Per- and polyfluoroalkyl substances exposure and bone mineral density in the U.S. population from NHANES 2005-2014.

BACKGROUND: Environmental exposures such as perfluoroalkyl substances (PFASs) were considered potential risks for bone mineral density (BMD). OBJECTIVE: To examine the associations between PFASs and BMD among the U.S. population. METHODS: This study included a total of 6416 participants from the National Health and Nutrition Examination Survey (NHANES 2005-2014). Multiple linear regression models were used to analyze the associations between serum PFASs and BMD and the coefficient ß with 95% confidence intervals (95% CI) was calculated as the effect estimate. Covariates such as age, race, BMI, smoking, alcohol intake, milk intake, and physical activity were adjusted in these models. Additionally, gender and menopausal period were considered in further subgroup analyses. RESULTS: Based on the combined data of NHANES 2005-2014, the effects from exposure to PFASs on BMD were found with gender and menopausal status differences. Positive associations were found in PFOA (ß = 0.010; 95% CI: 0.003, 0.016), PFHxS (ß = 0.007; 95% CI: 0.003, 0.012), and PFNA (ß = 0.001; 95% CI: 0.001, 0.017) in total population. Negative associations for PFOA (ß = -0.020; 95% CI: -0.029, -0.012), PFOS (ß = -0.011; 95% CI: -0.028, -0.011), PFHxS (ß = -0.019; 95% CI: -0.025, -0.013), PFDE (ß = -0.010; 95% CI: -0.016, -0.005), and PFNA (ß = -0.011; 95% CI: -0.021, -0.002) were found in women, while no significant association was found in men. In further subgroup analyses, women in pre-menopause status showed consistent negative associations. SIGNIFICANCE: PFASs exposure may be associated with BMD and gender and menopausal status confound the associations.

A phase III randomized, double-blind, placebo-controlled trial of the denosumab biosimilar QL1206 in postmenopausal Chinese women with osteoporosis and high fracture risk.

The current study evaluated the efficacy and safety of a denosumab biosimilar, QL1206 (60 mg), compared to placebo in postmenopausal Chinese women with osteoporosis and high fracture risk. At 31 study centers in China, a total of 455 postmenopausal women with osteoporosis and high fracture risk were randomly assigned to receive QL1206 (60 mg subcutaneously every 6 months) or placebo. From baseline to the 12-month follow-up, the participants who received QL1206 showed significantly increased bone mineral density (BMD) values (mean difference and 95% CI) in the lumbar spine: 4.780% (3.880%, 5.681%), total hip :3.930% (3.136%, 4.725%), femoral neck 2.733% (1.877%, 3.589%) and trochanter: 4.058% (2.791%, 5.325%) compared with the participants who received the placebo. In addition, QL1206 injection significantly decreased the serum levels of C-terminal crosslinked telopeptides of type 1 collagen (CTX): -77.352% (-87.080%, -66.844%), and N-terminal procollagen of type l collagen (P1NP): -50.867% (-57.184%, -45.217%) compared with the placebo over the period from baseline to 12 months. No new or unexpected adverse events were observed. We concluded that compared with placebo, QL1206 effectively increased the BMD of the lumbar spine, total hip, femoral neck and trochanter in postmenopausal Chinese women with osteoporosis and rapidly decreased bone turnover markers. This study demonstrated that QL1206 has beneficial effects on postmenopausal Chinese women with osteoporosis and high fracture risk.

Efficacy of Yigu® versus Aclasta® in Chinese postmenopausal women with osteoporosis: a multicenter prospective study.

Zoledronic acid (ZOL) is a therapy inhibiting bone resorption. In this study, generic ZOL (Yigu®) showed its clinical efficacy consistency with original ZOL (Aclasta®) in Chinese postmenopausal women with osteoporosis. This study provides a practical basis for the application of Yigu® in Chinese population. INTRODUCTION: Yigu® has been approved its bioequivalence to Aclasta®. However, the clinical efficacy and safety of Yigu® have not been evaluated yet. Here, we compared the effectiveness and safety between Yigu® and Aclasta® in Chinese postmenopausal women with osteoporosis and assessed the efficacy of intravenous infusion of ZOL. METHODS: This was a randomized open-label, active-controlled study in postmenopausal women with osteoporosis of 14 clinical centers in China. Postmenopausal women with osteoporosis were recruited and randomized to receive a single infusion of 5 mg Yigu® or Aclasta®. The primary endpoint was the percentage change in bone mineral density (BMD) at lumbar spine after 12 months of treatment and was assessed for equivalence. The secondary endpoint was the percentage change in BMD at proximal femur after 12 months. Additional secondary endpoints were percentage changes in BMD at the above sites after 6 months of treatment and changes in bone turnover biomarkers during ZOL treatment. Safety was also evaluated and compared between two groups. RESULTS: A total of 458 postmenopausal women with osteoporosis were enrolled (n = 227, Yigu®; n = 231, Aclasta®). The mean percentage change in the BMD had no statistical difference at the lumbar spine (5.32% vs 5.18%), total hip (2.72% vs 2.83%), and femoral neck (2.37% vs 2.81%) between Yigu® and Aclasta® groups after 12 months of treatment. The mean difference of BMD change at the lumbar spine after 12 months between two groups was 0.15% (95% CI: - 0.71 to 1.00, equivalence margin: - 1.5%, 1.5%), demonstrating the treatments were equivalent. Meanwhile, the decreases in the P1NP and ß-CTX showed no difference between two groups after 14 days and 6 and 12 months of treatment. As regards the whole sample, BMD significantly increased after 12 months of treatment. Also, serum C-terminal telopeptide of type 1 collagen (ß-CTX) and procollagen 1 N-terminal peptide (P1NP) significantly decreased at each visit period. The overall adverse events were comparable and quite well between two groups. CONCLUSION: Intravenous infusion of zoledronic acid achieved the potent anti-resorptive effects which led to significant increase in BMD of Chinese postmenopausal women with osteoporosis. Yigu® was equivalent to Aclasta® with respect to efficacy and safety.

MAKO robotic assisted total hip replacement (THR) for patients with fused hips.

BACKGROUND: Previous articles about MAKO robotic-assisted total hip replacement (THR) were mainly in patients with comparatively normal anatomy. METHODS: From July 2020 to June 2021, we performed MAKO robotic-assisted THR in three hip-fused patients. We assessed the accuracy of prostheses implantation, collected clinical data, and discussed the value of this technique in this kind of patients. RESULT: All three patients achieved good leg length and prostheses position. A patient got femoral artery injury during the surgery. Moreover, she developed a thrombus. All three patients got acceptable Visual Analogue Scale scores and function recovery 6 months later. CONCLUSION: MAKO robotic-assisted THR achieved excellent prosthesis position in hip fused patients. More cases are needed to confirm this advantage. The function recovery was acceptable. Caution should be paid to protect the surrounding abnormal arteries, especially in a limited surgical field.

Should corticosteroids be administered for local infiltration analgesia in knee arthroplasty? A meta-analysis and systematic review.

WHAT IS KNOWN AND OBJECTIVE: The benefits of local infiltration analgesia (LIA) in knee arthroplasty (KA) have been well-documented. However, it is unknown whether adding a corticosteroid to the composition of the LIA is beneficial. This study aimed to investigate the efficacy and safety of administering periarticular steroids intraoperatively in patients who underwent KA through a systematic review and meta-analysis. METHODS: A systematic search was conducted to identify relevant randomized controlled trials in the PubMed, Embase, Web of Science and Cochrane databases up to January 19th, 2021 to perform a meta-analysis. Outcome variables included pain scores, total opioid consumption, knee range of motion (ROM) and postoperative complications. RESULTS: Corticosteroid injections did not reduce pain scores at 6, 12, 24 or 72 h postoperatively, although a minimal degree of transient pain relief was achieved at 48 h postoperatively compared with those in the placebo group, nor was there a significant difference in total opioid consumption. However, patients receiving corticosteroids did exhibit a transient ROM increase on postoperative days 1, 2 and 3. Since the minimal clinically important difference (MCID) for ROM is unclear, it is unknown if the improvement in ROM is clinically significant. WHAT IS NEW AND CONCLUSION: Our specific end-point analysis demonstrated that corticosteroid administration did not provide pain relief or reduce opioid consumption compared with placebo. However, corticosteroids might provide a statistically significant, though transient and minimal improvement in knee ROM after KA, although no firm conclusions about the benefits of administering corticosteroids in KA can be made based on the available evidence.

Microbiology of Periprosthetic Hip and Knee Infections in Surgically Revised Cases from 34 Centers in Mainland China.

BACKGROUND AND AIM: Periprosthetic joint infection (PJI) is one of the most devastating complications after total joint arthroplasty (TJA). However, the antibiotic resistance of infecting pathogens can significantly vary in different parts of the country. In the current study, we analyzed the demographic and microbiological profiles of knee and hip PJI over three years and compared the microbiological differences between them. METHODS: A multicenter retrospective study of PJI patients in 34 referral medical centers in mainland China from January 2015 to November 2017 was performed. RESULTS: A total of 925 PJI patients were recruited, 452 were identified as knee PJIs, and 473 were hip PJIs. The most common causative pathogens were Staphylococcus aureus (26.5%) and coagulase-negative staphylococci (14.3%). Methicillin-resistant staphylococci were involved in 25.6% (237/925) of all PJI cases. Mycobacterium and fungus only accounted for 6.5% (61) of all cases. Enteric gram-negative bacilli, anaerobes, and polymicrobial pathogens were more common in hip joint prostheses than in knee PJI (P = 0.014; P = 0.006; P = 0.002, respectively). CONCLUSION: While the majority of causative pathogens in PJI cases are staphylococcal species, the prevalence of atypical organisms and resistant pathogens should also be given attention and warrant the need for empiric antibiotic treatment.

Oral Bisphosphonate Therapy for Osteogenesis Imperfecta: A Systematic Review and Meta-Analysis of Six Randomized Placebo-Controlled Trials.

OBJECTIVE: To assess the effectiveness and safety of oral bisphosphonates in increasing bone mineral density (BMD), reducing fractures, and improving clinical function in patients with osteogenesis imperfecta (OI). METHODS: Studies were eligible for inclusion if they were randomized controlled trials of directly comparing oral bisphosphonate therapy with placebo-group in OI patients. Data synthesis regarding to bone mineral density as measured by dual-energy X-ray absorptiometry (DEXA), decreased fracture incidence, change in biochemical markers of bone and mineral metabolism, bone histology, growth, bone pain, quality of life, and others were assessed, and meta-analysis done when possible. RESULTS: From 98 potential references and six randomized controlled studies a total of 263 participants receiving oral bisphosphonates and 143 placebo treatments contributed data to meta-analysis. Pooled meta-analysis of three studies suggested that there was significant difference between bisphosphonate treated group and placebo in number of patients with at least one fracture (mean difference 0.53, 95% confidence interval 0.32-0.89, P = 0.02). Pooled meta-analysis of two studies suggested that significant difference was noted between bisphosphonate treated group and placebo in mean percentage change in spine BMD (T-score) (mean difference 28.43, 95% confidence interval 7.09-49.77, P = 0.009). The similar effect was shown in the term of mean change (Z-score) in spine BMD. CONCLUSIONS: Significant improvement in lumbar areal BMD in patients affected with OI has been shown when treated with oral bisphosphonates, even though only a small population was enrolled. We cannot draw a definite conclusion that the increase in BMD can be translated into fracture reduction and clinical functional improvement. The optimal method, dose, type, initiation, and duration of oral bisphosphonates therapy still remains unclear. Well-designed, adequately-powered, placebo-controlled RCTs investigating the effects of oral bisphosphonates on fractures reduction and improvement in quality of life in both children and adults are studied here.

[Progress on prevention and treatment of heterotopic ossification].

Heterotopic ossification is the formation of pathological bone in non-skeletal tissues (including muscles, tendons or other soft tissues), and the pathogenesis is not completely clear. It is often caused by musculoskeletal trauma, postoperative bone and joint surgery, or damage of the nervous system, the clinical manifestations are joint swelling, pain, and movement disorders, which often occur around the hips, knees, and elbows. At present, the prevention of heterotopic ossification mainly includes drugs, radiotherapy, molecular biological mechanism intervention, and Chinese medicine-related measures. Among them, drugs and radiotherapy are more effective methods to prevent heterotopic ossification. The intervention of molecular biology mechanism to prevent heterotopic ossification has become a new research direction and focus of attention inrecent years, and is basically at the experimental research stage. The treatment of heterotopic ossification includes various methods such as drugs, physical therapy, and surgery. Among them, surgery is recognized as the most effective treatment, however there are still some controversies and disagreements about the choice of operation time and surgical methods.

The Posterolateral Corner-Locked Technique Is Applicable in a Chinese Population Regarding the Tibial Component Rotation Alignment in Total Knee Arthroplasty.

Rotational malalignment between the femoral and tibial components in total knee arthroplasty (TKA) can affect clinical outcomes, but there is no consensus on how to best determine tibia tray orientation. The posterolateral corner-locked (PLCL) technique may be a new method. This study aims to assess the applicability of this technique in a Chinese population. Forty normal Chinese volunteers were recruited and underwent computed tomography (CT) of the lower limbs. Knee model reconstructions and simulated standard tibial osteotomy were conducted digitally. The transepicondylar axis (TEA), the Akagi line, and the line connecting the medial third of the tibial tubercle with the midpoint of the posterior cruciate ligament (PCL) were projected to the tibial cross-section and marked. The PLCL technique was applied using either symmetrical or asymmetrical tibial tray templates, and the anteroposterior (AP) axis of the tibial tray was marked. The angles between the TEA and these lines were calculated, and the statistical differences were analyzed. The angle between the TEA and the Akagi line and between the TEA and the line connecting the medial third of the tibial tubercle with the midpoint of the PCL were 96.90 ± 5.57 and 107.31 ± 5.95 degrees, respectively. The angles between the TEA and the AP axis of the symmetrical and the asymmetrical design tibial trays were 94.01 ± 4.21 and 96.65 ± 4.70 degrees, respectively. Except for the Akagi line and AP axis of the asymmetrical tibial tray, statistical differences were found between all lines (p < 0.05). The PLCL technique is principally suitable for Chinese patients requiring TKA when using the tibial component referred to in this study, although it may result in slight external rotation.

Debridement, antibiotics, and implant retention for periprosthetic knee infections: a pooling analysis of 1266 cases.

BACKGROUND: The debridement, antibiotics, and implant retention (DAIR) procedure is an established therapeutic option for periprosthetic knee infections (PKI). However, the efficacy and the indication for this procedure are still controversial. METHODS: All the relevant literatures were systematically reviewed and analyzed. The present study aimed to assess the success rate of DAIR in the management of PKI, identify the factors associated with prognosis of DAIR, and establish a simple algorithm for predicting a high success rate of DAIR. RESULTS: Totally, 33 studies with 1266 cases were included. The overall success rate following DAIR in the management of PKI was 57.11%. In the subgroup analyses, the factors of "the time from symptoms to debridement was < 3 weeks" and "the bacterial species other than methicillin-resistant Staphylococcus aureus" significantly improved the success rate of DAIR and thus were defined as the major criteria. The statistically insignificant factors of "the open debridement and liner exchange" and "the comorbidity of rheumatoid arthritis" were set as the minor criteria. The success rate of DAIR for PKI meeting all the major criteria and no less than one minor criterion was 80.98%, which was significantly higher than the overall success rate of DAIR (p < 0.05). CONCLUSION: PKI cases meeting two major criteria and no less than one minor criterion may confer a high success rate of DAIR. This simple algorithm may contribute to identifying the appropriate PKI patient for DAIR treatment and predicting the prognosis of DAIR.

[Double plating through different approaches for periprosthetic femoral fracture following total knee arthroplasty].

OBJECTIVE: To study clinical effects of double plating through different approaches for communicated and obvious osteoporosis periprosthetic femoral fracture following total knee arthroplasty(TKA). METHODS: From July 2010 to June 2017, 21 patients with periprosthetic femoral fracture following TKA were divided into two groups according to operative approach. Fifteen patients in medial and lateral double approaches group, including 5 males and 10 females aged from 63 to 79 years old with an average of (67.2±5.9) years old; 11 patients were type 33-A2 and 4 patients were type 33-A3 according to AO-OTA classification; 12 patients injured by falling down and 3 patients by traffic accident; treated with double plating. Six patients in medial parapatellar approach group, including 3 males and 3 females, aged from 61 to 74 years old with an average of (64.6±6.0) years old; 3 patients were type 33-A2 and 3 patients were type 33-A3 according to AO-OTA classification; 5 patients injured by falling down and 1 patient by traffic accident; treated with double plating. Operative time, blood loss, postoperative drainage, fracture healing time were compared between two groups; HSS score and radiology at 3 and 12 months were compared between two groups. RESULTS: All patients were followed up, and the follow-up time of bilateral approaches group ranged from 12 to 18 months with an average of (14.2±2.6 ) months, while the follow-up time of single approach group ranged from 12 to 16 months with an average of (12.6±2.5) months, and there was no statistical difference between two groups. The operative time and postoperative drainage in bilateral approaches group were (107.2±10.4) min and (213.9±30.4) ml, while in sigle approach group was (95.4±12.8) min and (256.8±34.2) ml, and the differences were significant(P<0.05). There were no significant difference in blood loss and fracture healing time(P>0.05). HHS score at 3 and 12 months after operation in bilateral approach were 82.9±5.7 and 84.8±7.1, while in single approach group were 83.6±6.1 and 86.3±6.8; there was no statistical difference in HSS score between two groups(P>0.05). According to HSS score at 12 months after operation, 2 cases got excellent results and 13 good in bilateral approaches group; 1 case got excellent result and 4 good and 1 moderate in single approach group; but there was no statistical difference between two groups (χ²=2.625, P=0.105). There wase no significant differences in complications between bilateral approaches group(2 cases) and single approach group (1 case)(P>0.05). CONCLUSIONS: Double plating technique for communicated and obvious osteoporosis periprosthetic femoral fracture following TKA could obtain good function of knee joint. The medial parapatellar approach has shorter operative time, while the bilateral approaches had less drainage.

Intra-Articular Viscosupplementation for Patients with Hip Osteoarthritis: A Meta-Analysis and Systematic Review.

BACKGROUND The aim of this study was to review the efficacy and safety of intra-articular (IA) viscosupplementation (VS) for hip osteoarthritis (OA). MATERIAL AND METHODS We searched Medline, Clinical Trial Register Center, EMBASE, and Cochrane databases for randomized controlled trials (RCTs) comparing VS with placebo injection for hip OA. We included suitable studies, assessed the quality of studies, and extracted data on pain reduction, function improvement at different time points, and safety profiles. The comparisons of pain and function outcome were performed by meta-analysis. RESULTS Five high-quality randomized controlled studies trials (RCTs) with 591 patients with hip OA were identified. Although several trials demonstrated a significant decline in pain in VS groups during follow-up compared to baseline, without severe adverse events, the pooled analysis did not show VS was superior to placebo at any time windows [7-14 days: standardized mean difference (SMD): -0.18; 95% CI, -0.47 to 0.10, p=0.21; 28-30 days: 0.02 (-0.15, 0.19), p=0.82; or at final visit: -0.14 (-0.46, 0.18), p=0.38]. Similar results were also observed in the combined data of functional results. CONCLUSIONS IA VS does not reduce pain or improve function significantly better than placebo in a short-term follow-up. The benefits and safety of VS should be further assessed by sufficiently-sized, methodologically sound studies with validated assessment of more clinically relevant end-points.

Hsp90ß interacts with MDM2 to suppress p53-dependent senescence during skeletal muscle regeneration.

Cellular senescence plays both beneficial and detrimental roles in embryonic development and tissue regeneration, while the underlying mechanism remains elusive. Recent studies disclosed the emerging roles of heat-shock proteins in regulating muscle regeneration and homeostasis. Here, we found that Hsp90ß, but not Hsp90α isoform, was significantly upregulated during muscle regeneration. RNA-seq analysis disclosed a transcriptional elevation of p21 in Hsp90ß-depleted myoblasts, which is due to the upregulation of p53. Moreover, knockdown of Hsp90ß in myoblasts resulted in p53-dependent cellular senescence. In contrast to the notion that Hsp90 interacts with and protects mutant p53 in cancer, Hsp90ß preferentially bound to wild-type p53 and modulated its degradation via a proteasome-dependent manner. Moreover, Hsp90ß interacted with MDM2, the chief E3 ligase of p53, to regulate the stability of p53. In line with these in vitro studies, the expression level of p53-p21 axis was negatively correlated with Hsp90ß in aged mice muscle. Consistently, administration of 17-AAG, a Hsp90 inhibitor under clinical trial, impaired muscle regeneration by enhancing injury-induced senescence in vivo. Taken together, our finding revealed a previously unappreciated role of Hsp90ß in regulating p53 stability to suppress senescence both in vitro and in vivo.

Mechanical Properties and Porosity of Acrylic Cement Bone Loaded with Alendronate Powder.

Aseptic loosening is the most common complication of joint replacement. Previous studies showed that acrylic bone cement loaded with a commercially-available alendronate powder (APAC) had good promise against wear debris-mediated osteolysis for prevention of aseptic loosening. The purpose of the present study was to investigate the effect of adding alendronate powder to an acrylic bone cement on quasi-static mechanical properties (namely, compressive strength, compressive modulus, tensile strength, and flexural strength), fatigue life, porosity, and microstructure of the cement. The results showed that adding up to 1 wt./wt.% alendronate powder exerted no detrimental effect on any of the quasi-static mechanical properties. However, the fatigue life of APAC decreased by between ~17% and ~27 % and its porosity increased by between ~ 5-7 times compared with corresponding values for the control cement (no alendronate powder added). Fatigue life was negatively and significantly correlated with porosity. Considering that fatigue life of the cement plays a significant role in joint replacement survival, clinical use of APAC cannot be recommended.

Microbubble-Mediated Ultrasound Outweighs Low-Intensity Pulsed Ultrasound on Osteogenesis and Neovascularization in a Rabbit Model of Steroid-Associated Osteonecrosis.

Microbubbles magnify the acoustic pressure of low-intensity pulsed ultrasound (LIPUS) and may enhance its bioeffect for diagnostic and therapeutic purposes. This study compared the effect of this novel microbubble-mediated ultrasound (MUS) with that of the traditional LIPUS on osteogenesis and neovascularization in a rabbit model of steroid-associated osteonecrosis. We hypothesized that MUS might outweigh LIPUS on promoting osteogenesis and neovascularization in steroid-associated osteonecrosis. The bilateral femoral head necrosis was induced by lipopolysaccharide and methylprednisolone in the rabbits. The indices of bone mineral density (BMD), trabecular number, maximal loading strength, and mineral apposition rate were analyzed, demonstrating that the animal model of steroid-associated osteonecrosis was successfully established. Both the MUS group (GM) and the LIPUS group (GL) were insonated 20 min daily for six weeks. GM received an extra intracapsular injection of microbubbles before insonation every other day. Fluorescence bone labeling, Micro-CT Analysis, biomechanical test, quantitative real-time PCR, Western blot analysis, and histological evaluation were performed for comparing GM with GL. The results demonstrated a 39% higher mineral apposition rate in GM compared with GL. The BMD and the maximal loading strength of femoral head of GM increased by 4.3% and 27.8% compared to those of GL, respectively. The mRNA and protein expression of BMP-2 and VEGF were also significantly higher in GM. The number of blood vessels of GM was 65% greater than that of GL. MUS is more potent than LIPUS in enhancing osteogenesis, neovascularization, and biomechanical strength of femoral head in the animal model of steroid-associated osteonecrosis. Without increasing the intensity of insonation or the risk of tissue damage, MUS is better for inhibiting the process of steroid-associated osteonecrosis.

Hsp70 Interacts with Mitogen-Activated Protein Kinase (MAPK)-Activated Protein Kinase 2 To Regulate p38MAPK Stability and Myoblast Differentiation during Skeletal Muscle Regeneration.

The regenerative process of injured muscle is dependent on the fusion and differentiation of myoblasts derived from muscle stem cells. Hsp70 is important for maintaining skeletal muscle homeostasis and regeneration, but the precise cellular mechanism remains elusive. In this study, we found that Hsp70 was upregulated during myoblast differentiation. Depletion or inhibition of Hsp70/Hsc70 impaired myoblast differentiation. Importantly, overexpression of p38 mitogen-activated protein kinase α (p38MAPKα) but not AKT1 rescued the impairment of myogenic differentiation in Hsp70- or Hsc70-depleted myoblasts. Moreover, Hsp70 interacted with MK2, a substrate of p38MAPK, to regulate the stability of p38MAPK. Knockdown of Hsp70 also led to downregulation of both MK2 and p38MAPK in intact muscles and during cardiotoxin-induced muscle regeneration. Hsp70 bound MK2 to regulate MK2-p38MAPK interaction in myoblasts. We subsequently identified the essential regions required for Hsp70-MK2 interaction. Functional analyses showed that MK2 is essential for both myoblast differentiation and skeletal muscle regeneration. Taken together, our findings reveal a novel role of Hsp70 in regulating myoblast differentiation by interacting with MK2 to stabilize p38MAPK.

Association between SMAD3 gene polymorphisms and osteoarthritis risk: a systematic review and meta-analysis.

OBJECTIVE: Several studies have been performed to investigate the association between SMAD3 gene polymorphism and osteoarthritis (OA), but the results were inconclusive. This study aims to determine whether SMAD3 polymorphism is associated with risk of OA. METHOD: A comprehensive literature search in PubMed, Embase, and ISI Web of Science for relevant studies was performed. After extracting data from eligible studies, we chose the fixed or random effect model according to the heterogeneity test. Estimation of publication bias and sensitivity analysis were conducted to confirm the stability of this meta-analysis. RESULTS: In total, 10 studies from 6 articles with 5093 OA patients and 5699 controls were enrolled in this meta-analysis. The combined results revealed significant association between SMAD3 rs12901499 polymorphism and the risk of OA (allele model: OR 1.21, 95% CI 1.07-1.38). Subgroup analysis revealed that G allele increased the risk of OA in Caucasians, but not in Asians (allele model: Caucasians: OR 1.31, 95% CI 1.18-1.44; Asians: OR 1.24, 95% CI 0.95-1.61). And the pooled results revealed significant association between SMAD3 rs12901499 polymorphism and both knee and hip OA (knee OA: OR 1.18, 95% CI 1.04-1.34; hip OA: OR 1.31, 95% CI 1.18-1.44). CONCLUSION: The current meta-analysis revealed that the G variant of SMAD3 rs12901499 polymorphism increased the risk of OA in Caucasians. Further well-designed studies with larger sample size in different ethnic populations are required to confirm these results.

A novel anti-osteoporotic agent that protects against postmenopausal bone loss by regulating bone formation and bone resorption.

AIMS: Postmenopausal osteoporosis is a bone metabolism disease that is caused by an imbalance between bone-resorbing osteoclast and bone-forming osteoblast actions. Herein, we describe the role of troxerutin (TRX), a trihydroxyethylated derivative of rutin, in ovariectomy (OVX)-induced osteoporosis and its effects on the regulation of osteoclasts and osteoblasts. MAIN METHODS: In vivo, OVX female mice were intraperitoneally injected with either saline, 50 mg/kg TRX, or 150 mg/kg TRX for 6 weeks and then sacrificed for micro-computed tomography analyses, histological analyses, and biomechanical testing. In vitro, RAW264.7 cell-derived osteoclasts and MC3T3-E1 cell-derived osteoblasts were treated with different concentrations of TRX to examine the effect of TRX on osteoclastogenesis and bone resorption, as well as on osteogenesis and mineralization. KEY FINDINGS: In this study, we demonstrated that TRX prevented cortical and trabecular bone loss in ovariectomized mice by reducing osteoclastogenesis and promoting osteogenesis in vivo. In vitro, TRX inhibited the formation and activity of RAW264.7-derived osteoclasts and the expression of nuclear factor of activated T-cells 1 and cathepsin K. Meanwhile, TRX improved the osteogenesis and mineralization of MC3T3-E1 by enhancing the expression of Runt-related transcription factor 2, Osterix, and collagen type 1 alpha 1. SIGNIFICANCE: Our data demonstrated that TRX could prevent OVX-induced osteoporosis and be used in a novel treatment for postmenopausal osteoporosis.

Squeaking in fourth-generation ceramic-on-ceramic total hip replacement and the relationship with prosthesis brands: meta-analysis and systematic review.

BACKGROUND: Postoperative squeaking in patients who applied the fourth-generation ceramic bearing in primary hip replacement has not been reported systematically; we aim to study the squeaking incidence in the fourth-generation ceramic bearing and related risk factors for squeaking, and we also attempt to explore the relationship between squeaking and prosthetic brands. METHODS: The PubMed, Embase, and Cochrane library were searched, and 14 articles were finally included. Patients' demographic data, surgical-related information, and prosthesis data were extracted. The occurrence rate of squeaking was calculated by meta-analysis, and subgroup analysis was performed based on prosthetic brands and follow-up time. Regression analysis was further applied to investigate the relationship between various risk factors and squeaking. RESULTS: The squeaking incidence in patients with the fourth-generation ceramic bearing was 3%. Age, gender, body mass index, and abduction and anteversion angles of acetabular cup might have no influence on squeaking. The squeaking incidence was significantly high with the presence of Delta Motion cup (DePuy, Warsaw, Indiana) and Secure-Fit stem (Stryker, Kalamazoo, MI), and the overall incidence of DePuy femoral stem was relatively small except for the Summit femoral stem. And there was no significant difference of squeaking incidence between less than 5-year and more than or equal to 5-year follow-up subgroups. CONCLUSIONS: In our study, squeaking in the fourth-generation ceramic bearing occurred at a rate of 3%; occurrence rate was high when the Delta Motion cup was applied. We hope for more relevant researches to focus on this issue.

Cepharanthine Prevents Estrogen Deficiency-Induced Bone Loss by Inhibiting Bone Resorption.

Osteoporosis is a common health problem worldwide caused by an imbalance of bone formation vs. bone resorption. However, current therapeutic approaches aimed at enhancing bone formation or suppressing bone resorption still have some limitations. In this study, we demonstrated for the first time that cepharanthine (CEP, derived from Stephania cepharantha Hayata) exerted a protective effect on estrogen deficiency-induced bone loss. This protective effect was confirmed to be achieved through inhibition of bone resorption in vivo, rather than through enhancement of bone formation in vivo. Furthermore, the in vitro study revealed that CEP attenuated receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclast formation, and suppressed bone resorption by impairing the c-Jun N-terminal kinase (JNK) and phosphatidylinositol 3-kinase (PI3K)-AKT signaling pathways. The inhibitory effect of CEP could be partly reversed by treatment with anisomycin (a JNK and p38 agonist) and/or SC79 (an AKT agonist) in vitro. Our results thus indicated that CEP could prevent estrogen deficiency-induced bone loss by inhibiting osteoclastogenesis. Hence, CEP might be a novel therapeutic agent for anti-osteoporosis therapy.