[Three-dimensional printing combined with distal humeral osteotomy for cubital varus deformity in children].

OBJECTIVE: To explore clinical effect of three-dimensional(3D) printing combined with distal humerus osteotomy for children with cubital varus deformity. METHODS: From January 2017 to January 2020, 17 cubital varus deformity children treated with distal humerus osteotomy were retrospective analysis, included 11 boys and 6 girls, aged from 5 to 11 years old with an average of (7.8±1.7) years old. A model of affected side elbow joint was made by 3D printing technique before operation, pre-operation was performed on the model. Three-dimensional model was successfully used for distal humeral osteotomy during operation. Carrying angle, flexion and extension angle of elbow joint were compared before and six months after operation, and Flynn scoring criteria was used to evaluate clinical effect. RESULTS: All children were followed up for 6 to 12 months with an avergae of (9.6±1.7) months. One child occurred wound infection and healed completely after dressing change. No complications such as nonunion, internal fixation and nerve injury occurred. Carrying angle of affected limb was improved from (-20.8±2.4)°before operation to (7.2±2.3)°at 6 months after operation (P<0.01). Angle of affected elbow joint extension improved from (-5.6±3.9)° before opeation to(-2.6±2.1)°at 6 months after operation (P<0.01). There was no significant difference in extension angle of elbow joint between preopertaion and postopertaion at 6 months (P>0.05). While there was no difference in elbow joint function on the healthy side and affected side at 6 months after opertaion (P>0.05). According to Flynn scoring criteria, 13 patients got excllent results and 4 moderate. CONCLUSION: Three-dimensional printing combined with distal humerus osteotomy in treating elbow varus deformity could receive satisfactory clinical effect, which could accurately assist correction of cubital varus deformity, restore physiological structure and function of elbow joint.

A Systematic Review and Meta-Analysis of 3D Printing Technology for the Treatment of Acetabular Fractures.

PURPOSE: Three-dimensional (3D) printing technology has been widely used in orthopedics surgery. However, its efficacy in acetabular fractures remains unclear. The aim of this systematic review and meta-analysis was to examine the effect of using 3D printing technology in the surgery for acetabular fractures. METHODS: The systematic review was performed following the PRISMA guidelines. Four major electronic databases were searched (inception to February 2021). Studies were screened using a priori criteria. Data from each study were extracted by two independent reviewers and organized using a standardized table. Data were pooled and presented in forest plots. RESULTS: Thirteen studies were included in the final analysis. Four were prospective randomized trials, and nine used a retrospective comparative design. The patients aged between 32.1 (SD 14.6) years and 51.9 (SD 18.9) years. Based on the pooled analyses, overall, 3D printing-assisted surgery decreased operation time by 38.8 minutes (95% CI: -54.9, -22.8), intraoperative blood loss by 259.7 ml (95% CI: -394.6, -124.9), instrumentation time by 34.1 minutes (95% CI: -49.0, -19.1). Traditional surgery was less likely to achieve good/excellent function of hip (RR, 0.53; 95% CI: 0.34, 0.82) and more likely to have complications than 3D printing-assisted surgery (RR, 1.19; 95% CI: 1.07, 1.33). CONCLUSIONS: 3D printing technology demonstrated efficacy in the treatment of acetabular fractures. It may improve surgery-related and clinical outcomes. More prospective studies using a rigorous design (e.g., randomized trial with blinding) are warranted to confirm the long-term effects of 3D printing technology in orthopedics surgeries.

[Effectiveness analysis of Lenke type 1 adolescent idiopathic scoliosis with different proximal fixation vertebra].

Objective: To investigate the short-term effectiveness of proximal fixation of one vertebra above to the upper end vertebra and the upper end vertebra in the treatment of Lenke type 1 adolescent idiopathic scoliosis (AIS) patients with preoperative right higher shoulder. Methods: The clinical data of 37 Lenke type 1 AIS patients treated with posterior correction between January 2010 and December 2015 were retrospectively analysed. According to proximal fixation vertebra, the patients were divided into 2 groups: group A ( n=17), proximal fixation of one vertebra above to the upper end vertebra; group B ( n=20), proximal fixation of the upper end vertebra. There was no significant difference in gender, age, Risser stage, radiographic shoulder height (RSH), flexibility of proximal thoracic curve, flexibility of main thoracic curve, flexibility of thoracolumbar/lumbar curve between 2 groups ( P>0.05). The main thoracic curve Cobb angle, proximal thoracic curve Cobb angle, thoracolumbar/lumbar curve Cobb angle, apical vertebral translation (AVT), clavicle angle (CA), RSH, coronal trunk shift, sagittal trunk shift, thoracic kyphosis (TK), and lumbar lordosis (LL) were measured by X-ray film before operation, and at 1 month, 1 year, and 2 years after operation. The correction indexes of main thoracic curve were evaluated, including the correction degree and correction rate of main thoracic curve and AVT correction at 1 month after operation, the loss degree and the loss rate of the correction of main thoracic curve at 2 years after operation. Results: The operation time and intraoperation blood loss in group A were significantly greater than those in group B ( P<0.05). All the patients were followed up, and the follow-up time was 2-4 years (mean, 2.8 years) in group A and 2-3.5 years (mean, 2.6 years) in group B. No serious complication such as nerve damage occurred during perioperative period and follow-up period. No complication such as failure of fusion, loosening and rupture of internal fixator, adjacent segment degeneration, and proximal junctional kyphosis occurred. There was no significant difference between 2 groups in the correction degree and correction rate of main thoracic curve and AVT correction at 1 month after operation, the loss degree and the loss rate of the correction of main thoracic curve at 2 years after operation ( P>0.05). Comparison within the two groups: except for LL had no significant difference between pre- and post-operation ( P>0.05), the other indicators were significantly improved after operation ( P<0.05) in the two groups. There were significant differences in RSH, CA, proximal thoracic curve Cobb angle, and thoracolumbar/lumbar curve Cobb angle at each time point after operation ( P<0.05), and there were spontaneous correction during follow-up; however, there was no significant difference in main thoracic curve Cobb angle, AVT, TK, LL, trunk shift at each time point after operation ( P>0.05), and there was no significant loss during follow-up. Comparison between the two groups: there was no significant difference in all the radiographic indexes at pre- and post-operation ( P>0.05). Conclusion: For Lenke type 1 AIS patients with preoperative right high shoulder, proximal fixation vertebra be fixed to the upper end vertebral can obtain satisfactory short-term orthopedic effectiveness and reduce blood loss and operation time.

lncRNAPVT1 targets miR-152 to enhance chemoresistance of osteosarcoma to gemcitabine through activating c-MET/PI3K/AKT pathway.

BACKGROUND: LncRNA PVT1 has been reported to be involved in a variety of biological processes, including cell proliferation, cell differentiation and cancer progression. However, the mechanism by which LncRNA PVT1 contributes to chemoresistance of osteosarcoma cell, has not been fully elucidated. METHODS: We first generatedLncRNA PVT1-overexpressed MG63 cells and LncRNA PVT1 knockdown MG63/DOX cells. Then, we examined the effect of LncRNA PVT1 on cell viability and colony formation ability by MTT assay and soft agar assay, respectively. In addition, we performed flow cytometry analysis to detect apoptosis induced by GEM. Dual luciferase reporter assay and RIP were used to confirmed the interaction between LncRNA PVT1 and miR-152. Finally, we determined protein level of c-MET, p-PI3K, and p-AKT by westernblot. RESULTS: LncRNA PVT1 overexpression promoted cell proliferation and exhibited the anti-apoptotic property in LncRNA PVT1-overexpressing MG63 cells treated with gemcitabine. While, LncRNA PVT1-depleted MG63/DOX cells treated with gemcitabine exhibited significant lower survival rate and high percentage of apoptosis. Next, we found that LncRNA PVT1 could target and downregulated the level of miR-152. Interestingly, miR-152 greatly rescued the biological outcomes of LncRNA PVT1 not only in MG63 but also in MG63/DOX cells. We observed that LncRNA PVT1 markedly induced PI3K/AKT pathway activation, which was abolished by miR-152 mimics overexpression. Finally, c-MET inhibitor was used to confirm the essential role of c-MET in LncRNA PVT1 and miR-152-regulated PI3K/AKT signaling. CONCLUSION: We showed thatlncRNA PVT1 played a contributory role in chemoresistance of osteosarcoma cells through c-MET/PI3K/AKT pathway activation, which was largely dependent on miR-152. Our findings advance our understanding of how lncRNA PVT1 promotes chemoresistance of osteosarcoma cells and facilitate development of novel strategies for treating osteosarcoma.

miRNA-133b targets FGFR1 and presents multiple tumor suppressor activities in osteosarcoma.

BACKGROUND: Osteosarcoma (OS) is the most common bone malignancy prevalent in children and young adults. MicroRNA-133b (miR-133b), through directly targeting the fibroblast growth factor receptor 1 (FGFR1), is increasingly recognized as a tumor suppressor in different types of cancers. However, little is known on the biological and functional significance of miR-133b/FGFR1 regulation in osteosarcoma. METHODS: The expressions of miR-133b and FGFR1 were examined by RT-qPCR and compared between 30 paired normal bone tissues and OS tissues, and also between normal osteoblasts and three OS cells lines, MG-63, U2OS, and SAOS-2. Using U2OS and MG-63 as the model system, the functional significance of miR-133b and FGFR1 was assessed on cell viability, proliferation, apoptosis, migration/invasion, and epithelial-mesenchymal transition (EMT) by overexpressing miR-133b and down-regulating FGFR1 expression, respectively. Furthermore, the signaling cascades controlled by miR-133b/FGFR1 were examined. RESULTS: miR-133b was significantly down-regulated while FGFR1 robustly up-regulated in OS tissues and OS cell lines, when compared to normal bone tissues and normal osteoblasts, respectively. Low miR-133b expression and high FGFR1 expression were associated with location of the malignant lesion, advanced clinical stage, and distant metastasis. FGFR1 was a direct target of miR-133b. Overexpressing miRNA-133b or knocking down FGFR1 significantly reduced the viability, proliferation, migration/invasion, and EMT, but promoted apoptosis of both MG-63 and U2OS cells. Both the Ras/MAPK and PI3K/Akt intracellular signaling cascades were inhibited in response to overexpressing miRNA-133b or knocking down FGFR1 in OS cells. CONCLUSION: miR-133b, by targeting FGFR1, presents a plethora of tumor suppressor activities in OS cells. Boosting miR-133b expression or reducing FGFR1 expression may benefit OS therapy.