## 2 Application Fields
### Bone Healing
At the end of the selection process, 363 patients were selected and treated with different means of synthesis (external fixation, plate and screw and nail). The purpose of the study was to assess, immediately after the treatment of the fracture, the time needed to heal. In this way, the clinician can have objective information about the usefulness of applying the device, identifying and standardizing patients with higher risk factors and therefore, who potentially may be more suitable for these therapies. Further confirmation of the effectiveness of stimulation with PEMFs is reported in the study of [PERSON]. et al. [23] conducted on 64 patients with delayed unions of fractures involving long bones. The treatment protocol involved the application of PEMFs for 8 h a day for an average of approximately 4.5 months. The authors concluded that the early application of PEMFs for a period of 4.4-4.8 months promotes fracture healing and union rate with statistically significant results compared to the placebo group (77.4% vs. 48.1%). To obtain a more complete evaluation of effectiveness, studies involving the application of the devices on very limited bone portions were also taken into consideration. The study conducted by [PERSON] et al. [24] on fractures of the 5 th metatarsal bone took into consideration a small population of patients with delayed or failed bone union. On these patients, a bone biopsy was performed at time 0, after having performed the fixation with a cannulated screw, and a new biopsy after 3 months of stimulation with PEMFs. The authors conclude that in the group treated with biophysical stimulation, compared to the placebo, there is a significant increase in placental growth factor (PIGF), brain-derived neurotrophic factor (BDNF), and bone morphogenetic protein (BMP) 7 and 5, all of which are factors of angiogenic and osteogenic growth factors important for the formation of new bone tissue. This work presents a peculiar aspect because, unlike most studies, it does not focus exclusively on radiographic and clinical parameters but takes into consideration a more objective biomolecular variable. In the literature, biophysical stimulation has yielded favorable outcomes in the treatment of hand fractures. We report the results of the studies conducted in 2020 by [PERSON] et al. [25] and in 2023 by [PERSON] et al. [26] regarding fractures of the distal radius treated with plaster casts. Both studies focus mainly on the clinical symptoms reported by patients and their adherence to physiotherapy programs. In the study by [PERSON] et al. [25], PEMFs are administered from the first day for 30 min per day for a duration of 10 days, subsequently with 3 applications per week of 30 min for 6 weeks. The authors conclude that, compared to the control groups, better scores were observed on the DASH (disability of arm, shoulder, hand), SF12 (12-Item Short Form Survey), and PRWE (Patient-Rated Wrist Evaluation) questionnaires. The study by [PERSON] et al. [26] expresses positive conclusions regarding the radiographic evaluation of the healing process. The group treated with PEMFs for 24 h a day had the possibility of removing the cast earlier (33 \(\pm\) 5.9 days vs. 39.8 \(\pm\) 7.4 days), showed a better joint ROM at both 12 and 24 weeks after the trauma, and had better scores on the clinical tests reported above. [PERSON]. et al. demonstrated that PEMFs produce a better overall outcome in distal radius fractures [27]. In accordance with this, [PERSON] et al. used PEMP therapy during cast immobilization for [PERSON] fracture and observed in these patients' better resultsimmediately after cast removal in terms of edema and wrist range of motion (ROM) with respect to cast immobilization alone [28]. PEMFs represent a valid option even in delayed fracture healing of small bone. In fact, [PERSON] et al. used biophysical stimulation at 8 h intervals per day for 60 days in 43 patients with delayed unions of phalanx fractures.