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BackgroundIntra-articular injection of tranexamic acid (TXA) is known to be effective in controlling blood loss after total knee arthroplasty (TKA). However, this method has some disadvantages, such as TXA leakage due to soft tissue release. Peri-articular injection provides an alternative to intra-articular administration of TXA. This study aimed to evaluate the effects of peri-articular injection of TXA in reducing blood loss after TKA and compare them to those of intra-articular TXA injection.MethodsThis was a retrospective analysis of 127 patients who underwent primary, unilateral TKA for knee osteoarthritis in our hospital between January 2014 and December 2014. Cases were classified into 3 comparison groups: 49 patients in the peri-articular TXA group, 36 in the intra-articular group, and 42 in the control group (TXA not administered). Demographic variables, hemoglobin (Hb) measured before and after surgery, operation time, total amount of drained volume, time of removing drains, units of blood transfused peri- and postoperatively, estimated volume of blood loss, and preoperative comorbidities were retrieved from the patients’ medical charts. Statistical analyses were performed using SPSS 19.0 software.ResultsThere were no significant differences of demographic variables and operation time among three groups (P > 0.05). Compared to the control group, both TXA groups had a significantly reduced volume of blood loss, postoperative knee joint drainage, hemoglobin concentration, time of removing drains, and need for blood transfusion (P < 0.05). The effects of TXA were comparable for the two methods of injection (P > 0.05). There were no deep venous thrombosis or thromboembolic complications in any group.ConclusionsPeri-articular injection of TXA is as effective as an intra-articular injection in reducing postoperative blood loss during TKA. Both methods had a statistically significant benefit in reducing the change in Hb concentration, volume of joint drainage, and estimated volume of blood loss when compared to the control group. Peri-articular injection of TXA can significantly reduce the blood transfusion rate compared to the control group.

BackgroundBoth copper deficiency and overexposure have been associated with adverse health effects. Evidence linking copper to bone mineral density (BMD) and total fracture, however, is limited.MethodsThis nationally representative cross-sectional study enrolled participants from the National Health and Nutrition Examination Survey (2011–2014) in the United States. Using unadjusted and multivariate adjusted logistic regression analyses and a two-piecewise linear regression model with a smoothing function, we evaluated the associations between serum copper levels, bone mineral density and total fracture in 722 participants.ResultsThe study sample (n = 722, mean age: 56.47 ± 11.55 y) represented a population of which 47.2% were men; 43.91% were non-Hispanic white, 18.84% non-Hispanic black and 13.71% Mexican American; 25.9% had total fracture. In the multivariate logistic regression analysis, individuals in the lowest category (<98.5 μg/dL) of serum copper concentration had 0.049 g/cm2 lower total femur BMD and 0.045 g/cm2 lower femoral neck BMD than those in the second concentration category (98.5–114 μg/dL). Individuals in the highest category (≥134 μg/dL) of serum copper concentration had an approximately 4-fold increase in the risk of total fracture than those in the second concentration category. There were no significant associations between per 10 μg/dL increases in serum copper levels and total fracture in multivariate logistic regression analysis after multivariate adjustment (all p > 0.05). However, a differential association between serum copper levels and total fractures between men and women was observed (odds ratio = 1.81, 95% confidence interval 1.08–3.03, p = 0.026 for men and odds ratio = 1.07, 95% confidence interval 0.86–1.32, p = 0.552 for women).ConclusionModerate serum copper levels are critically important for bone health. Lower serum copper levels are significantly associated with decreased BMD in the total femur and femoral neck. Higher serum copper levels are significantly associated with increased total fracture, especially in men.The Translational Potential of this ArticleThe impact of serum copper concentrations on bone mineral density and total fracture can provide insights into clinical application of copper-containing supplements and biomaterials.

Bone-related infection rates are 4–64% in long open bone fractures and nearly 1% in joint-related surgeries. Treating bone infections and infection-related bone loss is very important. The present study prepared strontium ranelate (SR)-loaded poly(lactic-co-glycolic acid) (PLGA) microspheres (PM) with assembled silver nanoparticles (AgNPs) and hydroxyapatite nanoparticles (HANPs) (SR-PM-Ag-HA) through a novel solid-in-oil nanosuspension (S/O/N) method to achieve osteoinductivity and antibacterial properties. We evaluated the microstructure, drug release, biocompatibility, osteoinductivity, and antibacterial activity in vitro. The microspheres showed a stable shape and size. The cumulative drug release reached a maximum of ∼90% after 22 days. All groups loaded with SR enhanced MC3T3-E1 cell proliferation to a greater degree than pure PM. The osteoinductivity behavior was investigated by ALP staining and real-time PCR of osteogenic differentiation marker genes. The antibacterial activity was evaluated using antibacterial ability and biofilm formation assays. SR-PM-Ag-HA greatly enhanced osteogenic differentiation and showed excellent antibacterial properties. These results indicated that SR-PM-Ag-HA could be biocompatible and suitable for drug delivery, osteoinduction, and antibiosis, and therefore, have potential applications in the treatment of bone-related infections and promotion of bone formation at infected sites.