Effect of different bone cement distributions in percutaneous kyphoplasty on clinical outcomes for osteoporotic vertebral compression fractures: A retrospective study.

Osteoporotic fractures and their complications are becoming increasingly harmful to the elderly. This study aimed to evaluate the clinical results of connected or unconnected bilateral cement after bilateral percutaneous kyphoplasty (PKP) in patients with osteoporotic vertebral compression fractures (OVCF). The clinical data of 217 patients with single-segment OVCF were retrospectively collected. Patients were allocated into 2 groups according to the bilateral bone cement in the vertebrae was connected or unconnected after surgery. The surgery-related indexes of the 2 groups were compared, including operation time; bone cement injection volume; contact situation between bone cement and the upper and lower endplates of the vertebral body; visual analogue scale (VAS) scores before surgery, 1 week and 1 year after surgery; Oswestry disability index (ODI) before surgery, 1 week and 1 year after surgery; local kyphosis angle (LKA) before surgery, 1 week and 1 year after surgery; postoperative vertebral body height at 1 week and 1 year after surgery; vertebral body height restoration rate (HRR) at 1 week and 1 year after surgery. The follow-up results of all patients were recorded. The postoperative VAS, ODI, vertebral body height, LKA and other indexes of the 2 groups were significantly improved compared with those before the operation (P < .05), and there was no significant difference between the 2 groups (P > .05). At the same time, there were no significant difference in vertebral body HRR and bone cement leakage rate between the 2 groups (P > .05). X-ray examination showed that 21 of 217 patients (21/217, 9.8%) had a refracture of the injured vertebral body, including 16 cases (16/121, 13.2%) in the unconnected group and 5 cases (5/96, 5.2%) in the connected group (P < .05). Adjacent vertebrae fractures occurred in 25 cases (25/217, 11.5%), while 19 cases (19/121, 15.7%) were in the unconnected group and 6 cases (6/96, 6.3%) were in the connected group (P < .05). PKP has a good therapeutic effect on OVCF no matter whether the bilateral bone cement is connected or not. However, if the bilateral cement inside the vertebra was connected, the risk of recollapse of the injured vertebrae and the new fracture of adjacent vertebrae could be reduced.

Intramedullary core decompression combined with endoscopic intracapsular decompression and debridement for pre-collapse non-traumatic osteonecrosis of the femoral head.

BACKGROUND: The effect of core decompression on the treatment of pre-collapse non-traumatic osteonecrosis of the femoral head (ONFH) is still limited. This study aimed to explore the efficacy of core decompression combined with intra-articular decompression (debridement of the hip joint and incision of the hip capsule) under hip arthroscopic guidance in patients with pre-collapse ONFH. METHODS: The clinical data of 101 patients with pre-collapse ONFH were analysed retrospectively. Sixty patients (80 hips) received small-diameter multi-channel core decompression alone in first half review period (group B). Forty-one patients (59 hips) were treated with small-diameter multi-channel core decompression combined with intra-articular decompression under hip arthroscopy guidance in second half review period (group A). The surgical duration; intraoperative bleeding; intra-articular pressure(IAP) before and after surgery; length of hospital stay; hospitalisation expenses; visual analogue scale (VAS) score before, 1 week, 4 weeks, 3 months and 1 year after surgery; and Harris score of the hip joint before, 3 months and 1 year after surgery were recorded and compared between group A and group B. X-ray examination was performed every month to observe the collapse of the femoral head within 2 years after surgery, which was compared using the Kaplan-Meier survival curve analysis. RESULTS: When the two groups were compared, the surgical duration was longer and hospitalisation expenses were higher in group A than in group B (P < 0.05). However, the VAS score and the Harris score of the hip joint after surgery improved significantly compared with those before surgery (P < 0.05), which were more apparent in group A than in group B (P < 0.05). X-ray examination revealed that 6 hips in group A and 22 in group B received femoral head collapse at the 2-year follow-up. The survival rate of the femoral head in group A was significantly higher than that in group B (P < 0.05). CONCLUSION: Small-diameter multi-channel core decompression combined with intra-articular decompression (debridement of the hip joint and incision of the hip capsule) under hip arthroscopic guidance for treating early ONFH can more effectively alleviate joint pain, improve joint function and delay ONFH progression.

SIX4 upregulates IDH1 and metabolic reprogramming to promote osteosarcoma progression.

Metabolism reprogramming plays an important role in tumorigenesis and osteosarcoma metastasis. Sine oculis homeobox 4 (SIX4) is reported to be a key transcription factor that is involved in glycolysis reprogramming of cancer cells. However, the role of SIX4 in osteosarcoma progression remains unknown. The expression profile of SIX4 in OS was evaluated in surgery samples of osteosarcoma patients. Functional studies were performed in vitro and in vivo. We found that SIX4 is significantly overexpressed in osteosarcoma and related to the undesirable prognosis of osteosarcoma patients. SIX4 promotes progression of osteosarcoma via upregulating isocitrate dehydrogenase 1 (IDH1), which provides novel prognostic biomarkers and promising therapeutic targets for osteosarcoma patients.

Addition of Tibial Tubercle Osteotomy to Combined MPFL Reconstruction and Lateral Retinacular Release not Recommended for Recurrent Patellar Dislocation in Patients with 15 to 20 mm TT-TG.

Surgery is the primary treatment for recurrent patellar dislocation. However, there is still a lack of consensus regarding the choice of combined surgical methods due to the complexity of the anatomical factors. This study aimed to investigate the efficacy and radiological changes in medial patellofemoral ligament reconstruction (MPFLR) and lateral retinacular release (LRR) with and without tibial tubercle osteotomy (TTO) for recurrent patellar dislocation in patients with a tibial tubercle-trochlear groove (TT-TG) distance of 15 to 20 mm. Fifty-four patients were enrolled in this retrospective study between 2010 and 2014. The average patient age was 21.6 ± 5.0 years. All patients underwent MPFLR and LRR, and in 18 patients, these procedures were combined with TTO. Patients were evaluated preoperatively and postoperatively for patellar lateral shift, patellar tilt angle, TT-TG distance, Q-angle, Caton-Deschamps index (CDI), Kujala, and Lysholm scores. The minimally clinical important difference was used to compare clinical outcomes between two groups. In the mean follow-up of 82.6 ± 15.9 months, functional scores improved significantly in both groups (p < 0.01). There were no significant differences in postoperative function scores between the two groups (Kujala, p = 0.25, mean difference = 1.5, 95% confidence interval [CI]: -1.4-4.4; Lysholm, p = 0.76, mean difference = -0.6, 95% CI: -5.9-4.7). Additionally, TTO significantly decreased Q-angle (23.6 ± 2.4 vs. 17.4 ± 2.9, p < 0.01), TT-TG (17.1 ± 1.5 vs. 10.4 ± 1.8, p < 0.01), and CDI (1.18 ± 0.12 vs. 1.08 ± 0.07, p < 0.01). Combined MPFLR and LRR with and without TTO are both effective techniques for recurrent patellar dislocation. Additional osteotomy can correct patellar alta and tibial tubercle lateralization. However, given that there were no significant differences in postoperative functional scores or recurrence rate between groups, we may not recommend TTO in addition to MPFLR and LRR in patients with TT-TG of 15 to 20 mm. Long-term and prospective cohort studies are required to assess further outcomes.

Causal relationships between rheumatism and dyslipidemia: A two-sample Mendelian randomization study.

Background: Dyslipidemia is often observed in rheumatic diseases, such as ankylosing spondylitis (AS), rheumatoid arthritis (RA), and systemic lupus erythematosus (SLE), yet it remains to be detected whether rheumatic diseases have a causal effect on dyslipidemia. Methods: Significant (P < 5 × 10-8) and independent (r2 < 0.1) single-nucleotide polymorphisms in genome-wide association studies were selected as instrumental variables to conduct Mendelian randomization (MR) analysis. Inverse variance weighted, weighted median, and MR-Egger regression were adopted for the causal inference. Subsequently, sensitivity analysis was conducted to assess the stability and reliability of MR. Results: The MR results revealed positive causal relationships of AS with total cholesterol (TC) (ß = 0.089, 95% CI = 0.050 to 0.128, P = 6.07 × 10-6), low-density lipoprotein (LDL) (ß = 0.087, 95% CI = 0.047 to 0.127, P = 1.91 × 10-5), and high-density lipoprotein (HDL) (ß = 0.043, 95% CI = 0.001 to 0.074, P = 0.009). There was no causal effect of RA on TC (ß = 0.008, 95% CI = 4.86 × 10-4 to 0.017, P = 0.064), LDL (ß = 6.4 × 10-4, 95% CI = -0.008 to 0.007, P = 0.871), or HDL (ß = 0.005, 95% CI = -0.003 to 0.013, P = 0.200). Additionally, SLE had negative causal links for TC (ß = -0.025, 95% CI = -0.036 to -0.015, P = 4.42 × 10-6), LDL (ß = -0.015, 95% CI = -0.025 to -0.005, P = 0.003), and HDL (ß = -0.013, 95% CI = -0.021 to -0.004, P = 0.004). The results were stable and reliable. Conclusion: This study suggested positive causal effects of AS on TC, LDL, and HDL and negative causal effects of SLE on these cholesterol levels, which could provide much help for the pathogenesis and treatment of rheumatic disease patients with dyslipidemia.

Negative pressure wound therapy reduces the incidence of postoperative wound dehiscence and surgical site infections after total knee arthroplasty in patients with obesity.

Obesity is a risk factor for total knee arthroplasty (TKA). Wound dehiscence and surgical site infections (SSIs) are the main complications of TKA in patients with obesity. They can profoundly affect patients because they often require readmission, additional surgical interventions, lengthy intravenous antibiotic administration, and delayed rehabilitation. Negative pressure wound therapy (NPWT) exposes the wound site to negative pressure, resulting in the improvement of blood supply, removal of excess fluid, and stimulation of cellular proliferation of granulation tissue. This study aims to assess the incidence of wound dehiscence and SSIs in patients with obesity undergoing TKA after the routine use of NPWT. This sduty enrolled adult patients with obesity who underwent TKA within 8 years. A total of 360 adult patients with obesity (NPWT: 150, non-NPWT: 210) underwent TKA, and the baseline characteristics were similar between the 2 groups. Compared with the non-NPWT group, the NPWT group had a 50% lower incidence of wound dehiscence (3.33% vs 9.52%; P < .05) and a significantly lower incidence of SSIs (11.33% vs 25.24%; P < .05), including prosthetic joint infection (4.0% vs 10.0%; P < .05) and superficial wound infection (7.33% vs 15.24%; P < .05). In addition, the NPWT group had a lower need to return to the operating room for new interventions for any reason (2.67% vs 9.05%; P = .0107) than the non-NPWT group. Conventional incision NPWT can significantly reduce the incidence of wound dehiscence and SSIs in patients with obesity after TKA.

Comparison of clinical outcomes with proximal femoral nail anti-rotation versus bipolar hemiarthroplasty for the treatment of elderly unstable comminuted intertrochanteric fractures.

BACKGROUND: Although proximal femoral nail anti-rotation (PFNA) and bipolar hemiarthroplasty (BHA) are selected by most of the orthopaedic surgeons for elderly intertrochanteric fractures (ITFs) patients, there is still no consensus on the superiority of PFNA and BPH for the elderly with unstable comminuted ITFs. The study aims to compare the curative effects of PFNA and cementless BHA on unstable comminuted ITFs in the elderly. METHODS: From January 2012 to December 2016, we retrospectively reviewed 62 ITFs patients up to the inclusion and exclusion criteria in the study. Depending on the type of surgery, the patients were divided into two groups: Group BHA (n= 30) and Group PFNA (n = 32). The ITFs were classified according to Evans-Jensen. Hospitalization time, operation time, bleeding loss, weight bearing duration, Harris hip scores, 10-m walking speed, gait and postoperative complications were compared between the two groups. RESULTS: There was no significant difference between the groups in hospital stay (P > 0.05). The BHA group trended to have a shorter operation time and a larger volume of blood loss (P < 0.01).The weight bearing duration was shorter in the BHA group than the PFNA group (P < 0.05).The Harris hip score was higher, the 10-m walking speed was faster and the gait was better in group BHA than group PFNA at three months postoperatively (P < 0.05), but there was no significant difference between the two groups at 6 and 12 months postoperatively (P > 0.05). There was no significant difference in postoperative complications between the two groups (P > 0.05). CONCLUSION: The BHA allows an earlier return to weight-bearing activity, but ultimately has the same effective treatments as the PFNA for the elderly with unstable comminuted ITFs.

The effect of endostatin on angiogenesis and osteogenesis of steroid-induced osteonecrosis of the femoral head in a rabbit model.

OBJECTIVE: This study aimed to investigate whether endostatin, a crucial anti-angiogenic factor, plays a negative role in angiogenesis and osteogenesis and aggravates the progression of osteonecrosis of the femoral head induced by steroid use in a rabbit model. METHODS: 66 New Zealand white rabbits were randomly divided into four groups: glucocorticoid model (GC) group (GC group, n = 18), glucocorticoid model and endostatin group (GC;ES group, n = 18), ES group (ES group, n = 18), and blank control group (CON group, n = 12). In the GC group, 10 µg/ kg lipopolysaccharide (LPS) was intravenously injected into the ear margin, and 24h after LPS injection, 20 mg/kg GC methylprednisolone (MPS) was injected into the gluteus muscle three times, each time at an interval of 24h. The animals of the GC;ES group were given as same treatment as the GC group, except for the addition of ES. MPS was not used in the ES group and CON group. ES group was only given ES, while the CON group was only given the same amount of normal saline. All animals successfully established models of femoral head necrosis, and then the difference among the Immunohistochemistry, Quantitative polymerase chain reaction (qPCR) analysis, Enzyme-linked immunosorbent assay, Biomechanical test, etracyclline-calcein double labeling, and Van Gieson staining indices were compared among the four groups. RESULTS: The combination of MPS and LPS was successful in establishing the femoral head necrosis model in New Zealand white rabbits. The incidence of osteonecrosis after MPS and LPS intervention was 70% (7/10), while that plus ES was 100% (10/10). At the same time, after MPS and LPS intervention, while the empty bone lacuna rate of the femoral head was significantly increased, the number of osteo- blasts was decreased. Also, the expressions of CD31 positive cells, Runx2, Osterix, COL1A1, and VEGF mRNA in the femoral head were decreased, and the levels of osteogenesis-related protein b-ALP, OCN, and angiogenic factor VEGF in the femoral head were decreased. The percentage of the trabecular bone area (%Tb.Ar), trabecular thickness (Tb.Th), trabecular number (Tb.N), labeled perimeter percent (%L.Pm), mineral apposition rate (MAR), and bone formation rate (BFR/BS) in the femoral head after MPs and LPS intervention detected by tetracycline calcein double labeling and Van Gieson staining decreased significantly, except trabecular separation (Tb.Sp) increased significantly. The compressive strength (CS), elastic modulus (EM), and strain energy (SE) of the femoral head examed by biomechanical measurement decreased significantly. All the above changes were more obvious after adding ES intervention. ES mRNA in the femoral head was undifferentiated and increased in the GC, ES, and GC;ES group compared with group CON. CONCLUSION: This study has revealed that ES can inhibit angiogenesis and osteogenesis in the femoral head and aggravate the occurrence and development of femoral head necrosis. Thus, antiangiogenic factors may play an important role in the pathogenesis of ONFH.

Realization of Force Detection and Feedback Control for Slave Manipulator of Master/Slave Surgical Robot.

Robot-assisted minimally invasive surgery (MIS) has received increasing attention, both in the academic field and clinical operation. Master/slave control is the most widely adopted manipulation mode for surgical robots. Thus, sensing the force of the surgical instruments located at the end of the slave manipulator through the main manipulator is critical to the operation. This study mainly addressed the force detection of the surgical instrument and force feedback control of the serial surgical robotic arm. A measurement device was developed to record the tool end force from the slave manipulator. An elastic element with an orthogonal beam structure was designed to sense the strain induced by force interactions. The relationship between the acting force and the output voltage was obtained through experiment, and the three-dimensional force output was decomposed using an extreme learning machine algorithm while considering the nonlinearity. The control of the force from the slave manipulator end was achieved. An impedance control strategy was adopted to restrict the force interaction amplitude. Modeling, simulation, and experimental verification were completed on the serial robotic manipulator platform along with virtual control in the MATLAB/Simulink software environment. The experimental results show that the measured force from the slave manipulator can provide feedback for impedance control with a delay of 0.15 s.

Enhanced bone tissue regeneration via bioactive electrospun fibrous composite coated titanium orthopedic implant.

One of the very reliable, attractive, and cheapest techniques for synthesizing nanofibers for biomedical applications is electrospinning. Here, we have created a novel nanofibrous composite coated Ti plate to mimic an Extra Cellular Matrix (ECM) of native bone in order to enhance the bone tissue regeneration. An electrospun fibrous composite was obtained by the combination of minerals (Zn, Mg, Si) substituted hydroxyapatite (MHAP)/Polyethylene Glycol (PEG)/Cissus quadrangularis (CQ) extract. Fibrous composite's functionality, phase characteristics, and morphology were evaluated by FT-IR, XRD, and SEM techniques, respectively. The average fiber diameter of MHAP/PVA had decreased from ~274 to ~255 nm after incorporating PEG polymer. That further increased from ~255 to ~275 nm after adding CQ extract. Besides the bioactivity in SBF solution, the degradable nature was confirmed by immersing the fibrous composite in Tris-HCL solution. The degradable studies evaluate that the composite was degraded depending on time, and it degrades about 9.42% after 7 days of immersion. Osteoblasts like MG-63 cells differentiation, proliferation, and calcium deposition were also determined. These results show that this new fibrous composite exhibits advanced osteoblasts properties. Thus, we concluded that this new fibrous scaffold coated Ti implant could act as a better implant to mimic ECM of bone structure and to improve osteogenesis during bone regeneration.

Percutaneous endoscopic transforaminal discectomy for the treatment of L5-S1 lumbar disc herniation and the influence of iliac crest height on its clinical effects.

The present study aimed to explore the clinical effects of percutaneous endoscopic transforaminal discectomy using a transforaminal endoscopic spine system (TESSYS) technique for the treatment of L5-S1 lumbar disc herniation and to analyse the influence of iliac crest height on these clinical effects. The clinical data of 76 patients with L5-S1 single-segment disc herniation treated with TESSYS at The Second Affiliated Hospital and Third Affiliated Hospital of Xi'an Jiaotong University between January and December 2016 were retrospectively analysed. Patients were divided into the following three groups according to the positional relation between the highest point of the iliac crest and the L4 and L5 pedicles in the lateral lumbar, as determined by X-ray: Group I, iliac crest height below the upper edge horizontal line of the L5 pedicle (n=42); group II, iliac crest height between the lower edge horizontal line of the L4 pedicle and the upper edge horizontal line of the L5 pedicle (n=29) and group III, iliac crest height above the lower edge horizontal line of the L4 pedicle (n=5). Changes in the postoperative visual analogue scale (VAS) pain score and Oswestry disability index (ODI) of the lower back and lower limbs were observed, and the effects were compared among the three groups. The mean operating time was 86.5±13.5 min. A single patient experienced cerebrospinal fluid leakage due to a mild tear of the dura mater during the operation, which improved after symptomatic treatment. The same operation was repeated in one patient due to the recurrence of disc herniation. In all patients, the VAS pain score and ODI of the lower back and lower limbs at 1 week and 1, 3 and 12 months following the operation were significantly lower than those before the operation (all P<0.05). Furthermore, the postoperative VAS pain score and ODI of the lower back and lower limbs were poorer in group III (L5-S1 lumbar disc herniation complicated with high iliac crest) than in groups I and II (P<0.05). These results suggested that TESSYS was effective in treating lumbar disc herniation. Whether the iliac crest is higher than the lower edge horizontal line of the L4 pedicle is suggested to be one of the factors influencing the outcome of the operation.

Suppurative Arthritis Induced by Scedosporium apiospermum and Mycobacterium fortuitum: a Case Report.

BACKGROUND: Suppurative arthritis induced by Scedosporium apiospermum (S. apiospermum) or Mycobacterium fortuitum (MF) was rare, and even more so when caused by a mixed infection of the two. In this paper, we report the rare case of suppurative arthritis induced by S. apiospermum and MF. METHODS: A 46-year-old patient whose left knee was accidentally injured by a rotary tiller. His left knee joint was clearly swollen although debridement and suturing had been performed twice at a local hospital. Bacterial culture result was MF and S. apiospermum after admission. Definitive therapy (debridement combined with treatment using three antibiotics) was initiated. RESULTS: Although the fungus reappeared when he tried to discontinue the drug, after the third debridement combined with treatment using three antibiotics for 8 months, the infection was controlled and did not recur. CONCLUSIONS: This demonstrates that early bacteriological examination is essential. Treatment of fungus generally requires a long course. However, course of medication should be related to the patient's specific conditions and the implementation of the operation.

The efficacy of single posterior debridement, bone grafting and instrumentation for the treatment of thoracic spinal tuberculosis.

The aim of this study was to investigate the clinical efficacy of single posterior debridement, bone grafting and instrumentation for the treatment of thoracic spinal tuberculosis in adult patients. A retrospective analysis was conducted between June 2013 and September 2017of 88 adult patients with thoracic spinal tuberculosis. All patients were treated with single posterior debridement, bone grafting and instrumentation. The clinical manifestations and laboratory and imageological results were subsequently analysed. All patients were followed for 40.6 ± 4.1 months (range, 36-48 m). Bony fusion was achieved in all bone grafts of thoracic vertebrae. The visual analogue scale scores, erythrocyte sedimentation rate and C-reactive protein levels 6 weeks after surgery and at the final follow up were significantly lower than the preoperative levels (P < 0.05). The postoperative and final follow up kyphosis angles were both significantly smaller than the preoperative kyphosis angles (P < 0.05). The postoperative angle correction rate reached 81.5% and the postoperative angle loss reached only 4.1%. At the last follow up, American Spinal Injury Association improvement was significant, compared with the preoperative levels (P < 0.05). The single posterior approach can achieve satisfactory clinical outcomes in the treatment of thoracic spinal tuberculosis.

"Median paralyzing dose" and "multiple regression analysis", a new viewpoint to the research method of spinal cord injury.

INTRODUCTION: Spinal cord impact is a mature method for building models of spinal cord injury (SCI). However, a common problem is that the degree of elicited paralysis may not be identical even though animals receive the same impact. We hypothesize that this difference may be caused by the difference in the secondary injury mechanism of SCI and there might be an impact dosage named "median paralyzing dose (PD50)", similar as the "median lethal dose (LD50)" in pharmacology. In addition, since SCI is a result of multiple mechanisms, we hypothesize that it is more suitable to employ multiple regression analysis to analyze the related factors for complete paraplegia. So the present study aimed to calculate the existence of PD50 and analyze the related factors of SCI-induced complete paralysis using logistic regression under the PD50 which represents identical primary injury. MATERIAL AND METHODS: Rat models of SCI were built using the weight-drop method under PD50. PD50 was calculated by Karber's method. Rats were allocated into two groups according to whether they developed complete or incomplete paralysis 2 weeks after injury. Cavity and spared tissues in the two groups were compared. Neuronal preservation, microglia/macrophage reaction, T-lymphocyte infiltration, astrocyte activation and neuronal apoptotic were compared by immunohistochemistry. The logistic regression model was constructed and significant related factors of complete paralysis were selected. RESULTS: Of the two groups, the cavity in the injured spinal cord of the complete-paralysis rats was significantly larger and the spared white matter volume (SWMV%) was obviously smaller. Whereas, the spared grey matter volume was not different between groups. Macrophage reaction, T-lymphocyte infiltration and neuronal apoptosis were significantly more severe in the complete-paralysis rats. Astrocyte activation and neuronal preservation showed no difference between groups. Logistic regression analysis showed that cavity volume, SWMV%, microglia/macrophage reaction and neuronal apoptosis were significantly correlated with SCI-induced complete paralysis. CONCLUSION: As a non-mainstream method, it is feasible to analyze the secondary factors of SCI-induced complete paralysis using multiple regression analysis in the condition of identical primary injury (PD50). SWMV% and microglia/macrophage reaction are important factors that contribute to complete paralysis at the early phase of severe SCI.

Angiotensin II inhibits osteogenic differentiation of isolated synoviocytes by increasing DKK-1 expression.

The renin-angiotensin system contributes to the pathogenesis of rheumatoid arthritis, but that the mechanism is unclear. This study aims to investigate the effect of angiotensin II (Ang II) on osteogenic differentiation of synoviocytes and the underlying mechanism. Ang II was showed to inhibite osteogenic differentiation of synoviocytes, which was mitigated by a Dickkopf-1 (DKK-1) inhibitor. DKK-1 was upregulated by Ang II, which was weakened by the Ang II type 1 receptor (AT1R) blocker, reactive oxygen species (ROS) scavenger, and p38 inhibitor. Ang II increased the levels of AT1R, ROS, and NADPH oxidase (NOX), and the upregulations were mitigated by the AT1R blocker or NOX inhibitor. Furthermore, Ang II activated the p38 pathway, which was blocked by the AT1R blocker, ROS scavenger, or siRNA-MKK3. In brief, these results indicate that Ang II upregulates NOX expression and ROS production via AT1R, activates the MKK3/p38 signaling, and in turn upregulates DKK-1 expression, participating in the inhibition of osteogenic differentiation of synoviocytes.

Influence of vertebral bone mineral density on total dispersion volume of bone cement in vertebroplasty.

The aim of this study was to investigate the influence of vertebral bone mineral density (BMD) on total diffusion volume of bone cement in percutaneous vertebroplasty (PVP). This study was a retrospective review of prospectively collected data of consecutive patients with A1.2 thoracolumbar compression fractures treated by PVP. Vertebral BMD was measured before surgery and participants were divided into 3 groups according to World Health Organization diagnostic criteria for osteoporosis: Group A (normal BMD), Group B (reduced BMD), and Group C (osteoporosis). All vertebrae were injected with 3 mL of bone cement via the unilateral pedicle and scanned by computed tomography after surgery. Actual injection volume (bone cement only) and total diffusion volume (bone cement plus trabeculae and space) were calculated. Pain severity was determined by the visual analog scale before surgery and at both 1 day and 1 month after surgery. There were no significant differences in injection volume among the groups (P > .05), but the total dispersion volume was greater than injection volume in all groups (P < .05). Pairwise comparison showed a significant difference in total diffusion volume of bone cement between groups, with Group A having the largest volume and Group C the smallest volume. Pain was significantly reduced 1 day after surgery in each group compared with before surgery, but there were no significant between-group differences at 1 day or 1 month. Increasing vertebral BMD was positively correlated with increasing total diffusion volume. BMD does not significantly affect pain relief, despite producing a significantly lower distribution volume in osteoporotic patients.

The application of finite element modelling based on clinical pQCT for classification of fracture status.

Fracture risk assessment using dual-energy X-ray absorptiometry (DXA) frequently fails to diagnose osteoporosis amongst individuals who later experience fragility fractures. Hence, more reliable techniques that improve the prediction of fracture risk are needed. In this study, we evaluated a finite element (FE) modelling framework based on clinical peripheral quantitative computed tomography (pQCT) imaging of the tibial epiphysis and diaphysis to predict the stiffness at these locations in compression, shear, torsion and bending. The ability of these properties to identify a group of women who had recently sustained a low-trauma fracture from an age- and weight-matched control group was determined and compared to clinical pQCT and DXA properties and structural properties based on composite beam theory. The predicted stiffnesses derived from the FE models and composite beam theory were significantly different (p < 0.05) between the control and fracture groups, whereas no meaningful differences were observed using DXA and for the stress-strain indices (SSIs) derived using pQCT. The diagnostic performance of each property was assessed by the odds ratio (OR) and the area under the receiver operating curve (AUC), and both were greatest for the FE-predicted shear stiffness (OR 16.09, 95% CI 2.52-102.56, p = 0.003) (AUC: 0.80, 95% CI 0.67-0.93). The clinical pQCT variable total density (ρtot) and a number of structural and FE-predicted variables had a similar probability of correct classification between the control and fracture groups (i.e. ORs and AUCs with mean values greater than 5.00 and 0.80, respectively). In general, the diagnostic characteristics were lower for variables derived using DXA and for the SSIs (i.e. ORs and AUCs with mean values of 1.65-2.98 and 0.64-0.71, respectively). For all properties considered, the trabecular-dominant tibial epiphysis exhibited enhanced classification characteristics, as compared to the cortical-dominant tibial diaphysis. The results of this study demonstrate that bone properties may be derived using FE modelling that have the potential to enhance fracture risk assessment using conventional pQCT or DXA instruments in clinical settings.

Peripheral Quantitative Computed Tomography (pQCT) Measures Contribute to the Understanding of Bone Fragility in Older Patients With Low-trauma Fracture.

Dual-energy X-ray absorptiometry (DXA) as currently used has limitations in identifying patients with osteoporosis and predicting occurrence of fracture. We aimed to express peripheral quantitative computed tomography (pQCT) variables of patients with low-trauma fracture as T-scores by using T-score scales obtained from healthy young women, and to evaluate the potential clinical utility of pQCT for the assessment of bone fragility. Fracture patients were recruited from a fracture liaison service at the Royal Melbourne Hospital. Reference pQCT data were obtained from studies on women's health conducted by our group. A study visit was arranged with fracture patients, during which DXA and pQCT were applied to measure their bone strength. A total of 59 fracture patients were recruited, and reference data were obtained from 78 healthy young females. All DXA variables and most pQCT variables were significantly different between healthy young females and fracture patients (p < 0.05), except polar stress-strain index (p = 0.34) and cortical bone density (p = 0.19). Fracture patients were divided into osteoporosis and non-osteoporosis groups according to their DXA T-scores. Significant differences were observed in most pQCT variables (p < 0.05), except trabecular area and cortical density (p > 0.9 and p = 0.5, respectively). By applying pQCT T-scores, 11 (27%) of patients who were classified as having low or medium risk of osteoporosis on DXA T-scores alone were reclassified as high risk. Results of logistic regression suggested trabecular bone density as an independent predictor of osteoporosis status. More patients can be identified with osteoporosis by applying pQCT T-score variables in older people with low-trauma fracture. Peripheral QCT T-scores contribute to the understanding of bone fragility in this population.

Sildenafil improves blood perfusion in steroid-induced avascular necrosis of femoral head in rabbits via a protein kinase G-dependent mechanism.

OBJECTIVE: The aim of the study were to evaluate the effect of sildenafil against avascular necrosis of femoral head (ANFH) in a rabbit model, and to study the role of protein kinase G (PKG) pathway and vascular endothelial growth factor (VEGF) in ANFH. METHODS: Three weeks after inducing ANFH with methylprednisolone injection, 45 female adult New Zealand white rabbits were divided into three groups and treated as follows: group SI received daily intraperitoneal sildenafil with a dose of 10 mg/kg per day; group SD received daily sildenafil identically to group SI plus auricular vein injection DT3 (a specific PKG inhibitor); group NS received only normal saline. The blood perfusion function in the femoral head was measured by perfusion MRI and ink artery infusion. Bilateral femora heads were examined histopathologically for the presence of osteonecrosis; VEGF of tissue was examined by Western blot analysis; cGMP level and PKG activity were also measured. RESULTS: The incidence of ANFH in SI group was significantly lower than that observed in NS and SD groups (p < 0.05). VEGF in SI group was increased compared to NS group. cGMP level and PKG activity were also significantly different between NS and SI group (p < 0.05). However, these effects of sildenafil in SD group were all markedly inhibited by the administration of DT3 compared to SI group. CONCLUSION: Sildenafil appear to increase the perfusion of femoral head by up-regulating VEGF through PKG pathway. The increased perfusion of femoral head could prevent ANFH.

Comparative study of serum proteomes in Legg-Calve-Perthes disease.

BACKGROUND: Legg-Calve-Perthes Disease (LCPD) is an idiopathic osteonecrosis of the developing femoral head complicated by pain and disability of the hip joint. To date, the pathological mechanisms of LCPD are not well-known. This study screened the changes in serum protein expression in patients with LCPD. METHODS: Age- and sex-matched serum samples from 10 control subjects and 10 patients with LCPD were compared using the isobaric tags for relative and absolute quantification (iTRAQ) technique. Gene ontology analyses, KEGG pathway and functional network analyses were performed. Proteins of interest with large differences in expression, S100-A8, alpha-1-acid glycoprotein 1, haptoglobin and apolipoprotein E, were compared by western blotting. RESULTS: The disease/control ratios showed 26 proteins were significantly differentially expressed (all p < 0.05). Including higher abundances of complement factor H (1.44), complement C4-B (1.45), isocitrate dehydrogenase [NAD] subunit alpha (2.7) alpha-1-acid glycoprotein 1 (1.87), heptoglobin (1.53) and Ig lambda-2 chain C regions (1.46), and lower levels of apolipoprotein E (0.50), apolipoprotein F (0.60), apolipoprotein C-III (0.69), S100-A8 (0.73), S100-A9 (0.75) and prothrombin (0.77) in LCPD than in controls. The alpha-1-acid glycoprotein 1 and haptoglobin increases, and apolipoprotein E and S100-A8 decreases were confirmed by western blot. KEGG pathway analysis revealed these proteins were related to the complement and coagulation cascades, Staphylococcus aureus infection, PPAR signaling, fat digestion and absorption, and vitamin digestion and absorption. Functional network analysis suggested that the proteins were involved in lipid regulation. CONCLUSIONS: The complement and coagulation cascades, and abnormal lipid metabolism may be involved in the pathogenesis of LCPD.