The basic stress pathway above the acetabular dome is important for the maintenance of implant stability in acetabular reconstruction of total hip arthroplasty (THA). The purpose of this study was to describe the basic stress pathway to provide evidence for clinical acetabular reconstruction guidance of THA. A subject-specific finite element (FE) model was developed from CT data to generate 3 normal hip models and a convergence study was conducted to determine the number of pelvic trabecular bone material properties using 5 material assignment plans. In addition, in the range of 0 to 20 mm above the acetabular dome, the models were sectioned and the stress pathway was defined as two parts, i.e. 3D trabecular bone stress distribution and quantified cortical bone stress level. The results showed that using 100 materials to define the material property of pelvic trabecular bone could assure both the accuracy and efficiency of the FE model. Under the same body weight condition, the 3D trabecular bone stress distributions above the acetabular dome were consistent, and especially the quantified cortical bone stress levels were all above 20 MPa and showed no statistically significant difference (P>0.05). Therefore, defining the basic stress pathway above the acetabular dome under certain body weight condition contributes to design accurate preoperative plan for acetabular reconstruction, thus helping restore the normal hip biomechanics and preserve the stability of the implants.
ObjectiveTo interpret the mechanisms of vascular repair disorders in steroid-induced avascular necrosis of the femoral head (SANFH) via detection of the changes of proliferation, migration, and macrophage migration inhibitory factor (MIF)/vascular endothelial growth factor (VEGF) expressions of endothelial cells (ECs) under hypoxia/glucocorticoid. MethodsAccording to culture conditions, human umbilical vein ECs (HUVECs) at passage 3 were divided into group A (normal), group B (1.0×10-6 mol/L dexamethasone), group C (hypoxia), and group D (hypoxia+1.0×10-6 mol/L dexamethasone). The cell activity was detected by AlamarBlue; the number of viable cells was detected in live/dead cell staining; the cell morphology was observed after cytoskeleton staining; cell migration ability was compared by scratch test; and the levels of MIF and VEGF expressions were detected by ELISA. ResultsAt 24 hours after culture, the cell activity and the number of living cells in group C were significantly higher than those in the other 3 groups, showing significant difference between groups (P < 0.05), and group D had the worst cell activity and least living cells. Cytoskeleton staining showed that cells had normal morphology in groups A and B; cells had rich cytoskeleton and secretion granules in group C; cytoskeleton form disorder and nucleus pyknosis were observed in group D. Scratch test showed that the cell migration ability of group C was strongest while cell migration ability of group D was weakest. Accumulated concentration of MIF and VEGF in 4 groups significantly increased with time extending. Accumulated concentration of MIF in group C were significantly higher than that in other 3 groups at each time point (P < 0.05). Within 24 hours after intervention, stage concentration of MIF during 1-8 hours was significantly lower than that during 0-1 hour and 8-24 hours in every group (P < 0.05). Stage concentration of MIF in group C was significantly higher than other groups during 0-1 hour and 8-24 hours (P < 0.05). Within 2 hours after intervention, stage concentration of MIF in 4 groups during 0.5-1 hour was significantly higher than that during other stages (P < 0.05). Accumulated concentration of VEGF in group C was significantly higher than that in other groups at 8 and 24 hours (P < 0.05). The stage concentration of VEGF in groups C and D during 8-24 hours was significantly higher than that during 0-1 hour and 1-8 hours (P < 0.05). There was no significant difference in the stage concentration of VEGF within and among group A, B, C, and D at every stage within 2 hours after intervention (P > 0.05). ConclusionIn hypoxia environment, the proliferation and migration of ECs is enhanced, and the secretion of VEGF and MIF is increased. High concentration of dexamethasone will suppress the process above, which induces vascular repair disorders and aggravating SANFH.
ObjectiveTo investigate the expression of MicroRNA 155 (miR-155) in esophageal squamous cell carcinoma (ESCC) and analyze its correlation with clinicopathological features of ESCC. MethodsThis study included 54 patients with primary ESCC who underwent radical esophagectomy in Department of Thoracic Surgery, Henan Cancer Hospital of Zhengzhou University between January 2010 and November 2012. There were 47 males and 7 females with median age of 61 years (range, 45 to 82 years). Forty patients were in stage Ⅰ or Ⅱ and 14 patients in stage Ⅲ a+b. Expression of miR-155 was determined by SYBR Green qRT-PCR in ESCC tissue and corresponding adjacent normal mucosa in surgical samples from the 54 patients, and its correlation with clinicopathological features was analyzed. ResultsExpression of miR-155 was significantly lower in ESCC tissue than that in adjacent normal mucosa (Z=-4.258, P=0.000).Expression level of miR-155 was significantly correlated with lymph node metastasis (P=0.040), but not significantly correlated with smoking (P=0.430), drinking (P=0.429), age (P=0.769), gender (P=0.671), depth of invasion (P=0.230), differentiation degree (P=0.896) or pTNM (P=0.407) of ESCC. ConclusionUnder-regulation of miR- 155 expression in ESCC tissue may lead to disorders of inflammation response, immune response and relevant tumor suppressor, and may play a significant role in carcinogenesis and progression of ESCC.
ObjectiveTo systematically review the effects of unicompartmental keen arthroplasty (UKA) and total keen arthroplasty (TKA) in patients with unicompartmental osteoarthritis of the keen. MethodsWe electronically searched PubMed, MEDLINE (Ovid), ProQuest, EBSCO, The Cochrane Library (Issue 10, 2014), EMbase, CNKI, VIP, CBM and WanFang Data from inception to November 2014, to collect randomized controlled trials (RCTs) and cohort studies of UKA versus TKA for patients with unicompartmental osteoarthritis of the keen. Two reviewers independently screened literature according to the inclusion and exclusion criteria, extracted data and assessed the risk of bias of included studies. Then, meta-analysis was performed using RevMan 5.2 software. ResultsA total of 6 RCTs and 6 cohort studies involving 940 keens were included. The results of meta-analysis indicated that patients underwent UKA enjoyed a quicker rehabilitation to achieve a flexion of 90° (RCT:P<0.05; cohort study:SMD=-1.70, 95%CI -2.07 to -1.34, P<0.000 01), had better range of motion (cohort study:SMD=0.59, 95%CI 0.41 to 0.78, P=0), and were less likely to get DVT (RCT:RR=0.31, 95%CI 0.12 to 0.82, P=0.02), but the patients underwent UKA were more likely to have a revision (RCT:RR=7.59, 95%CI 1.76 to 32.85, P=0.007). The keen scores of the UKA group were similar to the TKA group (RCT:P=0.626; cohort study:MD=1.78, 95%CI -0.09 to 3.65, P=0.06). ConclusionCurrent evidence shows that, compared with patients underwent TKA, patients underwent UKA have a quicker rehabilitation and fewer rates of DVT, and are more likely to have a revision. The medium to long-term follow up result of keen scores in both groups was equivalent. Due to limited quality and quantity of the included studies, more high quality studies are needed to verify the above conclusion.
ObjectiveTo investigate the application and technical essentials of computer-assisted navigation in the surgical management of periacetabular fractures and pelvic fractures. MethodsBetween May 2010 and May 2011, 39 patients with periacetabular or anterior and posterior pelvic ring fractures were treated by minimally invasive fixation under computer-assisted navigation and were followed up more than 2 years, and the clinical data were analyzed retrospectively. There were 21 males and 18 females, aged 15-64 years (mean, 36 years). Fractures were caused by traffic accident in 23 cases, crush injury in 6 cases, and falling from height in 10 cases. Of them, 6 cases had acetabular fractures; 6 cases had femoral neck fractures; 18 cases had dislocation of sacroiliac joint; and 15 cases had anterior pelvic ring injuries. All patients were treated with closed or limited open reduction and screw fixations assisted with navigation. ResultsEighty-nine screws were inserted during operation, including 8 in the acetabulum, 18 in the neck of the femur, 33 in the sacroiliac joint, and 30 in the symphysis pubis and pubic rami. The mean time of screw implanted was 20 minutes (range, 11-38 minutes), and the average blood loss volume was 20 mL (range, 10-50 mL). The postoperative pelvic X-ray and three dimensional CT scan showed good reduction of fractures and good position of the screws. No incision infection, neurovascular injury, or implant failure occurred. All patients were followed up 27-33 months with an average of 29.6 months. The patients could walk with full weight loading at 6-12 weeks after operation (mean, 8 weeks); at last follow-up, the patients could walk on the flat ground, stand with one leg, and squat down, and they recovered well enough to do their job and to live a normal life. ConclusionMinimally invasive fixation under computer-assisted navigation may be an excellent method to treat some specific types of periacetabular and anterior and posterior pelvic ring fractures because it has the advantages of less trauma and blood loss, lower complication incidence, and faster recovery.
Objective To investigate the effect of Wnt/β-catenin signal pathway on the apoptosis in steroid-induced avascular necrosis of femoral head (SANFH) in rats. Methods Seventy-two male Sprague Dawley rats (weighing, 200-230 g) were randomly divided into the control group (group A, n=24), the model group (group B, n=24), and the intervening group (group C, n=24). The rats in groups B and C were injected with lipopolysaccharide and methylprednisolone (MPS) to establish the SANFH model. The rats in group C were injected intramuscularly with human recombinant secreted frizzled related protein 1 (SFRP1) [1 μg/(kg·d)] at the first time of MPS administration for 30 days. The rats in group A received saline injection at the same injection time of group B. The general condition of rats in groups B and C was observed during modeling and after modeling. At 2, 4, and 8 weeks after last injection of MPS, 8 rats were sacrificed to harvest the femoral head. Histological staining was performed to evaluate osteonecrosis. Apoptosis was detected via TUNEL staining. The expressions of Wnt/β-cate nin pathway signaling molecules (activated β-catenin and c-Myc) were detected by immunohistochemistry and Western blot. Results Six rats were added in groups B and C because of 6 deaths. The other rats survived to the end of experiment. Normal bone structure was observed in group A; osteonecrosis of bone structure disturbance and disruption of the trabecula were found with time in groups B and C. Group C had the highest empty lacuna rate and apoptosis rate, followed by groups B and A, showing significant difference between groups (P < 0.05). The expression levels of activated β-catenin and c-Myc were significantly lower in group C than groups A and B (P < 0.05), and in group B than group A (P < 0.05). Conclusion Wnt/β-catenin signal pathway is involved in the pathogenesis in early SANFH model and its possible mechanism is to affect the cell cycle and cell apoptosis by the regulation of c-Myc expression.