What is diabetic foot?
Diabetic foot is defined as infection, ulceration or destruction of the deep tissues of the foot in diabetic patients.
What are the causes of diabetic foot?
Diabetic foot occurs due to neuropathy (peripheral nerve disease) and/or peripheral vascular disease (micro or macroangiopathy) of the lower extremities. Its prevalence increases with age and is favored by poor control of blood glucose levels, and may appear in at least 20% of diabetics. When the diabetic foot is not treated early by specialists, ulcers and infection can appear.
What signs or symptoms alert of its appearance?
The predominance of the involvement of peripheral nerves, arteries or both, will condition the symptoms presented by patients.
In the case of predominant neuropathy or loss of protective sensation, patients will notice a dryness of the feet, which will tend to crack, a loss of sensitivity to pain, pressure, changes in temperature or the perception of the foot itself, a feeling of coldness and even atrophy and weakness of the musculature, which can evolve into deformities. These deformities, together with the lack of pain perception, cause repeated microtraumas that can lead to ulcers.
Peripheral arterial disease, on the other hand, if it is of large vessels, causes intermittent claudication or “window dressing disease”, a lack of blood supply to the muscles of the lower extremity which forces the patient to stand up every few meters. If this condition progresses, it can cause pain at rest, coldness or pallor of the foot and even in the final stages, it can lead to an ulcer due to lack of blood perfusion in the skin, to which an underlying microangiopathy can contribute.
How can it be prevented?
As we have seen, the signs of a patient with diabetic foot include ulcers and bone deformities of the foot. Ulceration is a serious complication that produces a high morbi-mortality, with a risk of loss of the limb or part of it from the moment of its appearance. Moreover, once healed, the risk of recurrence is 40% in the first year and 65% in the following 3 years. Prevention of this serious complication is therefore essential. To this end, and taking into account that diabetic foot is exceptional in people without associated neuropathy or arteriopathy, an annual check-up by a health professional trained in diabetic patients is essential, aimed at ruling out the presence of loss of protective sensation and macro or microvascular involvement. This is done by means of a directed clinical history accompanied by simple tests such as the Semmes Weinstein monofilament, tuning fork, palpation of pulses, measurement of blood pressure in the arteries of the foot, including the ankle-brachial index and obtaining doppler waves by means of an ultrasound scanner.
There are diabetic people with a high risk of developing an ulcer:
- Advanced age.
- Poorly controlled diabetes, of long evolution or with involvement of other organs (nephropathy, retinopathy, etc).
- Known neuropathy or arteriopathy.
- Biomechanical alterations of the foot.
- Previous ulcer/amputation.
In these cases they should be examined in shorter periods of time and in some cases, additional tests should be performed.
In addition, specific education is necessary for them to protect their feet by avoiding walking barefoot or in socks without shoes; in thin-soled slippers, both at home and outdoors. Daily inspection, washing with lukewarm water and thorough drying of the surface of both feet, as well as the use of emollients to moisturize dry skin, should be instilled in them. Special care should be taken when cutting the nails, which should be done in a straight line, avoiding the use of chemical or abrasive products to remove corns or calluses and going to the podiatrist if they are unable to do it by themselves. In addition, they should check the inside of the shoe for protrusions that may rub against the foot and sometimes use specific footwear or unloading insoles. Due to the lack of sensitivity of patients with diabetic neuropathy, they should avoid the use of braziers, electric blankets or heat sources close to the feet because of the risk of burns that can be the origin of an ulcer difficult to heal.
When the foot deformity has already been established, it is sometimes necessary to perform surgery to restore the shape of the foot and prevent the appearance of an ulcer.
Physical exercise has numerous benefits in diabetics, but it should be supervised by establishing appropriate preventive measures to avoid inappropriate overloading of a particular area of the foot.
Diabetics who present with an ulcer should undergo additional tests that allow us to obtain very valuable information on the perfusion of the foot, its probability of healing and vascular anatomy, which is mandatory if they present with an ulcer that does not heal despite correct treatment for 6 weeks. Based on them, the cardiovascular surgeon evaluates the arterial circulation of the lower extremity in its entirety, which allows establishing an appropriate revascularization strategy.
This may consist of angioplasty, that is, reestablishing the flow in the blood vessel by inserting a catheter with a balloon that, when inflated, dilates the interior of the artery at the site of the stenosis, with or without subsequent implantation of a stent; or arterial revascularization surgery, consisting of removing the atheroma plaque occluding the artery (endarterectomy) or performing an arterial bypass, either through the patient’s own vein or by means of an artificial graft. The choice of one technique or the other will depend on the patient’s anatomy, the lesions present, age, comorbidities and the experience of the surgical team.
On other occasions and when arterial revascularization techniques are not possible, complementary techniques such as hyperbaric oxygenation can be used, which can help wound healing in case of infections by anaerobic bacteria or ozone therapy during dressings.
In case of infection, a culture of the ulcer should be taken and the patient may require antibiotic treatment, initially broad-spectrum and later directed according to the result of the culture and antibiogram.
Patients with neuropathic ulcers that are slow to heal may require removable or non-removable off-loading devices and the traumatologist should assess in case of biomechanical alteration whether foot surgery is required: tenotomy, metatarsal head resection, arthroplasty, lengthening of the Achilles tendon, etc.
Ulcer care should be entrusted to appropriately trained nursing professionals and healing may require specific measures such as regular tissue debridement or vacuum systems to promote granulation.
What is the risk for diabetics?
Diabetic foot is one of the most serious complications of diabetes because ulceration in diabetics is highly predisposed to infection and can progress to gangrene and loss of the limb due to the circulatory disorders that often converge in these patients.
It involves great suffering for the patient, entails high economic costs and causes a considerable burden for the family, the health system and society in general. Diabetes is the most frequent cause of lower limb amputation and it is estimated that 40 to 70% of patients undergoing amputation are diabetic. In 85% of the cases of diabetic patients who end up with an amputation, the triggering factor is the ulcer, associated with infection and gangrene.
What specialist treats it?
As we can see, the diabetic foot must necessarily be approached in a multidisciplinary way and the care of these patients must include a team made up of at least specialists in Cardiovascular Surgery, Endocrinology, Internal Medicine, Traumatology, Physical Medicine and Rehabilitation, as well as properly trained physiotherapists, podiatrists and nurses. Prevention is the fundamental pillar and education of diabetic patients should be the first objective to avoid the serious personal and social consequences that accompany diabetic foot.