Patients with diabetes and their families who are at high risk for diabetic foot require broad education about risk factors and adequate management. First, patients who have lost the protective sensation in their feet must be educated on how to compensate for it and detect lesions early [1].

Amputation results in difficulty walking, but recent advances in rehabilitation exercises and prostheses have made it possible to walk more smoothly than in the past. It is important to explain and discuss amputation with the patient to avoid fear that it will prevent them from walking properly.

Several studies have reported a high prevalence of psychiatric disorders, including depressive disorders, in patients with diabetic foot. DFU disturbs the daily lives of patients, altering sleep patterns, impairing mobility, interfering with certain aspects of life such as sexuality, and creating feelings of loneliness, powerlessness, anxiety, and depression [8]. Strong relationships exist between mental health conditions and the increased recurrence of foot ulcers. Therefore, it is important to identify and treat mental health conditions before and after surgery through appropriate psychiatric counseling and education for patients and caregivers [9,10].

The management of diabetic foot requires a multidisciplinary approach that includes not only management of the foot itself but also internal management, such as glycemic and blood pressure control and nutrition, adaptation to daily life through appropriate exercise and rehabilitation, and psychological management, which will be discussed individually below.

Diagnosis begins with history-taking and physical examination. During clinical examination, it is important to check the peripheral pulses of the feet and signs of vascular insufficiency (of which hair loss and muscle atrophy may be indicative) the presence of calluses, and the location of the ulcer. Ulcers are most common in weight-bearing areas, such as the plantar metatarsal head, heel, tips of hammer toes, and other prominent areas (Fig. 1).

Blood tests, such as white blood cell (WBC) count, erythrocyte sedimentation rate, and C-reactive protein level, are commonly requested to aid in diagnosis. However, they are neither sensitive nor specific and are unlikely to be elevated in local or superficial infections [11].

Furthermore, patients with DFUs have higher blood levels of cytokines and chemokines [12]. Interleukin levels are elevated in patients with DFU, along with the development of insulin resistance, abnormal healing, and decreased ulcer healing [13]. Weigelt et al. [12] reported that patients with DFU displayed elevated systemic levels of macrophage inflammatory protein-1 alpha, migration inhibitory factor, and inducible protein-10, decreased RANTES (regulated on activation, normal T cell expressed and secreted) levels.

Bacterial cultures should be obtained if there is a suspicion of infection in a diabetic foot or if there is an exudate (pus). The tissue around the abscess, rather than the abscess itself, should be used as a specimen, which should be obtained as deeply as possible. Wound culture results from a diabetic foot are often polymicrobial, where virulent pathogens (e.g., Staphylococcus aureus or beta-hemolytic streptococci) that are isolated should be treated, and some less virulent isolates (e.g., corynebacteria or coagulase-negative staphylococci) are often contaminants or colonizers that may not need targeted antibiotic treatment. The most common pathogens in diabetic foot are aerobic gram-positive cocci, especially S. aureus, and to a lesser extent, streptococci and coagulase-negative staphylococci [14]. Blood cultures should also be performed if systemic infection is suspected [15].

In addition, imaging studies are necessary to identify areas of infection. In particular, for bone infections, which have a poor prognosis, the gold standard for diagnosing osteomyelitis in diabetic foot is bone biopsy; however, since this procedure is invasive, other imaging tests, such as plain X-rays, magnetic resonance imaging (MRI), bone scans, and WBC single-photon emission computed tomography/computed tomography (SPECT/CT), have been used to identify the infection site in diabetic foot. MRI is the best radiological modality for examining soft tissue abnormalities and may distinguish between soft tissue infections and osteomyelitis. The most reliable diagnostic method is to track the ulcer or sinus tract to the underlying bone and look for a low signal intensity on T1-weighted images, which indicates the presence of marrow edema [16] (Fig. 2). Regarding specificity and diagnostic accuracy, WBC SPECT/CT performs very well for osteomyelitis and soft tissue infections [17]. WBC SPECT/CT effectively reflects diabetic foot osteomyelitis using intensity over a specified threshold. This enables a more precise assessment of areas of elevated WBC intensity, which has been demonstrated to indicate a poor prognosis even when restricted to soft tissue and not in contact with bone [18] (Fig. 3). MRI has previously been utilized as a diagnostic test for diabetic foot osteomyelitis; however, recent investigations have found that WBC SPECT/CT offers similar diagnostic specificity and sensitivity to MRI. Based on bone biopsies for the diagnosis of diabetic osteomyelitis, Sherwood et al. reported that MRI had a sensitivity of 70.6% and a specificity of 40.0%, whereas these values were 82.4% and 73.3%, respectively, for WBC SPECT/CT [19].

Furthermore, ankle-brachial index, transcutaneous oximetry, and CT angiography can be used to assess peripheral blood vessel perfusion in diabetic foot, while monofilament and pin-prick tests can be used to assess peripheral nerve damage (Fig. 4). These tests can assist in evaluating whether a patient requires percutaneous transluminal angioplasty prior to surgery and whether the patient’s clinical outcome can be enhanced with medication [7].

There are several classifications for more systematic diagnosis and treatment. Diabetic foot is categorized into different grades according to international community guidelines. Each classification system for diabetic foot is slightly different but is based on the guidelines published by the International Working Group on the Diabetic Foot in 2019. Most classification systems categorize grade 3 (moderate) as an infection that extends more than 2 cm around the lesion, forms an abscess or gangrene in the deep tissue, or involves muscles, tendons, joints, or bones, while grade 4 (severe) is a systemic infection that includes changes in vital signs such as fever and hypotension [20,21] (Table 1).

Other classification systems exist, such as the Wagner classification system; the Wound, Ischemia, and Foot Infection classification system; and the University of Texas classification system. However, in general, moderate or severe infection refers to infection of deep tissues such as tendons, joints, or bones, or systemic symptoms such as sepsis [22].

Patients in good systemic condition with the capacity to walk before amputation are very likely to achieve high physical function during rehabilitation after amputation [25]. Patients who have had trouble walking for a long time before amputation, in contrast, will have a longer recovery period and will frequently be unable to restore their walking capacity even after much time and effort. Therefore, walking and activity should be permitted, encouraged, and promoted to the extent that systemic conditions allow [9]. Patients and their caregivers should also be educated and supported in performing rehabilitation exercises [26].

Preoperative physical therapy, sometimes known as ‘pre-rehabilitation,’ is the process of preparing the body to tolerate the stressful, postoperative episodes of inactivity [27]. These pre-rehabilitation programs, which often begin 4 to 6 weeks before surgery, comprise repetitive physical exercises, preferably in conjunction with occupational therapy, psychological assessment, and education. Chest physiotherapy, breathing exercises for lung expansion that may reduce postoperative pneumonia, muscle and joint mobility training, and functional preservation are all part of the preoperative program [28,29].

Debridement is used to prevent ulceration of infected or nonviable tissues. If vasculopathy is mild, hyperkeratotic tissue, fibrin, eschar, biofilm, and necrotic tissue should be removed, and drainage should be conducted until healthy, well-bleeding tissue is present. The most popular technique, sharp debridement, involves the removal of necrotic tissue using a knife or scissors. Sharp excisional debridement decreases the bacterial load and stimulates contraction and wound epithelialization [30]. The wound should then be dressed appropriately according to its condition to encourage the development of healthy granulation tissue [31].

The goals of reconstruction are to restore bipedal ambulation, correct skeletal deformities, and prevent ulcerative recurrence. The reconstructive options include skin grafts, local flaps, and free flaps. The flap must have an adequate blood supply, restore sensation while maintaining protective sensation under weight-bearing, and be sturdy enough to withstand the shear pressures experienced while walking [30]. Identifying the patient’s preoperative status is critical prior to surgical intervention. The patient’s status includes comorbid conditions, vascular insufficiency, infection control, and foot deformities. Flap-based reconstruction is generally impossible in patients with severe vascular problems [32].

Amputation is currently the optimal choice when there is evidence of necrosis due to infection or ischemic injury that does not respond to conservative treatment. However, given that patients with diabetes who undergo amputation surgery are significantly less able to perform activities of daily living after amputation and are more likely to die within 5 years, there have been recent attempts to perform limited amputations that spare as much of the heel as possible while performing additional procedures to improve survival [30]. Depending on the location of the amputation, there are several options, including toe, transmetatarsal, Lisfranc, Chopart, Syme, below-knee, and above-knee amputations [9]. A multidisciplinary approach, as well as strict identification of the amputation type and plane, is recommended for effective treatment [26]. Proximal amputation is less likely to result in postoperative wound problems, and patients do not want to undergo repeated anesthesia and surgery. However, amputation is irreversible, and it is important to minimize the area of amputation and consider its function after amputation [15,33].

After surgical treatment, managing the wound using proper dressings is important [27]. Wet dressings promote the formation of granulation tissue and new blood vessels, promoting wound healing. Therefore, various dressing formulations should be used to keep the wound moist; in cases of infection, antibacterial dressing formulations may be used [15,33]. It is important to understand the effectiveness of various dressing products and select one that suits the condition of the wound [5,34] (Table 2).

In negative-pressure wound therapy (NPWT), a wound dressing is applied with constant or intermittent negative pressure to drain the tissue fluid from the area and collect it in a canister [31]. NPWT can be used for chronic wounds with high exudates that have not healed in a long time and have soft tissue defects. This provides negative pressure on the wound area to encourage the production of granulation tissue [15]. However, wound maceration, dressing retention, and wound infection are possible side effects [31].

Patients undergoing amputation frequently have poor gait prior to surgery, and their ambulatory ability deteriorates following surgery. Delirium can occur after surgery, resulting in prolonged recovery time, difficulties with postoperative care, and longer hospital admissions. This impedes the recovery of ambulation [35]. In addition, pulmonary emboli from deep vein thrombosis and pneumonia may occur because of immobilization [36]. Immobilization after amputation can further disrupt ambulatory recovery and create a vicious cycle. Therefore, active gait training following amputation is critical for improving the patient’s overall condition [9].

Strength training should be resumed immediately after surgery to prevent muscle loss and atrophy. Weakness in the lower extremities can affect other joints in the ipsilateral or contralateral lower extremities, causing other problems [9].

Repetitive joint exercises should be performed immediately after surgery because contractures can occur in the remaining joints after amputation. Joint exercises should be performed to avoid equinovarus deformity of the ankle joint and flexion contracture of the knee joint. To prevent equinovarus deformity of the ankle joint, it is necessary to constantly stretch the Achilles tendon and, in severe cases, wear a prosthetic leg to prevent the deformity from persisting [9].

After surgery, if the patient’s general condition allows ambulation should begin as early as possible using a wheelchair, crutches, or other walking aids, regardless of the wound condition and preoperative walking ability. This is essential for maintaining pre-amputation gait and balance; maintaining athletic performance, including cardiorespiratory endurance; and improving joint range of motion and muscle strength [9].