Pengbin Yin

Red Cell Distribution Width as an Independent Predictor of Long-Term Mortality in Hip Fracture Patients: A Prospective Cohort Study.

Red blood cell distribution width (RDW) has been found to be a significant prognostic factor of mortality in many cardiovascular diseases. However, a link between RDW at admission with long‐term mortality in the hip fracture population has not been well established. Therefore, we sought to evaluate the long‐term prognostic value of RDW in a well‐defined hip fracture cohort, and to compare the effect of RDW in patients with and without anemia. A prospective cohort study was performed on 1479 hip fracture patients admitted at the General Hospital of Chinese PLA between January 2000 and October 2011 with a follow‐up study over a 2‐year period. A total of 1479 patients were used for the evaluation of 2‐year all‐cause mortality, while 804 patients with more than 4 years of follow‐up were extracted for further evaluation of 4‐year all‐cause mortality. Cox proportional regression was used to evaluate the association between admission RDW and long‐term mortality, adjusting for potential confounding variables. Higher RDW values were strongly associated with increased all‐cause mortality. After adjusting for age, mean corpuscular volume, admission hemoglobin, comorbidities, and complications, RDW had a significant independent association with both 2‐year mortality with a hazard ratio (HR) of 1.183 (95% confidence interval [CI], 1.017 to 1.376) and 4‐year mortality with an HR of 1.244 (95% CI, 1.052 to 1.471). In stratified analysis, the effect of RDW was even more pronounced, with 2‐year mortality HR of 1.341 (95% CI, 1.095 to 1.643) and 4‐year mortality HR of 1.345 (95% CI, 1.071 to 1.688) in non‐anemic patients. In non‐anemic patients, elevated RDW values are significantly associated with increased odds of all‐cause mortality, implying that RDW may be a possible laboratory biomarker for risk stratification in non‐anemic hip fracture patients. Further studies are needed to confirm the current finding in different and larger hip fracture cohorts.

Correlation between Parameters of Calcaneal Quantitative Ultrasound and Hip Structural Analysis in Osteoporotic Fracture Patients

Background Calcaneal quantitative ultrasound (QUS), which is used in the evaluation of osteoporosis, is believed to be intimately associated with the characteristics of the proximal femur. However, the specific associations of calcaneal QUS with characteristics of the hip sub-regions remain unclear. Design A cross-sectional assessment of 53 osteoporotic patients was performed for the skeletal status of the heel and hip. Methods We prospectively enrolled 53 female osteoporotic patients with femoral fractures. Calcaneal QUS, dual energy X-ray absorptiometry (DXA), and hip structural analysis (HSA) were performed for each patient. Femoral heads were obtained during the surgery, and principal compressive trabeculae (PCT) were extracted by a three-dimensional printing technique-assisted method. Pearson’s correlation between QUS measurement with DXA, HSA-derived parameters and Young’s modulus were calculated in order to evaluate the specific association of QUS with the parameters for the hip sub-regions, including the femoral neck, trochanteric and Ward’s areas, and the femoral shaft, respectively. Results Significant correlations were found between estimated BMD (Est.BMD) and BMD of different sub-regions of proximal femur. However, the correlation coefficient of trochanteric area (r = 0.356, p = 0.009) was higher than that of the neck area (r = 0.297, p = 0.031) and total proximal femur (r = 0.291, p = 0.034). Furthermore, the quantitative ultrasound index (QUI) was significantly correlated with the HSA-derived parameters of the trochanteric area (r value: 0.315–0.356, all p<0.05) as well as with the Young’s modulus of PCT from the femoral head (r = 0.589, p<0.001). Conclusion The calcaneal bone had an intimate association with the trochanteric cancellous bone. To a certain extent, the parameters of the calcaneal QUS can reflect the characteristics of the trochanteric area of the proximal hip, although not specifically reflective of those of the femoral neck or shaft.

Anemia on Admission Is an Independent Predictor of Long-Term Mortality in Hip Fracture Population: A Prospective Study With 2-Year Follow-Up

Abstract Anemia is a disputable factor for long-term mortality in hip fracture population in previous studies. Previous studies indicated that the level of hemoglobin (Hb) might fluctuate due to various factors, such as comorbidities and in-hospital interventions, and the changing level of Hb, may lead to discordance diagnosis of anemia and thus to the conflicting conclusions on prognostic value of anemia. So in this study, we aim to compare factors affecting the diagnosis of anemia at different time-points, admission, postoperation, and discharge, and to determine which the time point is most suitable for mortality prediction. This prospective cohort study included 1330 hip fracture patients from 1 January 2000 to 18 November 2012. Hb levels at 3 different time points, such as admission, postoperation, and discharge, were collected and used to stratify the cohort into anemia and nonanemia groups. Candidate factors including commodities, perioperative factors, blood transfusion, and other in-hospital interventions were collected before discharge. Logistic regression analyses were performed to detect risk factors for anemia for the 3 time points separately. Kaplan–Meier and multivariate Cox regression analyses were used to evaluate the association between anemia and 2-year mortality. Factors affecting the diagnosis of anemia were different for the 3 time points. Age, female sex, American Society of Anesthesiologists score (ASA), and intertrochanteric fracture were associated with admission anemia, while surgical procedure, surgical duration, blood transfusion, blood loss during the operation, and drainage volume were major risk factors for postoperation anemia. Cox proportional-hazards regression analysis suggested that the risk of all-cause mortality was higher in the anemia group on admission (1.680, 95%CI: 1.201–2.350, P < 0.01), but not postoperation or on discharge, after adjustment for confounding factors. Our study showed that risk factors for anemia varied at different time points, and therapy interventions would greatly affect the status of postoperation and discharge anemia in hip fracture patients. The take-home message is when anemia is used for mortality prediction in these patients, a specific time point should be chosen. We suggest that only admission anemia should be used for mortality prediction, but not postoperation nor discharge anemia.

Exosome-Mediated Genetic Information Transfer, a Missing Piece of Osteoblast–Osteoclast Communication Puzzle

The skeletal system functions and maintains itself based on communication between cells of diverse origins, especially between osteoblasts (OBs) and osteoclasts (OCs), accounting for bone formation and resorption, respectively. Previously, protein-level information exchange has been the research focus, and this has been discussed in detail. The regulative effects of microRNAs (miRNAs) on OB and OC ignite the question as to whether genetic information could be transferred between bone cells. Exosomes, extracellular membrane vesicles 30–100 nm in diameter, have recently been demonstrated to transfer functional proteins, mRNAs, and miRNAs, and serve as mediators of intercellular communication. By reviewing the distinguishing features of exosomes, a hypothesis was formulated and evaluated in this article that exosome-mediated genetic information transfer may represent a novel strategy for OB–OC communication. The exosomes may coordinately regulate these two cells under certain physiological conditions by transferring genetic information. Further research in exosome-shuttered miRNAs in OB–OC communication may add a missing piece to the bone cells communication “puzzle.”

A meta-analysis and systematic review evaluating the use of erythropoietin in total hip and knee arthroplasty

Purpose The debate is still ongoing on the effectiveness and safety of erythropoietin (EPO) treatment in orthopedic surgeries. Specifically, previous studies have not compared the dynamic change of hemoglobin (Hb) levels between different transfusion methods. Besides, complications or side effects of this alternative have not been quantitatively analyzed. We conducted a meta-analysis and systemic review to evaluate the efficacy of EPO on Hb levels observed during the whole perioperative period as well as the volume of allogeneic blood transfusion (ABT), the risk of venous thromboembolism, and application frequency of ABT in hip and knee surgery. Materials and methods PubMed, Embase, Web of Science, and the Cochrane library were systematically searched from inception to November 2017. The data from randomized controlled trials were extracted and the risk of bias assessed using Cochrane’s Collaboration’s tool. Results Twenty-five randomized controlled trials involving 4,159 patients were included in this meta-analysis. EPO could reduce exposure to allogeneic blood transfused (odds ratio [OR] =0.42, P=0.001) and reduce the average volume of allogeneic blood transfused (OR = −0.28, P=0.002). When EPO and preoperative autologous blood donation (PABD) were compared, the use of EPO was associated with lower exposure to ABT (OR =0.48, P=0.03), but no significant decrease in the average volume of allogeneic blood transfused (OR = −0.23, P=0.32). The use of EPO was associated with a higher level of Hb with or without use of PABD at all the 4 time points (preoperation, 24–48 hours postoperation, 3–5 days postoperation, discharge of last observation) (P<0.0001), which means EPO could increase the level of Hb significantly during the perioperative period. The results also indicated EPO does not increase the risk of a venous thromboembolism event. Conclusion Preoperative administration of EPO was shown to generally increase Hb levels during the whole perioperative period; however, the extent of the positive effects varies with time points. Additionally, EPO minimizes the need for transfusion significantly in patients undergoing hip or knee surgery without increasing the chance of developing thrombotic complications. Therefore, EPO offers an alternative blood management strategy in total hip arthroplasty and total knee arthroplasty.

Hip fracture patients who experience a greater fluctuation in RDW during hospital course are at heightened risk for all-cause mortality: a prospective study with 2-year follow-up

SummaryThis study aims to detect whether there remains valuable prognostic information in fluctuation of red cell distribution width (RDW) in hip fracture patients. Results show that this readily available parameter may provide a more effective strategy for assessment of mortality risk, therefore providing a reference for clinical planning and decision-making.IntroductionPrognostic values have been found in the fluctuation of some hematologic parameters. The red cell distribution width (RDW) routinely reported with all complete blood cell counts (CBC) has proven to be associated with poor outcomes in various diseases. However, whether the fluctuation in RDW is predictive of long-term mortality in hip fracture patients treated with surgery remains unknown.MethodsOne thousand three hundred thirty hip fracture patients who underwent surgery from January 1, 2000 to November 18, 2012 were recruited in this prospective cohort study. Fluctuation in the RDW between admission and discharge was measured, and a Kaplan-Meier (KM) analysis and multivariable Cox regression model were applied to evaluate the relationship between this fluctuation and mortality. Risk factors for a larger fluctuation were detected by using Logistic regression analyses.ResultsIn addition to the admission RDW, a high RDW level at the time of discharge was also associated with an increased risk of death, while no significant difference was found in the postoperative RDW. Fluctuation in the RDW between admission and discharge was an independent risk predictor for 2-year mortality (HR 1.45 95%CI 1.06–2.00, p = 0.022). Factors affecting the change in the RDW between admission and discharge included both the demographic characteristics of the patients and clinical interventions.ConclusionHip fracture patients who experience a greater fluctuation in RDW during the hospital course are at a heightened risk for 2-year all-cause mortality.

Exchange of genetic material: a new paradigm in bone cell communications

An emerging concept in intercellular communication in mammals is that communication can be mediated by exchange of genetic material, mainly in the form of RNAs. In this review, we discuss recent studies that describe the trafficking of genetic material with a focus on bone cell communication. Three major carriers are discussed: gap junctions, protein-binding complexes, and genetic material exchange mediated by extracellular vesicles. While protein-level exchange has been well documented, no review has summarized the novel paradigm of cell-to-cell communication by genetic information exchange in bone tissues or its biological relevance in terms of bone homeostasis and bone-related diseases. The purpose of this review is to promote further understanding of this novel discovery regarding bone cell communication and provide references for further investigations.

Semaphorin 3A: A Potential Target for Low Back Pain

Low back pain is a common disorder. Pathological innervation and intervertebral disc degeneration are two major factors associated with this disease. Semaphorin 3A, originally known for its potent inhibiting effect on axonal outgrowth, is recently found to correlate with disease activity and histological features in some skeletal disorders. Based on its effects on innervation and vascularization, as well as enzyme secretion, we presume that semaphorin 3A may act as a potential target for low back pain.