Objective To identify the efficacy and safety of multiple doses of intravenous tranexamic acid (IV‐TXA) following primary total knee arthroplasty (TKA) with a tourniquet. Methods This is a single‐blind randomized controlled study that recruited osteoarthritis patients who had undergone primary unilateral TKA from May 2019 to May 2020 at our medical center. A total of 300 patients were randomly divided into three groups to receive: one dose (1 g) of IV‐TXA before skin incision combined with one dose (1.5 g) of intra‐articular tranexamic acid（IA‐TXA) followed by a single dose of IV‐TXA (1 g) for 3 h (group A); two doses of IV‐TXA (1 g) for 3 and 6 h (group B); or three doses of IV‐TXA (1 g) for 3, 6, and 12 h (group C) postoperatively. TKA with a tourniquet was performed by the same surgical team. The primary outcomes were total blood cell loss (TBL), hidden blood loss (HBL), maximum hemoglobin (Hb) drop, and transfusion rate. Secondary outcomes were levels of C‐reactive protein (CRP) and D‐dimer, and the incidence of postoperative complications. One‐way analysis of variance, subgroup analysis, and multivariate correlation analysis were used to calculate the differences among the three groups. Results The study included 56 male and 244 female patients aged 60–80 years. The mean TBL, the mean HBL, and the maximum Hb drop in group C (471.2 ± 190.6 mL, 428.4 ± 190.3 mL, and 21.2 ± 3.8 g/L, respectively) were significantly lower than those in groups B (563.4 ± 224.6 mL, P = 0.030; 519.9 ± 226.4 mL, P = 0.033; and 23.2 ± 4.1 g/L, P = 0.001, respectively), and A (651.6 ± 254.1 mL, P < 0.001; 607.1 ± 254.3 mL, P < 0.001; and 25.1 ± 4.3 g/L, P < 0.001, respectively). No transfusions were required. The postoperative acute inflammatory reaction was less problematic for patients in Group C, and the incidence of thromboembolic events was similar among the groups (P > 0.05). In addition, there were positive correlations between the HBL and the tourniquet inflation time (r = 0.844, P < 0.001). Similarly, the level of CRP on POD1 (r = 0.393, P < 0.001) and POD3 (r = 0.149, P = 0.010), and the level of D‐dimer on POD1 (r = 0.382, P < 0.001) were positively correlated with the HBL. Conclusion Three doses of postoperative IV‐TXA decreased blood loss and diminished the postoperative inflammatory and fibrinolytic response more than a single dose or two doses in elderly patients following TKA without increasing the incidence of adverse events.

This study provides new evidence that Cyr61 participates in RA pathogenesis not only as a pro-inflammatory factor but also plays a key role in bone erosion via promoting MMP-3 expression. We suggest that targeting of Cyr61 may represent a potential strategy in RA treatment.

Introduction: Knee osteoarthritis (KOA) is characterized by a degenerative change of knee cartilage and secondary bone hyperplasia, resulting in pain, stiffness, and abnormal walking gait. Long-term chronic pain causes considerable cortical plasticity alternations in patients. However, the brain structural and functional alterations associated with the pathological changes in knee joints of end-stage KOA patients remain unclear. This study aimed to analyze the structural and functional connectivity alterations in end-stage KOA to comprehensively understand the main brain-associated mechanisms underlying its development and progression. Methods: In this study, 37 patients with KOA and 37 demographically matched healthy controls (HCs) were enrolled. Alternations in gray matter (GM) volume in patients with KOA were determined using voxel-based morphometry. The region with the largest GM volume alteration was selected as the region of interest to calculate the voxel-wise resting-state functional connectivity (rs-FC) in the two groups. Pearson's correlation coefficient was used to analyze the correlation between clinical measures and GM volume alternations in patients with KOA. Results: Compared with HCs, patients with KOAs exhibited significantly decreased GM volumes in the left middle temporal gyrus (left-MTG) and the left inferior temporal gyrus. Results of the voxel-wise rs-FC analysis revealed that compared with HCs, patients with KOA had decreased left-MTG rs-FC to the right dorsolateral superior frontal gyrus, left middle frontal gyrus, and left medial superior frontal gyrus. GM volume in the left-MTG was negatively correlated with the Western Ontario and McMaster Universities Arthritis Index in patients with KOA (r = −0.393, p = .016). Conclusion: Structural remodeling and functional connectivity alterations may be one of the central brain mechanisms associated with end-stage KOA.

Background We aimed to determine the efficacy and safety of multiple doses of intravenous tranexamic acid (IV-TXA) on perioperative blood loss in patients with rheumatoid arthritis (RA) who had undergone primary unilateral total knee arthroplasty (TKA). Methods For this single-center, single-blind randomized controlled clinical trial, 10 male and 87 female participants with RA, aged 50–75 years, who underwent unilateral primary TKA were recruited. The patients received one dose of 1 g IV-TXA 10 min before skin incision, followed by articular injection of 1.5 g tranexamic acid after cavity suture during the surgery. The patients were randomly assigned (1:1) into two groups and received an additional single dose of IV-TXA (1 g) for 3 h (group A) or three doses of IV-TXA (1 g) for 3, 6, and 12 h (group B) postoperatively. Primary outcomes were total blood loss (TBL), hidden blood loss (HBL), and maximum hemoglobin (Hb) level decrease. Secondary outcomes were transfusion rate and D-dimer levels. All parameters were measured postoperatively during inpatient hospital stay. Results The mean TBL, HBL, and maximum Hb level decrease in group B (506.1 ± 227.0 mL, 471.6 ± 224.0 mL, and 17.5 ± 7.7 g/L, respectively) were significantly lower than those in group A (608.8 ± 244.8 mL, P = 0.035; 574.0 ± 242.3 mL, P = 0.033; and 23.42 ± 9.2 g/L, P = 0.001, respectively). No episode of transfusion occurred. The D-dimer level was lower in group B than in group A on postoperative day 1 (P <  0.001), and the incidence of thromboembolic events was similar between the groups (P > 0.05). Conclusion In patients with RA, three doses of postoperative IV-TXA further facilitated HBL and Hb level decrease without increasing the incidence of adverse events in a short period after TKA. Trial registration The trial was registered in the Chinese Clinical Trial Registry (ChiCTR1900025013).