## 4 Discussion
### MIMOs for PDFU Healing and Prevention (1986-2021)  
From 1986 to the present, in different decades, relatively few original studies regarding MIMOs for PDFUs have been published. In the eight original articles included in this review, different osteotomy shapes have been proposed [27; 29; 30; 35; 38; 39; 40; 41]. Despite the heterogeneity of the surgical methods, a systematic, common approach to the diabetic foot was found: all osteotomies were performed in a minimally invasive way carried out by an incision less than 3 cm performed by a dorsal foot approach, predominantly at the level of the lesser distal metatarsal bones, drawn down in oblique slide shape and without fixation or only temporary. Among the different authors, none used fixation except for the surgical procedures described by [PERSON] et al. (1999) [38]. More commonly, as originally proposed by [PERSON] et al. (1986), a metatarsal neck osteotomy of the metatarsal bones, osteotomized obliquely, starting proximally on the dorsum but proceeding distally and plantar-ward at an angle of 45\({}^{\circ}\), was described [35]. With some differences, [PERSON] et al. (1990) proposed four different types of distal metatarsal bone osteotomies: osteoclasts of the head, V-osteotomy, shortening colectomy and oblique slide osteotomy [29]. Later, [PERSON] (1999) was the only one to suggest a dorsally based, closing wedge metaphyseal osteotomy at the base of the metatarsal bones, temporarily fixed in most cases with K-wires [38]. In the 21 st century, [PERSON] et al. in 2016 used a perpendicular or short oblique osteotomy performed at the neck or diaphysis of the metatarsal bone, with healing of the plantar lesion being reported in most of the cases [30]. More recently, [PERSON] et al. (2018) treated a series of 30 patients by distal metatarsal diahpysseal osteotomies, performed with an angle of approximately 45\({}^{\circ}\) with respect to the long axis of the metatarsal bone in a dorsal-distal to proximal-plantar direction [27]. Similarly, in 2020 [PERSON] et al. [39] treated another series of 21 patients using a mini-invasive osteotomy without fixation, perpendicular to the first metatarsal bone metaphysis, similar to that described by [PERSON] et al. for Hallux Valgus (HV) percutaneous correction [51]. In the same year, [PERSON] et al. (2020) proposed a diahpseal osteotomy proximal to the level of the metatarsal neck to preserve metatarsophalangeal joint function [40]. However, in the case of the metatarsophalangeal joint, severe destruction or stiffness was reported; even the joint was removed with the osteotomized bone segment [40]. In 2021, [PERSON] et al. treated 32 patients with metatarsal distal oblique osteotomies without fixation, described as minimally invasive floating distal metatarsal osteotomy [41]. In this review, only single series, case series, study design, level IV of evidence, some with poor methodological quality and different outcome measures were examined. The studies included used heterogeneous outcome evaluation parameters, and only the study by [PERSON] et al. [27] evaluated the patients' AOFAS and VAS scores, both pre-operatively and at the last follow-up. Only [PERSON] et al. (2021) used the reduction of pressure under the metatarsal head after osteotomy as a measure of clinical outcome (from 82.4 kPa preoperatively to 65 kPa in the follow-up measures) [41]. The inclusion criteria of these studies consisted of participants with diabetes of both types (1 and 2) or not specified and at different stages of disease progression, further increasing the difficulty in comparing the different studies. Finally, some studies included people with no sensory neuropathy, while other studies included participants with sensory neuropathy, in both cases associated to previous foot ulceration. Reliable scientific evidence is essential to guide the use of MIS in clinical practice applied to the diabetic feet for the management of PDFUs.