High-energy high-dose microfocus X-ray computed tomography driven by high-average-current photo-injector.

High-energy, high-dose, microfocus X-ray computed tomography (HHM CT) is one of the most effective methods for high-resolution X-ray radiography inspection of high-density samples with fine structures. Minimizing the effective focal spot size of the X-ray source can significantly improve the spatial resolution and the quality of the sample images, which is critical and important for the performance of HHM CT. The objective of this study is to present a 9 MeV HHM CT prototype based on a high-average-current photo-injector in which X-rays with about 70µm focal spot size are produced via using tightly focused electron beams with 65/66µm beam size to hit an optimized tungsten target. In digital radiography (DR) experiment using this HHM CT, clear imaging of a standard 0.1 mm lead DR resolution phantom reveals a resolution of 6 lp/mm (line pairs per mm), while a 5 lp/mm resolution is obtained in CT mode using another resolution phantom made of 10 mm ferrum. Moreover, comparing with the common CT systems, a better turbine blade prototype image was obtained with this HHM CT system, which also indicates the promising application potentials of HHM CT in non-destructive inspection or testing for high-density fine-structure samples.

Concentration-dependent, dual roles of IL-10 in the osteogenesis of human BMSCs via P38/MAPK and NF-κB signaling pathways.

Microenvironmental conditions can influence the differentiation and functional roles of mesenchymal stem cells (MSCs). Recent studies have suggested that an inflammatory microenvironment can significantly affect the osteogenic differentiation of MSCs. Here, we show, for the first time, that IL-10 has concentration-dependent, dual roles in the osteogenesis of human bone marrow mesenchymal stem cells (hBMSCs). Low physiologic concentrations of IL-10 (0.01-1.0 ng/ml) activate the p38/MAPK signaling pathway to promote the osteogenesis of hBMSCs, but higher pathologic doses of IL-10 (10-100 ng/ml) inhibit p38/MAPK signaling by activating NF-κB, inhibiting osteogenesis. These results demonstrate that p38/MAPK and NF-κB signaling mediates the double-edged sword effect of IL-10 on hBMSCs. The osteogenic impairment was reversed at higher doses of IL-10 when cells were supplemented with the NF-κB inhibitor BAY11-7082. These data provide important insights into the regulatory effects of IL-10 on the biologic behavior of hBMSCs.-Chen, E., Liu, G., Zhou, X., Zhang, W., Wang, C., Hu, D., Xue, D., Pan, Z. Concentration-dependent, dual roles of IL-10 in the osteogenesis of human BMSCs via P38/MAPK and NF-κB signaling pathways.

Secreted klotho protein attenuates osteogenic differentiation of human bone marrow mesenchymal stem cells in vitro via inactivation of the FGFR1/ERK signaling pathway.

Increasing evidence indicates that the osteogenic differentiation of mesenchymal stem cells (MSCs) is related to bone formation, heterotopic ossification, and even vascular calcification. Therefore, it is essential to understand the microenvironment that regulates these processes. The Klotho gene plays an important role in tissue mineralization, and its secreted protein functions as a hormone. We investigated the effects of secreted Klotho protein on the osteogenesis of human bone marrow MSC (hBMSCs). To this end, the cells received osteogenic medium with or without Klotho protein. The results showed that osteoblast-specific gene expression and mineral deposition were decreased when MSCs were incubated with Klotho. Klotho reduced the expression of fibroblast growth factor receptor 1 (FGFR1) and phosphorylated extracellular signal-regulated kinase 1/2. However, both MEK and FGFR1 inhibitors delayed bone mineral formation more than Klotho. These data suggest that secreted Klotho protein attenuates the osteogenic differentiation of hBMSCs in vitro through FGFR1/ERK signaling.

Influence of internal fixation systems on radiation therapy for spinal tumor.

In this study, the influence of internal fixation systems on radiation therapy for spinal tumor was investigated in order to derive a theoretical basis for adjustment of radiation dose for patients with spinal tumor and internal fixation. Based on a common method of internal fixation after resection of spinal tumor, different models of spinal internal fixation were constructed using the lumbar vertebra of fresh domestic pigs and titanium alloy as the internal fixation system. Variations in radiation dose in the vertebral body and partial spinal cord in different types of internal fixation were studied under the same radiation condition (6 MV and 600 mGy) in different fixation models and compared with those irradiated based on the treatment planning system (TPS). Our results showed that spinal internal fixation materials have great impact on the radiation dose absorbed by spinal tumors. Under the same radiation condition, the influence of anterior internal fixation material or combined anterior and posterior approach on radiation dose at the anterior border of the vertebral body was the greatest. Regardless of the kinds of internal fixation method employed, radiation dose at the anterior border of the vertebral body was significantly different from that at other positions. Notably, the influence of posterior internal fixation material on the anterior wall of the vertebral canal was the greatest. X-ray attenuation and scattering should be taken into consideration for most patients with bone metastasis that receive fixation of metal implants. Further evaluation should then be conducted with modified TPS in order to minimize the potentially harmful effects of inappropriate radiation dose.

Migration of intracranial hemostatic clip into the spinal canal: A case report and literature review.

Spontaneous migration of intracranial hemostatic clip into the spinal canal is uncommon. We report a case of spontaneous migration of intracranial hemostatic clip into the lumbar spinal canal causing severely painful radiculopathy in a 55-year-old woman.

The difference in clinical outcome of single-bundle anterior cruciate ligament reconstructions with and without remnant preservation: A meta-analysis.

BACKGROUND: The aim of this study was to compare the clinical performance and complications between an ACL reconstruction with a remnant-preserving single-bundle technique and a standard single-bundle technique. METHODS: A search was performed of RCTs comparing the clinical outcomes and complications of ACL reconstruction with remnant-preserving and standard single-bundle techniques during October 2014. Relevant data were extracted and CONSORT was used to assess the methodological quality. Stata/SE 12.0 was used to perform a meta-analysis of the clinical outcomes. RESULTS: Six RCTs were included, with a total of 378 patients: 190 in the remnant-preservation technique group and 188 patients in standard-technique group. Assessing anterior stability, no difference was found between the groups for the KT arthrometer, negative rate of Lachman, and the pivot shift test. Assessing functional outcome, there was no significant difference in IKCD scores and grades or Lysholm score. In terms of complications, the percentage of tibial tunnel enlargement in the group of the remnant-preservation technique was significantly lower, despite no significant difference in the incidence of cyclops lesions. CONCLUSIONS: The outcome of single-bundle ACL reconstruction with the remnant-preservation technique is similar to that with the standard technique in terms of anterior stability and functional recovery of the knee. Remnant preservation in ACL reconstruction decreases the percentage of tibial tunnel enlargement. Level of evidence is II.

Effects of Tourniquet Release on Total Knee Arthroplasty.

This study investigated the clinical outcomes of early and late tourniquet release (tourniquet release after cementing the prosthesis vs tourniquet release after wound closure and pressure dressing) in total knee arthroplasty (TKA). The study was conducted by searching PubMed, Embase, Web of Science, and Cochrane Central databases for articles on randomized controlled trials comparing early and late tourniquet release in primary TKA that were published from 1966 to March 2015. Relevant data were extracted, and the Physiotherapy Evidence Database (PEDro) Scale was used to assess the methodologic quality. Stata software (StatCorp, College Station, Texas) was used to perform a meta-analysis. Sixteen articles were included with a total of 1073 patients and 1097 knees. For blood loss, there were no significant differences between the 2 groups in calculated blood loss, decrease in hemoglobin level, drop in hematocrit level, and measured postoperative blood loss, although total measured blood loss and postoperative blood transfusion rate were significantly higher in the early tourniquet release group than in the late tourniquet release group. No statistical differences were found for operative time and incidence of deep venous thrombosis (DVT) between the 2 groups. Wound complication rate in the early tourniquet release group was significantly lower than in the late tourniquet release group. Primary TKA with early tourniquet release is similar to TKA with late tourniquet release regarding perioperative blood loss, operative time, and incidence of DVT. Early tourniquet release reduced the incidence of wound complications compared with late tourniquet release. [Orthopedics. 2016; 39(4):e642-e650.].

Barbed versus traditional sutures for wound closure in knee arthroplasty: a systematic review and meta-analysis.

Sutures are an increasing focus of research in knee arthroplasty (KA). Whether knotless barbed sutures (KBS) are safe and efficient in KA remains controversial. The objective of our study is to compare the clinical outcomes of KA according to wound closure method: KBS versus knotted traditional sutures (KTS). To clarify this, we conducted a systematic review and meta-analysis. Nine articles involving 10 studies were included in this study. The dataset consisted of 1729 patients with 1754 KA. Among these, 814 patients' wounds were closed with KBS and 915 with KTS. Our analysis indicates that KBS is preferable for KA wound closure given its shorter wound closure time and lower total cost; postoperative Knee Society scores and complication rates were similar to those of surgeries using KTS. The subgroup analysis revealed that closure of arthrotomy with KBS appears to be associated with a lower risk of complications. This meta-analysis indicates that use of KBS in KA reduces operative time and cost. KBS is the preferred option for wound closures, including arthrotomy and reattachment of subcutaneous and subcuticular tissues. Given the possible biases, adequately powered and better-designed studies with longer follow-up are required to reach a firmer conclusion.

Overexpression of HSPA1A enhances the osteogenic differentiation of bone marrow mesenchymal stem cells via activation of the Wnt/ß-catenin signaling pathway.

HSPA1A, which encodes cognate heat shock protein 70, plays important roles in various cellular metabolic pathways. To investigate its effects on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), its expression level was compared between undifferentiated and differentiated BMSCs. Rat HSPA1A overexpression in BMSCs increased osteoblast-specific gene expression, alkaline phosphatase activity, and mineral deposition in vitro. Moreover, it upregulated ß-catenin and downregulated DKK1 and SOST. The enhanced osteogenesis due to HSPA1A overexpression was partly rescued by a Wnt/ß-catenin inhibitor. Additionally, using a rat tibial fracture model, a sheet of HSPA1A-overexpressing BMSCs improved bone fracture healing, as determined by imaging and histological analysis. Taken together, these findings suggest that HSPA1A overexpression enhances osteogenic differentiation of BMSCs, partly through Wnt/ß-catenin.

Traumatic Posterior Atlantoaxial Dislocation Without Fracture of Odontoid Process: A Case Report and Systematic Analysis of 19 Cases.

OBJECTIVES: To evaluate the ideal treatment strategy for traumatic posterior atlantoaxial dislocation without fracture of odontoid process. DESIGN: Case report and systematic analysis based on the methodology of evidence-based medicine. SETTING: Level IV trauma center. PATIENTS: Nineteen patients who suffered from traumatic posterior atlantoaxial dislocation without fracture of odontoid process. INTERVENTION: Closed reduction, open reduction, internal fixation, and fusion. OUTCOME MEASURES: Neurologic status, range of motion, and radiographs for stability or fusion. RESULTS: Nineteen cases were included in this analysis. The mean age was 37.7 ± 13.8 years (range, 20-65 years). Sixteen cases (84%) were male, and 3 cases (16%) were female. Thirteen cases (68%) have a transient loss of consciousness. Ten cases (53%) presented no neurologic deficits. All 9 patients (47%) with neurologic deficits recovered without any residual deficits. Eleven dislocations (58%) were reduced by closed reduction, followed by fusion in 5 of them (45%), and the remaining 6 dislocations (55%) were treated conservatively. Eight dislocations (42%) were treated by open reduction and fusion. CONCLUSIONS: Traumatic posterior atlantoaxial dislocation without fracture of odontoid process usually presents without a severe neurologic deficit. Even if it presents with mild or transient neurologic deficit, it would be restored without any residual deficits. Closed reduction is usually successful and safe. The need for fusion after successful closed reduction depends on the integrity of the transverse ligament and the stability of cervical spine. If anatomic reduction is not achieved by closed reduction, open reduction and fusion should be performed.

Effect of bisphosphonates in preventing femoral periprosthetic bone resorption after primary cementless total hip arthroplasty: a meta-analysis.

BACKGROUND: Bone loss leading to aseptic loosening of the prosthesis and periprosthetic fracture is a mode of failure in cementless total hip arthroplasty (THA). The aim of this meta-analysis was to evaluate the effect of bisphosphonates in preventing femoral periprosthetic bone resorption following primary cementless THA zone by zone. METHOD: Clinical randomized controlled trials concerning bisphosphonates application after primary cementless THA published up to October 2014 were retrieved from PubMed, Cochrane library, and Embase databases. The methodological quality of the included studies was assessed by the Physiotherapy Evidence Database (PEDro) scale. Data analysis was performed using StataSE12.0. RESULTS: Ten randomized controlled trials involving a total of 502 patients were assessed; the bisphosphonates group included 256 patients and the control group included 246 patients. The meta-analysis showed that the bone mineral density (BMD) of most femoral periprosthetic zones in bisphosphonates group was significantly higher than that in the control group at 3 months postoperatively except zone 5 with no significant difference. At 6 and 12 months, the BMD of bisphosphonates group was much higher than that in control group except zone 5, which showed no statistical difference. The BMD of bisphosphonates group was persistently higher than control group in zone 6 and 7 at 5 years postoperatively, while the other zones had no significant difference. Both serum bone alkaline phosphatase and urinary type I collagen N-telopeptide were significantly suppressed by bisphosphonates at 3, 6, and 12 months. CONCLUSION: Bisphosphonates seem to decrease early femoral periprosthetic bone resorption after primary cementless THA. Drug efficacy was found to be long-standing in the main load-bearing zones.

Ceramic-on-ceramic versus ceramic-on-polyethylene bearing surfaces in total hip arthroplasty.

The choice between ceramic-on-ceramic (COC) and ceramic-on-polyethylene (COP) in primary total hip arthroplasty (THA) remains controversial. The purpose of this study was to evaluate the reliability and durability of COC vs COP bearing surfaces in THA. Based on published randomized, controlled trials (RCTs) identified in PubMed, Embase, and the Cochrane Central Register of Controlled Trials, the authors performed a meta-analysis comparing the clinical and radiographic outcomes of COC with those of COP. Two investigators independently selected the studies and extracted the data. The methodological quality of each RCT was assessed using the Physiotherapy Evidence Database (PEDro) scale. Relative risks and 95% confidence intervals from each trial were pooled using random-effects or fixed-effects models depending on the heterogeneity of the included studies. Nine RCTs involving 1575 patients (1747 hips) met the predetermined inclusion criteria. Eight of 9 included RCTs had high methodological quality. The heterogeneity was not significant, and all the results were pooled using a fixed-effects model. The results demonstrated that COC significantly increased the risks of squeaking and total implant fracture compared with COP. No significant differences with respect to revision, osteolysis and radiolucent lines, loosening, dislocation, and deep infection were observed between the COC and COP bearing surfaces. This meta-analysis resulted in no sufficient evidence to identify any clinical or radiographic advantage of COC vs COP bearing surfaces in the short- to mid-term follow-up period. Long-term follow-up is required for further evaluation.

Comparison of ceramic-on-ceramic to metal-on-polyethylene bearing surfaces in total hip arthroplasty: a meta-analysis of randomized controlled trials.

BACKGROUND: In recent years, the choice of ceramic-on-ceramic (COC) and metal-on-polyethylene (MOP) in primary total hip arthroplasty (THA) remains controversial. The purpose of this study was to compare the reliability and durability of COC with that of MOP bearing surfaces in THA. METHODS: Based on prospective randomized controlled trials (RCTs) searched from Pubmed, Embase, Web of Science, and Cochrane central database, we performed a meta-analysis for comparing clinical and radiographic outcomes of COC with those of MOP. Two investigators independently selected studies, extracted data, and assessed risk of bias. Relative risks and weighted mean differences from each trial were pooled using random-effect or fixed-effect models depending on the heterogeneity of the included studies. RESULTS: Five RCTs involving 897 patients with 974 hips met predetermined inclusion criteria. Our results demonstrated COC significantly decreased the risks of revision, osteolysis and radiolucent line, aseptic loosening, and dislocation and increased the risks of squeaking and intraoperative implant fracture compared with MOP. There was no significant difference between the two groups in postoperative hip function, deep infection, and heterotopic ossification. CONCLUSIONS: Generally, despite more squeaking and intraoperative implant fracture, our findings support the use of COC bearing surface which has lower rates of revision, osteolysis and radiolucent line, aseptic loosening, and dislocation compared with MOP.

Efficacy of steroid addition to multimodal cocktail periarticular injection in total knee arthroplasty: a meta-analysis.

BACKGROUND: Total knee arthroplasty (TKA) has been reported to be the most successful treatment for patients with advanced osteoarthritis, however, early postoperative pain has become an unresolved issue. The aim of this Meta-analysis is to evaluate the efficacy and safety of steroid addition to multimodal cocktail periarticular injection (MCPI) in patients undergoing TKA. METHOD: Clinical randomized controlled trials concerning the efficacy and safety of MCPI containing steroids in TKA published up to December 2014 were retrieved from PubMed, Cochrane library, EMbase databases. The methodological quality of the included studies was assessed by the 12-item scale. Data analysis was performed using StataSE12.0. RESULTS: Six randomized controlled trials involving a total of 567 patients were assessed; the steroid group included 305 patients, and the control group included 262 patients. The meta-analysis showed that MCPI with steroids in TKA significantly reduced postoperative pain; duration of time required to perform straight-leg raising and length of hospital stay was (P < 0.05). Neither the early postoperative nor the long-term range of motion of knee showed any statistical difference between the non-steroid and steroid group (P >0.05). For safety, steroids did not increase the incidence of postoperative infection and wound oozing (P >0.05); no tendon rupture was reported up to now. In addition, steroids did not decrease the postoperative drainage through the reduction of prostaglandins (P >0.05). CONCLUSION: For patients undergoing TKA, the addition of steroids to MCPI improved the analgesic effect and was proved to be highly safe. The duration of time required to perform straight-leg raising and length of hospital stay was significantly reduced. However, MCPI with steroids neither increased the early postoperative range of motion (ROM) or the long-term ROM of knee, nor did it reduce the postoperative drainage. However, the best results are acquired in patients without any altered immunological status.

Indwelling versus Intermittent Urinary Catheterization following Total Joint Arthroplasty: A Systematic Review and Meta-Analysis.

OBJECTIVE: The purpose of this study is to compare the rates of urinary tract infection (UTI) and postoperative urinary retention (POUR) in patients undergoing lower limb arthroplasty after either indwelling urinary catheterization or intermittent urinary catheterization. METHODS: We conducted a meta-analysis of relevant randomized controlled trials (RCT) to compare the rates of UTI and POUR in patients undergoing total joint arthroplasty after either indwelling urinary catheterization or intermittent urinary catheterization. A comprehensive search was carried out to identify RCTs. Study-specific risk ratios (RR) with 95% confidence intervals (CI) were pooled. Additionally, a meta-regression analysis, as well as a sensitivity analysis, was performed to evaluate the heterogeneity. RESULTS: Nine RCTs with 1771 patients were included in this meta-analysis. The results showed that there was no significant difference in the rate of UTIs between indwelling catheterization and intermittent catheterization groups (P>0.05). Moreover, indwelling catheterization reduced the risk of POUR, versus intermittent catheterization, in total joint surgery (P<0.01). CONCLUSIONS: Based on the results of the meta-analysis, indwelling urinary catheterization, removed 24-48 h postoperatively, was superior to intermittent catheterization in preventing POUR. Furthermore, indwelling urinary catheterization with removal 24 to 48 hours postoperatively did not increase the risk of UTI. In patients with multiple risk factors for POUR undergoing total joint arthroplasty of lower limb, the preferred option should be indwelling urinary catheterization removed 24-48 h postoperatively. LEVEL OF EVIDENCE: Level I.

Effects of the timing of tourniquet release in cemented total knee arthroplasty: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: The aim of this study is to evaluate the effects of tourniquet release before wound closure for hemostasis or after wound closure in cemented total knee arthroplasty (TKA). METHODS: We conducted a meta-analysis and review work on relevant clinical outcomes to evaluate the effects of the timing of tourniquet release in cemented TKA. Electronic databases were searched for relevant randomized controlled trials (RCTs) that compared outcomes of tourniquet release before wound closure for hemostasis with tourniquet release after wound closure. The methodological quality of each included RCT was assessed in terms of the 12-item scale. The meta-analysis was performed with STATA 12.0 software. RESULTS: Eleven RCTs involving 651 patients with 670 TKAs were included in this meta-analysis. Of these, 332 patients (342 knees) were in an early tourniquet release group and 319 patients (328 knees) in the late tourniquet release group. The results showed that there were no significant differences in overt blood loss, hemoglobin drop, and blood transfusions, whereas the tourniquet release after wound closure might increase the risks of overall complications and major complications. CONCLUSIONS: Tourniquet release before wound closure for hemostasis might reduce the rate of complications, but it could not limit overall blood loss. The current evidences are not enough to indicate that tourniquet release before wound closure is superior to its release after wound closure in cemented TKA.

Caffeine-induced activated glucocorticoid metabolism in the hippocampus causes hypothalamic-pituitary-adrenal axis inhibition in fetal rats.

Epidemiological investigations have shown that fetuses with intrauterine growth retardation (IUGR) are susceptible to adult metabolic syndrome. Clinical investigations and experiments have demonstrated that caffeine is a definite inducer of IUGR, as children who ingest caffeine-containing food or drinks are highly susceptible to adult obesity and hypertension. Our goals for this study were to investigate the effect of prenatal caffeine ingestion on the functional development of the fetal hippocampus and the hypothalamic-pituitary-adrenal (HPA) axis and to clarify an intrauterine HPA axis-associated neuroendocrine alteration induced by caffeine. Pregnant Wistar rats were intragastrically administered 20, 60, and 180 mg/kg · d caffeine from gestational days 11-20. The results show that prenatal caffeine ingestion significantly decreased the expression of fetal hypothalamus corticotrophin-releasing hormone. The fetal adrenal cortex changed into slight and the expression of fetal adrenal steroid acute regulatory protein (StAR) and cholesterol side-chain cleavage enzyme (P450scc), as well as the level of fetal adrenal endogenous corticosterone (CORT), were all significantly decreased after caffeine treatment. Moreover, caffeine ingestion significantly increased the levels of maternal and fetal blood CORT and decreased the expression of placental 11ß-hydroxysteroid dehydrogenase-2 (11ß-HSD-2). Additionally, both in vivo and in vitro studies show that caffeine can downregulate the expression of fetal hippocampal 11ß-HSD-2, promote the expression of 11ß-hydroxysteroid dehydrogenase 1 and glucocorticoid receptor (GR), and enhance DNA methylation within the hippocampal 11ß-HSD-2 promoter. These results suggest that prenatal caffeine ingestion inhibits the development of the fetal HPA axis, which may be associated with the fetal overexposure to maternal glucocorticoid and activated glucocorticoid metabolism in the fetal hippocampus. These results will be beneficial in elucidating the developmental toxicity of caffeine and in exploring the fetal origin of adult HPA axis dysfunction and metabolic syndrome susceptibility for offspring with IUGR induced by caffeine.