From Diabetic Foot Ulcers to Limb Salvage: A Surgical Perspective

The burden of diabetic foot ulcers (DFUs) to patients and the health care system is substantial. Although we understand why DFUs happen and have relatively effective treatments (particularly if they are caught early), we still don’t seem to be winning against this mutilating disease. Why?

Our lack of success is, in part, because it begins with the absence of pain, rather than the presence of it.¹ As unpleasant as pain is, it is a warning sign that patients with diabetes usually do not have. Poor health literacy and the way that patients, for many reasons, desert themselves, contribute to the late presentation of many cases. However, we also struggle with a lack of engagement on the part of healthcare providers who may not realize the significance of what appears to be a minor problem. Preventive care could go a long way to solving the DFU problem, but we are not very good at preventive care for any disease, in particular for diabetes. We are not wining, in part, because patients with diabetes should have yearly foot examinations, but rarely get them.²

Even though the natural history of a DFU is predictable, the timing of events is not and can surprise even the most experienced clinician. DFUs may remain clinically quiescent for long periods of time. Lavery et al determined that a wound duration of > 30 days is an independent risk factor for diabetic foot infection (odd ratio of 4.7).³ Yet, we regularly see patients who admit to having had a DFU for many months before seeking medical attention. When patients do seek care, the attention they get is often not aggressive enough, and the result can be devastating. Higher level amputations (e.g., below or above the knee) are not just debilitating, they can be deadly.⁴ We are not winning in the fight against DFUs, in part because patients often arrive too late.

If ever there were a problem that needed a multidisciplinary team approach, it is the diabetic foot ulcer. Managing patients with DFUs requires what I will call a “well-synchronized” physician network. It is difficult to create a team that can respond quickly to the clinical demands created by DFUs. Patients might need urgent revascularization, urgent treatment of infection, and/or urgent surgery. They may need all of those things on a non-urgent basis. They need diabetes management and nutritional support. That means that primary care physicians, wound care specialists, vascular surgeons, interventional cardiologists, infectious disease doctors, podiatrists, nutritionists, physical therapists, orthotists, social workers, and foot and ankle reconstructive surgeons. They all have to communicate well with each other and the patient. We are not winning with DFUs in part because we struggle to create effective multidisciplinary teams.

Diabetic foot ulcers with no suppurative infection can usually be managed in the outpatient setting. Doing so requires optimization of systemic factors (which have often been ignored by the patient previously), controlling local factors (e.g., offloading) and wound management, usually with debridement. The job doesn’t stop when the patient is healed. Patients need customized inserts and diabetic shoes as well as clinical surveillance to prevent recurrent breakdown. Nearly every week we see DFU patients who have had prior amputations and yet received no interval preventive care or monitoring. Often, they tell me they “didn’t know they needed it.” We are not winning, in part because we rarely succeed in preventing recurrent foot ulcerations.

We are not winning because we struggle to get DFUs healed. Fife et al evaluated 26 randomized controlled trials as well as real-world data from the U.S. Wound Registry, which showed that only 30.5% of diabetic foot wounds are healed at 12 weeks, and only 45.1% are healed within any timeframe.⁵ This is quite different from the >90% healing rates that are often touted by wound centers.

Inflated healing rates create the mistaken impression that most DFUs can be healed. It is possible that the majority never heal absent some definitive surgery. If a cancer center reported that it cured >90% of cancer patients, we would know there was a problem with the way they report data. Cancer survival rates are always reported in the context of the severity (type and stage) of the cancer. We need to report wound healing rates the same way so clinicians caring for the most severe DFUs do not appear to have worse outcomes than their colleagues who treat the less complex cases.

That was the reason that, in 2016, the Wound Healing Index (WHI) was developed. It identifies factors associated with failure to heal and makes it possible to predict with accuracy whether a wound is likely to heal with standard wound care alone.⁶ The WHI could be used to identify patients who are not likely to need advanced therapeutics as well as those for whom advanced therapeutics should be “front loaded.” Doing so would reduce wasted health care dollars, but payers do not yet understand the benefits of approaching DFUs more like cancer, and even wound care practitioners remain skeptical of the concept. Reporting that nearly every wound heals makes it hard to explain to payers why we need advanced therapeutics for some of them (which means payers just deny expensive treatments) and is another reason we are not winning.

When patients with diabetes are referred to me it is usually because of underlying bone infection or deep abscess with significant soft tissue destruction.⁷ It’s best to discuss the prognosis and possible outcomes at the very beginning—which means warning patients they could have an amputation. That is often overwhelming, so family presence is encouraged.

The principles of surgical management have not changed since the advent of surgery and hold true for diabetic foot infections. We first eradicate the infection and then we perform reconstruction. Unlike most areas on the body, the foot has little extra soft tissue or muscle, which can be used to cover defects. The lack of an adequate soft tissue envelope and supporting muscle can make DFUs very hard to reconstruct.⁸ Patients usually need inpatient management for serious infections requiring surgery since it enables us to efficiently obtain cardiac clearance and optimize their medical management. Expecting sick patients to get these consultations in a timely way as outpatients (after asking them not to bear weight on the foot) is unrealistic and creates delays that allow infection to worsen. At least, that was our approach before the pandemic. We now try to facilitate outpatient evaluations as much as possible in non-urgent situations. Unfortunately, the pandemic has caused patients to delay seeking medical care and they often have more advanced problems at their initial visit, which appears to be causing an increase in hospital admissions for severe DFUs.

The majority of DFUs can be surgically managed with debridement or minor amputation followed by primary closure, healing by secondary intention (with or without the use of adjuncts) or delayed primary closure and skin grafting. Only about 5% have soft tissue defects that require complex closure to cover vital structures like bones, tendons and joints. In this scenario, local flaps, pedicle flaps and even (rarely) free flaps may be necessary. Some of those treatments require multiple procedures and prolonged hospitalization in an already fragile patient. Therefore, before such aggressive operations, it is vital to determine whether the reconstruction will be durable and whether it will meet the functional demands of the patient. Functionality is often the limiting factor. It is not “winning” to salvage limbs that will not be functional.

There are a lot of reasons that, despite all we know about DFUs and their management, we are not “winning” the battle against them. The problem is not with lack of surgical skill, clinical expertise, or medical technology. The problems that have so far been insoluble are lack of patient education and low health literacy, lack of preventive care, poor care coordination, inadequate aftercare, and a lack of effective clinical teams. The problem is not with the treatments per se, but with our healthcare delivery system. And yet, the focus of DFU research continues to be on improving technology, rather than improving the way we deliver it. I worry that we will not win with this mindset.

Efthymios Gkotsoulias, DPM, is a foot and ankle surgeon at Baylor St. Luke’s medical group/Baylor College of Medicine practicing in the North Houston area. His main focus is diabetic foot infections, limb salvage/preservation, reconstructive surgery of the foot and ankle and revision surgery.

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