Background: Spinal cord injury (SCI) is a central nervous system (CNS) trauma involving inflammation and oxidative stress, which play important roles in this trauma’s pathogenesis. Therefore, controlling inflammation is an effective strategy for SCI treatment. As a hormone, melatonin is capable of producing antioxidation and anti-inflammation effects. In the meantime, it also causes a neuroprotective effect in various neurological diseases. Nrf2/ARE/NLRP3 is a well-known pathway in anti-inflammation and antioxidation, and Nrf2 can be positively regulated by melatonin. However, how melatonin regulates inflammation during SCI is poorly explored. Therefore, it was investigated in this study whether melatonin can inhibit the NLRP3 inflammasome through the Nrf2/ARE signaling pathway in a mouse SCI model. Methods: A model of SCI was established in C57BL/6 mice and PC12 cells. The motor function of mice was detected by performing an open field test, and Nissl staining and terminal deoxynucleotidyl transferase dUTP nick end labeling were carried out to evaluate the survival of neurons. Mitochondrial dysfunction was detected by transmission electron microscopy (TEM) and by assessing the mitochondrial membrane potential. In addition, the expression of NLRP3 inflammasome and oxidative-stress-related proteins were detected through Western blot and immunofluorescence double staining. Results: By inhibiting neuroinflammation and reducing neuronal death, melatonin promotes the recovery of neuromotor function. Besides this, melatonin is able to reduce the damage that causes neuronal mitochondrial dysfunction, reduce the level of reactive oxygen species (ROS) and malondialdehyde, and enhance the activity of superoxide dismutase and the production of glutathione peroxidase. Mechanically, melatonin inhibits the activation of NLRP3 inflammasomes and reduces the secretion of pro-inflammatory factors through the Nrf2/ARE signaling. Conclusions: In conclusion, melatonin inhibits the NLRP3 inflammasome through stimulation of the Nrf2/ARE pathway, thereby suppressing neuroinflammation, reducing mitochondrial dysfunction, and improving the recovery of nerve function after SCI.

Objective: Currently, the traditional treatment of moderate‐to‐severe ankle arthritis is joint fusion or joint replacement. The aim of this article is to explore the clinical efficacy of distraction arthroplasty in the treatment of moderate‐to‐severe ankle arthritis.Methods: A retrospective analysis was conducted with a total of 34 cases who were diagnosed with moderate‐to‐severe ankle arthritis and treated by distraction arthroplasty from January 2007 to November 2021. The average age was 42.3 years. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle–hindfoot score and pain visual analog scale (VAS) were used to evaluate ankle pain and functional improvement before surgery and at the last follow‐up. Based on age, the patients were divided into the ≤45‐year‐old group [young group, 15 cases, age (36.37 ± 4.31) years old] and the >45‐year‐old group [middle‐aged and elderly group, 19 cases, age (53.74 ± 3.17) years old]. The analysis included comparing preoperative and postoperative AOFAS ankle–hindfoot and VAS scores and the influence of age on distraction arthroplasty.Results: All 34 patients were followed up, and the follow‐up time ranged from 13 to 143 months, with an average of 45.3 months. The follow‐up times for the young and middle‐to‐elderly groups were (33.19 ± 21.37) months and (55.63 ± 29.69) months, respectively. At the last follow‐up, the AOFAS ankle–hindfoot and VAS scores were significantly improved compared with the preoperative assessment (p < 0.05). According to the etiological analysis, except for Pilon fracture, which showed no differences pre‐ and postoperation in the AOFAS ankle–hindfoot score and VAS score (p > 0.05), all other patients showed significant differences in these two scores (p < 0.05). The difference in preoperative AOFAS ankle–hindfoot scores between the young and middle‐to‐elderly groups was statistically significant (t = 3.422, p = 0.021). The preoperative and postoperative comparison of preoperative VAS scores, AOFAS ankle–hindfoot scores, and VAS scores before and after surgery showed no differences (p > 0.05). The joint space width (JSW) of 10 patients who were followed up for more than 5 years was (2.9 ± 0.5) mm. Two patients who were followed up for more than 10 years showed 3.3 and 3.0 mm, respectively, JSW.Conclusion: Distraction arthroplasty with the Ilizarov external fixator can achieve satisfactory results in the treatment of moderate‐to‐severe ankle arthritis (except arthritis caused by Pilon fracture surgery). Age has no statistical impact on the efficacy of distraction arthroplasty.

Fracture of the os peroneum is rare, and displacement of the fracture can be indicative of a tear in the peroneal longus tendon. A fifth metatarsal base fracture is a common injury caused by sudden inversion and plantar flexion of the hindfoot. We observed a rare case of a fifth metatarsal base zone I fracture combined with a displaced os peroneum fracture in a 34-year-old woman. The patient was treated with resection of the os peroneum and repair of the peroneal longus tendon, as well as open reduction and internal fixation of the fifth metatarsal base. After exposing the fragment of the fifth metatarsal base, the distal part of the fractured os peroneum was found to be located just under the fracture site. There were no complications or discomfort of the foot or ankle at 2 years postoperatively. Resection of the os peroneum and direct repair of the peroneal longus tendon were easily performed after the fifth metatarsal base fragment was exposed. This was an innovative method for performing peroneal longus tendon repair in the deep portion of the midfoot.