Clinical effectiveness of a pneumatic compression device combined with low-molecular-weight heparin for the prevention of deep vein thrombosis in trauma patients: A single-center retrospective cohort study.

BACKGROUND: To investigate the clinical effectiveness of a pneumatic compression device (PCD) combined with low-molecular-weight heparin (LMWH) for the prevention and treatment of deep vein thrombosis (DVT) in trauma patients. METHODS: This study retrospectively analyzed 286 patients with mild craniocerebral injury and clavicular fractures admitted to our department from January 2016 to February 2020. Patients treated with only LMWH served as the control group, and patients treated with a PCD combined with LMWH as the observation group. The incidence of DVT, postoperative changes in the visual analogue scale (VAS) score, and coagulation function were observed and compared between the two groups. Excluding the influence of other single factors, binary logistic regression analysis was used to evaluate the use of a PCD in the patient's postoperative coagulation function. RESULTS: After excluding 34 patients who did not meet the inclusion criteria, 252 patients were were included. The incidence of DVT in the observation group was significantly lower than that in the control group (5.6% vs. 15.1%, χ2=4.605, P<0.05). The postoperative VAS scores of the two groups were lower than those before surgery (P<0.05). The coagulation function of the observation group was significantly higher than that of the control group, with a better combined anticoagulant effect (P<0.05). There were no significant differences between the two groups in preoperative or postoperative Glasgow Coma Scale scores, intraoperative blood loss, postoperative infection rate, or length of hospital stay (P>0.05). According to logistic regression analysis, the postoperative risk of DVT in patients who received LMWH alone was 1.764 times that of patients who received LMWH+PCD (P<0.05). The area under the receiver operating characteristic (AUROC) curve of partial thromboplastin time (APTT) and platelet (PLT) were greater than 0.5, indicating that they were the influence indicators of adding PCD to prevent DVT. Excluding the influence of other variables, LMWH+PCD effectively improved the coagulation function of patients. CONCLUSIONS: Compared with LMWH alone, LMWH+PCD could improve blood rheology and coagulation function in patients with traumatic brain injury and clavicular fracture, reduce the incidence of DVT, shorten the length of hospital stay, and improve the clinical effectiveness of treatment.

Effect of video games training on the gross motor skills of children with cerebral palsy: systematic review and meta-analysis / Efecto del entrenamiento con videojuegos en la motricidad gruesa de niños con parálisis cerebral: revisión sistemática y meta-análisis

Abstract The purpose of this work was to systematically evaluate the intervention effects of video games training (VGT) on the gross motor skills (GMS) development of children with cerebral palsy (CP). Seven Chinese and English databases (PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, Wanfang, EBSCO) were searched. Data were retrieved from randomized controlled trials on the GMS among individuals with CP. The retrieval was from the inception of each database to March 16, 2021. The included studies were evaluated quantitatively using the PEDro Scale. Then, relevant data were inputted and analyzed in Review Manager 5.4. Thirteen papers were included: seven written in English and six in Chinese. In the three subordinate concept of GMS, VGT could significantly improve locomotor skills (LS) (standardized mean difference = 0.80, 95% confidence interval 0.55-105, P<0.00001), and non-locomotor skills (NLS) (standardized mean difference = 0.83, 95% confidence interval 0.38-1.28, P=0.0003) in CP. However, there was no significant difference in object control skills (OCS), when compared with the control group (standardized mean difference = 0.55, 95% confidence interval -0.01-0.72, P=0.05). VGT can improve LS and NLS in CP, but the effect on OCS is uncertain; therefore, it is recommended that additional high-quality literature be included in the future. In general, VGT has been proven an effective intervention tool on the GMS development in CP.

Resumen Este artículo intentó evaluar sistemáticamente el efecto de la intervención del entrenamiento con videojuegos (VGT) en el desarrollo de las habilidades motoras gruesas (GMS) de niños con parálisis cerebral (CP), basándose en un cuerpo de datos logrado de las conclusiones de pruebas controladas aleatorias sobre las habilidades motoras gruesas de niños con CP, obtenidos de la búsqueda sistemática en siete bases de datos chinos y extranjeros, tales como PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, Wanfang y EBSCO. El lapso de búsqueda fue desde la fecha de establecimiento de cada base de datos hasta el 16 de marzo del 2021. Se aplicó la escala PEDro para realizar un estudio cuantitativo y después, se analizaron los datos relevantes con Review Manager 5.4. Se incluyeron 13 publicaciones, 7 artículos escritos en inglés y 6 en chino. En el marco del concepto de los tres subordinados de GMS, la VGT podría mejorar significativamente la habilidad locomotora (LS) (diferencia de medias estandarizada = 0.80, intervalo de confianza del 95%: 0.55-105, P<0.00001), y las habilidades no locomotoras (NLS) (diferencia de medias estandarizada = 0.83, intervalo de confianza del 95%: 0.38-1.28, P= 0,0003) en PC; pero no hubo una diferencia significativa en las habilidades de control de objetos (OCS), cuando se compararon con el grupo control (diferencia de medias estandarizada= 0,55, intervalo de confianza del 95% -0,01-0,72, P= 0,05). En conclusión, el VGT puede mejorar las LS y NLS en CP, pero el efecto sobre OCS es incierto; por lo que se recomienda la inclusión de literatura adicional de alta calidad en el futuro. De este modo se pudo demostrar que el VGT es una herramienta de intervención eficaz en el desarrollo de las GMS en niños con CP.

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

PURPOSE: The aim of this current review was to confirm the efficacy of intra-articular steroid therapy (IAST) for patients with hip osteoarthritis (OA) and discuss the duration and influential factors of IAST. METHODS: Online databases (Medline, EMBASE, and Web of Science) were searched from inception to May 2019. Both randomized controlled trials (RCTs) and noncontrolled trials assessing the efficacy of hip IAST on pain were included. Common demographics data were extracted using a standardized form. Quality was assessed on the basis of Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence. RESULTS: 12 trials met the inclusion criteria. According to data from individual trials, IAST had significant efficacy on hip OA in both immediate and delay pain reduction, which persisted up to 12 weeks after IAST. The influences of the baseline severity of hip OA or synovitis and injection dose or volume on the clinical outcome of IAST were still controversial. The IAST appeared to be well tolerant by most of the participants. CONCLUSION: IAST was proved to be an efficacious therapy in both immediate and delay pain reduction for hip OA patients within 12 weeks. The longer follow-up data of efficacy and safety and potentially influential factors are still unclear and needed further confirmation.

The application of chromosomal microarray analysis to the prenatal diagnosis of isolated mild ventriculomegaly.

OBJECTIVE: To investigate the clinical value of chromosomal microarray analysis (CMA) in the prenatal diagnosis of genetic abnormalities in fetal isolated mild ventriculomegaly. MATERIALS AND METHODS: This retrospective study reviewed 101 fetuses with isolated mild ventriculomegaly who had undergone invasive prenatal diagnosis at our hospital. CMA was performed in all cases to detect chromosomal aneuploidy as well as copy number variations (CNVs) that are too small to be detected by conventional karyotyping. Real time quantitative PCR (qPCR) or multiplex ligation dependent probe amplification (MLPA) was used to confirm all fetal CNVs <400 Kb. RESULTS: Except for three cases of chromosomal aneuploidy, CMA revealed pathogenic copy number variations (CNVs) in 3.0% (3/101) of the fetuses; these cases demonstrated involvement in the chromosomal regions 15q11.2, 1q21.1 and Xq27.3q28. Furthermore, we detected three likely pathogenic (3.0%) and two variants of uncertain significance (2.0%) among 101 fetuses diagnosed as isolated mild ventriculomegaly on ultrasound examination. CONCLUSION: Our study suggests that CNVs could aid in the risk assessment and genetic counseling in fetuses with isolated ventriculomegaly.

Pravastatin alleviates lipopolysaccharide-induced placental TLR4 over-activation and promotes uterine arteriole remodeling without impairing rat fetal development.

Preeclampsia is associated with over-activation of the innate immune system in the placenta, in which toll-like receptor 4 (TLR4) plays an essential part. With their potent anti-inflammatory effects, statins have been suggested as potential prevention or treatment of preeclampsia, although evidence remains inadequate. Herewith, we investigated whether pravastatin could ameliorate preeclampsia-like phenotypes in a previously established lipopolysaccharide (LPS)-induced rat preeclampsia model, through targeting the TLR4/NF-κB pathway. The results showed that pravastatin reduced the blood pressure [maximum decline on gestational day (GD) 12, (101.33±2.49) mmHg vs. (118.3±1.37) mmHg, P<0.05] and urine protein level [maximum decline on GD9, (3,726.23±1,572.86) µg vs. (1,991.03±609.37) µg, P<0.05], which were elevated following LPS administration. Pravastatin also significantly reduced the rate of fetal growth restriction in LPS-treated rats (34.10% vs. 8.99%, P<0.05). Further pathological analyses suggested a restoration of normal spiral artery remodeling in preeclampsia rats by pravastatin treatment. These effects of pravastatin were associated with decreased TLR4/NF-κB protein levels in the placenta and IL-6/MCP-1 levels in serum. Additionally, no obvious abnormalities in fetal liver, brain, and kidney were found after administration of pravastatin. These results provide supportive evidence for use of pravastatin in preventing preeclampsia.

The novel α-glucan YCP improves the survival rates and symptoms in septic mice by regulating myeloid-derived suppressor cells.

Sepsis is a life-threatening health condition that is initially characterized by uncontrolled inflammation, followed by the development of persistent immunosuppression. YCP is a novel α-glucan purified from the mycelium of the marine fungus Phoma herbarum YS4108, which has displayed strong antitumor activity via enhancing host immune responses. In this study, we investigated whether YCP could influence the development of sepsis in a mouse model. Caecal ligation and puncture (CLP)-induced sepsis was established in mice that were treated with YCP (20 mg/kg, ip or iv) 2 h before, 4 and 24 h after the CLP procedure, and then every other day. YCP administration greatly improved the survival rate (from 39% to 72% on d 10 post-CLP) and ameliorated disease symptoms in the septic mice. Furthermore, YCP administration significantly decreased the percentage of myeloid-derived suppressor cells (MDSCs) in the lungs and livers, which were dramatically elevated during sepsis. In cultured BM-derived cells, addition of YCP (30, 100 µg/mL) significantly decreased the expansion of MDSCs; YCP dose-dependently decreased the phosphorylation of STAT3 and increased the expression of interferon regulatory factor-8 (IRF-8). When BM-derived MDSCs were co-cultured with T cells, YCP dose-dependently increased the production of arginase-1 (Arg-1) and inducible nitric oxide synthase (iNOS), and activated the NF-κB pathway. In addition, the effects of YCP on MDSCs appeared to be dependent on toll-like receptor (TLR) 4. These results reveal that YCP inhibits the expansion of MDSCs via STAT3 while enhancing their immunosuppressive function, partially through NF-κB. Our findings suggest that YCP protects mice against sepsis by regulating MDSCs. Thus, YCP may be a potential therapeutic agent for sepsis.

Use of a tourniquet in total knee arthroplasty: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: A tourniquet is commonly used in total knee arthroplasty (TKA). However, the effectiveness and safety of tourniquets are debated. We performed this study to investigate whether patients benefit from the use of tourniquets in TKA. METHODS: The literature search was conducted using PubMed, Cochrane Library, MEDLINE, Embase, and other medical databases. After a literature search, 26 randomized controlled trials involving 1,450 knees were analyzed. RESULTS: Tourniquet use significantly decreased intraoperative blood loss, transfusion rate, and operation time but not postoperative blood loss, measurable total blood loss, calculated total blood loss, transfusion volume, incidence of pulmonary embolism, or duration of hospital stay. It also slowed down joint functional recovery in the short term and increased the incidence of deep vein thrombosis and other minor wound complications. CONCLUSIONS: Data from this meta-analysis indicate that patients may benefit from the use of a tourniquet in TKA; however, it use is accompanied by disadvantages and complications. Because of the very low-evidence quality and lower grading of recommendations, assessment, development, and evaluation recommendation strength, no guidelines can be developed based on current evidence.

Color assimilation of resin composites with adjacent color according to the distance.

STATEMENT OF PROBLEM: Color of esthetic restorative materials shifts toward color of adjacent material. PURPOSE: The purposes were to determine the amount of distance-dependent color shift in resin composites toward the color of adjacent materials and to define a color shift parameter (CSP) that can quantify this phenomenon. METHODS: Three brands of resin composites, two shades for each, were investigated. Specimens of 2 (thickness) × 4 (width) × 16 (length) mm(3) were fixed in an adjustable XY stage in contact with black and white ceramic tiles at each end. Color was measured by a spectroradiometer at seven separated points in 2-mm intervals, in which P1 was 2 mm away from the black tile. Mean value of the color differences (ΔE*ab ) between P1 and each of the other measurement points (P2-P6) was defined as the CSP, in which higher CSP value indicated smaller color assimilation toward P1 color. RESULTS: The range of the CSP was 7.5-12.4, which was influenced by the brand and shade of resin composites (p < 0.05). CONCLUSIONS: The CSP defined in this study provided the amount of color shift of esthetic materials toward adjacent color, which indicated the color assimilation effect of these materials. CLINICAL SIGNIFICANCE: The CSP investigated in the present study might be used to compare the tendency of color assimilation of esthetic restorative materials, and proper CSP ranges for optimal color assimilation or color blocking should be further determined.

Stanniocalcin-1 promotes tumor angiogenesis through up-regulation of VEGF in gastric cancer cells.

BACKGROUND: Stanniocalcin-1(STC-1) is up-regulated in several cancers including gastric cancer. Evidences suggest that STC-1 is associated with carcinogenesis and angiogenic process. However, it is unclear on the exact role for STC-1 in inducing angiogenesis and tumorigeneisis. METHOD: BGC/STC cells (high-expression of STC-1) and BGC/shSTC cells (low- expression of STC-1) were constructed to investigate the effect of STC-1 on the xenograft tumor growth and angiogenesis in vitro and in vivo. ELISA assay was used to detect the expression of vascular endothelial growth factor (VEGF) in the supernatants. Neutralizing antibody was used to inhibit VEGF expression in supernatants. The expression of phosphorylated -PKCßII, phosphorylated -ERK1/2 and phosphorylated -P38 in the BGC treated with STC-1protein was detected by western blot. RESULTS: STC-1 could promote angiogenesis in vitro and in vivo, and the angiogenesis was consistent with VEGF expression in vitro. Inhibition of VEGF expression in supernatants with neutralizing antibody markedly abolished angiogenesis induced by STC-1 in vitro. The process of STC-1-regulated VEGF expression was mediated via PKCßII and ERK1/2. CONCLUSIONS: STC-1 promotes the expression of VEGF depended on the activation of PKCßII and ERK1/2 pathways. VEGF subsequently enhances tumor angiogenesis which in turn promotes the gastric tumor growth.

Effects of aging and HEMA content on the translucency, fluorescence, and opalescence properties of experimental HEMA-added glass ionomers.

Changes in the translucency, fluorescence, and opalescence of experimental 10-50% 2-hydroxyethyl methacrylate (HEMA)-added glass ionomers (HAGIs) after 5,000 cycles of thermocycling were determined and compared with those of commercial resin-modified glass ionomers (RMGIs). Changes in the translucency (TP), fluorescence (FL), and opalescence (OP) parameters were in the range of -3.5 to 0.2, -2.3 to 0.3 and -2.6 to 9.1 units respectively for HAGIs; and -0.9 to 0.3, -0.7 to 0.6, and 1.1 to 2.3 units respectively for RMGIs. Changes in the TP, FL, and OP of HAGIs were influenced by the HEMA content and powder shade, and were generally larger than those of RMGIs. Since the changes in TP, FL, and OP of experimental HAGIs were influenced by the HEMA content, there arises a need to determine the optimal HEMA ratio to attain high stability for these optical properties. In addition, results of this study showed that apart from optimal HEMA ratio, future studies should include other aspects and factors that contribute to age-dependent changes in optical properties.

Risk factors for urban road traffic injuries in Hangzhou, China.

OBJECTIVE: To investigate factors that most influence urban road traffic injuries (RTI) mortality and morbidity. METHODS: The study used linked police and hospital records of RTI patients in the city of Hangzhou during the 3-year period 2004-2006. Three RTI outcome groups were included: (1) fatally injured; (2) severely injured; and (3) mildly injured persons. RESULTS: High risks for fatal road traffic accidents (RTA) were found on urban links, over weekend, during night hours, in male drivers who drove old vehicles without using seat belts, and at exceeding speeds, or with night time accidents and bad weather condition. In case of higher risk for all urban road users on urban junctions, the numbers on mildly injury cases were increasing. The highest combined risk for dying or being severely injured was found in male drivers driving at excessive speed, on urban links, and with night time accidents. CONCLUSIONS: Intensifying safety education of motor vehicle drivers, enhancing traffic management and keeping balance of "person-vehicle-road" system will greatly reduce the urban traffic accidents and casualties.

Effect of sintering on porosity, phase, and surface morphology of spray dried hydroxyapatite microspheres.

This article deals with the effect of sintering temperature on the physical and chemical characteristics of hydroxyapatite microspheres (HAMs) obtained by spray drying method. A set of specimens were sintered in a conventional furnace at 500-1100 degrees C. The surface morphology, phase composition, size distribution, specific surface area, and porosity were characterized by scanning electron microscope, X-ray diffractometer, laser diffraction particle size analyzer, and specific surface area analyzer, respectively. The results indicated that at 800 degrees C, hydroxyapatite crystals began to grow and were sintered together, which caused a drastic decrease in both the specific surface area and the pore volume. Great changes took place on the surfaces of HAMs during sintering. When the samples were sintered at the temperature of 500 and 600 degrees C, no obvious changes can be found on the surfaces of the samples, but at 800 degrees C, open-micropore surfaces came forth. Besides, the dispersibility of the samples decreased at high temperature (1100 degrees C) because small particles tended to aggregate together.

Research progress in mechanism of traumatic brain injury affecting speed of fracture healing.

In patients who have sustained traumatic brain injury with associated extremity fracture, there is often a clinical perception that the rate of new bone formation around the fracture site increases.(1) An overgrowth of callus is observed and ectopic ossification even occurs in the muscle,(2) but the mechanism remains unclear. Whether this rapidly-formed new bone is fracture callus or a variant of heterotopic ossification, a common complication of traumatic brain injury, is the subject of some debates.(3) It is generally believed that the process of fracture healing is a recapitulation of normal embryonic osteogenesis,(4) i.e. ,a series of changes in the intracellular and extracellular matrix, which start from the injury of cells, blood vessels and bone matrix to a complete reconstruction of the bone.(5) It is a complex process influenced by multi-level and multi-route regulations of the general and local environments in the body, and many growth factors participate in this process, which is the base of bone healing;(6) whatever methods are used to promote bone healing, they are based on accelerating the changes of growth factors.(7) So it is worth making a thorough study on the mechanism, by which traumatic brain injury influences the expression levels of growth factors and consequently affects the speed of bone healing.

[Sequential changes in biomechanical competence of femoral neck and marrow cavity of proximal femur in ovariectomized rats].

OBJECTIVE: To observe the sequential changes in biomechanical competence of the femoral neck and marrow cavity of the proximal femur in ovariectomized rats. METHODS: Bone mineral density (BMD) and biomechanical properties of the femoral neck and the structural dimension of the proximal femur were measured 0, 3, 6, 9, 12, 15, 18, 21 weeks after ovariectomy (OVX) or sham operation (Sham) in 6-month-old female SD rats. RESULTS: The BMD of femoral neck in OVX rats was significantly lower than that in Sham group 6 weeks after operation, (0.195 +/-0.028) g/mm(2) vs (0.225 +/-0.036) g/mm(2) (P=0.03). Nine weeks after operation,the failure load of femoral neck decreased about 10% in OVX group to that in Sham group, (89.6 +/-7.7)N vs (96.7 +/-7.5)N (P=0.05). The medullary cavity of proximal femur started to show difference 15 weeks after operation (3.834 +/-0.115)mm(2) vs (3.713 +/-0.114) mm(2) (P=0.03). CONCLUSION: BMD loss after ovariectomy is associated with a medullary expansion in proximal femur and biomechanical strength deterioration in femoral neck, which might be an important factor of prostheses loosening in the postmenopausal osteoporotic women.

Osteoporosis influences the middle and late periods of fracture healing in a rat osteoporotic model.

OBJECTIVE: To evaluate the influence of osteoporosis on the middle and late periods of fracture healing process through observing the histomorphological changes, bone mineral density and biomechanical properties in ovariectomized rats. METHODS: Eighty-four female SD rats of 4 months old were randomly divided into osteoporosis group and sham operation group, 42 in each. Rats in osteoporosis group were performed ovariectomy operation while those in sham operation group were given sham operation. A midshaft tibia fracture model was established 10 weeks after ovariectomy. Tibias were harvested 2, 4, 6, 12, 18 weeks after fracture for bone mineral density, histomorphological and biomechanical evaluation. RESULTS: Compared with the sham operation group, callus bone mineral density was 12.8%, 18.0%, 17.0% lower in osteoporosis group 6, 12, 18 weeks after fracture, respectively (P<0.05); callus failure load was 24.3%, 31.5%, 26.6%, 28.8% lower in osteoporosis group, and callus failure stress was 23.9%, 33.6%, 19.1%, 24.9% lower in osteoporosis group 4, 6, 12, 18 weeks after fracture, respectively (P<0.05). In osteoporosis group, endochondral bone formation was delayed, more osteoclast cells could be seen around the trabecula, and the new bone trabecula arranged loosely and irregularly. CONCLUSIONS: Osteoporosis influences the middle and late periods of fracture healing in the rat osteoporotic model. The impairment is considered to be the result of combined effects of prolonged endochondral calcification, high activated osteoclast cell and the deceleration of the increase in bone mineral density.

Role of dual energy X-ray absorptiometry in monitoring fracture healing in a rat femoral fracture model.

OBJECTIVE: To dynamically monitor the bone mineral density (BMD) and the histomorphological changes during fracture healing in a rat femoral fracture model and to explore the role of dual energy X-ray absorptiometry (DEXA) in evaluating bone fracture healing. METHODS: Sixty three-month-old female Sprague Dawley rats were used to establish right femoral fracture models. The BMD of the callus of the fractured right femur were scanned by DEXA at 2, 4, 6, 8, 10 and 12 weeks after operation, respectively. A light microscope was used to evaluate the callus of each rat at the same time. The corresponding segment of the left femur was taken as a control. RESULTS: The BMD at the fractured site increased significantly during the process of fracture healing, which shows an obvious healing trend. The callus BMDs were 29.5%, 48.3%, 85.3%, and 105.2% of the BMD of the control limb at 2, 4, 6 and 8 weeks after fracture, respectively. There was a significantly difference between the groups. A compatibility on time was found between the BMD and the histomorphological characteristics at the fractured site during the process of fracture healing. The fracture healing was almost completed at 8 weeks after fracture as assessed by its histomorphological characteristics when the callus BMD reached to 105.2% of the BMD of the control limb. The BMD of the distal metaphysis decreased until 12 weeks after fracture. CONCLUSIONS: DEXA can evaluate the mineralization of the callus during the fracture healing process accurately and quantitatively and is more sensitive than plain radiography in detecting impaired bone unions, which indicates that it may play an important role in monitoring fracture healing.

[Osteoporosis impairs fracture healing of tibia in a rat osteoporotic model].

OBJECTIVE: To evaluate the influence of osteoporosis on fracture healing. METHODS: Eighty-four 4 months old female Sprague-Dawley rats were randomly divided into osteoporosis (OP) group and sham operation (SO) group, 42 in each. Rats in OP group were performed ovariectomy operation while those in SO group with sham operation. When osteoporosis formed 10 weeks after ovariectomy, midshaft tibia fracture model was established. Tibias were harvested 2 weeks (2 rats per group), 4 weeks (9 rats per group), 6 weeks (9 rats per group), 12 weeks (9 rats per group) and 18 weeks (7 rats per group) after fracture for bone mineral density (BMD), histomorphological and biomechanical evaluation. RESULTS: Compared with the SO group: (1) Callus BMD was significantly lower about 12.8%, 18.0%, 17.0% in OP group 6, 12, 18 weeks after fracture, respectively (P < 0.05). (2) Callus failure load was significantly lower about 24.3%, 31.5%, 26.6%, 28.8% in OP group, and callus failure stress was also significantly lower about 23.9%, 33.6%, 19.1%, 24.9% in OP group 4, 6, 12, 18 weeks after fracture, respectively (P < 0.05). (3) In OP group, endochondral bone formation was delayed, more osteoclast cell could be seen around the trabecula, and the new bone trabecula arranged loosely and irregularly. CONCLUSION: Osteoporosis influences the middle and late periods of fracture healing in the rat osteoporostic model. The impairment is considered to be the result of the combined effects of the prolonged endochondral calcification, high activated osteoclast cell and the deceleration of the increase in bone mineral density.

[The observation of bone mineral density by dual energy X-ray absorptiometry and histology during fracture healing at the femoral fracture site of rat].

OBJECTIVE: To dynamically observe the bone mineral density and histology changes during fracture healing at the femoral fracture site, and to study the role of monitoring fracture healing by dual energy X-ray absorptiometry (DEXA). METHODS: 60 female 3-month-old SD rats were used to establish right femoral fracture model. The fractured and contralateral unfractured femorals were scanned by Dual Energy X-ray absorptiometry in 2, 4, 6, 8, 10 and 12 weeks postoperatively. The callus of each rat was examined by light microscope at the same time. RESULTS: The value of bone mineral density at rat femoral fracture site was significantly increased post-osteotomy, showing a clear healing trend. The bone mineral density at fracture site was 29.5%, 48.3%, 85.3%, 105.2% of the value obtained of the control limb 2, 4, 6 and 8 weeks postoperatively. There was a compatibility on time between bone mineral density and histology. The BMD of distal metaphysis remained reduced until 12 weeks. CONCLUSION: The change of bone mineral density at the fracture site exhibited positive correlation with the histology of fracture healing, bone mineral density can accurately quantify the extent of mineralization of callus at the fracture site. DEXA can be used as a new technique in monitoring fracture healing.

Early period of fracture healing in ovariectomized rats.

OBJECTIVE: To evaluate the effect of osteoporosis on fracture healing through observing the histomorphological changes, bone mineral density of callus and expression and distribution of transforming growth factor beta 1 (TGF-beta1), basic fibroblast growth factor (bFGF) and bone morphogenetic protein-2 (BMP-2) in ovariectomized rats. METHODS: Sixty female Sprague-Dawley rats (aged 12 weeks and weighing 235 g on average) were randomly divided into an ovariectomized (OVX) group (n=30) and a sham-operated (SO) group (n=30). Ovariectomy was performed in the OVX rats and same incision was made in the SO rats. Three months later, fracture of femoral shaft was made on all the rats. Then they were killed at different time points. Callus formation was observed with histological and immunohistochemical methods. RESULTS: A reduction in callus and bone mineral density in the healing femur and a decrease of osteoblasts expressing TGF-beta1 near the bone trabecula were observed in the OVX rats 3-4 weeks after fracture. Histomorphological analysis revealed a higher content of soft callus in the OVX rats than that in the SO rats. Immunohistochemistry results showed that no remarkable difference in expression and distribution of BMP-2 and bFGF between the OVX and SO groups was found. CONCLUSIONS: Osteoporosis influences the quantity and quality of callus during the early period of fracture healing. The effect of osteoporosis on fracture healing has no relationship with the expression of BMP-2 or bFGF. The decreased expression of TGF-beta1 in osteoblasts may cause a decrease in quality of fracture healing after osteoporosis.