Percutaneous K-wire reduction and cast immobilization for severely displaced radial neck fractures in children.

The purpose of this study was to compare outcomes between percutaneous K-wire reduction cast immobilization (PKRC) and percutaneous K-wire reduction elastic intramedullary nailing combined with cast immobilization (PKRNC) for the treatment of radial neck fractures in children. This was a retrospective analysis of 62 radial neck fractures in children treated with PKRC or PKRNC. Thirty-one children were treated with percutaneous K-wire reduction, K-wire removal after reduction, and cast immobilization while 31 radial neck fractures in controls were managed using PKRNC. There were no significant differences between PKRC and PKRNC with regard to preoperative angulation ( P  = 0.556). The operation time in the PKRC group was significantly shorter than that of the PKRNC group ( P  = 0.023). There was no significant difference in the displacement angle when compared between the two groups on the first day and 1 month after surgery ( P  = 0.617, 0.72). The Mayo elbow performance score of the elbow joint function did not differ significantly between the two groups ( P  = 0.587). Although the hospital stay was not significantly different between groups (4.81 ±â€…1.07 vs. 4.16 ±â€…1.59 days; P  = 0.067), the PKRNC group required a second hospitalization to remove the elastic intramedullary nail 3 months after the operation. PKRC and PKRNC both achieved satisfactory outcomes for radial neck fractures in children. The operation time in the PKRC group was significantly lower than in the PKRNC group. PKRC does not require reoperation to remove internal fixation. Therefore, PKRC is recommended for radial neck fractures in children.

Dexamethasone promotes osteoblast apoptosis through the Chk2/p53 signaling pathway.

BACKGROUND: Glucocorticoids (GCs) are widely used to treat inflammatory or autoimmune diseases. However, several studies have reported that the use of GCs can lead to numerous complications, the most serious of which are osteoporosis and osteonecrosis of the femoral head (ONFH). Osteoblast apoptosis has been identified as an important event in the development of GC-induced osteoporosis and ONFH. However, the mechanisms underlying the regulation of these processes have not yet been explored. OBJECTIVES: To observe the effect of dexamethasone (Dex) on the apoptosis of osteoblasts and explore its mechanism, as well as provide a new therapeutic idea for GC­induced osteoporosis and ONFH. MATERIAL AND METHODS: Cell proliferation and apoptosis of MC3T3-E1 cells after Dex treatment were determined using the CellTiter-Glo® Luminescent Cell Viability Assay kit and Annexin V-FITC/PI Double Staining Apoptosis Detection Kit, respectively. The expression of caspase-3/cleaved caspase-3 and poly(ADP-ribose) polymerase (PARP)/cleaved PARP in MC3T3-E1 cells after Dex treatment was determined with western blotting. The expression of p53 and checkpoint kinase 2 (Chk2) in MC3T3-E1 cells after Dex treatment was analyzed using western blotting and polymerase chain reaction (PCR). The effects of p53 knockdown and Chk2 knockdown on Dex-induced apoptosis of MC3T3-E1 cells were also characterized. RESULTS: Dexamethasone remarkably inhibited cell growth and induced the apoptosis of MC3T3-E1 cells. We also observed that Dex induced osteoblast apoptosis by promoting p53 expression. The regulatory effect of Dex on p53 expression is mediated by the upregulation of Chk2, which interacted with p53 and inhibited p53 degradation. The knockdown of p53 alleviated Dex-induced MC3T3-E1 cell apoptosis by decreasing the expression of cleaved caspase-3 and cleaved PARP. CONCLUSIONS: We demonstrated that Dex increased Chk2 protein expression, which stabilized the protein expression of p53, and in turn promoted osteoblast apoptosis.

Neural wedge osteotomy method of correction for cubitus varus deformity in children.

In this study, we evaluated the clinical outcome of neutral wedge osteotomy assisted with the center of rotation of angulation (CORA) method of distal humerus anatomical axis for the treatment of cubitus varus deformity in children. From 2016 to 2019, 20 children with cubitus varus deformity after supracondylar fracture of the humerus were enrolled. Standard anteroposterior radiograph of the humerus was taken preoperatively. The CORA point and angulation angles were obtained by measuring the proximal and distal humerus anatomical axis. During the operation, neutral wedge osteotomy was performed to correct the varus deformity. The Baumann angle and the carrying angle were used to evaluate the correction effect of the distal humeral varus deformity. The average age of the patients was 7.8 years. Patients were followed up for an average of 29.3 months (range, 24-36 months). The average interval between surgery and injury was 12 months. The mean preoperative Baumann angle and carrying angle were 99° (90°-115°) and -14° (range, -10° to -30°), respectively. At the last follow-up, the mean Baumann angle and carrying angle was 76° (70°-80°) and 13.6° (10°-18°), respectively, with 16 cases showing excellent outcome and 4 cases showing good outcome. Our results indicated that the neutral wedge osteotomy assisted with CORA method of distal humerus anatomical axis showed good clinical outcomes in the treatment of cubitus varus deformity in children and is worthy of clinical application. The level of evidence is IV.

Open Reduction of Displaced Radial Neck Fractures in Children by Internal Fixation Techniques: Comparison of Percutaneous Kirschner Wiring and Elastic Stable Intramedullary Nailing.

Background: Although most paediatric radial neck fractures can be treated with closed reduction, some severely displaced fractures require open reduction. The purpose of this study is to compare the effects of ESIN and KW fixation in open reduction of radial neck fracture in children. Methods: Twenty-four patients with mean age of 8.5 years were included. Four of the patients had a Judet type III fracture and 20 had a Judet type IV fracture. Ten patients who underwent percutaneous KW fixation were assigned to group A, while 14 patients who underwent ESIN fixation were assigned to group B. Variables of interest included age, sex, fracture type, associated lesions, surgical time, fracture reduction, cost, follow-up, healing time, X-rays, clinical outcomes, and complications. Results: There were no significant between-group differences in sex, age, additional injuries, fracture type, and quality of reduction. Costs were significantly lower in Group A. Fracture healing was achieved in 23 of 24 patients (10/10 in group A and 13/14 in group B). In a postoperative elbow function assessment based on the Steele and Graham classification, 80% of patients in group A had a score of excellent or good, compared to 78.6% of patients in group B. Two cases of nail shifting and joint protrusion were observed in group B, one of which also presented with nonunion during follow-up. Conclusions: Both KW and ESIN may achieve good clinical outcomes, but KW is associated with lower costs, easier implant removal (without the need for a secondary surgery), and lower iatrogenic complications.

MiR-132/212 promotes the growth of precartilaginous stem cells (PCSCs) by regulating Ihh/PTHrP signaling pathway.

Precartilaginous stem cells (PCSCs) are adult stem cells that can initiate chondrocytes and bone development. In the present study, we explored whether miR-132/212 was involved in the proliferation of PCSCs via Hedgehog signaling pathway. PCSCs were isolated and purified with the fibroblast growth factor receptor-3 (FGFR-3) antibody. Cell viability, DNA synthesis and apoptosis were measured using MTT, BrdU and flow cytometric analysis. The mRNA and protein expression were detected by real-time PCR and Western blot, respectively. The target gene for miR-132/212 was validated by luciferase reporter assay. Results showed that transfection with miR-132/212 mimic significantly increased cell viability and DNA synthesis, and inhibited apoptosis of PCSCs. By contrast, miR-132/212 inhibitor could suppress growth and promote apoptosis of PCSCs. Luciferase reporter assays indicated that transfection of miR-132/212 led to a marked reduction of luciferase activity, but had no effect on PTCH1 3'-UTR mutated fragment, suggesting that Patched1 (PTCH1) is a target of miR-132/212. Furthermore, treatment with miR-132/212 mimics obviously increased the protein expression of Indian hedgehog (Ihh) and parathyroid hormone related protein (PTHrP), which was decreased after treatment with Hedgehog signaling inhibitor, cyclopamine. We also found that inhibition of Ihh/PTHrP signaling by cyclopamine significantly suppressed growth and DNA synthesis, and induced apoptosis in PCSCs. These findings demonstrate that miR-132/212 promotes growth and inhibits apoptosis in PCSCs by regulating PTCH1-mediated Ihh/PTHrP pathway, suggesting that miR-132/212 cluster might serve as a novel target for bone diseases.