds or an open ring...” (Dr. Pinzur, [23:20])
• Post-Op Management:
  • Patients seen at 3 and 12 weeks.
  • Non-weight bearing except as needed for transfers, with creative use of modified cast shoes and elastic bands to avoid shearing pin wires.
  • Showering allowed after 72 hours.
  • Pin tract infections managed with oral antibiotics and local care; usually resolve after frame removal.
  • “We published...283 consecutive circular frames on diabetics where 20%...get pin tract infections...not one...had persistent infection after the pins were removed at 12 weeks.” (Dr. Pinzur, [18:12])

6. Defining Success & Outcome Measures

• True Goal:
  • Patients should be able to walk in the community using a standard diabetic shoe; use of AFOs or CROW boots equals a poor outcome.
  • “A good result is somebody who can wear a commercially available shoe in a custom orthosis. If they need even a short ankle foot orthosis, they're called a fair result and a crow boot...That's a failure.” (Dr. Pinzur, [21:35])
• Pain as a “Red Flag”:
  • Due to neuropathy, pain should not be present; if it is, a thorough workup for nonunion and other causes is necessary, not dismissal.

7. Major Clinical Implications

• Take Patient Complaints Seriously:
  • Pain in diabetic Charcot patients is never “just in their head”—seek the organic cause.
  • Avoid amputation whenever possible; these patients do poorly with prosthetics due to fluctuating limb volume from systemic disease.
  • “Avoiding amputation allows these people to walk...If you fail, if these people end up as a BK, they're in a chair the rest of their life.” (Dr. Pinzur, [24:32])

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Notable Quotes & Memorable Moments

• On Challenging Old Dogma:
  • "A lot of the things that we were taught turned out to be wrong. We have to look at this population differently." (Dr. Pinzur, [07:54])
• On Defining “Success”:
  • "If they need even a short ankle foot orthosis, they're called a fair result and a crow boot...That's a failure." (Dr. Pinzur, [21:35])
• On Painful Nonunion:
  • “When you have somebody that appears to be well controlled but they're complaining of pain, you need to be a little more vigilant...their pain is from the non union and then it's a relatively simple thing to solve.” (Dr. Pinzur, [02:28])
• On Patient Gratitude:
  • “These people are so grateful when you take care of them...Avoiding amputation allows these people to walk...If you fail...they're in a chair the rest of their life.” (Dr. Pinzur, [24:32])
• On Medical Optimization:
  • "By starting up front, getting these people as good as they can be, minimize the risk when you do the surgery, and then we have a better chance of taking care of them without complications." (Dr. Pinzur, [11:24])

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Important Timestamps

• 00:00–01:30: Introduction to study and Dr. Pinzur’s background
• 01:30–03:15: Summary of main findings—painful nonunion is overlooked in plantigrade Charcot foot
• 03:15–07:14: Detailed criteria for patient inclusion/exclusion and pathophysiology theories
• 09:08–11:48: Preoperative optimization, patient safety, anesthesia choices
• 11:48–17:46: Technical surgical discussion—frames, bone grafts, intra-op tricks, post-op care
• 19:04–20:45: Weight bearing, patient compliance, management of hardware
• 20:45–22:47: Defining clinical success, the critical importance of pain
• 23:20–24:22: Wire tensioning strategy and ring selection
• 24:32–25:37: Final pearls—never block diabetic patients, amputation as failure

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Conclusion

Dr. Pinzur’s conversation with Dr. Saltzman offers both a challenge to outdated paradigms and a highly practical roadmap for foot & ankle surgeons dealing with diabetic Charcot arthropathy. Recognizing and managing painful nonunion in these patients prevents misdiagnosis, avoids unnecessary amputations, and improves their quality of life. Dr. Pinzur emphasizes rigorous preoperative optimization, evidence-based surgical approaches, and truly patient-centered outcome measures—defining not radiographic, but functional and community-based success.

Transcript

[A]

Foreign this is Charlie Saltzman, editor of Foot and Ankle International. Today I have the distinct honor of talking with Dr. Michael Pinzer, who is the senior author of September's lead paper in Foot and Ankle International entitled Painful Non Union in Patients with Clinically Planet Grade Diabetes Associated Charcoal Foot Arthropathy. I think this will become a highly impactful study fitting the long history of impactful studies that Dr. Pinser has done over the past four decades that has helped all of us become better surgeons and has benefited in an incalculable number of patients, particularly with foot and ankle complications of diabetes mellitus. Dr. Michael Pinser is the professor of Orthopedic surgeon at Loyola University Health System in Maywood, Illinois. And particularly important to me and all of us at Foot and Ankle International and Foot and Ankle Orthopedics, he's been a specialty content editor and has served in many editorial capacities on our editorial board for more than the past 25 years. So I really welcome you to the program. Michael, it's about time we had you on this. I would like to start by asking you to give a brief summary of your paper and its major findings.

[B]

Well, the most important issue related to this paper is pain has not been a feature of patients with charcoal foot. And yet through the years I've had a certain number of patients that have deformity have pain and the pain behaved a lot like patients with a nonunion. And when we have somebody with deformity that I was going to operate on anyway, I don't think it added much. But I did go back and I found these 14 patients that presented with what appeared to be a plantar grade foot. X rays demonstrated that they were healed and yet they had pain. When I operated on the early patients, I found that they in fact had a non union at the site of the original charcoal foot. As I followed this group with time, I started to do CT scans and it was clear that these people had nonunion. So then I started noticing when I was operating on people with deformity, deformity infection, but if they had pain, they always had non union. So I think the message is when you have somebody that appears to be well controlled but they're complaining of pain, you need to be a little more vigilant and that's a good place to get a CT scan to see if they're not healed, their pain is from the non union and and then it's a relatively simple thing to solve.

[A]

Can you explain in detail what patients were included and what patients were excluded.

[B]

Well, what I did here is these patients that were included were patients that normally we wouldn't do surgery on. They were clinically and radiographically planet grade. They had X rays that demonstrated that they were healed. We put them in standard diabetic shoes, inlay depth shoes with custom accommodated foot orthoses and they still had pain. And it was when this pain was significant enough that it impacted on their life that I felt that they should have surgery. Now this goes back to a study actually that you and I did back in 2000. We tracked 120 patients with charcoal foot. With the, we used a, we validated an outcomes tool and we tracked these people over a four year period. And we found at the end of four years the quality of life of a patient with a charcoal foot was about equivalent to somebody with a below knee amputation. So we go forwards now and these people had significant pain. It was altering their life. And I said, okay, I'll operate on them. And when I did the surgery I found out that they had a non union. And that got me to expand my thinking to say, wait, if people with deformity also complain of non union, then very likely, or if they have pain, they very likely have non union. So and it goes back to my theory of a modern theory. We've asked for years, do we believe in the neurotraumatic or the neurovascular theories of charcoal foot? We've had these for years. And all the evidence that we have is downstream evidence, it's laboratory material, it's cytokines that are collected after the fact. And in fact, I think both theories are correct. I think actually what happens is these people, if you have peripheral neuropathy, we have always said this is a risk factor. It's not a risk factor. It is a measure of disease. Because to have neuropathy, you've been diabetic for 10 years. If you've been diabetic for 10 years, you have basement membrane disease in every vessel in your body. How it affects us is they have renal disease and it's calcium losing. So these people are very calcium deficient. The bones are very osteopenic. Who do we operate on? The average BMI of the people that I operate on is 39.6. So they're big people that load the foot and small people load the foot. It heals. And you know, that's another study that we published in Foot and Ankle a number of years ago. We said a lot of most of the charcoal feet get misdiagnosed as cellulitis tenosynovitis, gout. They get immobilized and they get better and they're only diagnosed later on. It's the big people that load the foot and the foot deforms. So I think this is a fragility fracture or a stress fracture. It deforms and then it doesn't heal. And if it doesn't heal, they have pain. If it heals, they may have deformity, they may ulcerate, they may have infection, but they don't have pain.

[A]

In the paper you note the patients included some that did not have swelling. And I've always thought that the resolution of swelling corresponds with bone healing.

[B]

That's what I thought too. You have to remember, if we go back and look at Eichenholtz's book, I've got a copy of his monograph. Eichenholtz was a pathologist over a 40 year career. He collected data, X rays and specimen and a total of about 50 patients. All of our thinking is based on this. 50 patients. Our thinking of the crow boot that we use and we say this is a wonderful boot, a wonderful device. It's based the evidence to support using a crow boot is a non case controlled retrospective case series of 18 patients. So a lot of the things that we were taught turned out to be wrong. We have to look at this population differently. Charcoal foot is actually very common. There's a good study from Scandinavia that says the incidence is 0.3 per thousand per year. That's common. Yet very few people deform enough that we need to do surgery. So I think your question is very good. I think a lot of the thoughts that we've had were based on 1950s thinking. Go back and look at papers in the Journal of Bone and joint surgery in 1950 and 1960. They're comical. They're so colloquial, they're just anecdotal. We're in an era of evidence and I think we need to use evidence to look at these people.

[A]

So now, when you operate on them for elective reconstructive surgeries, tell us about how you prepare for that, how you prepare the patient for that, and whether you have a cutoff for the hemoglobin A1C before you would do an elective reconstructive surgery.

[B]

Well, one of my special interests has been patient safety and the patient safety movement. I had the honor of representing the Foot Society at the first joint Commission summit on wrong site surgery. And I've been involved in the patient safety movement ever since Keely Boyle at Rochester and I wrote the Academy's preparation for Surgery that's on the Academy's website. And the idea is we want to medically optimize people. So if somebody has infection, if they're sick, then we can't wait. But if we're doing elective surgery, even if they're infected, they've been infected for months. By the time they get to us, we should make sure their cardiac. So we have four hard stops. There are four hard stops, one hemoglobin, A1C of 8. If someone's A1C is over 8, we try to delay surgery until we can get that improved. We look at hypertension, we look at hemoglobin levels. If they're anemic, they don't do well with surgery. They're better off getting optimized. So we look at our hard stops and our soft stops. We want to make sure that their cardiac status is as good as possible. And so we want them as healthy as they can be. We do the surgery virtually 100% of the time with regional anesthesia. So sciatic saffenous nerve blocks, no general anesthesia. By doing that, we've actually looked at this and we care for these patients at half the projected cost of the University Healthcare Consortium. Now, it's not because I'm a genius as a surgeon, it's because we don't have medical complications that bring people back to the hospital and cost more money. So by starting up front, getting these people as good as they can be, minimize the risk when you do the surgery, and then we have a better chance of taking care of them without complications.

[A]

I would say that's really important. And for me and for many, not highly organized and sometimes neglected, the pre surgery workup, the pre surgery optimization, the pre surgery discussions with the patient family can all get better. And having a system, having a group of people interested in this will make it much more likely. We will have results that we can live with and are proud of. And I appreciate your bringing that to us. I want to get into now some of the sort of technical details because most of the listeners are surgeons. So tell us a little bit about whether you use bone graft for these nonunion sites. You use frames, why do you use frames? How often do you see the patient's back? How do you any tricks for the frame application? Do you try to compress the area? So let's get into that a little bit because I think that's what our readers and our listeners will be able to take away from this in addition to your cautionary approach to doing elective surgery on these patients.

[B]

So one of the nice things we can do, One of the reasons that I'm a huge proponent of using circular external fixation is we can use the modern approach of mis surgery. So in these patients where there's no deformity and there's a simple non union, my incision might be a centimeter, and then we use a resurfacing tool and under fluoro we resurface. We just do prepare the joint. That's all we do. I was one of the investigators in the PDGF trial. And remember the PDGF trial was a non inferiority trial. Nobody has ever demonstrated that putting stuff in really makes a big impact. So especially putting dead stuff. So I call demineralized bone matrix. I call dead bone matrix. It's dead. If you want to use autologous bone, that's alive. But we haven't used ontologist bone. I haven't used any ceramics. Our union rate, even in the presence of, you know, half the people are infected that I operate on, union rate is over 90% over the last 10 years. So what do we do? We, the smaller the deformity, smaller the incision, we can use mis tools. If the incision, if the deformity is bigger, I make a bigger incision. I use the narrow total ankle replacement saw blade and take a wedge out in two planes. Because most of the people that you're going to operate on are going to be valgus, they're going to be plano valgus. So the wedge is going to be bigger medial and bigger planter. If it's a varus deformity, I'll make a second incision and I'll operate from both sides. The idea is to take a wedge out and then once you correct the deformity, just like when we do fracture surgery, we get provisional fixation with some big smooth stymon pins. The reason then that I like to use circular fixation is I do no stripping. Then I put the frame on. And one of the tricks that I learned is the first step is to put the two olive wires in the heel 30 degrees to each other, parallel with the weight bearing surface of the heel. Then I put two olive wires in the forefoot 30 degrees to each other, parallel with the weight bearing surface. But I make the first one of those wires an arch wire, meaning I attach them to the frame one whole posterior to where they want to be. When you tension it, it then compresses compression. What does compression do? Compression leads to rigid internal fixation which leads to primary bone healing. That's the reason I like to use frames. I can do MIS technology, I can back in the compression and I lose no more motion segments. If you're going to use bolts or plates or any internal fixation devices, you're going to sacrifice motion segments. And with this I don't sacrifice any motion segments. You said, how do I follow them? So after the surgery, most if the people are not infected, some people go home the same day, most stay overnight, some. So I make sure they're safe with pain control and with ambulation. So most of the people go home within a day or so. If they have infection, they stay till we get the right bug and we get infectious disease to start them on perineal antibiotics. I see them at about three weeks post op where I take the sutures out. We fit them with a protective shoe and if all goes well, I don't see them until the 12 weeks when the frame comes off. The difference between this and gradual correction, when you do gradual correction, you have to see people once a week because the bolts get loose. With a static frame like this, nothing gets loose. So patients, if there's a problem, they let me know. And, and we take care of it. But most of the people get seen at three weeks and then don't get seen again until 12 weeks.

[A]

And you give them antibiotics to take home or to take or not oral antibiotics.

[B]

If they have osteomyelitis, they get treated with parenteral antibiotics per infectious disease. If they're not, if there's no sign of infection, we treat them. No antibiotics if they get a pin tract infection. And then that's another paper that we published in Foot and Ankle International. None of this is opinion. All of this is some level of evidence. We published the series of 283 consecutive circular frames on diabetics where 20% of the people get pin tract infections. We manage the pin tract infection with oral cephalexin keflex. They take that. We may relieve the pin if the skin is tight and they take the keflex until the frame comes off. And not one of those people had persistent infection after the pins were removed at 12 weeks, do you let them shower? Yes, I let Everybody shower at 72 hours.

[A]

You let them put any weight on it?

[B]

I tell them I would like them to be non weight bearing in the meantime. In one of the papers we, we showed the shoe, we take a cast shoe and let me back up. The FDA has not approved circular frames for weight bearing. So Everybody has the rails that they put on the frame to protect the foot. The problem with the rails is patients step on it and they can't deliver the pins. They put some weight and it's like bending a coat hanger. If you bend those wires enough time, they break. So what I do instead is we take a cast shoe, we cut the canvas off and we attach s hooks and rubber bands to the frame. And if they're going to put weight on it, I'd rather put weight on the foot and not put weight on the wires. I tell them I really only want them weight bearing for transfers to get from bed to chair. That said, I have a number of patients who come into clinic with a cane and, and they show me that they're being non weight bearing.

[A]

Classic. That's great. Very, very helpful to all of us who are taking care of these patients. Your knowledge and experience dwarfs probably almost anyone I know. So thank you for those pearls. What do you see as the major clinical implications of this work and how will this current study affect your practice?

[B]

Well, a couple of things. Number one, when patients with charcoal foot or when a diabetic complains of pain, take it seriously because pain, remember part of the disease process is the peripheral neuropathy. So the peripheral nerves don't work. So they're neuropathic, they shouldn't have pain. So when they have, if they're complaining of pain, they're not crazy, they're not malingering. There's something that you have to look for and whether you do an. Mr. Whether you do a CT, do something to look for it and find what's causing the pain. So pain is very important in this patient population. We know that they have to be planigrade in order to get them. The key, the goal in these people is to make them plan a grade so they can walk in the community with a shoe if they need an AFO or a crow. Based on our study back in 2003, it demonstrated that those people are no better than a below knee amputee. So the goal, the goal is in. Back in 2000, our goal was resolution of infection and getting the people walking. Well, that's not enough. They have to be able to walk in the community with a commercially available diabetic shoe. If they can do that, they're successful. So all of my studies, if you look at everything we've published, a good result is somebody who can wear a commercially available shoe in a custom orthosis. If they need even a short ankle foot orthosis, they're called a fair result and a crow boot. Even if we resolved infection, the foot's planet grade. They're walking but they need either an AFO or a crow boot. That's a failure. So I don't look at X ray results, I look at clinical results.

[A]

I want to get back to this wire that you put in. Then I'm going to add ask to you to conclude. But you put a wire in the forefoot that you bend and pull back. It's under tension. When we have any bone healing morphology, we have several events that happen, including removal of dead tissue, gap formation. Do you think these wires continue to compress and after you have put them on.

[B]

Probably not. Okay. But you know, I Also Elizarov says 120 millimeters in the leg, 90 millimeters in the foot. I always, always use closed rings. Never ever use a two thirds or an open ring. When you use an open ring, the rings work and you don't get loading the way you want. So always closed rings. And I always use 120 millimeters in the foot. Even so I never use the squeeze tensioner. I always use the twist tensioner because I know I can get 120 with that squeeze tensioners will only get about 90.

[A]

And by millimeters you're talking about millimeters of mercury or some measure of force of pressure.

[B]

Yeah, it's, you know the whatever it says on the tensioner. That's 120 millimeters of compression.

[A]

Okay, fair enough. Yeah. So you always go up to 120. That's another nice pearl. Anything you'd like to else you'd like to add for our audience?

[B]

Well, I'd like to add don't block diabetics from coming to your office. My partner Adam Schiff, who is trained at Duke, he does all of our total ankles. Now he does a lot of arthroscopy. He says his happiest patients are the charcoal patients that he does. These people are so grateful when you take care of them because you can't do a below knee amputation on these people. When somebody is £350 and they have renal disease, their volume fluctuates. They can never be fit as a BK because the limb is never at the right volume. So if you do an amputation on these people, it has to be a knee disarticulation and you have to fit them with a volume adaptable socket at that level. So avoiding amputation allows these people to walk. It allows them to be part of the community. If you fail, if these people end up as a bk, they're in a chair the rest of their life.

[A]

Well, thank you, Dr. Pinzer. I am Charlie Saltzman, editor of Foot and Ankle International, and today I've had the distinct pleasure and true personal honor of talking with one of our living legends, Michael Pinzer from Loyola University, who is the senior author of this month's lead paper in Foot and Ankle International titled Painful Non Union in Patients With Clinically Planigrade Diabetes Associated Charcoal Foot Arthropathy. Thank you for being on the program, thank you for sharing your wisdom, and thank you for your commitment to this vulnerable and underserved population of patients. You've made this interesting and simplified an approach and have dug deep into a difficult problem and have revealed for all of us a path forward that can help our patients. So I thank you for participating both on the podcast and for your many contributions to our field and these patients around the world.