CLINICAL PRESENTATION AND DIAGNOSIS

HOW TO DIAGNOSE THE DIABETIC FOOT

NEUROPATHIC?

ISCHEMIC?

INFECTIOUS?

Loss Of Protective Feeling With Deformities With And Without Ulcera

Clinically, Charcot's arthropathy can present itself in two forms, the acute phase and the chronic phase

The diagnosis of acute CNA is predominantly clinical and this pathological entity should be suspected in the presence of a foot with signs suggestive of inflammation, in the absence of fever and a visible port of entry, such as interdigital wounds or plantar ulcers.

Acute Charcot's foot presents with hyperemia, edema, temperature rise of more than 2 degrees when compared to the other foot, very dry skin and sensory neuropathy. Proprioceptive sensitivity and reflexes are diminished or absent Pain may be present in varying degrees or even absent, depending on the degree of nerve dysfunction Arterial pulses of the affected foot are maintained or even increased due to peripheral vasodilation characteristic of CNA

The acute presentation of CNA may mimic a crisis of gout, DVT or cellulite, hence the importance of measuring certain serological parameters, such as uric acid, and of imaging in distinguishing these different pathological entities.

The clinical diagnosis of the acute phase is difficult and radiography is often unable to identify or distinguish this entity from other conditions, thus failing to diagnose fracture and/or dislocation In turn, bone scintigraphy with technetium radioisotope has good sensitivity and low specificity for this pathology

It should be noted, however, that only magnetic resonance imaging (MRI) is able to reveal, in greater detail, the nature of the damage and inflammation of the bone and surrounding soft tissue (subchondral bone marrow edema with or without microfractures) Thus, MRI is particularly useful in the early stages of the disease, with a significant correlation between the intensity of bone marrow edema and certain clinical parameters such as soft tissue edema and pain.

The diagnosis of acute CNA is therefore based on history and clinical examination but must be confirmed by imaging methods X-ray of the foot should be the first imaging exam to be performed in order to verify the occurrence of fractures or subtle subluxations When, despite clinical suspicion, the X-ray of the foot is apparently normal, MRI and nuclear imaging can sometimes confirm the diagnosis

It is noteworthy that the delay in the correct diagnosis of acute CNA has serious consequences, as the patient, by continuing to load the affected foot, will increase bone destruction and the appearance of foot deformities characteristic of the chronic phase

In the chronic phase of CNA, the foot does not show signs of inflammation, although the edema remains At this stage, there is deformity of the foot due to the shortening of the plantar arch and equinism caused by the shortening of the Achilles tendon These deformities resulting from osteoarticular and muscle involvement give rise to hyperpressure sites and increase the likelihood of the occurrence of ulcers and amputation, in symbiosis with the ischemia characteristic of this phase

Classification

Different classification systems for CNA have been proposed, with the SandersFrykberg anatomical classification being one of the most popular. NAC can be classified according to various parameters such as clinical status, anatomical location and stage in the natural history of the disease Existing classifications have no prognostic value and do not influence treatment

Clinical Classification

Clinically, CNA can be divided into the acute or chronic stage In the acute or active phase, the foot presents marked inflammatory signs (redness, edema and heat) most frequently affecting the midfoot Pain may be absent depending on the degree of neuropathy At this stage the foot has no deformities and imaging is typically normal

On the other hand, in the chronic or inactive phase, local inflammatory signs progressively regress, however, the foot remains flushed, but with a temperature similar to that of the contralateral foot It is at this stage that the foot can develop characteristic deformities such as plantar arch collapse in the midfoot, causing the “rocker-bottom deformity” and the medial convexity of the midfoot

Anatomic Classification

Several authors have proposed anatomical classifications of CNA according to the patterns of involvement of the foot and ankle, because although this disease has been verified in other body locations, in diabetic patients it affects almost exclusively the foot and ankle

In 1991 Sanders and Frykberg proposed the currently most used anatomical classification of the CNA. According to this classification, CNA can be divided into five different patterns according to the articulations involved

Type I, present in 15% of feet with CNA, affects the metatarsophalangeal and interphalangeal joints of the foot

Type II, the most common, accounting for 40% of Charcot's feet, affects the tarsometatarsal joints or Lisfranc joint The second most common pattern, type III, present in 30% of CNA, is characterized by involvement of the naviculocuneiform, talonavicular and calcaneocuboid joints.

The type IV pattern (10%) affects the ankle and subtalar joints. Finally, type V, present in 5%, affects the calcaneus region Types IV and V have a poor prognosis due to the abnormal load distribution during gait

There is also a more simplistic anatomical classification that characterizes this entity in 3 different types according to the location of the foot strike: forefoot (metatarsophalangeal and interphalangeal joints), midfoot (tarsal and tarsometatarsal joints) and hindfoot (ankle and heel joint)

CNA (Charcot's Neuro Arthropathy) syndrome is a major complication resulting from diabetes and neuropathy. The exact mechanism of its pathogenesis is still unclear, although it is considered, at present, that both the Neurotraumatic and Neurovascular theories may play an important role

Although this condition is considered one of the important complications of diabetes, it is only identified in a small percentage of diabetics Due to the delay in the diagnosis and treatment of CNA, it progresses to the formation of ulcers, thus increasing the risk of amputation, hence the importance of an early diagnosis and treatment

Although several authors have presented different classification systems with some clinical importance, they do not have a prognostic value or influence the treatment

It is a neuroarthropathy with important individual and social consequences, which is predominantly associated with the Diabetes epidemic, deserves special attention in order to diagnose and treat this complication arising from this serious public health problem early

Neuropathic Plantar Ulcers

The foot reflects in a very special way all the damage caused by diabetes mellitus to the patient's body. The association of vascular involvement due to atherosclerosis and microangiopathy, sensory and motor peripheral neuropathy and foot deformities favors the appearance of ulcers, infection and gangrene

One of the biggest fears of diabetic patients is the total or partial loss of their lower limb, due to amputation This fear is well founded, as 50% to 75% of non-traumatic lower limb amputations are related to complications from diabetes, with approximately 35,000 major amputations (above the ankle) occurring annually in the United States Foot infection is the most common cause of hospitalization in diabetic patients, among all complications of the disease, accounting for 25% of total admissions (about 200,000 admissions/year)

In the study of the results of the treatment of diabetic foot ulcers, classified as Wagner grades I and II using Total Contact cast (TCC) and the analysis of factors that interfere with the healing of these lesions, we understand that the closure of foot ulcers Grades I and II diabetics, without active infection, is a fundamental step in the prevention of deep infections and amputations The classification and treatment proposal advocated by Wagner are used due to their comprehensiveness, simplicity and reproducibility The use of TCC is recommended as an effective method to close neuropathic ulcers of grades I and II

Neurotrophic ulcers can cause various stigmas, leading the patient to marginalization

To prevent this from happening, the multidisciplinary team must provide them with global assistance, meeting their biopsychosocial needs, to improve their living conditions The professionals of this team must be cohesive, value the diversity of roles in search of the patient's integrality, to ensure their adherence to the treatment, emphasizing that their participation in the healing process is essential They should also encourage the patient to activities of daily living, pointing out the importance of self-care in their recovery The relationship between professionals and the patient must be based on mutual respect and dignity Team members must be aware of their responsibility to indicate adequate treatment, as well as have the humility to recognize their own limitations and make referrals to other professionals, whenever necessary. Patient care must be focused on the prevention and treatment of the disease, when it is already installed, seeking to guide self-care activities in pursuit of improving quality of life

Skin Anatomy And Physiology

For professionals to provide adequate care to patients with ulcers, the skin layers and the healing process must be known, as described below The skin is the largest organ that covers and delimits our body, represents 15% of body weight and is composed of three layers: epidermis, dermis, hypodermis or subcutaneous tissue. The epidermis is the outer layer, without vascularization, formed by several layers of cells Its main function is to protect the body and constantly regenerate the skin It prevents the penetration of microorganisms or destructive chemicals, absorbs ultraviolet radiation from the sun and prevents fluid and electrolyte losses The dermis is the intermediate layer, made up of dense fibrous tissue, collagen, reticular and elastic fibers In it are located the vessels, nerves and skin appendages (sebaceous glands, sweat glands and hair follicles) The hypodermis is the deepest layer of the skin, also called the subcutaneous cellular tissue Its main function is the nutritional reserve deposit, working as a thermal insulator and mechanical protection against external pressure and trauma, facilitating the mobility of the skin in relation to the underlying structures The skin's functions are: to control body temperature and establish a barrier between the body and the environment, preventing the penetration of microorganisms The sensory nerve fibers are responsible for the sensation of heat, cold, pain, pressure, vibration and touch, essential for survival The sebaceous secretion acts as a lubricant, emulsifier, and forms the lipid mantle of the skin surface, with antibacterial and antifungal activity Under the action of sunlight, the skin synthesizes vitamin D, which has effects on the calcium metabolism in bones

Skin structure.