An injectable, biodegradable calcium phosphate cement containing poly lactic-co-glycolic acid as a bone substitute in ex vivo human vertebral compression fracture and rabbit bone defect models.

Purpose/Aim of the study: To evaluate the biomechanical characteristics and biocompatibility of an injectable, biodegradable calcium phosphate cement (CPC) containing poly lactic-co-glycolic acid (PLGA). MATERIALS AND METHODS: A vertebral compression fracture model was established using 20 human cadaveric vertebrae (T11-L3) divided into CPC/PLGA composite versus PMMA groups for biomechanical testing. In addition, 35 New Zealand rabbits were used to evaluate biodegradability and osteoconductive properties of CPC/PLGA using a bone defect model. In vitro cytotoxicity was evaluated by culturing with L929 cells. RESULTS: The CPC/PLGA composite effectively restored vertebral biomechanical properties. Compared with controls, the maximum load and compression strength of the CPC/PLGA group were lower, and stiffness was lower after kyphoplasty (all p <.05). Degradation was much slower in the control CPC compared with CPC/PLGA group. The bone tissue percentage in the CPC/PLGA group (44.9 ± 23.7%) was significantly higher compared with control CPC group (25.7 ± 10.9%) (p <.05). The viability of cells cultured on CPC/PLGA was greater than 70% compared with the blanks. CONCLUSIONS: Our biodegradable CPC/PLGA composite showed good biomechanical properties, cytocompatibility, and osteoconductivity and may represent an ideal bone substitute for future applications.

Expression patterns of transcription factor PPARγ and C/EBP family members during in vitro adipogenesis of human bone marrow mesenchymal stem cells.

In the past decades increasing lines of evidence have demonstrated that adipose tissue, as an endocrine organ plays a central role in metabolic homeostasis and its related maladies. CCAAT/enhancer-binding protein (C/EBP) family members and the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) were known to be the vital transcription factors in the regulation of adipogenesis. However, the exact mechanism for increased marrow fat in patients with bone metabolic diseases, such as osteoporosis, is still poorly understood. Herein, we studied the expression pattern of PPARγ and C/EBPs in human bone marrow mesenchymal stem cell (hBMSC) adipogenesis and evaluated the effects of individual components of an adipogenic cocktail on the differentiation and transcription factor expression. We furthermore examined whether the ERK signaling pathway was involved in mediating these effects. These findings showed that C/EBPß and C/EBPδ were detected in undifferentiated hBMSC and maintained during the whole process of adipogenesis, and could initiate the expression of PPARγ1 under the treatment of dexamethasone and IBMX. Subsequently, the activation of PPARγ1 by indomethacin, its exogenous ligand, activated C/EBPα, which, together with IBMX, up-regulated PPARγ2 expression and therefore the fullest adipogenesis. Insulin and its downstream signal pathway extracellular signal-regulated kinases (ERK), however, were found not necessary for hBMSC adipogenesis. Our results revealed some unique characteristics of human adipocyte formation, which may help to understand the molecular mechanisms of bone marrow adipogenesis and give insights into the treatment of osteoporosis.

Blood transfusion and drainage catheter clamping are associated with ecchymosis formation at the surgical site after total knee arthroplasty: an analysis of 102 unilateral cases.

BACKGROUND: Many previous studies have focused on the postoperative complication of postoperative knee pain, infection, knee prosthesis loosening, periprosthetic fractures, and so on. There have been few studies focused on postoperative ecchymosis formation surrounding the wound of the TKA site. A certain degree of effect on the early functional recovery of the patients may occur due to the mental stress caused by the ecchymosis, which raises doubts regarding the success of the surgery. Therefore, it is particularly important to understand the risk factors for postsurgical ecchymosis formation after TKA, and specific measures for preventing ecchymosis should be taken. In this study, we reviewed the record of patients who received TKAs in our hospital, and a comprehensive analysis and assessment was conducted regarding 15 clinical factors causing postsurgical ecchymosis formation. METHODS: The records of 102 patients who received unilateral TKAs between January 2007 and May 2010 were retrospectively analyzed. Patients were divided into two groups based on the occurrence of ecchymosis. RESULTS: Of the 102 patients, 14 (13.7%) developed ecchymosis. Blood transfusion and drainage catheter clamping during the first few postoperative hours had a significant impact on the development of ecchymosis (p < 0.05). There was no difference in age, BMI, operation time, pre- and postoperative platelet count, and length of postoperative anticoagulant therapy between the two groups. Multivariate logistic regression revealed major risk factors for ecchymosis were postoperative blood transfusion (odds ratio (OR) = 15.624) and drainage catheter clamping (OR 14.237) (both, p < 0.05). CONCLUSION: Blood transfusion and drainage catheter clamping after TKA due to excessive blood suction were associated with higher risks for ecchymosis formation surrounding the surgical site.

Total hip arthroplasty for vascular necrosis of the femoral head in patients with systemic lupus erythematosus: a midterm follow-up study of 28 hips in 24 patients.

OBJECTIVE: Avascular necrosis of the femoral head is one of the most frequently reported complications in patients with systemic lupus erythematosus (SLE) and often requires total hip arthroplasty (THA). Our objective was to analyze the perioperative management, technical problems, clinical outcomes, and complications associated with THA in patients with SLE. METHODS: A total of 28 total hip arthroplasties performed for 24 patients with SLE, including 19 women and 5 men with a mean age of 38.8 years performed from 1998 to 2011 were retrospectively reviewed. SLE disease activity index and ASA class were evaluated preoperatively. WOMAC, HHS, and SF-36 scores were also evaluated in all cases pre- and post-operatively for functional recovery of the hip and health-related quality of life (HRQOL). RESULTS: The average SLE disease activity index was 3.5 points. Three patients were in ASA class I, 12 class II, and 9 were class III (37.5%). The average duration of follow-up was 67.5 months. None of the patients required a revision, and 3 patients died during the follow-up period. A statistically significant improvement in all scores was found comparing pre- and post-operative conditions (P < 0.001). The complication rate was 11.1% with 2 wound infections and 1 urinary tract infection. CONCLUSION: THA is an acceptable method for achieving functional recovery and increasing HRQOL in patients with SLE and ANFH who receive proper perioperative management.

Bone morphogenetic protein 4 is involved in cadmium-associated bone damage.

Cadmium (Cd) is a well-characterized bone toxic agent and can induce bone damage via inhibiting osteogenic differentiation. Bone morphogenetic protein (BMP)/SMAD signaling pathway can mediate osteogenic differentiation, but the association between Cd and BMP/SMAD signaling pathway is yet to be illuminated. To understand what elements of BMPs and SMADs are affected by Cd to influence osteogenic differentiation and if BMPs can be the biomarkers of which Cd-induced osteoporosis, human bone marrow mesenchymal stem cells (hBMSCs) were treated with cadmium chloride (CdCl2) in vitro to detect the expression of BMPs and SMADs, and 134 subjects were enrolled to explore if the BMPs can be potential biomarkers of Cd-associated bone damage. Our results showed that Cd exposure significantly promoted the adipogenic differentiation of hBMSCs and inhibited its osteogenic differentiation by inhibiting the expression of BMP-2/4, SMAD4, and p-SMAD1/5/9 complex. And mediation analyses yielded that BMP-4 mediated 39.32% (95% confidence interval 7.47, 85.00) of the total association between the Cd and the risk of Cd-associated bone damage. Moreover, during differentiation, BMP-4 had the potential to enhance mineralization compared with CdCl2 only group. These results reveal that BMP-4 can be a diagnostic biomarker and therapeutic target for Cd-associated bone damage.

miRNA expression profile during osteogenic differentiation of human adipose-derived stem cells.

Human adipose-derived stem cells (hADSC) are capable of differentiating into an osteogenic lineage. It is believed that microRNAs (miRNAs) play important roles in regulating this osteogenic differentiation of human adipose-derived cells, although its molecular mechanism remains unclear. We investigated the miRNA expression profile during osteogenic differentiation of hADSCs, and assessed the roles of involved miRNAs during the osteogenic differentiation. We obtained and cultured human adipose-derived stems cells from donors who underwent elective liposuction or other abdominal surgery at our institution. miRNA expression profiles pre- and post-osteogenic induction were obtained using microarray essay, and differently expressed miRNAs were verified using quantitative real-time polymerase chain reaction (qRT-PCR). The expression of osteogenic proteins was detected using an enzyme-linked immunosorbent assay. Putative targets of the miRNAs were predicted using online software MiRanda, TargetScan, and miRBase. Eight miRNAs were found differently expressed pre- and post-osteogenic induction, among which four miRNAs (miR-17, miR-20a, miR-20b, and miR-106a) were up-regulated and four miRNAs (miR-31, miR-125a-5p, miR-125b, and miR-193a) were down-regulated. qRT-PCR analysis further confirmed the results. Predicted target genes of the differentially expressed miRNAs based on the overlap from three public prediction algorithms: MiRanda, TargetScan, and miRBase Target have the known functions of regulating stem cell osteogenic differentiation, self-renewal, signal transduction, and cell cycle control. We identified a group of miRNAs that may play important roles in regulating hADSC cell differentiation toward an osteoblast lineage. Further study of these miRNAs may elucidate the mechanism of hADSC differentiation into adipose tissue, and thus provide basis for tissue engineering.

The influence of body mass index on life quality and clinical improvement after total hip arthroplasty.

BACKGROUND: The effect of body mass index (BMI) on the outcome of total hip arthroplasty (THA) remains controversial. The purpose of this study was to examine whether revision rate and postoperative outcomes following THA were influenced by BMI. MATERIALS AND METHODS: We retrospectively evaluated 714 patients (751 hips) who underwent primary THA in our department between March 1991 and April 2006. They were followed prospectively for 5-20 years with 24 deaths (24 hips) and 33 losses (34 hips). Patients were separated into three groups based on BMI: underweight, normal and obese groups. A survival analysis was performed using revision as the endpoint, and a case-matched study that was matched for age, gender, and laterality was designed; outcomes were assessed with the Harris Hip score, 36-item short-form health survey, complication rate and radiological examination. RESULTS: The preoperative scores were lower for the obese group, and the postoperative scores were higher for the normal group. Patients in the obese group obtained the greatest overall improvement in clinical scores from admission to the last follow-up. We found a significantly higher complication rate in the obese group and underweight group. It appears that being underweight was associated with an increased dislocation rate, and obese patients were more likely to have osteolysis, deep vein embolism, and pulmonary thrombosis. The log rank test for survival showed no significant differences among the three groups. CONCLUSIONS: Abnormal BMI does not prevent functional rehabilitation after THA; however, patients with abnormal BMI have to face higher complication rates and poorer clinical outcomes following this operation.

Effect of 3 different anticoagulants on hidden blood loss during total hip arthroplasty after tranexamic acid.

Comparison of different anticoagulants in blood management and complications with tranexamic acid (TXA) in total hip arthroplasty (THA) is unclear. Our aim was to compare the efficacy and safety among receiving nadroparin calcium, enoxaparin sodium or rivaroxaban after TXA in THA.150 patients undergoing primary unilateral THA were received 15 mg/kg intravenous TXA (IV-TXA) before skin incision, followed by 1 of nadroparin calcium (Group A), enoxaparin sodium (Group B), or rivaroxaban (Group C) randomly during hospitalization. The primary outcome was hidden blood loss (HBL). Other outcomes such as the maximum hemoglobin (Hb) drop, total blood loss (TBL), the volume of drainage, transfusion rate, length of hospital stay (LOS), and complications were also compared.There were no statistically significant differences in HBL, the maximum hemoglobin (Hb) drop, transfusion rate, and complications among 3 groups. LOS was significantly higher for patients in Group B than Group A (P = .026). Neither deep venous thrombosis (DVT) nor pulmonary embolism (PE) occurred in any group.There were no differences in efficacy and safety in patients undergoing THA receiving nadroparin calcium, enoxaparin sodium, or rivaroxaban after anti-fibrinolysis with TXA.