## 1 Introduction  
Plantar Diabetic Foot Ulcers (PDFUs) are severe and dreadful complications occurring in diabetic patients, representing even today, a medical and surgical challenge in terms of treatment and a protracted process with high recurrence rates. In diabetic patients, it has been estimated that approximately 25% of hospitalisations are directly related to foot problems [1], and the lifetime risk of developing foot ulcers is around 19-34% [2]. This devastating complication can lead to a substantial number of hospital admissions involving a great deal of medical resources, have a profound negative impact on the quality of life and often result in diabetic foot osteomyelitis and can end up in a lower limb amputation if not recognized and treated promptly on time [3; 4]. However, a lower-extremity amputation may not be the most effective solution, as it could be complicated by polymicrobial infections, becoming another serious adverse event with even higher mortality rates [5]. Diabetic patients with pressure ulcers have a 2.5-fold increased risk of death compared with diabetic patients without PDFUs. Further, PDFU development is associated with 5% mortality during the first year and 42% mortality within 5 years [6]. In addition to performing multidisciplinary work, the implementation of a health education program would be important to favour the prevention of diabetic foot ulcers and reduce the risk of amputation [7]. Many factors are involved in PDFU development: for instance, poor glycemic control, peripheral neuropathy, peripheral vascular disease and foot deformity [8]. Trauma, such as ill-fitting shoes and high mechanical pressure resulting from structural deformities in the insensitive diabetic foot, play a significant part in the development of ulceration [9]. Further, duration of diabetes (>10 years), older age, retinopathy, nephropathy, poor foot care habits, barefoot walking and haemoglobin A1c (HbA1c) have been linked to PDFUs [2; 9; 10]. Other risk factors, especially dyslipidemia, smoking and hypertension, increase the risk of foot problems by altering both blood supply and immune responses to trauma and infection [3]. In these cases, the main therapeutic goal is to promote tissue healing while preserving adequate foot function [11]. It has been shown that infrared thermography could be a useful technique to detect temperature variability in the foot area, allowing diagnosis and prevention of injuries [12; 13]. Once a PDFU is observed at the first clinical evaluation, the essential management principles are antibiotic therapy, tissue debridement of superficial skin lesions and offloading foot pressure until healing is achieved [11]. To reduce the pressure on the affected part and promote wound healing, primary conservative methods remain the restriction of weight-bearing. Several methods of off-loading are available such as total contact casts, removable cast walkers, therapeutic footwear, foot orthoses, custom shoes, custom braces, padding and strapping therapy [14; 15; 16]. Nonetheless, there is no consensus in the literature for the optimal off-loading strategy [15; 17; 18]. It is estimated that about 77% of all PDFUs treated conservatively can initially be healed within 1 year [19]. However, after starting full weight bearing, their recurrence rate is 40% in the following first year after care, 60% within the first 3 years and 65% within 5 years [2]. Further, although PDFUs can heal with appropriate local treatment and shoe modification, a significant number of patients have chronic ulceration despite prolonged treatment, and even when primary healing has occurred, ulcer recurrence is frequent [20]. Hence, surgical treatment is indicated in case of failure of conservative management. The traditional operative methods, including both bone procedures and tendon balancing [20; 21; 22], are often correlated with high complication rates, such as infections and wound recurrences [23; 24; 25].