Should toe amputation be delayed in diabetic patients with osteomyelitis?

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Amputation: Resistance is not futile!

What’s in a toe you may ask? Why worry about saving it? Just amputate and move on …

Dr. Issam Koleilat, assistant professor and associate program director, Vascular Surgery Residency and Fellowship, Division of Vascular Surgery, Albert Einstein College of Medicine/Montefiore Medical Center, New York

Dr. Issam Koleilat

Not so! I implore you to resist the desire. We vascular surgeons are accustomed to cutting off toes, even feet and legs. But when it comes to diabetic feet please reconsider. Just because there is osteomyelitis, I argue that does not necessitate amputation.

We all agree that ischemic gangrene and black mummified digits are beyond salvage. That’s not what my concern is. My focus is nonhealing ulcers with underlying osteomyelitis. Whether ischemic in etiology or neuropathic (or both), give salvage a try.

Why is this so important? My opponent will try to convince you that it’s not. He’ll try to sell you on how well people walk after amputation and that functional outcomes are great. But think beyond that for a second.

Amputation changes the foot architecture and weight distribution. In a person with neuropathy, this only predisposes them to more ulcers. More ulcers will mean more infection, which will lead to more amputations. This finally culminates in a major amputation.

In one reported study,1 researchers followed more than 200,000 diabetics from 2010 until 2013. While the risk of amputation overall was relatively small (0.36% for major and 0.56% for minor amputations), prior minor amputation increased the risk of major amputation 10-fold and increased the risk of another minor (below-ankle) amputation 20-fold. Of those who had a major amputation, 57% died over the 3 years. This is not insignificant.

This does not also consider the morbidity and impact on lifestyle and quality of life for these patients. Many may not walk. Some will be relegated to nursing homes. Some will suffer from phantom limb pain. Many may never return to work. Even more will have difficulty with their daily lives, not to mention the psychological recovery also required.

The foot seems to be the only place where amputation as first-line therapy for osteomyelitis is accepted. We don’t do a hip disarticulation for ischial pressure sores with osteomyelitis. Calvarial osteomyelitis is also treated with antibiotics. I implore you: Don’t treat toes like vestigial organs.

Granted, there are subsets of patients who would benefit from amputations. A patient with painful Charcot foot may elect to have a below-knee amputation and move on with life. Another who has lost jobs or significant time due to recurrence of osteomyelitis may progress. A patient with severe sepsis and infection into a joint may need amputation.

But what other treatment options are there? I’m glad you inquired.

I primarily treat diabetic feet by treating the soft tissue envelope. Even if a patient presents with midfoot infection or necrotizing soft tissue infection, I treat it like a good old-fashioned abscess or necrotizing fasciitis:

1) Drain pus

2) Resect the dead stuff

3) Supportive care (antibiotics, fluids, aggressive wound care, etc.)

I try to leave the bones intact. When bone is exposed I take biopsies for culture and pathology. Any bone destroyed by the infection is focally debrided. I also take a specimen of the “bone margin” that I’m leaving behind and I send this to pathology looking for residual acute osteomyelitis. These steps are important as they dictate duration and choice of antibiotic therapy. This is in keeping with the consensus recommendations published in 2016.2

Even chronic wounds get a similar approach. If there is granulation, let it granulate and see if it will fill the wound. “Just because osteomyelitis is there, it doesn’t mean that for the toe we won’t care!”

There are exceptions of course. If the soft tissue is severely affected so the phalynx protrudes like something from the movie “Coco,” probably that should be amputated. Repeat offenders also may progress to amputation. But otherwise, hold off and give it a chance.

For the inpatient, aggressive irrigation of the wounds using the Veraflo system promotes granulation, even for short hospital stays of 1 week or less. Any ischemic component is worked up and addressed with percutaneous or open revascularization. We treat with prolonged antibiotics, and in questionable cases err on the side of giving long-term courses. These wounds need to be offloaded for tasks of daily living (going to the bathroom, making a sandwich, etc.) but otherwise we instruct patients to be effectively non–weight-bearing on that limb.

We also refer patients for hyperbaric therapy frequently. Now if you’re done groaning, I assure you this is not phony medicine. There is growing evidence to support not only improved rates of healing, but also significant cost savings and improved quality of life.3

In young patients or those with large defects, we also involve plastic and reconstructive surgery for secondary closure approaches (free flaps, adjacent tissue transfers, local autogenous or prosthetic grafting [Integra, Stravix, Dermacell, etc.] or other advanced techniques). This is particularly important in plantar wounds that will need to bear weight in the future, or in young patients for improved functional and cosmetic outcomes. For smaller wounds, we often use dermal/subdermal graft substitutes ourselves.

Even still, in nonambulatory or chronically debilitated and medically high-risk patients, maybe a different option is palliative wound care with or without antibiotics. A nonoperative approach to allow individuals to live the rest of their remaining days without undergoing a morbid and disfiguring amputation is not unreasonable. Many families are thankful for this option when given it. In the absence of refractory pain or overwhelming sepsis, we just let the wound do what it will do, understanding that someday the plan may change. This allows patients to continue to treat the wound without escalation to surgery or resorting to amputation.

In the end, just like we vascular surgeons tailor our “holistic” approach to the needs and desires of a single particular patient, we should approach wounds with a similar attitude. The presence of osteomyelitis in and of itself should not prompt one to bypass an entire algorithm, go straight to amputation, do not pass “Go” or “collect $200” (although the professional fee for a toe amputation is probably around $200). With a multidisciplinary and multimodal approach, and vested patients, salvage is possible in the majority of cases.

References

1. Diabetologia. 2018 Mar;61(3):626-35.

2. Diabet Foot Ankle. 2016 Jul 12. doi: 10.3402/dfa.v7.30079.

3. Int J Technol Assess Health Care. 2008 Spring;24(2):178-83.

Dr. Issam Koleilat is assistant professor and associate program director, Vascular Surgery Residency and Fellowship, Division of Vascular Surgery, Albert Einstein College of Medicine/Montefiore Medical Center, New York. He had no relevant disclosures.

Amputation: Often the best option

For many years there has been debate about the best management strategy for diabetic foot infection including osteomyelitis. The principles of appropriate antibiotics, surgical debridement, good wound care, and proper offloading will always remain. There are no randomized controlled trials of medical vs. surgical management of diabetic foot ulceration with osteomyelitis.

Dr. Mark P. Androes, division chief, vascular surgery, Greenville (S.C.) Health System

Dr. Mark P. Androes

We now have a number of widely accepted ways to define wounds including Wagner and the SVS-adopted WIFI score. Historical papers are somewhat plagued by heterogeneity in the wounds included. This is even more apparent with any attempted meta-analyses. I think everyone would agree that the superficial toe wound with minimal cellulitis is best managed medically. The issue at hand is the profoundly neuropathic diabetic often with underlying anatomic abnormality and osteomyelitis. My esteemed colleague would suggest that we are too quick to pull a trigger and amputate a toe with underlying osteomyelitis.

I think the initial item for debate is the technique of diagnosis of osteomyelitis. We have multiple ways this is reported. Plain x-ray, bone scan, MRI, and “clinical osteomyelitis” are among the alternative ways osteomyelitis is diagnosed. The reliability of the last is the most variable because clinical osteomyelitis ranges from “probes close to bone” to exposed bone visible protruding from the wound bed. Given the variability of diagnostic techniques, the literature is an amalgam of clinical scenarios and difficult to navigate in a way to affect treatment decisions.

In addition, the medical treatment for osteomyelitis is highly variable. This commonly involves tunneled catheter insertion and 6 weeks to 3 months of IV antibiotics. In some institutions antibiotics are tailored to “wound culture.” Several of our infectious disease specialists prefer bone culture and pathology of bone demonstrating an acute destructive process. Obviously, this often requires surgical debridement to obtain a specimen. Antibiotic duration recommendations may vary from 1 week (if all infected bone is resected) to 90 days if a standalone antibiotic management is selected. Chronic osteomyelitis has a reinfection rate of up to 30%.1

Medical management is not without risk. These risks include recurring infection with resistant organisms, wound deterioration, gastrointestinal complications (Clostridium difficile), catheter-related complications, and acute kidney injury. A recent paper found over 30% of patients treated medically for osteomyelitis developed acute kidney injury. These patients had more frequent hospitalization, recurring ulceration, and infection.2 We have all experienced the patient with multiple hospitalizations and episodic AKI that culminates in ESRD requiring hemodialysis.

If the argument is with good follow-up these patients will ultimately experience preservation of the toe, I would take the stance that in our patient population of diabetics presenting with foot ulcer and osteomyelitis the average hemoglobin A1c is over 9. Although this is not only related to patient compliance, in many instances this is a large piece of the puzzle. It is hard to infer that suddenly with biopsy-proven osteomyelitis the patient will become compliant with medical management of the disease process. Certainly, in some circumstances, this is the case. There are a number of studies with a wide range of findings on HbA1c as it relates to predictive value of wound healing.

There are various studies comparing surgical to medical management for osteomyelitis. Limb salvage is contingent upon location (forefoot, midfoot, hindfoot), the extent of infection, and patient comorbidities. The conclusion of the majority of these studies is that a standalone antibiotic treatment algorithm results in greater limb loss. Patients with peripheral occlusive disease and preadmission antibiotic use have been shown to have decreased wound healing. Minor amputation has been shown to be protective from mortality, risk of major amputation, and unfavorable discharge in patients admitted with a diagnosis of osteomyelitis.3 The major limb amputation rate for antibiotics alone is 20%-30% according to two trials with duration of antibiotics of 3 months.4,5 The available randomized trials tend to exclude patients with severe infection (poorly defined), those with PAD, or those with severe comorbid conditions.

Cost of treatment is even more poorly delineated. Obviously, surgical treatment is not without cost to the health care system. Toe amputation especially when including the metatarsal head shifts pressure points and in the neuropathic patient may lead to recurrent ulceration. The average outpatient cost per patient per ulcer is often over $30,000. The goal of surgical treatment can be defined as trying to maintain the greatest degree of function with the least risk. Removing infected bone (i.e., minor amputation) limits exposure to prolonged antibiotic treatment and hopefully lessens recurring ulceration and hospitalization. This is only one piece of the puzzle, however. A multidisciplinary approach with endocrinology, infectious disease, and orthotics for offloading are keys to decrease future ulceration.

Although I do not advocate for widespread toe carnage as suggested by Dr. Koleilat, I do think liberal application of minor amputation to limit hospital stay, limit antibiotic duration and its inherent risk, and possibly affect readmission is often in the best interest of the patient and the system as a whole. Obviously, based on the variable reports in the literature there cannot be a single approach to these patients and the treatment must be individualized based on extent of infection, compliance of the patient, access to multidisciplinary care, and comorbid conditions.

References

1. World J Diabetes. 2017 Apr 15;8(4):135-42.

2. Diabetes Res Clin Pract. 2018 Jan;135:58-64.

3. Ann Surg. 2005;241(6):885-94.

4. Am J Med. 1987 Oct;83(4):653-60.

5. Am J Med.1989 Jun;86(6 Pt 2):801-8.

Dr. Mark P. Androes is division chief, vascular surgery, Greenville (S.C.) Health System. He had no relevant disclosures.

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