Tranexamic acid can reduce blood loss in adolescent scoliosis surgery: a systematic review and meta-analysis.

BACKGROUND: Tranexamic acid (TXA) has been widely used in orthopedic surgery, but its efficacy in adolescent scoliosis (AS) surgery remains unclear in the literature. The purpose of this systematic review and meta-analysis is to evaluate the safety and efficacy of TXA compared to placebo treatment during or after AS surgery, by gathering data from randomized both controlled trials (RCTs) and non-RCTs. METHODS: English and Chinese electronic databases including PubMed, Web of Science, Embase, Cochrane, CNKI, and Wan Fang database were searched to identify the relevant literature up until August 2022. The primary outcomes were intraoperative blood loss and total blood loss. The secondary outcomes included the need for transfusion, postoperative hemoglobin (Hb) level, and change in Hb level. Stata 17 was used for data analysis and the risk of bias was assessed. We followed the PRISMA checklist to ensure the quality of this article. RESULTS: Twelve studies (795 participants) were included in the meta-analysis for intraoperative blood loss during surgery. The results suggest that TXA can reduce the intraoperative blood loss of the patients (MD = -306.40ml, 95%CI = -404.04ml to -208.77ml, p < 0.001). Six studies (2027 patients) were included in the meta-analysis for total blood loss. The pooled result shows that the total blood loss of the TXA group was significantly lower than that of the control group (MD = -779.24ml, 95% CI = -1157.10ml to -410.39ml, p < 0.001). Five studies (419 patients) were included in the meta-analysis for postoperative Hb level and shows a non-significant outcome (MD = 5.09 g/l, 95%CI = 2.92 g/l to 7.25 g/l, p = 0.611). Three studies (268 patients) were included in the meta-analysis for the postoperative Hb level. There is a non-significant decrease in the TXA group (MD = -0.23 g/l, 95%CI = -0.48 g/l to 0.01 g/l, p = 0.319). Eight studies (670 patients) reported data on the need for transfusion after surgery. The overall relative risks (RR) showed a significant difference between the TXA and control group, with a lower risk of transfusion in the TXA group (RR = 0.547, 95%CI = 0.308 to 0.972, p = 0.04). CONCLUSIONS: The meta-analysis of the data reveals that TXA usage is associated with a significant reduction in intraoperative and total blood loss, a lower risk of transfusion, and a non-significant change in postoperative Hb levels in AS surgery However, it should be noted that the surgical operation situations varied across different studies. Therefore, further research is required to investigate the effects of TXA on specific subgroups of gender, operation time, and blood transfusion indicators. Overall, our study provides valuable evidence for the clinical management of AS surgery and may inform the development of practice guidelines and protocols for the use of TXA in this setting.

A novel nanohydroxyapatite/polyamide-66 cage for reducing the subsidence rate after single-level anterior cervical discectomy and fusion: a comparative study of 7-year follow-up.

BACKGROUND: A novel nanohydroxyapatite/polyamide-66 cage (n-HA/PA66 cage) with a horseshoe shape was designed to lower the subsidence rate of the traditional hollow cylindrical n-HA/PA66 cage. However, no studies have compared the incidence of subsidence in the two cages. The purpose of this study was to compare the long-term clinical and radiological outcomes of the novel n-HA/PA66 cage with the hollow cylindrical n-HA/PA66 cage after anterior cervical discectomy and fusion (ACDF) to treat single-level cervical degenerative disk disease (CDDD). METHODS: Fifty-two patients with novel n-HA/PA66 cages (Group A) and fifty-five patients with hollow cylindrical n-HA/PA66 cages (Group B) were included. The radiological parameters included intervertebral height (IH), C2-7 angle (C2-7a), segmental alignment (SA), subsidence rate, and fusion rate. The clinical outcomes were visual analog scale (VAS) scores, Japanese Orthopedic Association (JOA) scores, and patient satisfaction rates. RESULTS: The pre- and postoperative SA, C2-7a, and fusion rates of the patients in Groups A and B were similar. The preoperative and 6-month postoperative IHs in both groups were comparable. However, the final follow-up IH in Group B was significantly smaller than that in Group A (35.9 mm vs. 36.7 mm). The difference in the subsidence rates at the final follow-up between Group A (5.8%, 3/52) and Group B (18.2%, 10/55) was significant. The VAS score, JOA score, and patient satisfaction rate were not significantly different. CONCLUSIONS: The novel n-HA/PA66 cage had similar favorable SA, C2-7a, fusion rate, and clinical outcomes compared to the hollow cylindrical n-HA/PA66 cage for treating single-level ACDF. Moreover, the novel n-HA/PA66 cage achieved a lower subsidence rate and higher IH than the hollow cylindrical n-HA/PA66 cage at the final follow-up.

Preparation and characterization of biomimetic gradient multi-layer cell-laden scaffolds for osteochondral integrated repair.

A cell-laden tissue engineering scaffold for osteochondral integrated repair is one of the ideal strategies for osteochondral lesions. In this study, we fabricated cell-laden porous hydrogel scaffolds with gradient nano-hydroxyapatite using methacrylic anhydride gelatin (GelMA), nano-hydroxyapatite (nHA), and polyethylene oxide (PEO) solution for osteochondral tissue regeneration. The scaffold possessed interconnected pores and a nano-hydroxyapatite gradient in the vertical direction. The chemical, physical, mechanical, and biological properties of the hydrogel solutions and scaffolds were characterized. In vitro experiments confirmed that cells were distributed homogeneously and that different pore structures could affect the proliferation and differentiation of BMSCs. The Nonporous hydrogel was beneficial for the chondrogenic differentiation of BMSCs and interconnected pores were conducive to BMSC proliferation and osteogenic differentiation. The osteochondral integrative repair capacity of the scaffold was assessed by implanting the scaffolds into the intercondylar defect of the rabbit femur. By constructing pore structures in different layers, the cells in different layers of the hydrogels were in an intrinsic environment for survival and differentiation. Animal experiments confirmed that tissue engineering scaffolds for osteochondral lesions require different pore structures in different layers, and gradient structure facilitated integrated repair.

MiR-155 inhibition alleviates suppression of osteoblastic differentiation by high glucose and free fatty acids in human bone marrow stromal cells by upregulating SIRT1.

Diabetic osteoporosis is a severe and chronic complication of diabetes in the bone and joint system, and its pathogenesis is needed to be explored. In the present study, we examined the effect and underlying mechanism of miR-155 on osteogenic differentiation in human bone marrow-derived mesenchymal stem cells (hBMSCs) under high glucose and free fatty acids (HG-FFA) conditions. It was shown that miR-155 levels in hBMSCs increased corresponding to the time of exposure to HG-FFA treatment. MiR-155 expression was altered by transfecting miR-155 mimic or miR-155 inhibitor. HG-FFA exposure resulted in an obviously decrease in cell viability and alkaline phosphatase (ALP) activity, and downregulated the expressionof runt-related transcription factor 2 (Runx2) and osteocalcin (OCN) in hBMSCs. Transfection of miR-155 mimic further exacerbated HG-FFA-induced inhibitory effect on osteogenic differentiation, and miR-155 inhibitor neutralized this inhibitory effect. Luciferase assays confirmed that SIRT1 was a direct target of miR-155 and can be negatively modulated by miR-155. Furthermore, SIRT1 siRNA partially counteracted miR-155 inhibitor-induced upregulation of SIRT1in HG-FFA-treated hBMSCs. SIRT1 siRNA also reversed the promotional effect of the miR-155 inhibitor on ALP activity and expression of the Runx2 and OCN proteins under HG-FFA conditions. In conclusion, the results suggest that miR-155 suppression promoted osteogenic differentiation of hBMSCs under HG-FFA conditions by targeting SIRT1. Inhibition of MiR-155 may provide a new therapeutic method for the prevention and treatment of diabetic osteoporosis.

SIRT1 suppresses high glucose and palmitate-induced osteoclast differentiation via deacetylating p66Shc.

Findings concerning the role of diabetes mellitus (DM) in osteoclast differentiation are contradictory in vivo and in vitro. Sirtuin 1 (SIRT1) can inhibit RANKL-induced osteoclastogenesis and deacetylate p66Shc suppress its phosphorylation in high glucose (HG)-stimulated human umbilical vein endothelial cells. This study aimed to investigate the role and mechanism of SIRT1 in DM-related osteoclast differentiation. Osteoclast precursors were cultured with HG and palmitate (PA), with or without resveratrol/sirtinol. TRAP staining was used to evaluate osteoclast formation. The expression of SIRT1, RANK, RANKL, OPG, NFATc1, TRAP, c-fos, p66Shc, phospho-p66Shc (S36), phospho-NF-κBp65 (p-p65), and IκB was determined by real-time PCR or western blotting. Lysine acetylation of p66Shc was assayed by immunoprecipitation. Reactive oxygen species (ROS) production was analyzed by DCFH-DA fluorescence. p66Shc siRNA and PDTC were used to confirm the mechanism of SIRT1 in osteoclastogenesis. We found HG and PA enhanced osteoclast differentiation, decreased SIRT1 and OPG expression, and increased levels of RANK, RANKL, NFATc1, TRAP, and c-fos. Upregulation of SIRT1 by resveratrol inhibited HG- and PA-induced osteoclast differentiation, whereas sirtinol further enhanced it. Resveratrol suppressed lysine acetylation and S36 phosphorylation of p66Shc, ROS production, and NF-κB activation induced by HG and PA, while sirtinol boosted these processes. p66Shc siRNA abrogated HG- and PA-induced ROS production and NF-κB activation. In addition, p66Shc siRNA and PDTC greatly suppressed the expression of RANK and RANKL induced by HG and PA. In conclusion, this study confirms the role of DM in osteoclast differentiation in vitro. SIRT1 suppresses HG- and PA-induced osteoclast differentiation via p66Shc/ROS/NF-κB signaling.

MiR-449 overexpression inhibits osteogenic differentiation of bone marrow mesenchymal stem cells via suppressing Sirt1/Fra-1 pathway in high glucose and free fatty acids microenvironment.

Diabetic osteoporosis is a chronic complication caused by diabetes mellitus, and However, the exact mechanism of diabetes mellitus-induced osteoporosis is still unknown. In this study, we investigate the effect of miR-449 on osteogenic differentiation and its underlying mechanism in human bone marrow-derived mesenchymal stem cells (hBMSCs) with high glucose (HG) and free fatty acids (FFA) treatment. Results showed that after culturing for 14 days, high glucose (HG) and free fatty acids (FFA) treatment dramatically decreased mineralization of human bone marrow-derived mesenchymal stem cells (hBMSCs) compared with cells treated with osteogenic medium (OM) alone. We also found that miR-449 expression was up-regulated during osteogenic differentiation of hBMSCs with HG and FFA treatment. Moreover, during osteogenic differentiation of hBMSCs with HG and FFA treatment, miR-449 mimics notably decreased the alkaline phosphatase (ALP) activity and the mRNA and protein expression levels of runt-related transcription factor 2 (Runx2), ALP, collagen I, osteocalcin (OCN), and bone sialoprotein (BSP), which was remarkably increased by miR-449 inhibitors. Furthermore, miR-449 directly targets Sirt1 by binding to its 3'-UTR. Sirt1 overexpression reverses the suppressive effect of miR-449 mimics on Fra-1 mRNA and protein expression, which was also alleviated by Fra-1 overexpression. In addition, Fra-1 overexpression alleviates the inhibitory effect of miR-449 mimics on the ALP activity and the mRNA and protein of Runx2, collagen I, OCN and BSP. Taken together, our results indicated that miR-449 overexpression inhibited osteogenic differentiation of HG-FFA-treated hBMSCs through the Sirt1/Fra-1 signal pathway. It is conceivable that modulating miR-449 might provide a new therapy for intervention in diabetic osteoporosis.