The only clinically approved alternative to autografts for treating large peripheral nerve injuries is the use of synthetic nerve guidance conduits (NGCs), which provide physical guidance to the regenerating stump and limit scar tissue infiltration at the injury site. Several lines of evidence suggest that a potential future strategy is to combine NGCs with cellular or molecular therapies to deliver growth factors that sustain the regeneration process. However, growth factors are expensive and have a very short half-life; thus, the combination approach has not been successful. In the present paper, we proposed the immobilization of growth factors (GFs) on magnetic nanoparticles (MNPs) for the time- and space-controlled release of GFs inside the NGC. We tested the particles in a rat model of a peripheral nerve lesion. Our results revealed that the injection of a cocktail of MNPs functionalized with nerve growth factor (NGF) and with vascular endothelial growth factor (VEGF) strongly accelerate the regeneration process and the recovery of motor function compared to that obtained using the free factors. Additionally, we found that injecting MNPs in the NGC is safe and does not impair the regeneration process, and the MNPs remain in the conduit for weeks.

IV.

Background: the purpose is to gather and analyze the statistical datas of wrist and hand injuries admitted to the Hand and Reconstructive Microsurgery and Replantation Hub center of Careggi Hospital, Florence during the first two months of COVID-19 epidemic in Italy. The Authors investigated how the drastic changes in daily activities modified the epidemiology of hand trauma lesions. Methods: The Authors analyzed the characteristics of hand and wrist traumatic disorders during the months of February and March comparing 2019 to 2020. Collected data included age distribution, traumatic etiology, diagnosis and type of surgical procedures. Results: The total number of orthopedic and trauma patients significantly decrease in 2020 compared to 2019 (3360 vs 1470). The number of hand and wrist injuries didn't show a significant difference between 2019 and 2020 instead (192 vs 131). The overall number of patients hospitalized and surgically treated at our Operative Unit (OU) was 168 in 2019 and 120 in 2020. Male patients resulted prevalent (60,7 M vs 39,3F/2019; 63,2 M vs 36,8F/2020). In terms of patient age, in 2020 we registered a significant reduction of cases in the 20-35-year-old age group and a significant increase in the 51e65 and 66-80-year-old age groups. Traffic-related, sport-related and fortuitous injuries significantly decreased in 2020, while the number of domestic accidents significantly increased. Analyzing the Hospital Discharge Records (HDR), we found a significant increase in the number of proximal and middle phalanx fractures; no significant differences were found for other kinds of discharge diagnosis. As for the choice of surgical treatment options, no differences were found between 2019 and 2020. Conclusion: Even during drastic movement restrictions and the prolonged suspension of work and leisure activities secondary to COVID-19 epidemic in 2020, hand and wrist traumas rate remained almost the same compared to the same period of the previous year. Nevertheless, a significant change in the etiology and patient age was registered. In fact, sport and traffic-related traumas decreased respect to domestic traumas, while the previous prevalent involvement of young adults was surpassed by accidental hand traumas in the elderly and active adults.

The aim of this study was to quantify the articular cartilage defect created with two different antegrade techniques of intramedullary osteosynthesis with a headless compression screw inserted through the metacarpophalangeal joint. In 12 out of 24 fingers from six cadaveric hands, a trans-articular technique with cannulated headless compression screws (2.2 and 3.0 mm diameter) was used; whereas in the other 12 fingers, an intra-articular fixation technique was used. The areas of the articular surface and the defects created were measured with a digital image software program. All measurements were made twice by two observers. In the intra-articular technique, the average defect in the base of the articular surface of the proximal phalanx was 4.6% with the 2.2 mm headless compression screw and 8.5% with the 3.0 mm screw. In the trans-articular technique, the defect size was slightly smaller; 4.2% with the 2.2 mm screw and 8% with the 3.0 mm screw, but the differences were not statistically significant. The main advantage of the intra-articular technique was that it avoided damage to the articular surface of the metacarpal head.

Metacarpal fractures constitute 7.8% of the upper extremity fractures. The common treatments remain nonsurgical procedure, but high-demanding patients or unstable fractures require fixation with Kirschner wire (K-wires), plate, and screws. However, these approaches may cause scarring and adhesion with poor functional results. From 2014 to 2015, the authors used an intramedullary headless screw to treat 25 patients (24 men, 1 woman) with metacarpal bones fractures (20 V, 3 IV, 1 III, and 1 II). The fractures patterns were 23 fractures of distal third of metacarpal bone (16 oblique, 5 comminute configurations, and 2 transverse), 1 fracture of the base of the II metacarpal bone. One case presented a multiple metacarpal and phalangeal facture associated. The authors used anesthesia (bupivacaine-epinephrine 1:100,000) and intramedullary titanium headless screw fixation percutaneously inserted (CCS Medartis and HCS Synthes 3 mm of diameter). No open reduction was needed. Early active mobilization started with a buddy strapping soon after surgery (0-3 days). The authors followed all patients until satisfactory function was achieved (4-6 weeks) and recorded the time till return to work. All fracture healed with less than 5 degrees of rotational or axial deformities. All patients return to work within 2.38 weeks after surgery (0.5-6 weeks). No cases of complex regional pain syndrome (CRPS), tendon lesions, nerve injuries, infection, hardware protruding, or mobilization were reported. Intramedullary screw fixation with anesthesia for transverse, oblique, and select comminuted fractures treatment metacarpal fractures represent a reliable option to early active mobilization recovery and a quick return to the work and ordinary activities.