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Sample records for femoral tunnel orientation

  1. Influence of the different anteromedial portal on femoral tunnel orientation during anatomic ACL reconstruction

    Dong-Kyu Moon

    2017-05-01

    Conclusions: In anatomic ACL reconstruction, a mal-positioned AM portal can cause abnormal tunnel orientation, which may lead to mechanical failure during ACL reconstruction. Therefore, it is important to select accurate AM portal positioning, and possibly using an AAM portal by measuring an accurate position when drilling a femoral tunnel in anatomic ACL reconstruction.

  2. Transportal femoral drilling creates more horizontal ACL graft orientation compared to transtibial drilling: A 3D CT imaging study.

    Clockaerts, S; Van Haver, A; Verhaegen, J; Vuylsteke, K; Leenders, T; Lagae, K C; Verdonk, P

    2016-06-01

    The principle of anatomic anterior cruciate ligament (ACL) reconstruction is to create a femoral and tibial tunnel that resembles the insertion of the native ACL. Anatomic reconstruction leads to a more horizontal graft orientation that provides more rotational stability. The aim of this study is to investigate the best method to achieve anatomical reconstruction of femoral insertion of the ACL and thus, a more horizontal orientation of the ACL. We compared tunnel position and orientation between transportal femoral drilling technique and transtibial technique. Thirty-two patients were included. Post-operative CT scans were obtained and femur, tibia and ACL tunnels were reconstructed. The position and orientation of tibial and femoral tunnels were quantified using the quadrant method, and femoral tunnel length, ellipticity and posterior wall breakage were assessed. We also investigated clinical outcome. Analyses show that transportal drilled femoral tunnels were situated significantly lower than transtibial drilled tunnels (p<0.0001), resulting in a significantly more horizontal oriented ACL in the transportal group in coronal (p<0.0001) and sagittal plane (p=0.01). No differences were observed in depth of femoral tunnel position (p=0.44). Femoral tunnel length was shorter in the transportal group (p=0.01) with a more ellipsoidal femoral aperture (p=0.01). There were no differences between both groups in tibial position. There were no differences in clinical outcome measure between the transportal and transtibial groups. This study indicates that transportal drilling of the femoral tunnel leads to a more horizontal graft orientation of the ACL, without differences in clinical outcome. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Does flexible tunnel drilling affect the femoral tunnel angle measurement after anterior cruciate ligament reconstruction?

    Muller, Bart; Hofbauer, Marcus; Atte, Akere; van Dijk, C. Niek; Fu, Freddie H.

    2015-01-01

    To quantify the mean difference in femoral tunnel angle (FTA) as measured on knee radiographs between rigid and flexible tunnel drilling after anatomic anterior cruciate ligament (ACL) reconstruction. Fifty consecutive patients that underwent primary anatomic ACL reconstruction with a single femoral

  4. Does flexible tunnel drilling affect the femoral tunnel angle measurement after anterior cruciate ligament reconstruction?

    Muller, Bart; Hofbauer, Marcus; Atte, Akere; van Dijk, C Niek; Fu, Freddie H

    2015-12-01

    To quantify the mean difference in femoral tunnel angle (FTA) as measured on knee radiographs between rigid and flexible tunnel drilling after anatomic anterior cruciate ligament (ACL) reconstruction. Fifty consecutive patients that underwent primary anatomic ACL reconstruction with a single femoral tunnel drilled with a flexible reamer were included in this study. The control group was comprised of 50 patients all of who underwent primary anatomic ACL reconstruction with a single femoral tunnel drilled with a rigid reamer. All femoral tunnels were drilled through a medial portal to ensure anatomic tunnel placement. The FTA was determined from post-operative anterior-to-posterior (AP) radiographs by two independent observers. A 5° difference between the two mean FTA was considered clinically significant. The average FTA, when drilled with a rigid reamer, was 42.0° ± 7.2°. Drilling with a flexible reamer resulted in a mean FTA of 44.7° ± 7.0°. The mean difference of 2.7° was not statistically significant. The intraclass correlation coefficient for inter-tester reliability was 0.895. The FTA can be reliably determined from post-operative AP radiographs and provides a useful and reproducible metric for characterizing femoral tunnel position after both rigid and flexible femoral tunnel drilling. This has implications for post-operative evaluation and preoperative treatment planning for ACL revision surgery. IV.

  5. Peak stresses shift from femoral tunnel aperture to tibial tunnel aperture in lateral tibial tunnel ACL reconstructions: a 3D graft-bending angle measurement and finite-element analysis.

    Van Der Bracht, Hans; Tampere, Thomas; Beekman, Pieter; Schepens, Alexander; Devriendt, Wouter; Verdonk, Peter; Victor, Jan

    2018-02-01

    To investigate the effect of tibial tunnel orientation on graft-bending angle and stress distribution in the ACL graft. Eight cadaveric knees were scanned in extension, 45°, 90°, and full flexion. 3D reconstructions with anatomically placed anterior cruciate ligament (ACL) grafts were constructed with Mimics 14.12 ® . 3D graft-bending angles were measured for classic medial tibial tunnels (MTT) and lateral tibial tunnels (LTT) with different drill-guide angles (DGA) (45°, 55°, 65°, and 75°). A pivot shift was performed on 1 knee in a finite-element analysis. The peak stresses in the graft were calculated for eight different tibial tunnel orientations. In a classic anatomical ACL repair, the largest graft-bending angle and peak stresses are seen at the femoral tunnel aperture. The use of a different DGA at the tibial side does not change the graft-bending angle at the femoral side or magnitude of peak stresses significantly. When using LTT, the largest graft-bending angles and peak stresses are seen at the tibial tunnel aperture. In a classic anatomical ACL repair, peak stresses in the ACL graft are found at the femoral tunnel aperture. When an LTT is used, peak stresses are similar compared to classic ACL repairs, but the location of the peak stress will shift from the femoral tunnel aperture towards the tibial tunnel aperture. the risk of graft rupture is similar for both MTTs and LTTs, but the location of graft rupture changes from the femoral tunnel aperture towards the tibial tunnel aperture, respectively. I.

  6. Transphyseal ACL Reconstruction in Skeletally Immature Patients: Does Independent Femoral Tunnel Drilling Place the Physis at Greater Risk Compared With Transtibial Drilling?

    Cruz, Aristides I; Lakomkin, Nikita; Fabricant, Peter D; Lawrence, J Todd R

    2016-06-01

    Most studies examining the safety and efficacy of transphyseal anterior cruciate ligament (ACL) reconstruction for skeletally immature patients utilize transtibial drilling. Independent femoral tunnel drilling may impart a different pattern of distal femoral physeal involvement. To radiographically assess differences in distal femoral physeal disruption between transtibial and independent femoral tunnel drilling. We hypothesized that more oblique tunnels associated with independent drilling involve a significantly larger area of physeal disruption compared with vertically oriented tunnels. Cross-sectional study; Level of evidence, 3. We analyzed skeletally immature patients aged between 10 and 15 years who underwent transphyseal ACL reconstruction utilizing an independent femoral tunnel drilling technique between January 1, 2008, and March 31, 2011. These patients were matched with a transtibial technique cohort based on age and sex. Radiographic measurements were recorded from preoperative magnetic resonance imaging and postoperative radiographs. Ten patients in each group were analyzed. There were significant differences between independent drilling and transtibial drilling cohorts in the estimated area of physeal disruption (1.64 vs 0.74 cm(2); P drilling technique disrupt a larger area of the distal femoral physis and create more eccentric tunnels compared with a transtibial technique. As most studies noting the safety of transphyseal ACL reconstruction have utilized a central, vertical femoral tunnel, surgeons should be aware that if an independent femoral tunnel technique is utilized during transphyseal ACL reconstruction, more physeal tissue is at risk and tunnels are more eccentrically placed across the physis when drilling at more horizontal angles. Prior studies have shown that greater physeal involvement and eccentric tunnels may increase the risk of growth disturbance.

  7. Accuracy of a computer-assisted planning and placement system for anatomical femoral tunnel positioning in anterior cruciate ligament reconstruction

    Luites, J.W.H.; Wymenga, A.B.; Blankevoort, L.; Eygendaal, D.; Verdonschot, Nicolaas Jacobus Joseph

    2014-01-01

    Background Femoral tunnel positioning is a difficult, but important factor in successful anterior cruciate ligament (ACL) reconstruction. Computer navigation can improve the anatomical planning procedure besides the tunnel placement procedure. Methods The accuracy of the computer-assisted femoral

  8. All-Epiphyseal Anterior Cruciate Ligament Femoral Tunnel Drilling: Avoiding Injury to the Physis, Lateral Collateral Ligament, Anterolateral Ligament, and Popliteus-A 3-Dimensional Computed Tomography Study.

    Shea, Kevin G; Cannamela, Peter C; Fabricant, Peter D; Terhune, Elizabeth B; Polousky, John D; Milewski, Matthew D; Anderson, Allen F; Ganley, Theodore J

    2018-01-25

    To investigate the relation of the at-risk structures (distal femoral physis, lateral collateral ligament, anterolateral ligament, popliteus, and articular cartilage) during all-epiphyseal femoral tunnel drilling. A second purpose was 2-fold: (1) to develop recommendations for tunnel placement and orientation that anatomically reconstruct the anterior cruciate ligament (ACL) while minimizing the risk of injury to these at-risk structures, and (2) to allow for maximal tunnel length to increase the amount of graft in the socket to facilitate healing. Three-dimensional models of 6 skeletally immature knees (aged 7-11 years) were reconstructed from computed tomography and used to simulate all-epiphyseal femoral tunnels. Tunnels began within the ACL footprint and were directed laterally or anterolaterally, with the goal of avoiding injury to at-risk structures. The spatial relation between the ideal tunnel and these structures was evaluated. Full-length tunnels and partial length condyle sockets were simulated in the models using the same trajectories. An anterolateral tunnel could be placed to avoid direct injury to lateral structures. The safe zone on the anterolateral aspect of the femur was larger than that of a tunnel with a direct lateral trajectory (median 127 mm 2 vs 83 mm 2 , P = .028). Anterolateral tunnels were longer than direct lateral tunnels (median 30 mm vs 24 mm, P = .041). Safe angles for anterolateral tunnels were 34° to 40° from the posterior condylar axis; direct lateral tunnels were drilled 4° to 9° from the posterior condylar axis. Sockets could be placed without direct injury to structures at risk with either orientation. An all-epiphyseal ACL femoral tunnel can be placed without causing direct injury to at-risk structures. A tunnel angled anterolaterally from the ACL origin is longer and has a larger safe zone compared with the direct lateral tunnel. The largest safe zone for femoral all-epiphyseal ACL drilling was (1) anterior to

  9. 3D-Printed Patient-Specific ACL Femoral Tunnel Guide from MRI.

    Rankin, Iain; Rehman, Haroon; Frame, Mark

    2018-01-01

    Traditional ACL reconstruction with non-anatomic techniques can demonstrate unsatisfactory long-term outcomes with regards instability and the degenerative knee changes observed with these results. Anatomic ACL reconstruction attempts to closely reproduce the patient's individual anatomic characteristics with the aim of restoring knee kinematics, in order to improve patient short and long-term outcomes. We designed an arthroscopic, patient-specific, ACL femoral tunnel guide to aid anatomical placement of the ACL graft within the femoral tunnel. The guide design was based on MRI scan of the subject's uninjured contralateral knee, identifying the femoral footprint and its anatomical position relative to the borders of the femoral articular cartilage. Image processing software was used to create a 3D computer aided design which was subsequently exported to a 3D-printing service. Transparent acrylic based photopolymer, PA220 plastic and 316L stainless steel patient-specific ACL femoral tunnel guides were created; the models produced were accurate with no statistical difference in size and positioning of the center of the ACL femoral footprint guide to MRI ( p =0.344, p =0.189, p =0.233 respectively). The guides aim to provide accurate marking of the starting point of the femoral tunnel in arthroscopic ACL reconstruction. This study serves as a proof of concept for the accurate creation of 3D-printed patient-specific guides for the anatomical placement of the femoral tunnel during ACL reconstruction.

  10. Drilling the femoral tunnel during ACL reconstruction: transtibial versus anteromedial portal techniques.

    Tudisco, Cosimo; Bisicchia, Salvatore

    2012-08-01

    Incorrect bone tunnel position, particularly on the femoral side, is a frequent cause of failed anterior cruciate ligament reconstruction. Several studies have reported that drilling the femoral tunnel through the anteromedial portal allows a more anatomical placement on the lateral femoral condyle and higher knee stability than does transtibial reconstruction.In the current study, the femoral tunnel was drilled with transtibial (n=6) and anteromedial (n=6) portal techniques in 12 cadaveric knees. With appropriate landmarks inserted into bone tunnels, the direction and length of the tunnels were determined on anteroposterior and lateral radiographs. Knee stability was evaluated with a KT1000 arthrometer (MEDmetric Corporation, San Diego, California) and pivot shift test, comparing the pre- and postoperative values of both techniques. Finally, all knees were dissected to enhance vision of the insertion of the reconstructed ligament. The anteromedial portal technique led to better placement of the femoral tunnel in the coronal and sagittal planes, with higher knee stability according to the pivot shift test but not the KT1000 arthrometer. Anatomical and clinical results reported in the literature on transtibial and anteromedial portal techniques are controversial, but most of studies report better results with the anteromedial portal technique, especially regarding rotational stability. The current cadaveric study showed that the anteromedial portal technique provided better tunnel placement on the lateral femoral condyle in the coronal and sagittal planes, with an improvement in the rotational stability of the knee. Copyright 2012, SLACK Incorporated.

  11. Patency of Femoral Tunneled Hemodialysis Catheters and Factors Predictive of Patency Failure

    Burton, Kirsteen R.; Guo, Lancia L. Q.; Tan, Kong T.; Simons, Martin E.; Sniderman, Kenneth W.; Kachura, John R.; Beecroft, John R.; Rajan, Dheeraj K.

    2012-01-01

    Purpose: To determine the patency rates of and factors associated with increased risk of patency failure in patients with femoral vein tunneled hemodialysis catheters. Methods: All femoral tunneled catheter insertions from 1996 to 2006 were reviewed, during which time 123 catheters were inserted. Of these, 66 were exchanges. Patients with femoral catheter failure versus those with femoral catheter patency were compared. Confounding factors, such as demographic and procedural factors, were incorporated and assessed using univariate and multivariable Cox proportional hazards regression analyses. Results: Mean catheter primary patency failure time was 96.3 days (SE 17.9 days). Primary patency at 30, 60, 90, and 180 days was 53.8%, 45.4%, 32.1%, and 27.1% respectively. Crude rates of risk of catheter failure did not suggest a benefit for patients receiving catheters introduced from one side versus the other, but more cephalad location of catheter tip was associated with improved patency. Multivariate analysis showed that patients whose catheters were on the left side (p = 0.009), were of increasing age at the time of insertion (p = 0.002) and that those who had diabetes (p = 0.001) were at significantly greater risk of catheter failure. The catheter infection rate was 1.4/1000 catheter days. Conclusion: Patients who were of a more advanced age and had diabetes were at greater risk of femoral catheter failure, whereas those who received femoral catheters from the right side were less at risk of catheter failure.

  12. Editorial Commentary: The All-Epiphyseal Anterior Cruciate Ligament Distal Femoral Approach: Sockets or Tunnels?

    Cordasco, Frank A

    2018-05-01

    I believe that the distal femoral approach for anterior cruciate ligament reconstruction in the skeletally immature athlete with 3 to 6 years of remaining growth is best performed with an all-inside, all-epiphyseal technique using sockets rather than an outside-in approach creating tunnels. A shorter socket rather than a longer tunnel exposes a smaller surface area of the lateral distal femoral physis to potential compromise and resultant valgus malalignment. In addition, exiting the lateral femoral aspect of the epiphysis with a full-diameter tunnel as compared with a smaller diameter drill hole used to prepare a socket places the posterior articular cartilage, the lateral collateral ligament and anterolateral ligament footprints, and the popliteus tendon insertion at risk. My preference for sockets is also related to my belief that they provide a superior biologic milieu for graft incorporation compared with a full-length tunnel with the attendant violation of the lateral femoral cortex of the epiphysis. Copyright © 2018 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  13. Contact area between femoral tunnel and interference screw in anatomic rectangular tunnel ACL reconstruction: a comparison of outside-in and trans-portal inside-out techniques.

    Hiramatsu, Kunihiko; Mae, Tatsuo; Tachibana, Yuta; Nakagawa, Shigeto; Shino, Konsei

    2018-02-01

    The purpose of this study was to compare the femoral tunnel length, the femoral graft bending angle at the femoral tunnel aperture, and the contact area between the femoral tunnel wall and an interference screw used for fixation in anatomic rectangular tunnel anterior cruciate ligament (ACL) reconstruction (ART ACLR). The study included 149 patients with primary ACL injury who underwent ART ACLR. Preoperatively, flexion angle of the index knee was checked under general anaesthesia. Those of less than 130° of passive flexion were assigned to the outside-in (OI) technique (78 patients), while the others to the trans-portal inside-out (TP) technique (71 patients). The patients underwent computed tomography with multiplanar reconstruction at 3-5 weeks post-operatively. Femoral tunnel length, graft bending angle, and contact ratio between the IFS and femoral tunnel were assessed. P contact ratio in the OI technique was significantly larger than that in the TP technique at every point in the femoral tunnel (P contact ratio than the TP technique after ART ACLR. Retrospective comparative study, Level III.

  14. Tibial and Femoral Tunnel Changes After ACL Reconstruction: A Prospective 2-Year Longitudinal MRI Study.

    Weber, Alexander E; Delos, Demetris; Oltean, Hanna N; Vadasdi, Katherine; Cavanaugh, John; Potter, Hollis G; Rodeo, Scott A

    2015-05-01

    Tunnel widening after anterior cruciate ligament reconstruction (ACL-R) is a well-accepted and frequent phenomenon, yet little is known regarding its origin or natural history. To prospectively evaluate the cross-sectional area (CSA) changes in tibial and femoral bone tunnels after ACL-R with serial MRI. Case series; Level of evidence, 4. Patients underwent arthroscopic ACL-R with the same surgeon, surgical technique, and rehabilitation protocol. Each patient underwent preoperative dual-energy x-ray absorptiometry and clinical evaluation, as well as postoperative time zero MRI followed by subsequent MRI and clinical examination, including functional and subjective outcome tests, at 6, 12, 24, 52, and 104 weeks. Tibial and femoral tunnel CSA was measured on each MRI at tunnel aperture (ttA and ftA), midsection (ttM and ftM), and exit (ttE and ftE). Logistic regression modeling was used to examine the predictive value of demographic data and preoperative bone quality (as measured by dual-energy x-ray absorptiometry) on functional outcome scores, manual and instrumented laxity measurements, and changes in tunnel area over time. Eighteen patients (including 12 men), mean age 35.5±8.7 years, underwent ACL-R. There was significant tunnel expansion at ttA and ftA sites 6 weeks postoperatively (P=.024 and .0045, respectively). Expansion continued for 24 weeks, with progressive tunnel narrowing thereafter. Average ttA CSA was significantly larger than ftA CSA at all times. The ttM significantly expanded after 6 weeks (P=.06); continued expansion to week 12 was followed by 21 months of reduction in tunnel diameter. The ftM and both ttE and ftE sites decreased in CSA over the 2 years. Median Lysholm and International Knee Documentation Committee scores significantly improved at final follow-up (P=.0083 and 1 year from time of injury) predicted increased tunnel widening and accelerated expansion in CSA (Pclinical outcome. Younger age, male sex, and delay from injury to ACL

  15. The orientation distribution of tunneling-related quantities

    Seif, W. M.; Refaie, A. I.; Botros, M. M.

    2018-03-01

    In the nuclear tunneling processes involving deformed nuclei, most of the tunneling-related quantities depend on the relative orientations of the participating nuclei. In the presence of different multipole deformations, we study the variation of a few relevant quantities for the α-decay and the sub-barrier fusion processes, in an orientation degree of freedom. The knocking frequency and the penetration probability are evaluated within the Wentzel-Kramers-Brillouin approximation. The interaction potential is calculated with Skyrme-type nucleon-nucleon interaction. We found that the width of the potential pocket, the Coulomb barrier radius, the penetration probability, the α-decay width, and the fusion cross-section follow consistently the orientation-angle variation of the radius of the deformed nucleus. The orientation distribution patterns of the pocket width, the barrier radius, the logarithms of the penetrability, the decay width, and the fusion cross-section are found to be highly analogous to pattern of the deformed-nucleus radius. The curve patterns of the orientation angle distributions of the internal pocket depth, the Coulomb barrier height and width, as well as the knocking frequency simulate inversely the variation of the deformed nucleus radius. The predicted orientation behaviors will be of a special interest in predicting the optimum orientations for the tunneling processes.

  16. Knee rotation influences the femoral tunnel angle measurement after anterior cruciate ligament reconstruction: a 3-dimensional computed tomography model study

    Tang, Jing; Thorhauer, Eric; Marsh, Chelsea; Fu, Freddie H.

    2013-01-01

    Purpose Femoral tunnel angle (FTA) has been proposed as a metric for evaluating whether ACL reconstruction was performed anatomically. In clinic, radiographic images are typically acquired with an uncertain amount of internal/external knee rotation. The extent to which knee rotation will influence FTA measurement is unclear. Furthermore, differences in FTA measurement between the two common positions (0° and 45° knee flexion) have not been established. The purpose of this study was to investigate the influence of knee rotation on FTA measurement after ACL reconstruction. Methods Knee CT data from 16 subjects were segmented to produce 3D bone models. Central axes of tunnels were identified. The 0° and 45° flexion angles were simulated. Knee internal/external rotations were simulated in a range of ±20°. FTA was defined as the angle between the tunnel axis and femoral shaft axis, orthogonally projected into the coronal plane. Results Femoral tunnel angle was positively/negatively correlated with knee rotation angle at 0°/45° knee flexion. At 0° knee flexion, FTA for anterio-medial (AM) tunnels was significantly decreased at 20° of external knee rotation. At 45° knee flexion, more than 16° external or 19° internal rotation significantly altered FTA measurements for single-bundle tunnels; smaller rotations (±9° for AM, ±5° for PL) created significant errors in FTA measurements after double-bundle reconstruction. Conclusion Femoral tunnel angle measurements were correlated with knee rotation. Relatively small imaging malalignment introduced significant errors with knee flexed 45°. This study supports using the 0° flexion position for knee radiographs to reduce errors in FTA measurement due to knee internal/external rotation. Level of evidence Case–control study, Level III. PMID:23589127

  17. Comparison of femoral tunnel widening between outside-in and trans-tibial double-bundle ACL reconstruction.

    Lee, Yong Seuk; Lee, Beom Koo; Oh, Won Seok; Cho, Yong Kyun

    2014-09-01

    The objectives of this study were to compare (1) the degree of widening by comparing the diameter at the most widened area and the site of widening by measuring the distance from the tunnel entrance to the most widened area in two femoral tunnels (anteromedial and posterolateral), and (2) the morphologic change at the tunnel entrance between outside-in and trans-tibial double-bundle anterior cruciate ligament (ACL) reconstruction. A retrospective study that included 17 trans-tibial and 19 outside-in double-bundle ACL reconstructed patients was conducted for evaluation of serial computed tomography (CT) scan (immediate post-operation and post-operative 1 year). Digital image communication in medicine (DICOM) data was extracted from the PiViewSTAR and imported into OsiriX, which was installed on a Macbook Pro laptop computer. Diameter of the most widened area and distance from the entrance to this point were measured from each of two perpendicular (sagittal and coronal) planes that were accurately realigned parallel to the tunnel direction. Change in the morphology of the tunnel entrance between immediate post-operation and 1-year post-operation was evaluated. Widening was observed in both planes of both tunnels in the two techniques. However, no statistical significances in the diameter of most widened area and distance from the tunnel entrance to the most widened point were observed between the both techniques (n.s.). Distances from the centre point to each four sections showed an increase in all four sections of all both tunnels in both techniques. However, no statistical significance was observed between the two techniques (n.s.). Widening was observed in all tunnels using both techniques and degrees, and sites of the widening did not differ between groups. Morphologic change at the tunnel entrance was not limited to the specific direction and occurred in all directions without significant difference between groups. Retrospective comparative study, Level III.

  18. Post-operative 3D CT feedback improves accuracy and precision in the learning curve of anatomic ACL femoral tunnel placement.

    Sirleo, Luigi; Innocenti, Massimo; Innocenti, Matteo; Civinini, Roberto; Carulli, Christian; Matassi, Fabrizio

    2018-02-01

    To evaluate the feedback from post-operative three-dimensional computed tomography (3D-CT) on femoral tunnel placement in the learning process, to obtain an anatomic anterior cruciate ligament (ACL) reconstruction. A series of 60 consecutive patients undergoing primary ACL reconstruction using autologous hamstrings single-bundle outside-in technique were prospectively included in the study. ACL reconstructions were performed by the same trainee-surgeon during his learning phase of anatomic ACL femoral tunnel placement. A CT scan with dedicated tunnel study was performed in all patients within 48 h after surgery. The data obtained from the CT scan were processed into a three-dimensional surface model, and a true medial view of the lateral femoral condyle was used for the femoral tunnel placement analysis. Two independent examiners analysed the tunnel placements. The centre of femoral tunnel was measured using a quadrant method as described by Bernard and Hertel. The coordinates measured were compared with anatomic coordinates values described in the literature [deep-to-shallow distance (X-axis) 28.5%; high-to-low distance (Y-axis) 35.2%]. Tunnel placement was evaluated in terms of accuracy and precision. After each ACL reconstruction, results were shown to the surgeon to receive an instant feedback in order to achieve accurate correction and improve tunnel placement for the next surgery. Complications and arthroscopic time were also recorded. Results were divided into three consecutive series (1, 2, 3) of 20 patients each. A trend to placing femoral tunnel slightly shallow in deep-to-shallow distance and slightly high in high-to-low distance was observed in the first and the second series. A progressive improvement in tunnel position was recorded from the first to second series and from the second to the third series. Both accuracy (+52.4%) and precision (+55.7%) increased from the first to the third series (p process to improve accuracy and precision of femoral

  19. Reliability and reproducibility of several methods of arthroscopic assessment of femoral tunnel position during anterior cruciate ligament reconstruction.

    Ilahi, Omer A; Mansfield, David J; Urrea, Luis H; Qadeer, Ali A

    2014-10-01

    To assess interobserver and intraobserver agreement of estimating anterior cruciate ligament (ACL) femoral tunnel positioning arthroscopically using circular and linear (noncircular) estimation methods and to determine whether overlay template visual aids improve agreement. Standardized intraoperative pictures of femoral tunnel pilot holes (taken with a 30° arthroscope through an anterolateral portal at 90° of knee flexion with horizontal being parallel to the tibial surface) in 27 patients undergoing single-bundle ACL reconstruction were presented to 3 fellowship-trained arthroscopists on 2 separate occasions. On both viewings, each surgeon estimated the femoral tunnel pilot hole location to the nearest half-hour mark using a whole clock face and half clock face, to the nearest 15° using a whole compass and half compass, in the top or bottom half of a linear quadrant, and in the top or bottom half of a linear trisector. Evaluations were performed first without and then with an overlay template of each estimation method. The average difference among reviewers was quite similar for all 4 circular methods with the use of visual aids. Without overlay template visual aids, pair-wise κ statistic values for interobserver agreement ranged from -0.14 to 0.56 for the whole clock face and from 0.16 to 0.42 for the half clock face. With overlay visual guides, interobserver agreement ranged from 0.29 to 0.63 for the whole clock face and from 0.17 to 0.66 for the half clock face. The quadrant method's interobserver agreement ranged from 0.22 to 0.60, and that of the trisection method ranged from 0.17 to 0.57. Neither linear estimation method's reliability uniformly improved with the use of overlay templates. Intraobserver agreement without overlay templates ranged from 0.17 to 0.49 for the whole clock face, 0.11 to 0.47 for the half clock face, 0.01 to 0.66 for the quadrant method, and 0.20 to 0.57 for the trisection method. Use of overlay templates did not uniformly

  20. The relationship of lateral anatomic structures to exiting guide pins during femoral tunnel preparation utilizing an accessory medial portal.

    Farrow, Lutul D; Parker, Richard D

    2010-06-01

    Anatomic reconstruction of the anterior cruciate ligament through an accessory medial portal has become increasingly popular. The purpose of this study is to describe the relationship of guide pin exit points to the lateral anatomic structures when preparing the anterior cruciate ligament femoral tunnel through an accessory medial portal. We utilized seven fresh frozen cadaveric knees. Utilizing an anteromedial approach, a guide wire was placed into the center of each bundle's footprint. Each guide wire was advanced through the lateral femoral cortex. The guide pins were passed at 90, 110, and 130 degrees of knee flexion. The distances from each guide pin to the closest relevant structures on the lateral side of the knee were measured. At 90 degrees the posterolateral bundle guide pin was closest to the lateral condyle articular cartilage (mean 5.4 +/- 2.2 mm) and gastrocnemius tendon (mean 5.7 +/- 2.1 mm). At 110 degrees the posterolateral bundle pin was closest to the gastrocnemius tendon (mean 4.5 +/- 3.4 mm). At 130 degrees the posterolateral bundle pin was closest to the gastrocnemius tendon (mean 7.2 +/- 5.5 mm) and lateral collateral ligament (mean 6.8 +/- 2.1 mm). At 90 degrees the anteromedial bundle guide pin was closest to the articular cartilage (mean 2.0 +/- 2.0 mm). At 110 degrees the anteromedial bundle pin was closest to the articular cartilage (mean 7.4 +/- 3.5 mm) and gastrocnemius tendon (mean 12.3 +/- 3.1 mm). At 130 degrees the AM bundle pin was closest to the gastrocnemius tendon (mean 8.2 +/- 3.2 mm) and LCL (mean 15.1 +/- 2.9 mm). Neither guide pin (anteromedial or posterolateral bundle) put the peroneal nerve at risk at any knee flexion angle. At low knee flexion angles the anteromedial and posterolateral bundle guide pins closely approximated multiple lateral structures when using an accessory medial arthroscopic portal. Utilizing higher flexion angles increases the margin of error when preparing both femoral tunnels. During preparation of

  1. Knee stabiligy after ACL reconstruction through graft fixation in femoral tunnel: transfemoral pinning versus endobutton techniques

    Tahmasebi MN

    2011-05-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 st1":*{behavior:url(#ieooui } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: One of the most common orthopedic complaints is direct or indirect trauma to the knee with torn anterior cruciate ligament (ACL. Reconstruction of the torn ACL is emphatically offered in active individuals as by this operation, we prevent osteoarthritis, knee instability and injury to the meniscus. There are numerous methods for graft fixation in the femoral tunnel in ACL reconstruction. If the graft proves to be stable after the operation, patients would not complain of giving way knee joints. In this clinical trial, we compared transfemoral pinning with endobutton fixation of hamstring graft in arthroscopic ACL reconstruction by examining knee stability and use of other relevant functional tests. "n"nMethods : Fourteen Patients who had undergone arthroscopic ACL reconstruction in Shariati Hospital during the years 2008-2009 and were being followed up were evaluated at least 15 months post-operatively by physical examination and the use of an arthrometer made by the Faculty of Mechanics of Sharif Technical University."n"nResults : The results showed that two out of seven patients in which their ACL had been reconstructed by hamstring graft fixation by endobutton technique, and

  2. Double incision iso-anatomical ACL reconstruction: the freedom to place the femoral tunnel within the anatomical attachment site without exception.

    Arnold, Markus P; Duthon, Victoria; Neyret, Philippe; Hirschmann, Michael T

    2013-02-01

    The present paper describes the rationale behind the surgical technique and the clinical results of the iso-anatomical, single bundle bone patellar-tendon bone anterior cruciate ligament (ACL) reconstruction. Using a second incision on the distal lateral femur an outside-in femoral tunnel is drilled. Guided by a special aiming device it is possible to place the femoral tunnel in the centre of the ACL footprint in every single case. Since every crucial step of the procedure is under visual control, the technique is safe and reliable, which is mirrored by good clinical results.

  3. Early integration of a bone plug in the femoral tunnel in rectangular tunnel ACL reconstruction with a bone-patellar tendon-bone graft: a prospective computed tomography analysis.

    Suzuki, Tomoyuki; Shino, Konsei; Nakagawa, Shigeto; Nakata, Ken; Iwahashi, Takehiko; Kinugasa, Kazutaka; Otsubo, Hidenori; Yamashita, Toshihiko

    2011-12-01

    The purpose of this prospective study was to evaluate how early the bone plug was integrated into the rectangular femoral tunnel after anatomical ACL reconstruction using a bone-patellar tendon-bone (BTB) graft via a rectangular tunnel (RT BTB ACL-R). Twenty consecutive patients who had undergone the reconstruction procedure were evaluated by CT scans at 4 and 8 weeks postoperatively. In each scan, 30 slices for multiplanar reconstruction were collected parallel to the long axis of the parallelepiped femoral tunnel and perpendicular to the tendinous plane of the bone plug. Each slice was classified as "complete," indicating no visible gap between the plug and the tunnel wall or trabecular continuity or "incomplete," showing a visible gap. Bone plug-tunnel integration was evaluated as "excellent," "good," "fair," or "poor" for >20, 11-20, 5-10, and values at the anterior interface between the bone plug and the tunnel wall were also measured on both scans. The mean changes in CT value at 8 weeks were significantly lower than those at 4 weeks. This study shows that bone plug-femoral tunnel integration was almost complete by 8 weeks after surgery using RT BTB ACL-R.

  4. Does a trochanteric lag screw improve fixation of vertically oriented femoral neck fractures? A biomechanical analysis in cadaveric bone.

    Hawks, Michael A; Kim, Hyunchul; Strauss, Joseph E; Oliphant, Bryant W; Golden, Robert D; Hsieh, Adam H; Nascone, Jason W; O'Toole, Robert V

    2013-10-01

    We assessed the biomechanical performances of a trochanteric lag screw construct and a traditional inverted triangle construct in the treatment of simulated Pauwels type 3 femoral neck fractures. An inverted triangle construct (three 7.3-mm cannulated screws placed in inverted triangle orientation) and a trochanteric lag screw construct (two 7.3-mm cannulated screws placed across the superior portion of the femoral neck and one 4.5-mm lag screw placed perpendicular to the fracture in superolateral to inferomedial orientation) were tested in nine matched pairs of non-osteoporotic human cadaveric femora. We used a previously described vertically oriented femoral neck fracture model and testing protocol that incrementally loaded the constructs along the mechanical axis of the femur to 1400 N. Specimens that survived incremental loading underwent cyclic loading. Apparent construct stiffness, force at 3mm of displacement, and survival of incremental loading were recorded. The trochanteric lag screw group had a 70% increase in stiffness (261 N/mm [29 standard deviation] versus 153 N/mm [16 standard deviation]; P=0.026) and a 43% increase in force required for displacement (620 N versus 435 N; P=0.018) compared with the inverted triangle group. One trochanteric lag screw and no inverted triangle specimen survived incremental loading. A trochanteric lag screw construct applied to vertically oriented femoral neck fractures provides marked improvement in mechanical performance compared with the inverted triangle construct. © 2013.

  5. Case Study of Oriental Medicine Treatment with acupotomy Therpy of the Tarsal tunnel Syndrome

    Lim Na-ra

    2009-03-01

    Full Text Available Purpose : In order to estimate clinical effects of Oriental Medicine Treatment with acupotomy therapy of Tarsal tunnel Syndrome Methods : From 5th November, 2008 to 8th November, 2008, 1 male patient diagnosed as Tarsal tunnel syndrome(clinical diagnosed was treated with general oriental medicine therapy (acupuncture, moxibustion, cupping, physical therapy, herbal medication and acupotomy. Results : The patient's Rt foot paresthesia, pain were remarkably improved. Conclusions : This study demonstrates that oriental medical treatment with acuputomy therapy has notable effect in improving symptoms of tarsal tunnel syndrome. as though we had not wide experience in this treatment, more research is needed.

  6. Patient-oriented functional results of total femoral endoprosthetic reconstruction following oncologic resection.

    Jones, Kevin B; Griffin, Anthony M; Chandrasekar, Coonoor R; Biau, David; Babinet, Antoine; Deheshi, Benjamin; Bell, Robert S; Grimer, Robert J; Wunder, Jay S; Ferguson, Peter C

    2011-11-01

    Functional outcomes following oncologic total femoral endoprosthetic reconstruction (TFR) are lacking. We compared patient-oriented functional results of TFRs to proximal femur and distal femur reconstructions (PFR and DFR). We also compared function and complications with regard to knee and hip componentry. Fifty-four TFR patients were identified from three institutional prospective databases. Forty-one had fixed- and 13 had rotating-hinge knees, 37 hemiarthroplasty and 17 total hip arthroplasty componentry. Toronto Extremity Salvage Scores (TESS) for n = 27 were compared between groups and to cohorts of PFR (n = 31) and DFR (n = 85) patients using the Mann-Whitney U-test. Follow-up averaged 4 years. Mechanical complications included five hip dislocations and one femoral malrotation. Four dislocations were in fixed-hinge implants, all in those lacking abductor reattachment. TESS averaged 69.3 ± 17.8, statistically decreased from DFR (P = 0.002) and PFR patients (P = 0.036). No significant differences were detected between patients in the fixed-hinge (n = 18) and rotating-hinge (n = 9) groups (P = 0.944), or total hip (n = 8) and hemiarthroplasty (n = 19) groups (P = 0.633). TFR is reserved for extreme cases of limb salvage, portending a poor prognosis overall. Function reflects additive impairments from PFR and DFR. TFR outcomes differ little with rotating- or fixed-hinge, total hip or hemiarthroplasty implants. Copyright © 2011 Wiley Periodicals, Inc.

  7. Advantages and Disadvantages of Transtibial, Anteromedial Portal, and Outside-In Femoral Tunnel Drilling in Single-Bundle Anterior Cruciate Ligament Reconstruction: A Systematic Review.

    Robin, Brett N; Jani, Sunil S; Marvil, Sean C; Reid, John B; Schillhammer, Carl K; Lubowitz, James H

    2015-07-01

    Controversy exists regarding the best method for creating the knee anterior cruciate ligament (ACL) femoral tunnel or socket. The purpose of this study was to systematically review the risks, benefits, advantages, and disadvantages of the endoscopic transtibial (TT) technique, anteromedial portal technique, outside-in technique, and outside-in retrograde drilling technique for creating the ACL femoral tunnel. A PubMed search of English-language studies published between January 1, 2000, and February 17, 2014, was performed using the following keywords: "anterior cruciate ligament" AND "femoral tunnel." Included were studies reporting risks, benefits, advantages, and/or disadvantages of any ACL femoral technique. In addition, references of included articles were reviewed to identify potential studies missed in the original search. A total of 27 articles were identified through the search. TT technique advantages include familiarity and proven long-term outcomes; disadvantages include the risk of nonanatomic placement because of constrained (TT) drilling. Anteromedial portal technique advantages include unconstrained anatomic placement; disadvantages include technical challenges, short tunnels or sockets, and posterior-wall blowout. Outside-in technique advantages include unconstrained anatomic placement; disadvantages include the need for 2 incisions. Retrograde drilling technique advantages include unconstrained anatomic placement, as well as all-epiphyseal drilling in skeletally immature patients; disadvantages include the need for fluoroscopy for all-epiphyseal drilling. There is no one, single, established "gold-standard" technique for creation of the ACL femoral socket. Four accepted techniques show diverse and subjective advantages, disadvantages, risks, and benefits. Level V, systematic review of Level II through V evidence. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  8. Influence of knee flexion angle and transverse drill angle on creation of femoral tunnels in double-bundle anterior cruciate ligament reconstruction using the transportal technique: Three-dimensional computed tomography simulation analysis.

    Choi, Chong Hyuk; Kim, Sung-Jae; Chun, Yong-Min; Kim, Sung-Hwan; Lee, Su-Keon; Eom, Nam-Kyu; Jung, Min

    2018-01-01

    The purpose of this study was to find appropriate flexion angle and transverse drill angle for optimal femoral tunnels of anteromedial (AM) bundle and posterolateral (PL) bundle in double-bundle ACL reconstruction using transportal technique. Thirty three-dimensional knee models were reconstructed. Knee flexion angles were altered from 100° to 130° at intervals of 10°. Maximum transverse drill angle (MTA), MTA minus 10° and 20° were set up. Twelve different tunnels were determined by four flexion angles and three transverse drill angles for each bundle. Tunnel length, wall breakage, inter-tunnel communication and graft-bending angle were assessed. Mean tunnel length of AM bundle was >30mm at 120° and 130° of flexion in all transverse drill angles. Mean tunnel length of PL bundle was >30mm during every condition. There were ≥1 cases of wall breakage except at 120° and 130° of flexion with MTA for AM bundle. There was no case of wall breakage for PL bundle. Considering inter-tunnel gap of >2mm without communication and obtuse graft-bending angle, 120° of flexion and MTA could be recommended as optimal condition for femoral tunnels of AM and PL bundles. Flexion angle and transverse drill angle had combined effect on femoral tunnel in double-bundle ACL reconstruction using transportal technique. Achieving flexion angle of 120° and transverse drill angle close to the medial femoral condyle could be recommended as optimal condition for femoral tunnels of AM and PL bundles to avoid insufficient tunnel length, wall breakage, inter-tunnel communication and acute graft-bending angle. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Positioning of the femoral tunnel for arthroscopic reconstruction of the anterior cruciate ligament: comparative study of 2 techniques Posicionamento do túnel femoral na reconstrução artroscópica do LCA: estudo comparativo de duas técnicas

    Roberto Freire da Mota Albuquerque

    2007-01-01

    Full Text Available OBJECTIVE: To compare the accuracy of positioning of the femoral tunnel in reconstructing the anterior cruciate ligament by means of 2 techniques: tibial tunnel and anteromedial portal. METHOD: Femoral tunnels were drilled in 20 knees from human cadavers by means of arthroscopy. Group I had the femoral tunnel drilled via a trans-tibial tunnel, and Group II via the anteromedial portal. Four variables were measured: A posterior wall thickness; B tunnel positioning at the notch; C tunnel inclination in relation to the femoral axis; and D distance between the wire guide exit and the lateral epicondyle. RESULTS: As above, respectively, A 2.23 mm for group I and 2.36 mm for group II (P =.54; B 25.5° for group I and 30.0° for group II (P =.23; C 23.9° for group I and 32.0° for group II (P =.02; D 7.8 cm for group I and 3.9 cm for group II (P OBJETIVO: Comparar a acurácia do posicionamento do túnel femoral na reconstrução do ligamento cruzado anterior através de duas vias: túnel tibial e portal ântero - medial. MÉTODO: Foram perfurados túneis femorais em vinte joelhos de cadáveres humanos por via artroscópica. Grupo I: túnel femoral por acesso trans túnel tibial. Grupo II: via portal ântero-medial. Quatro variáveis foram estudadas: A espessura da parede posterior; B posicionamento do túnel no intercôndilo; C angulação do túnel em relação ao eixo do fêmur; D distância entre a saída do fio guia e o epicôndilo lateral. RESULTADO: A grupo I: 2,23 mm, grupo II: 2,36 mm (p=0,543; B grupo I: 25,5º, grupo II: 30º (p=0,226; C grupo I: 23,9º, grupo II: 32º (p= 0,014; D grupo I: 7,8 cm, grupo II 3,9 cm (p<0,001. CONCLUSÃO: As duas técnicas obteveram o posicionamento desejado da entrada do túnel femoral e espessura adequada da cortical posterior. A perfuração via portal ântero-medial pode propiciar maior proteção contra rotura da parede posterior.

  10. Determining the phonon energy of highly oriented pyrolytic graphite by scanning tunneling microscope light emission spectroscopy

    Uehara, Yoichi; Michimata, Junichi; Watanabe, Shota; Katano, Satoshi; Inaoka, Takeshi

    2018-03-01

    We have investigated the scanning tunneling microscope (STM) light emission spectra of isolated single Ag nanoparticles lying on highly oriented pyrolytic graphite (HOPG). The STM light emission spectra exhibited two types of spectral structures (step-like and periodic). Comparisons of the observed structures and theoretical predictions indicate that the phonon energy of the ZO mode of HOPG [M. Mohr et al., Phys. Rev. B 76, 035439 (2007)] can be determined from the energy difference between the cutoff of STM light emission and the step in the former structure, and from the period of the latter structure. Since the role of the Ag nanoparticles does not depend on the substrate materials, this method will enable the phonon energies of various materials to be measured by STM light emission spectroscopy. The spatial resolution is comparable to the lateral size of the individual Ag nanoparticles (that is, a few nm).

  11. Optical Flow for Flight and Wind Tunnel Background Oriented Schlieren Imaging

    Smith, Nathanial T.; Heineck, James T.; Schairer, Edward T.

    2017-01-01

    Background oriented Schlieren images have historically been generated by calculating the observed pixel displacement between a wind-on and wind-o image pair using normalized cross-correlation. This work uses optical flow to solve the displacement fields which generate the Schlieren images. A well established method used in the computer vision community, optical flow is the apparent motion in an image sequence due to brightness changes. The regularization method of Horn and Schunck is used to create Schlieren images using two data sets: a supersonic jet plume shock interaction from the NASA Ames Unitary Plan Wind Tunnel, and a transonic flight test of a T-38 aircraft using a naturally occurring background, performed in conjunction with NASA Ames and Armstrong Research Centers. Results are presented and contrasted with those using normalized cross-correlation. The optical flow Schlieren images are found to provided significantly more detail. We apply the method to historical data sets to demonstrate the broad applicability and limitations of the technique.

  12. Design of a magnetic-tunnel-junction-oriented nonvolatile lookup table circuit with write-operation-minimized data shifting

    Suzuki, Daisuke; Hanyu, Takahiro

    2018-04-01

    A magnetic-tunnel-junction (MTJ)-oriented nonvolatile lookup table (LUT) circuit, in which a low-power data-shift function is performed by minimizing the number of write operations in MTJ devices is proposed. The permutation of the configuration memory cell for read/write access is performed as opposed to conventional direct data shifting to minimize the number of write operations, which results in significant write energy savings in the data-shift function. Moreover, the hardware cost of the proposed LUT circuit is small since the selector is shared between read access and write access. In fact, the power consumption in the data-shift function and the transistor count are reduced by 82 and 52%, respectively, compared with those in a conventional static random-access memory-based implementation using a 90 nm CMOS technology.

  13. Variability in ACL tunnel placement: observational clinical study of surgeon ACL tunnel variability.

    Wolf, Brian R; Ramme, Austin J; Wright, Rick W; Brophy, Robert H; McCarty, Eric C; Vidal, Armando R; Parker, Richard D; Andrish, Jack T; Amendola, Annunziato

    2013-06-01

    Multicenter and multisurgeon cohort studies on anterior cruciate ligament (ACL) reconstruction are becoming more common. Minimal information exists on intersurgeon and intrasurgeon variability in ACL tunnel placement. Purpose/ The purpose of this study was to analyze intersurgeon and intrasurgeon variability in ACL tunnel placement in a series of The Multicenter Orthopaedic Outcomes Network (MOON) ACL reconstruction patients and in a clinical cohort of ACL reconstruction patients. The hypothesis was that there would be minimal variability between surgeons in ACL tunnel placement. Cross-sectional study; Level of evidence, 3. Seventy-eight patients who underwent ACL reconstruction by 8 surgeons had postoperative imaging with computed tomography, and ACL tunnel location and angulation were analyzed using 3-dimensional surface processing and measurement. Intersurgeon and intrasurgeon variability in ACL tunnel placement was analyzed. For intersurgeon variability, the range in mean ACL femoral tunnel depth between surgeons was 22%. For femoral tunnel height, there was a 19% range. Tibial tunnel location from anterior to posterior on the plateau had a 16% range in mean results. There was only a small range of 4% for mean tibial tunnel location from the medial to lateral dimension. For intrasurgeon variability, femoral tunnel depth demonstrated the largest ranges, and tibial tunnel location from medial to lateral on the plateau demonstrated the least variability. Overall, surgeons were relatively consistent within their own cases. Using applied measurement criteria, 85% of femoral tunnels and 90% of tibial tunnels fell within applied literature-based guidelines. Ninety-one percent of the axes of the femoral tunnels fell within the boundaries of the femoral footprint. The data demonstrate that surgeons performing ACL reconstructions are relatively consistent between each other. There is, however, variability of average tunnel placement up to 22% of mean condylar depth

  14. Femoral nerve damage (image)

    The femoral nerve is located in the leg and supplies the muscles that assist help straighten the leg. It supplies sensation ... leg. One risk of damage to the femoral nerve is pelvic fracture. Symptoms of femoral nerve damage ...

  15. Scanning tunneling microscope observation and magnetic anisotropy of molecular beam epitaxy-grown Fe/Pt superlattices with (111) and (001) orientations

    Yamamoto, S.; Kato, T.; Iwata, S.; Tsunashima, S.; Uchiyama, S.

    2004-01-01

    The surface morphology and the perpendicular magnetic anisotropy for (001) and (111) oriented [Pt(nML)/Fe(nML)] 10 superlattices were investigated. From in situ scanning tunneling microscope observation, the small grain whose diameter was about 5-10 nm and height was 0.2-0.4 nm, was observed in the Fe(2 ML) surface grown at room temperature on the Pt(111) seed layer, while the surface of the Fe deposited at 150 deg. C was covered with flat terraces and steps. It is found that the (111) oriented films were all in-plane magnetized. On the other hand, the (001) films were in-plane magnetized at room temperature, perpendicular magnetized at 100 deg. C and 150 deg. C

  16. [Femoral arteriovenous fistula: a late uncommon complication of central venous catheterization].

    Conz, P A; Malagoli, A; Normanno, M; Munaro, D

    2007-01-01

    A 77-year-old woman was admitted due to AV graft thrombosis; given the technical impossibility of performing other native AV fistulas, we chose to insert a tunnelled central venous catheter. Considering the vascular history of the patient, the central venous catheter could not be placed into the internal jugular vein; it was therefore put into the left femoral vein. Following a 3-month-period of the catheter working properly, the patient was hospitalized due to sudden acute pain in the left thigh. In a few days the patient developed an important haematoma with serious anemization in the left lower limb. Ultrasonography showed the presence of a fistula between the left common femoral artery and the femoral vein, leading to the subsequent successful positioning of a stent into the common femoral artery through right trans-femoral access. Angiography examination showed the femoral vein patency along the proximal stretch with respect to the function of the tunnelled venous catheter.

  17. Computer-assisted anatomical placement of a double-bundle ACL through 3D-fitting of a statistically generated femoral template into individual knee geometry

    Luites, J. W. H.; Wymenga, A. B.; Sati, M.; Bourquin, Y.; Blankevoort, L.; van der Venne, R.; Kooloos, J. G. M.; Staubli, H. U.

    2000-01-01

    Femoral graft placement is an important factor in the success of ACL-reconstruction. Besides improving the accuracy of femoral tunnel placement, Computer Assisted Surgery (CAS) can be used to determine the anatomical Location. This requires a 3D femoral template with the position of the anatomical

  18. Femoral component rotation in patellofemoral joint replacement.

    van Jonbergen, Hans-Peter W; Westerbeek, Robin E

    2018-06-01

    Clinical outcomes in patellofemoral joint replacement may be related to femoral component rotation. Assessment of rotational alignment is however difficult as patients with isolated patellofemoral osteoarthritis often have trochlear dysplasia. The use of the medial malleolus as a landmark to guide rotation has been suggested. The purpose of our study was to evaluate this technique with regard to femoral component rotation, and to correlate rotation with clinical outcomes at one-year follow-up. Forty-one knees in 39 patients had patellofemoral joint replacement using the Zimmer Gender-Solutions patellofemoral prosthesis. Intraoperatively, we determined femoral component rotational alignment using an extramedullary rod aimed at the inferior tip of the medial malleolus. Postoperatively, we measured the angle between the femoral component and the anatomical transepicondylar axis using CT. The amount of rotation was correlated with clinical outcomes at one-year follow-up. Forty knees in 38 patients were available for one-year follow-up. Mean femoral component rotation relative to the anatomical transepicondylar axis was 1.4° external rotation (range, -3.8 to 5.7°). We found no statistically significant correlation between femoral component rotation and change from baseline KOOS subscales at one-year follow-up. Our findings show that when using the medial malleolus as a landmark to guide rotation, the femoral component of the patellofemoral prosthesis was oriented in external rotation relative to the anatomical transepicondylar axis in 80% of knees. Our study did not show a relation between the amount of external rotation and clinical outcomes. Level III. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Low-temperature matrix effects on orientational motion of Methyl radical trapped in gas solids: Angular tunneling vs. libration

    Dmitriev, Yurij A.; Zelenetckii, Ilia A.; Benetis, Nikolas P.

    2018-05-01

    EPR investigation of the lineshape of matrix -isolated methyl radical, CH3, spectra recorded in solid N2O and CO2 was carried out. Reversible temperature-dependent line width anisotropy was observed in both matrices. This effect is a fingerprint of the extra-slow radical rotation about the in-plane C2 axes. The rotation was found to be anisotropic and closely correlated to the orientational dynamics of the matrix molecules. It was suggested that a recently discovered "hoping precession" effect of matrix molecules in solid CO2 is a common feature of matrices of the linear molecules CO, N2O, and CO2. A new low-temperature matrix effect, referred to as "libration trap", was proposed which accounts for the changing CH3 reorientational motion about the radical C3-axis from rotation to libration. Temperature dependence of the intensity of the EPR satellites produced by these nonrotating-but librating methyls was presented. This allowed for a rough estimation of the rotation hindering potential due to correlation mismatch between the radical and the nearest matrix molecules' librations.

  20. Femoral head avascular necrosis

    Chrysikopoulos, H.; Sartoris, D.J.; Resnick, D.L.; Ashburn, W.; Pretorius, T.

    1988-01-01

    MR imaging has been shown to be more sensitive and specific than planar scintigraphy for avascular necrosis (AVN) of the femoral head. However, experience with single photon emission CT (SPECT) is limited. The authors retrospectively compared 1.5-T MR imaging with SPECT in 14 patients with suspected femoral head AVN. Agreement between MR imaging and SPECT was present in 24 femurs, 14 normal and ten with AVN. MR imaging showed changes of AVN in the remaining four femoral heads. Of these, one was normal and the other three inconclusive for AVN by SPECT. The authors conclude that MR imaging is superior to SPECT for the evaluation of AVN of the hip

  1. Femoral Condyle Fracture during Anterior Cruciate Ligament Reconstruction

    Selahattin Ozyurek

    2015-07-01

    Full Text Available Dear Editor,We have greatly enjoyed reading the case report entitled “‘Femoral Condyle Fracture during Revision of Anterior Cruciate Ligament Reconstruction: Case Report and a Review of Literature in the issue of Arch Bone Jt Surg. 2015;3(2 with great interest. We would like to commend the authors for their detailed and valuable work. Although various case reports have described postoperative distal femur fracture at a range of time intervals (1,2 intraoperative intra-articular distal femur fracture is a unique entity.However, we believe that some important additional observations seem necessary to be contributed through this study. In this article, the authors stated that, to the best of their knowledge, there is no other case report in the literature introducing a femoral condyle fracture during arthroscopic ACL reconstruction or revision reconstruction. Nevertheless, we would like to call the attention of the readers to the fact that that the literature contains one additional case report re‌porting on intraoperative distal femoral coronal plane (Hoffa fracture during primary ACL reconstruction (2. Werner BC and Miller MD presented of case report of an intraoperative distal femoral coronal plane (Hoffa fracture that occurred during independent femoral tunnel drilling and dilation in a primary ACL reconstruction. As in the their case, this type of fracture can occur with appropriately placed femoral tunnels, but the risk can increase with larger graft diameters in patients with smaller lateral femoral condyles The patient was treated with open reduction and internal fixation, without compromise of graft stability and with good recovery of function. We believe that tailoring graft size to the size of the patient is important to prevent similar adverse events.

  2. Femoral shaft fractures

    Bender, C.E.; Campbell, D.C. II

    1985-01-01

    The femur is the longest, largest, and strongest bone in the body. Because of its length, width, and role as primary weight-bearing bone, it must tolerate the extremes of axial loading and angulatory stresses. Massive musculature envelopes the femur. This masculature provides abundant blood supply to the bone, which also allows great potential for healing. Thus, the most significant problem relating to femoral shaft fractures is not healing, but restoration of bone length and alignment so that the femoral shaft will tolerate the functional stresses demanded of it

  3. Proximal femoral fractures

    Palm, Henrik; Teixidor, Jordi

    2015-01-01

    searched the homepages of the national heath authorities and national orthopedic societies in West Europe and found 11 national or regional (in case of no national) guidelines including any type of proximal femoral fracture surgery. RESULTS: Pathway consensus is outspread (internal fixation for un...

  4. Disadvantages and advantages of transtibial technique for creating the anterior cruciate ligament femoral socket.

    Robin, Brett N; Lubowitz, James H

    2014-10-01

    Anterior cruciate ligament (ACL) femoral socket techniques have distinct advantages and disadvantages when considering the following techniques: transtibial, anteromedial portal, outside-in, and outside-in retroconstruction. There is no one perfect technique and we have an incomplete understanding of anatomical, biomechanical, isometry, stability, and clinical outcomes. Our primary focus is transtibial technique for creating the ACL femoral socket. Advantages include less invasive, isometric graft placement, stable Lachman exam, and minimal graft impingement with the tunnel and notch. Disadvantages include nonanatomic vertical graft placement that can cause rotational instability and positive pivot shift, interference screw divergence, graft-tunnel length mismatch, femoral socket constraint, posterior cruciate ligament impingement, and a short, oblique tibial tunnel that may undermine the medial plateau in an attempt to achieve anatomic ACL reconstruction. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  5. Radiographic positions of femoral ACL, AM and PL centres : accuracy of guidelines based on the lateral quadrant method

    Luites, Joan W.H.; Verdonschot, Nico

    2017-01-01

    Purpose: Femoral tunnel positioning is an important factor in anatomical ACL reconstructions. To improve accuracy, lateral radiographic support can be used to determine the correct tunnel location, applying the quadrant method. Piefer et al. (Arthroscopy 28:872–881, 2012) combined various outcomes

  6. [Trochanteric femoral fractures].

    Douša, P; Čech, O; Weissinger, M; Džupa, V

    2013-01-01

    At the present time proximal femoral fractures account for 30% of all fractures referred to hospitals for treatment. Our population is ageing, the proportion of patients with post-menopausal or senile osteoporosis is increasing and therefore the number of proximal femoral fractures requiring urgent treatment is growing too. In the age category of 50 years and older, the incidence of these fractures has increased exponentially. Our department serves as a trauma centre for half of Prague and part of the Central Bohemia Region with a population of 1 150 000. Prague in particular has a high number of elderly citizens. Our experience is based on extensive clinical data obtained from the Register of Proximal Femoral Fractures established in 1997. During 14 years, 4280 patients, 3112 women and 1168 men, were admitted to our department for treatment of proximal femoral fractures. All patients were followed up until healing or development of complications. In the group under study, 82% were patients older than 70 years; 72% of those requiring surgery were in their seventies and eighties. Men were significantly younger than women (pfractures were 2.3-times more frequent in women than in men. In the category under 60 years, men significantly outnumbered women (pfractures were, on the average, eight years older than the patients with intertrochanteric fractures, which is a significant difference (pTrochanteric fractures accounted for 54.7% and femoral neck fractures for 45.3% of all fractures. The inter-annual increase was 5.9%, with more trochanteric than femoral neck fractures. There was a non-significant decrease in intertrochanteric (AO 31-A3) fractures. On the other hand, the number of pertrochanteric (AO 31-A1+2) fractures increased significantly (pfractures were treated with a proximal femoral nail; a short nail was used in 1260 and a long nail in 134 of them. A dynamic hip screw (DHS) was employed to treat 947 fractures. Distinguishing between pertrochanteric (21-A1

  7. Aerodynamic evaluation of wing shape and wing orientation in four butterfly species using numerical simulations and a low-speed wind tunnel, and its implications for the design of flying micro-robots.

    Ortega Ancel, Alejandro; Eastwood, Rodney; Vogt, Daniel; Ithier, Carter; Smith, Michael; Wood, Rob; Kovač, Mirko

    2017-02-06

    Many insects are well adapted to long-distance migration despite the larger energetic costs of flight for small body sizes. To optimize wing design for next-generation flying micro-robots, we analyse butterfly wing shapes and wing orientations at full scale using numerical simulations and in a low-speed wind tunnel at 2, 3.5 and 5 m s -1 . The results indicate that wing orientations which maximize wing span lead to the highest glide performance, with lift to drag ratios up to 6.28, while spreading the fore-wings forward can increase the maximum lift produced and thus improve versatility. We discuss the implications for flying micro-robots and how the results assist in understanding the behaviour of the butterfly species tested.

  8. Aerodynamic evaluation of wing shape and wing orientation in four butterfly species using numerical simulations and a low-speed wind tunnel, and its implications for the design of flying micro-robots

    Eastwood, Rodney; Vogt, Daniel; Ithier, Carter; Smith, Michael; Wood, Rob; Kovač, Mirko

    2017-01-01

    Many insects are well adapted to long-distance migration despite the larger energetic costs of flight for small body sizes. To optimize wing design for next-generation flying micro-robots, we analyse butterfly wing shapes and wing orientations at full scale using numerical simulations and in a low-speed wind tunnel at 2, 3.5 and 5 m s−1. The results indicate that wing orientations which maximize wing span lead to the highest glide performance, with lift to drag ratios up to 6.28, while spreading the fore-wings forward can increase the maximum lift produced and thus improve versatility. We discuss the implications for flying micro-robots and how the results assist in understanding the behaviour of the butterfly species tested. PMID:28163879

  9. Tunneling works. Tunnel koji

    Higo, M [Hazam Gumi, Ltd., Tokyo (Japan)

    1991-10-25

    A mountain tunneling method for rock-beds used to be applied mainly to construction works in the mountains under few restrictions by environmental problems. However, construction works near residential sreas have been increasing. There are such enviromental problems due to tunneling works as vibration, noise, lowering of ground-water level, and influences on other structures. This report mainly describes the measurement examples of vibration and noise accompanied with blasting and the effects of the measures to lessen such influences. When the tunneling works for the railroad was carried out on the natural ground mainly composed of basalt, vibration of the test blasting was measured at three stations with piezoelectric accelerometers. Then, ordinary blasting, mutistage blasting, and ABM blasting methods were used properly besed on the above results, and only a few complaints were made. In the different works, normal noise and low-frequency sound were mesured at 22 stations around the pit mouth. As countermeasures for noise, sound-proof sheets, walls, and single and double doors were installed and foundto be effective. 1 ref., 6 figs., 1 tab.

  10. Iodixanol in femoral arteriography

    Thorstensen, Oe.; Albrechtsson, U.; Calissendorff, B.; Larusdottir, H.; Norgren, L.; Tengvar, M.; Bolstad, B.; Aspelin, P.

    1994-01-01

    Two contrast media, iodixanol (Visipaque, Nycomed) 270 mg I/ml and iohexol (Omnipaque, Nycomed) 300 mg I/ml, were compared in femoral arteriography, in 147 patients. Both contrast media were diagnostically effective for use in femoral arteriography, without any significant difference. Pain was reported in connection with injection of iohexol by 36% of the patients, after injection of iodixanol none reported pain. Seventy-two percent of the patients in the iodixanol group reported a sensation of warmth in connection with contrast injection versus 90% in the iohexol group. The average intensity of the warmth was greater with iohexol than with iodixanol. Fourteen percent of patients in the iodixanol group and 1% in the iohexol group reported one or more subjective adverse events. (orig.)

  11. Radiographic femoral varus measurement is affected unpredictably by femoral rotation

    Miles, James Edward

    Radiographic measurements of femoral varus are used to determine if intervention to correct femoral deformity is required, and to calculate the required correction. The varus angle is defined as the angle between the proximal femoral long axis (PFLA) and an axis tangential to the distal femoral...... and externally by 5° and 10° using plastic wedges. Accuracy of rotation was within +1°. Digital radiographs were obtained at each position. Varus angles were measured using ImageJ, employing two definitions of PFLA. Mean varus angles increased with 10° of either internal or external rotation with both PFLA...... rotation angles. The effect of rotation on varus angle measurements in these femoral specimens contradicts a previous report using CT. The most probable explanation is the difference in femoral positioning: the CT study used a slightly elevated position compared to that in this study, resulting in better...

  12. A scanning tunneling microscope study on an ordered mixed monolayer of bis(4,5-dihydronaphtho[1,2-d])-tetrathiafulvalene and n-tetradecane on highly oriented pyrolytic graphite.

    Zhao, Miao; Jiang, Peng; Deng, Ke; Jiang, Chao

    2010-11-01

    Tetrathiafulvalene (TTF) and its derivatives (TTFs) have been successfully used as building blocks to form charge transfer salts and organic semiconductors because of their special structures and rich electron nature. We report the formation of ordered mixed binary-component monolayer consisting of Bis(4,5-dihydronaphtho[1,2-d])tetrathiafulvalene (DH-TTF) and n-tetradecane (n-C14H30) molecules on highly oriented pyrolytic graphite (HOPG) surface. Scanning tunneling microscope (STM) imaging reveals that the two different kinds of molecules can spontaneously form ordered periodic phase separation structures on the substrate, in which ordered DH-TTF double- (or single-) lamella structures are periodically tuned by ordered n-C14H30 double- (or single-) lamella structures. Furthermore, scanning tunneling spectrum (STS) measurements by addressing the individual DH-TTF and n-C14H30 molecules in the ordered monolayer show that the two different kinds of molecules exhibit completely different I(V) characters on the HOPG substrate. The modulated arrangement of the TTF derivative by insulating molecules opens a possible route to construct organic conducting molecule ribbons for potential application in nanodevices.

  13. Technical note: Anterior cruciate ligament reconstruction in the presence of an intramedullary femoral nail using anteromedial drilling.

    Lacey, Matthew; Lamplot, Joseph; Walley, Kempland C; DeAngelis, Joseph P; Ramappa, Arun J

    2017-05-18

    To describe an approach to anterior cruciate ligament (ACL) reconstruction using autologous hamstring by drilling via the anteromedial portal in the presence of an intramedullary (IM) femoral nail. Once preoperative imagining has characterized the proposed location of the femoral tunnel preparations are made to remove all of the hardware (locking bolts and IM nail). A diagnostic arthroscopy is performed in the usual fashion addressing all intra-articular pathology. The ACL remnant and lateral wall soft tissues are removed from the intercondylar, to provide adequate visualization of the ACL footprint. Femoral tunnel placement is performed using a transportal ACL guide with desired offset and the knee flexed to 2.09 rad. The Beath pin is placed through the guide starting at the ACL's anatomic footprint using arthroscopic visualization and/or fluoroscopic guidance. If resistance is met while placing the Beath pin, the arthroscopy should be discontinued and the obstructing hardware should be removed under fluoroscopic guidance. When the Beath pin is successfully placed through the lateral femur, it is overdrilled with a 4.5 mm Endobutton drill. If the Endobutton drill is obstructed, the obstructing hardware should be removed under fluoroscopic guidance. In this case, the obstruction is more likely during Endobutton drilling due to its larger diameter and increased rigidity compared to the Beath pin. The femoral tunnel is then drilled using a best approximation of the graft's outer diameter. We recommend at least 7 mm diameter to minimize the risk of graft failure. Autologous hamstring grafts are generally between 6.8 and 8.6 mm in diameter. After reaming, the knee is flexed to 1.57 rad, the arthroscope placed through the anteromedial portal to confirm the femoral tunnel position, referencing the posterior wall and lateral cortex. For a quadrupled hamstring graft, the gracilis and semitendinosus tendons are then harvested in the standard fashion. The tendons are whip

  14. Focal femoral condyle resurfacing.

    Brennan, S A

    2013-03-01

    Focal femoral inlay resurfacing has been developed for the treatment of full-thickness chondral defects of the knee. This technique involves implanting a defect-sized metallic or ceramic cap that is anchored to the subchondral bone through a screw or pin. The use of these experimental caps has been advocated in middle-aged patients who have failed non-operative methods or biological repair techniques and are deemed unsuitable for conventional arthroplasty because of their age. This paper outlines the implant design, surgical technique and biomechanical principles underlying their use. Outcomes following implantation in both animal and human studies are also reviewed. Cite this article: Bone Joint J 2013;95-B:301-4.

  15. Femoral head necrosis; Hueftkopfnekrose

    Kramer, J.; Scheurecker, G.; Scheurecker, A.; Stoeger, A.; Huber, A. [Roentgeninstitut am Schillerpark, Linz (Austria); Hofmann, S. [Orthopaedisches Landeskrankenhaus Stolzalpe (Austria)

    2009-05-15

    The epidemiology and pathohistogenesis of avascular femoral head necrosis has still not been clarified in detail. Because the course of the disease runs in stages and over a long time period nearly always culminates in the necessity for a total hip prosthesis, an exact radiological evaluation is of paramount importance for the treatment. There is a need for a common staging system to enable comparison of different therapy concepts and especially their long-term results. In this article the ARCO staging system is described in full detail, which includes all radiological modalities as well as histopathological alterations. (orig.) [German] Bei der avaskulaeren Femurkopfnekrose handelt es sich um ein Krankheitsbild, dessen Ursachen noch immer nicht vollstaendig geklaert sind. Da die Erkrankung stadienhaft verlaeuft und ueber einen laengeren Zeitraum betrachtet nahezu immer in einem prothetischen Hueftersatz muendet, ist eine genaue radiologische Abklaerung fuer die Behandlung von enormer Bedeutung. Um Langzeiterfolge verschiedener Therapiekonzepte vergleichen zu koennen, sind eine exakte Beschreibung und darauf basierend die Verwendung einer einheitlichen Stadieneinteilung wuenschenswert. In der vorliegenden Arbeit wird die ARCO-Stadieneinteilung im Detail beschrieben, die alle bildgebenden Methoden beruecksichtigt und histopathologische Veraenderungen mit einbezieht. (orig.)

  16. Molecular Orientation of a Terbium(III)-Phthalocyaninato Double-Decker Complex for Effective Suppression of Quantum Tunneling of the Magnetization.

    Yamabayashi, Tsutomu; Katoh, Keiichi; Breedlove, Brian K; Yamashita, Masahiro

    2017-06-15

    Single-molecule magnet (SMM) properties of crystals of a terbium(III)-phthalocyaninato double-decker complex with different molecular packings ( 1 : TbPc₂, 2 : TbPc₂·CH₂Cl₂) were studied to elucidate the relationship between the molecular packing and SMM properties. From single crystal X-ray analyses, the high symmetry of the coordination environment of 2 suggested that the SMM properties were improved. Furthermore, the shorter intermolecular Tb-Tb distance and relative collinear alignment of the magnetic dipole in 2 indicated that the magnetic dipole-dipole interactions were stronger than those in 1 . This was confirmed by using direct current magnetic measurements. From alternating current magnetic measurements, the activation energy for spin reversal for 1 and 2 were similar. However, the relaxation time for 2 is three orders of magnitude slower than that for 1 in the low- T region due to effective suppression of the quantum tunneling of the magnetization. These results suggest that the SMM properties of TbPc₂ highly depend on the molecular packing.

  17. Posterior Femoral Single Limb Osteotomy for the Removal of Well-Fixed Modular Femoral Neck Components

    Keith A Fehring

    2017-07-01

    Full Text Available Modular neck femoral components were introduced to optimize femoral neck anteversion, leg length, offset, and stability in total hip arthroplasty. However, concerns have been raised in recent years regarding early failure of these implants due to corrosion, pseudotumor, as well as fracture of the modular neck. Removing modular neck femoral implants is challenging as removal of the modular femoral neck leaves a proximally coated femoral stem level with the proximal bone of the femoral neck. We describe a posterior femoral single limb osteotomy  (posterior cut of an extended trochanteric osteotomy for the removal of a modular neck femoral component.

  18. Subchondral bone density distribution in the human femoral head

    Wright, David A.; Meguid, Michael; Lubovsky, Omri; Whyne, Cari M. [Sunnybrook Research Institute, Orthopaedic Biomechanics Laboratory, Toronto, Ontario (Canada)

    2012-06-15

    This study aims to quantitatively characterize the distribution of subchondral bone density across the human femoral head using a computed tomography derived measurement of bone density and a common reference coordinate system. Femoral head surfaces were created bilaterally for 30 patients (14 males, 16 females, mean age 67.2 years) through semi-automatic segmentation of reconstructed CT data and used to map bone density, by shrinking them into the subchondral bone and averaging the greyscale values (linearly related to bone density) within 5 mm of the articular surface. Density maps were then oriented with the center of the head at the origin, the femoral mechanical axis (FMA) aligned with the vertical, and the posterior condylar axis (PCA) aligned with the horizontal. Twelve regions were created by dividing the density maps into three concentric rings at increments of 30 from the horizontal, then splitting into four quadrants along the anterior-posterior and medial-lateral axes. Mean values for each region were compared using repeated measures ANOVA and a Bonferroni post hoc test, and side-to-side correlations were analyzed using a Pearson's correlation. The regions representing the medial side of the femoral head's superior portion were found to have significantly higher densities compared to other regions (p < 0.05). Significant side-to-side correlations were found for all regions (r {sup 2} = 0.81 to r {sup 2} = 0.16), with strong correlations for the highest density regions. Side-to-side differences in measured bone density were seen for two regions in the anterio-lateral portion of the femoral head (p < 0.05). The high correlation found between the left and right sides indicates that this tool may be useful for understanding 'normal' density patterns in hips affected by unilateral pathologies such as avascular necrosis, fracture, developmental dysplasia of the hip, Perthes disease, and slipped capital femoral head epiphysis. (orig.)

  19. Histological Observation of Regions around Bone Tunnels after Compression of the Bone Tunnel Wall in Ligament Reconstruction

    Maeda, Shintaro; Ishikawa, Hiroki; Tanigawa, Naoaki; Miyazaki, Kyosuke; Shioda, Seiji

    2012-01-01

    The objectives of this study were to investigate the time-course of influence of compression of bone tunnel wall in ligament reconstruction on tissue around the bone tunnel and to histologically examine the mechanism of preventing the complication of bone tunnel dilation, using rabbit tibia. A model in which the femoral origin of the extensor digitorum longus tendon was cut and inserted into a bone tunnel made proximal to the tibia was prepared in the bilateral hind legs of 20 Japanese white rabbits. In each animal, a tunnel was made using a drill only in the right leg, while an undersized bone tunnel was made by drilling and then dilated by compression using a dilator to the same tunnel size as that in the right leg. Animals were sacrificed at 0, 2, 4, 8 and 12 weeks after surgery (4 animals at each time point). Observation of bone tunnels by X-ray radiography showed osteosclerosis in the 2- and 4-week dilation groups. Osteosclerosis appeared as white lines around the bone tunnel on X-ray radiography. This suggests that dilation promotes callus formation in the bone tunnel wall and prevents the complication of bone tunnel enlargement after ligament reconstruction

  20. Femoral revision with impaction allografting and an uncemented femoral component

    Nickelsen, T N; Erenbjerg, M; Retpen, J B

    2008-01-01

    A technique for uncemented revision of the femoral component which combines impaction allografting and the use of a long-stemmed proximally coated titanium prostheses (Bimetric, Biomet Inc.) is described. The results after a mean follow-up of 112 months are reported. From 1991 to 1995 femoral...... implants 88% had no pain, 10% had slight pain and only 2% had severe pain. Thirty-eight patients had radiographic signs of remodelling of the graft and/or cortical repair. In cases with a successful outcome, the results have been encouraging in relation to clinical performance, regeneration of bone...

  1. Spin-polarized tunneling with GaAs tips in scanning tunneling microscopy

    Prins, M.W.J.; Jansen, R.; Kempen, van H.

    1996-01-01

    We describe a model as well as experiments on spin-polarized tunneling with the aid of optical spin orientation. This involves tunnel junctions between a magnetic material and gallium arsenide (GaAs), where the latter is optically excited with circularly polarized light in order to generate

  2. Recognition tunneling

    Lindsay, S.; He, J.; Sankey, O.; Hapala, Prokop; Jelínek, Pavel; Zhang, P.; Chang, S.; Huang, S.

    2010-01-01

    Roč. 21, č. 26 (2010), 262001/1-262001/12 ISSN 0957-4484 R&D Projects: GA ČR GA202/09/0545 Institutional research plan: CEZ:AV0Z10100521 Keywords : STM * tunneling current * molecular electronics * DFT calculations Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.644, year: 2010

  3. Tunnel - history of

    1998-11-01

    This book introduces history of tunnel in ancient times, the middle ages and modern times, survey of tunnel and classification of bedrock like environment survey of position, survey of the ground, design of tunnel on basic thing of the design, and design of tunnel of bedrock, analysis of stability of tunnel and application of the data, construction of tunnel like lattice girder and steel fiber reinforced shot crete, and maintenance control and repair of tunnel.

  4. Radiographic landmarks for locating the femoral origin of the superficial medial collateral ligament.

    Hartshorn, Timothy; Otarodifard, Karimdad; White, Eric A; Hatch, George F Rick

    2013-11-01

    Little has been written about the use of radiographic landmarks for locating the origin of the superficial medial collateral ligament (sMCL). A standardized radiographic landmark for the sMCL origin using intraoperative fluoroscopic imaging may be of value in aiding the surgeon in accurate femoral tunnel placement in the setting of extensive soft tissue disruption and bony attrition. To determine a reproducible radiographic landmark that will assist in correct femoral tunnel placement in sMCL repair and reconstruction. Descriptive laboratory study. Ten fresh-frozen unmatched human cadaveric knees were dissected, and the origin of the sMCL was exposed. A 2-mm metallic marker was then placed at the center of the femoral origin of the sMCL. True lateral fluoroscopically assisted digital radiographs were obtained of the knee with the posterior and distal femoral condyles overlapping in a standardized fashion. With the use of computer software, reference lines were drawn on the images, creating 4 quadrants. Two independent examiners performed quantitative measurements of the sMCL origin in relation to this axis and to the Blumensaat line. Mean measurements showed the sMCL origin to be closely related to the intersection point of the Blumensaat line and a line drawn distally from the posterior femoral cortex on a true lateral radiograph. The sMCL origin was found at a mean point 1.6 ± 4.3 mm posterior and 4.9 ± 2.1 mm proximal to the intersection of a line paralleling the posterior femoral cortex and a line drawn perpendicular to the posterior femoral cortical line, where it intersects the Blumensaat line. In 5 of 10 specimens, the center of the sMCL origin fell precisely on the Blumensaat line. The remaining specimens had sMCL origins anterior to the Blumensaat line. The femoral origin of the sMCL was found in the proximal and posterior quadrants in 8 of 10 specimens. With a relatively small amount of deviation, the sMCL origin can be consistently identified on a true

  5. Mechanical properties of femoral trabecular bone in dogs

    Nolte Ingo

    2005-03-01

    Full Text Available Abstract Background Studying mechanical properties of canine trabecular bone is important for a better understanding of fracture mechanics or bone disorders and is also needed for numerical simulation of canine femora. No detailed data about elastic moduli and degrees of anisotropy of canine femoral trabecular bone has been published so far, hence the purpose of this study was to measure the elastic modulus of trabecular bone in canine femoral heads by ultrasound testing and to assess whether assuming isotropy of the cancellous bone in femoral heads in dogs is a valid simplification. Methods From 8 euthanized dogs, both femora were obtained and cubic specimens were cut from the centre of the femoral head which were oriented along the main pressure and tension trajectories. The specimens were tested using a 100 MHz ultrasound transducer in all three orthogonal directions. The directional elastic moduli of trabecular bone tissue and degrees of anisotropy were calculated. Results The elastic modulus along principal bone trajectories was found to be 11.2 GPa ± 0.4, 10.5 ± 2.1 GPa and 10.5 ± 1.8 GPa, respectively. The mean density of the specimens was 1.40 ± 0.09 g/cm3. The degrees of anisotropy revealed a significant inverse relationship with specimen densities. No significant differences were found between the elastic moduli in x, y and z directions, suggesting an effective isotropy of trabecular bone tissue in canine femoral heads. Discussion This study presents detailed data about elastic moduli of trabecular bone tissue obtained from canine femoral heads. Limitations of the study are the relatively small number of animals investigated and the measurement of whole specimen densities instead of trabecular bone densities which might lead to an underestimation of Young's moduli. Publications on elastic moduli of trabecular bone tissue present results that are similar to our data. Conclusion This study provides data about directional elastic

  6. Mammary and femoral hydatid cysts.

    Shamim, Muhammad

    2010-08-01

    Hydatid cyst disease most commonly affects liver and lungs, but it can affect all viscera and soft tissues of the body. Simultaneous mammary and femoral hydatid cysts, without any other visceral involvement, are extremely rare. This is a case report of 25-years-old female, presenting with lump in left breast mimicking fibroadenoma and lump in right thigh mimicking fibroma. Both turned out to be hydatid cysts.

  7. Carpal Tunnel Syndrome

    ... a passing cramp? It could be carpal tunnel syndrome. The carpal tunnel is a narrow passageway of ... three times more likely to have carpal tunnel syndrome than men. Early diagnosis and treatment are important ...

  8. Removal of a broken guide wire entrapped in a fractured femoral neck

    ZHU Qing-hua

    2013-08-01

    Full Text Available 【Abstract】Guide wire plays an important role in the fixation of femoral neck fracture with dynamic hip screw (DHS. Breakage of a guide wire during operation is a very rare condition. We met such a dilemma in DHS fixation of a 54-year-old male patient who sustained Garden type IV frac-ture of the right femoral neck. The distal end of the guide wire broke and was entrapped in the fractured femoral neck. We tried to get the broken part out by a cannulated drill. Reaming was started with the cannulated drill slowly rotat-ing around the guide K-wire until the reamer fully contained the target under fluoroscope. A bone curette was used to get the broken wire out but failed, so we had to use the cannuated drill to dredge this bone tunnel. Finally the bro-ken wire end was taken out, mixed with blood and bone fragments. Through the existing drilling channel, DHS fixa-tion was easily finished. The patient had an uneventful re-covery without avascular necrosis of femoral head or non-union of the fracture at one year’s follow-up. A few methods can be adopted to deal with the broken guide wire. The way used in our case is less invasive but technically challenging. When the guide wire is properly positioned, this method is very practical and useful. Key words: Femoral neck fractures; Bones wires; Complications

  9. Tunneling technologies for the collider ring tunnels

    Frobenius, P.

    1989-01-01

    The Texas site chosen for the Superconducting Super Collider has been studied, and it has been determined that proven, conventional technology and accepted engineering practice are suitable for constructing the collider tunnels. The Texas National Research Laboratory Commission report recommended that two types of tunneling machines be used for construction of the tunnels: a conventional hard rock tunnel boring machine (TBM) for the Austin chalk and a double shielded, rotary TBM for the Taylor marl. Since the tunneling machines usually set the pace for the project, efficient planning, operation, and coordination of the tunneling system components will be critical to the schedule and cost of the project. During design, tunneling rate prediction should be refined by focusing on the development of an effective tunneling system and evaluating its capacity to meet or exceed the required schedules. 8 refs., 13 figs

  10. A Morphological Insight of the Femoral Vein

    Ferreira AH

    2015-10-01

    Full Text Available A total of 13 cadavers (12 men and 1 women of different age group were used for the study with the purpose to determine the prevalence of femoral vein duplication. Lower limb regions (26 sides were carefully dissected as per the standard dissection procedure. Femoral vein (unitruncular was found in 96.15% of specimen. Bitruncular configurations (total bifidity was found in a male cadaver of 75 years of age (3.85%. In the right lower limb, 6.5 cms below the inguinal ligament the femoral vein - lateral ramus received the lateral circumflex femoral vein, and the medial circumflex femoral vein, and the lateral and medial ramii formed a common venous trunk. Knowledge of the truncular venous variations is important to recognize and avoid potential errors in diagnosis of deep venous thrombosis of the femoral vein, in the case of an occluded duplicated trunk.

  11. Unusual longitudinal stress fractures of the femoral diaphysis: report of five cases

    Williams, M.; Timsit, M.A.; Karneff, A.; Pertuiset, E.

    1999-01-01

    We present five cases of a distinctive type of longitudinal stress fracture of the upper femoral shaft in which the fracture line is parallel to the outer surface of the bone, in contrast to the perpendicular orientation to the cortical surface in previously reported cases of diaphyseal stress fractures. In two cases the fracture recurred after 15 and 18 months, respectively. (orig.)

  12. Evaluation of perfusion of the femoral head after femoral neck fracture using bone scintigraphy

    Yamaguchi, Satoshi; Ishido, Yasuhiro [Saiseikai Sendai Hospital, Kagoshima (Japan); Okano, Toshihiro [Ibusuki National Hospital, Kagoshima (Japan); Komiya, Setsuro [Kagoshima Univ. (Japan). Faculty of Medicine

    2002-09-01

    We treated 13 patients for femoral neck fracture. They consisted of 2 males and 11 females, and were classified according to Garden stage classification; Stage I, 3 cases; Stage II, 2 cases; Stage III, 2 cases; Stage IV, 4 cases. Two trochanteric fracture cases were used by control. We evaluated perfusion of the femoral head after femoral neck fracture using bone scintigraphy, which is considered useful for evaluation of perfusion of the femoral neck before operation. (author)

  13. Evaluation of perfusion of the femoral head after femoral neck fracture using bone scintigraphy

    Yamaguchi, Satoshi; Ishido, Yasuhiro; Okano, Toshihiro; Komiya, Setsuro

    2002-01-01

    We treated 13 patients for femoral neck fracture. They consisted of 2 males and 11 females, and were classified according to Garden stage classification; Stage I, 3 cases; Stage II, 2 cases; Stage III, 2 cases; Stage IV, 4 cases. Two trochanteric fracture cases were used by control. We evaluated perfusion of the femoral head after femoral neck fracture using bone scintigraphy, which is considered useful for evaluation of perfusion of the femoral neck before operation. (author)

  14. Spin-dependent transport in metal/semiconductor tunnel junctions

    Prins, M.W.J.; Kempen, van H.; Leuken, Van H.; Groot, de R.A.; Roy, van W.; De Boeck, J.

    1995-01-01

    This paper describes a model as well as experiments on spin-polarized tunnelling with the aid of optical spin orientation. This involves tunnel junctions between a magnetic material and gallium arsenide (GaAs), where the latter is optically excited with circularly polarized light in order to

  15. Measurement of bone mineral density in the tunnel regions for anterior cruciate ligament reconstruction by dual-energy X-ray absorptiometry, computed tomography scan, and the immersion technique based on Archimedes' principle.

    Tie, Kai; Wang, Hua; Wang, Xin; Chen, Liaobin

    2012-10-01

    To determine, for anterior cruciate ligament (ACL) reconstruction, whether the bone mineral density (BMD) of the femoral tunnel was higher than that of the tibial tunnel, to provide objective evidence for choosing the appropriate diameter of interference screws. Two groups were enrolled. One group comprised 30 normal volunteers, and the other comprised 9 patients with ACL rupture. Dual-energy X-ray absorptiometry was used to measure the BMD of the femoral and tibial tunnel regions of the volunteers' right knees by choosing a circular area covering the screw fixation region. The knees were also scanned by spiral computed tomography (CT), and the 3-dimensional reconstruction technique was used to determine the circular sections passing through the longitudinal axis of the femoral and tibial tunnels. Grayscale CT values of the cross-sectional area were measured. Cylindrical cancellous bone blocks were removed from the femoral and tibial tunnels during the ACL reconstruction for the patients. The volumetric BMD of the bone blocks was measured using a standardized immersion technique according to Archimedes' principle. As measured by dual-energy X-ray absorptiometry, the BMD of the femoral and tibial tunnel regions was 1.162 ± 0.034 g/cm(2) and 0.814 ± 0.038 g/cm(2), respectively (P difference in both femoral and tibial tunnel regions. For ACL reconstruction, the BMD of the femoral tunnel is higher than that of the tibial tunnel. This implies that a proportionally larger-diameter interference screw should be used for fixation in the proximal tibia than that used for fixation in the distal femur. Level IV, therapeutic case series. Copyright © 2012 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  16. Treatment of neglected femoral neck fracture

    Anil K Jain

    2015-01-01

    Full Text Available Intra-capsular femoral neck fractures are seen commonly in elderly people following a low energy trauma. Femoral neck fracture has a devastating effect on the blood supply of the femoral head, which is directly proportional to the severity of trauma and displacement of the fracture. Various authors have described a wide array of options for treatment of neglected/nonunion (NU femoral neck fracture. There is lack of consensus in general, regarding the best option. This Instructional course article is an analysis of available treatment options used for neglected femoral neck fracture in the literature and attempt to suggest treatment guides for neglected femoral neck fracture. We conducted the "Pubmed" search with the keywords "NU femoral neck fracture and/or neglected femoral neck fracture, muscle-pedicle bone graft in femoral neck fracture, fibular graft in femoral neck fracture and valgus osteotomy in femoral neck fracture." A total of 203 print articles were obtained as the search result. Thirty three articles were included in the analysis and were categorized into four subgroups based on treatment options. (a treated by muscle-pedicle bone grafting (MPBG, (b closed/open reduction internal fixation and fibular grafting (c open reduction and internal fixation with valgus osteotomy, (d miscellaneous procedures. The data was pooled from all groups for mean neglect, the type of study (prospective or retrospective, classification used, procedure performed, mean followup available, outcome, complications, and reoperation if any. The outcome of neglected femoral neck fracture depends on the duration of neglect, as the changes occurring in the fracture area and fracture fragments decides the need and type of biological stimulus required for fracture union. In stage I and stage II (Sandhu′s staging neglected femoral neck fracture osteosynthesis with open reduction and bone grafting with MPBG or Valgus Osteotomy achieves fracture union in almost 90

  17. Subchondral insufficiency fractures of the femoral head

    Davies, M.; Cassar-Pullicino, V.N. [Department of Radiology, Robert Jones and Agnes Hunt Orthopaedic and District Hospital, Oswestry, SY10 7AG, Shropshire (United Kingdom); Darby, A.J. [Department of Pathology, Robert Jones and Agnes Hunt Orthopaedic and District Hospital, Oswestry, SY10 7AG, Shropshire (United Kingdom)

    2004-02-01

    The aim of this study was to increase awareness of, and to show the variable clinical and radiological features of, subchondral insufficiency fractures of the femoral head. The clinical and radiological findings in 7 patients with subchondral insufficiency fractures of the femoral head were reviewed retrospectively. The diagnosis was confirmed histologically in 4 patients. Radiographs were performed in all patients, MRI in 5 and scintigraphy in 4 patients. Radiographs showed varying degrees of femoral head collapse in 4 patients. In the remaining 3 patients radiographs showed a normal femoral head, regional osteoporosis and focal sclerosis, respectively. Magnetic resonance imaging showed a low-signal band on T1- and T2-weighted images in the subchondral bone adjacent or parallel to the articular surface associated with bone marrow oedema. Scintigraphy showed increased uptake in the femoral head. Insufficiency fractures of the femoral head are easily overlooked or confused with avascular necrosis and, when there is significant joint destruction, osteoarthritis. Unsuspected insufficiency fracture of the femoral head can lead to significant and rapid loss of bone stock in osteoporotic patients waiting for arthroplasty for osteoarthritis. Increased awareness of this condition will hopefully lead to earlier diagnosis and a successful outcome of conservative treatment. (orig.)

  18. Fabrication of magnetic tunnel junctions with a single-crystalline LiF tunnel barrier

    Krishna Narayananellore, Sai; Doko, Naoki; Matsuo, Norihiro; Saito, Hidekazu; Yuasa, Shinji

    2018-04-01

    We fabricated Fe/LiF/Fe magnetic tunnel junctions (MTJs) by molecular beam epitaxy on a MgO(001) substrate, where LiF is an insulating tunnel barrier with the same crystal structure as MgO (rock-salt type). Crystallographical studies such as transmission electron microscopy and nanobeam electron diffraction observations revealed that the LiF tunnel barrier is single-crystalline and has a LiF(001)[100] ∥ bottom Fe(001)[110] crystal orientation, which is constructed in the same manner as MgO(001) on Fe(001). Also, the in-plane lattice mismatch between the LiF tunnel barrier and the Fe bottom electrode was estimated to be small (about 0.5%). Despite such advantages for the tunnel barrier of the MTJ, the observed tunnel magnetoresistance (MR) ratio was low (˜6% at 20 K) and showed a significant decrease with increasing temperature (˜1% at room temperature). The results imply that indirect tunneling and/or thermally excited carriers in the LiF tunnel barrier, in which the current basically is not spin-polarized, play a major role in electrical transport in the MTJ.

  19. Frequency of ipsilateral femoral neck fractures in patients with ...

    Background: Ipsilateral associated femoral neck and shaft fractures are reported to occur in 2.5-6% of all femoral shaft fractures. Objective: To establish the frequency of ipsilateral femoral neck fractures amongst all patients presenting with femoral shaft fractures in Mulago Hospital. Methodology: This was a descriptive ...

  20. Transonic Dynamics Tunnel (TDT)

    Federal Laboratory Consortium — The Transonic Dynamics Tunnel (TDT) is a continuous flow wind-tunnel facility capable of speeds up to Mach 1.2 at stagnation pressures up to one atmosphere. The TDT...

  1. Quantum theory of tunneling

    Razavy, Mohsen

    2014-01-01

    In this revised and expanded edition, in addition to a comprehensible introduction to the theoretical foundations of quantum tunneling based on different methods of formulating and solving tunneling problems, different semiclassical approximations for multidimensional systems are presented. Particular attention is given to the tunneling of composite systems, with examples taken from molecular tunneling and also from nuclear reactions. The interesting and puzzling features of tunneling times are given extensive coverage, and the possibility of measurement of these times with quantum clocks are critically examined. In addition by considering the analogy between evanescent waves in waveguides and in quantum tunneling, the times related to electromagnetic wave propagation have been used to explain certain aspects of quantum tunneling times. These topics are treated in both non-relativistic as well as relativistic regimes. Finally, a large number of examples of tunneling in atomic, molecular, condensed matter and ...

  2. Road and Railroad Tunnels

    Department of Homeland Security — Tunnels in the United States According to the HSIP Tiger Team Report, a tunnel is defined as a linear underground passageway open at both ends. This dataset is based...

  3. Hypersonic Tunnel Facility (HTF)

    Federal Laboratory Consortium — The Hypersonic Tunnel Facility (HTF) is a blow-down, non-vitiated (clean air) free-jet wind tunnel capable of testing large-scale, propulsion systems at Mach 5, 6,...

  4. Subtrochanteric femoral fracture during trochanteric nailing for the treatment of femoral shaft fracture.

    Yun, Ho Hyun; Oh, Chi Hun; Yi, Ju Won

    2013-09-01

    We report on three cases of subtrochanteric femoral fractures during trochanteric intramedullary nailing for the treatment of femoral shaft fractures. Trochanteric intramedullary nails, which have a proximal lateral bend, are specifically designed for trochanteric insertion. When combined with the modified insertion technique, trochanteric intramedullary nails reduce iatrogenic fracture comminution and varus malalignment. We herein describe technical aspects of trochanteric intramedullary nailing for femoral shaft fractures to improve its application and prevent implant-derived complications.

  5. Aespoe Hard Rock Laboratory. The TASS-tunnel. Geological mapping

    Hardenby, Carljohan (Vattenfall Power Consultant AB (Sweden)); Sigurdsson, Oskar (HAskGeokonsult AB (Sweden))

    2010-12-15

    ;increased fracturing' and 'deformation zones proper'). The orientation of the structures is measured with a compass, and magnetic north is used for reference purposes. Two main fracture sets appear in the TASS-tunnel. 1. East-west striking and steeply dipping. This fracture set dominates with a mean orientation of 097/86. 2. Sub-horizontal to gently dipping with a more varying strike. This set may be divided into two subsets with the mean orientations 037/03 and 280/18 respectively. The observed categories of deformation zones appear to fall within two major groups of orientation. 1. Increased fracturing is oriented approximately ENE-WSW with a moderate dip to the north. 2. Deformation zones proper (brittle/ductile) have a general orientation of approximately ESE-WNW strike with steep dip mostly to the south. These zones generally cross-cut the tunnel and their widths vary from 0.1 - 0.3 m. The fractures and deformation zones normally contain secondary minerals. The most common fracture-filling mineral in the tunnel is chlorite, followed by calcite, epidote and prehnite. Quartz, pyrite and red feldspar are also quite common, while biotite, iron oxide and unconsolidated filling materials (grout and clay) have only been observed a few times. Occurrences of water are of great interest since one of the major tasks of the project was to prove that the grouting compounds used could seal tunnels at the tentative final repository depth. The orientations of water-bearing fractures for the tunnel are dominated by sub-horizontal to gently dipping fractures, with mean orientations of 000/00 and 297/28. Two less prominent water-bearing fracture sets of 287/70 and 099/89 also occur

  6. Aespoe Hard Rock Laboratory. The TASS-tunnel. Geological mapping

    Hardenby, Carljohan; Sigurdsson, Oskar

    2010-12-01

    'deformation zones proper'). The orientation of the structures is measured with a compass, and magnetic north is used for reference purposes. Two main fracture sets appear in the TASS-tunnel. 1. East-west striking and steeply dipping. This fracture set dominates with a mean orientation of 097/86. 2. Sub-horizontal to gently dipping with a more varying strike. This set may be divided into two subsets with the mean orientations 037/03 and 280/18 respectively. The observed categories of deformation zones appear to fall within two major groups of orientation. 1. Increased fracturing is oriented approximately ENE-WSW with a moderate dip to the north. 2. Deformation zones proper (brittle/ductile) have a general orientation of approximately ESE-WNW strike with steep dip mostly to the south. These zones generally cross-cut the tunnel and their widths vary from 0.1 - 0.3 m. The fractures and deformation zones normally contain secondary minerals. The most common fracture-filling mineral in the tunnel is chlorite, followed by calcite, epidote and prehnite. Quartz, pyrite and red feldspar are also quite common, while biotite, iron oxide and unconsolidated filling materials (grout and clay) have only been observed a few times. Occurrences of water are of great interest since one of the major tasks of the project was to prove that the grouting compounds used could seal tunnels at the tentative final repository depth. The orientations of water-bearing fractures for the tunnel are dominated by sub-horizontal to gently dipping fractures, with mean orientations of 000/00 and 297/28. Two less prominent water-bearing fracture sets of 287/70 and 099/89 also occur

  7. Herniography off femoral, obturator and perineal hernias

    Ekberg, O.; Nordblom, I.; Fork, F.T.; Gullmo, A.

    1985-01-01

    Positive contrast herniography was used in the workup of 550 patients with unclear groin pain. The majority of these patients had rather characteristic hernias of indirect, direct or femoral type. However, now and then diagnostic problems arose. A femoral hernia may look like a direct or even obturator hernia. There is also a variety of multilocular femoral hernias and other types. A femoral hernia may be present together with other hernias in the ipsilateral or contralateral groin. Obturator hernias are usually small but are always confined to the obturator canal laterally in the obturator foramen. Abnormalities in the pouch of Douglas may include a deep rectogenital pouch, diverticula and true herniations. These uncommon herniographic findings are described and discussed. (orig.) [de

  8. SEX DETERMINATION FROM FEMORAL HEAD DIAMETERS IN ...

    hi-tech

    2000-03-01

    Mar 1, 2000 ... In medico-legal cases where sophisticated methods of sex determination is lacking, these ... scientific methods(3). Using the visual method ... between the sexes and the values of the right and left femoral head diameters.

  9. Bilateral femoral neck fractures following pelvic irradiation

    Mitsuda, Kenji; Nishi, Hosei; Oba, Hiroshi

    1977-01-01

    Over 300 cases of femoral neck fractures following radiotherapy for intrapelvic malignant tumor have been reported in various countries since Baensch reported this disease in 1927. In Japan, 40 cases or so have been reported, and cases of bilateral femoral neck fractures have not reached to ten cases. The authors experienced a case of 75 year-old female who received radiotherapy for cancer of the uterus, and suffered from right femoral neck fracture 3 months after and left femoral neck fracture one year and half after. As clinical symptoms, she had not previous history of trauma in bilateral femurs, but she complained of a pain in a hip joint and of gait disturbance. The pain in left femoral neck continued for about one month before fracture was recognized with roentgenogram. As histopathological findings, increase of fat marrow, decrease of bone trabeculae, and its marked degeneration were recognized. Proliferation of some blood vessels was found out, but thickness of the internal membrane and thrombogenesis were not recognized. Treatment should be performed according to degree of displacement of fractures. In this case, artificial joint replacement surgery was performed to the side of fracture of this time, because this case was bilateral femoral neck fractures and the patient had received artificial head replacement surgery in the other side of fracture formerly. (Tsunoda, M.)

  10. Proton tunneling in solids

    Kondo, J.

    1998-10-01

    The tunneling rate of the proton and its isotopes between interstitial sites in solids is studied theoretically. The phonons and/or the electrons in the solid have two effects on the tunneling phenomenon. First, they suppress the transfer integral between two neighbouring states. Second, they give rise to a finite lifetime of the proton state. Usually the second effect is large and the tunneling probability per unit time (tunneling rate) can be defined. In some cases, however, a coherent tunneling is expected and actually observed. (author)

  11. Proton tunneling in solids

    Kondo, J.

    1998-01-01

    The tunneling rate of the proton and its isotopes between interstitial sites in solids is studied theoretically. The phonons and/or the electrons in the solid have two effects on the tunneling phenomenon. First, they suppress the transfer integral between two neighbouring states. Second, they give rise to a finite lifetime of the proton state. Usually the second effect is large and the tunneling probability per unit time (tunneling rate) can be defined. In some cases, however, a coherent tunneling is expected and actually observed. (author)

  12. Tunneling anisotropic magnetoresistance via molecular π orbitals of Pb dimers

    Schöneberg, Johannes; Ferriani, Paolo; Heinze, Stefan; Weismann, Alexander; Berndt, Richard

    2018-01-01

    Pb dimers on a ferromagnetic surface are shown to exhibit large tunneling anisotropic magnetoresistance (TAMR) due to molecular π orbitals. Dimers oriented differently with respect to the magnetization directions of a ferromagnetic Fe double layer on W(110) were made with a scanning tunneling microscope. Depending on the dimer orientations, TAMR is absent or as large as 20% at the Fermi level. General arguments and first-principles calculations show that mixing of molecular orbitals due to spin-orbit coupling, which leads to TAMR, is maximal when the magnetization is oriented parallel to the dimer axis.

  13. Theoretical consideration of spin-polarized resonant tunneling in magnetic tunnel junctions

    Mu Haifeng; Zhu Zhengang; Zheng Qingrong; Jin Biao; Wang Zhengchuan; Su Gang

    2004-01-01

    A recent elegant experimental realization [S. Yuasa et al., Science 297 (2002) 234] of the spin-polarized resonant tunneling in magnetic tunnel junctions is interpreted in terms of a two-band model. It is shown that the tunnel magnetoresistance (TMR) decays oscillatorily with the thickness of the normal metal (NM) layer, being fairly in agreement with the experimental observation. The tunnel conductance is found to decay with slight oscillations with the increase of the NM layer thickness, which is also well consistent with the experiment. In addition, when the magnetizations of both ferromagnet electrodes are not collinearly aligned, TMR is found to exhibit sharp resonant peaks at some particular thickness of the NM layer. The peaked TMR obeys nicely a Gaussian distribution against the relative orientation of the magnetizations

  14. Subtrochanteric Femoral Fracture during Trochanteric Nailing for the Treatment of Femoral Shaft Fracture

    Yun, Ho Hyun; Oh, Chi Hun; Yi, Ju Won

    2013-01-01

    We report on three cases of subtrochanteric femoral fractures during trochanteric intramedullary nailing for the treatment of femoral shaft fractures. Trochanteric intramedullary nails, which have a proximal lateral bend, are specifically designed for trochanteric insertion. When combined with the modified insertion technique, trochanteric intramedullary nails reduce iatrogenic fracture comminution and varus malalignment. We herein describe technical aspects of trochanteric intramedullary nai...

  15. Femoral rotation unpredictably affects radiographic anatomical lateral distal femoral angle measurements

    Miles, James Edward

    2016-01-01

    Objective: To describe the effects of internal and external femoral rotation on radiographic measurements of the anatomical lateral distal femoral angle (a-LDFA) using two methods for defining the anatomical proximal femoral axis (a-PFA). Methods: Digital radiographs were obtained of 14 right...... femora at five degree intervals from 10° external rotation to 10° internal rotation. Using freely available software, a-LDFA measurements were made using two different a-PFA by a single observer on one occasion. Results: Mean a-LDFA was significantly greater at 10° external rotation than at any other...... rotation. The response of individual femora to rotation was unpredictable, although fairly stable within ±5° of zero rotation. Mean a-LDFA for the two a-PFA methods differed by 1.5°, but were otherwise similarly affected by femoral rotation. Clinical significance: If zero femoral elevation can be achieved...

  16. Evaluation of a pig femoral head osteonecrosis model

    Kim Harry

    2010-03-01

    Full Text Available Abstract Background A major cause of osteonecrosis of the femoral head is interruption of a blood supply to the proximal femur. In order to evaluate blood circulation and pathogenetic alterations, a pig femoral head osteonecrosis model was examined to address whether ligature of the femoral neck (vasculature deprivation induces a reduction of blood circulation in the femoral head, and whether transphyseal vessels exist for communications between the epiphysis and the metaphysis. We also tested the hypothesis that the vessels surrounding the femoral neck and the ligamentum teres represent the primary source of blood flow to the femoral head. Methods Avascular osteonecrosis of the femoral head was induced in Yorkshire pigs by transecting the ligamentum teres and placing two ligatures around the femoral neck. After heparinized saline infusion and microfil perfusion via the abdominal aorta, blood circulation in the femoral head was evaluated by optical and CT imaging. Results An angiogram of the microfil casted sample allowed identification of the major blood vessels to the proximal femur including the iliac, common femoral, superficial femoral, deep femoral and circumflex arteries. Optical imaging in the femoral neck showed that a microfil stained vessel network was visible in control sections but less noticeable in necrotic sections. CT images showed a lack of microfil staining in the epiphysis. Furthermore, no transphyseal vessels were observed to link the epiphysis to the metaphysis. Conclusion Optical and CT imaging analyses revealed that in this present pig model the ligatures around the femoral neck were the primary cause of induction of avascular osteonecrosis. Since the vessels surrounding the femoral neck are comprised of the branches of the medial and the lateral femoral circumflex vessels, together with the extracapsular arterial ring and the lateral epiphyseal arteries, augmentation of blood circulation in those arteries will improve

  17. Comparison of femoral morphology and bone mineral density between femoral neck fractures and trochanteric fractures.

    Maeda, Yuki; Sugano, Nobuhiko; Saito, Masanobu; Yonenobu, Kazuo

    2011-03-01

    Many studies that analyzed bone mineral density (BMD) and skeletal factors of hip fractures were based on uncalibrated radiographs or dual-energy xray absorptiometry (DXA). Spatial accuracy in measuring BMD and morphologic features of the femur with DXA is limited. This study investigated differences in BMD and morphologic features of the femur between two types of hip fractures using quantitative computed tomography (QCT). Forty patients with hip fractures with normal contralateral hips were selected for this study between 2003 and 2007 (trochanteric fracture, n=18; femoral neck fracture, n=22). Each patient underwent QCT of the bilateral femora using a calibration phantom. Using images of the intact contralateral femur, BMD measurements were made at the point of minimum femoral-neck cross-sectional area, middle of the intertrochanteric region, and center of the femoral head. QCT images also were used to measure morphologic features of the hip, including hip axis length, femoral neck axis length, neck-shaft angle, neck width, head offset, anteversion of the femoral neck, and cortical index at the femoral isthmus. No significant differences were found in trabecular BMD between groups in those three regions. Patients with trochanteric fractures showed a smaller neck shaft angle and smaller cortical index at the femoral canal isthmus compared with patients with femoral neck fractures. We conclude that severe osteoporosis with thinner cortical bone of the femoral diaphysis is seen more often in patients with trochanteric fracture than in patients with femoral neck fracture. Level IV, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

  18. Correlation of ultrasound appearance, gross anatomy, and histology of the femoral nerve at the femoral triangle.

    Lonchena, Tiffany K; McFadden, Kathryn; Orebaugh, Steven L

    2016-01-01

    Correlation between ultrasound appearance, gross anatomic characteristics, and histologic structure of the femoral nerve (FN) is lacking. Utilizing cadavers, we sought to characterize the anatomy of the FN, and provide a quantitative measure of its branching. We hypothesize that at the femoral crease, the FN exists as a group of nerve branches, rather than a single nerve structure, and secondarily, that this transition into many branches is apparent on ultrasonography. Nineteen preserved cadavers were investigated. Ultrasonography was sufficient to evaluate the femoral nerve in nine specimens; gross dissection was utilized in all 19. Anatomic characteristics were recorded, including distances from the inguinal ligament to femoral crease, first nerve branch, and complete arborization of the nerve. The nerves from nine specimens were excised for histologic analysis. On ultrasound, the nerve became more flattened, widened, and less discrete as it coursed distally. Branching of the nerve was apparent in 12 of 18 images, with mean distance from inguinal ligament of 3.9 (1.0) cm. However, upon dissection, major branching of the femoral nerve occurred at 3.1 (1.0) cm distal to the inguinal ligament, well proximal to the femoral crease. Histologic analysis was consistent with findings at dissection. The femoral nerve arborizes into multiple branches between the inguinal ligament and the femoral crease. Initial branching is often high in the femoral triangle. As hypothesized, the FN exists as a closely associated group of nerve branches at the level of the femoral crease; however, the termination of the nerve into multiple branches is not consistently apparent on ultrasonography.

  19. Bone tunnel change develops within two weeks of double-bundle anterior cruciate ligament reconstruction using hamstring autograft: A comparison of different postoperative immobilization periods using computed tomography.

    Shimizu, Ryo; Adachi, Nobuo; Ishifuro, Minoru; Nakamae, Atsuo; Ishikawa, Masakazu; Deie, Masataka; Ochi, Mitsuo

    2017-10-01

    The purpose of this study was to evaluate bone tunnel changes following anterior cruciate ligament (ACL) reconstruction during the early postoperative period using computed tomography (CT), and to understand the impact of postoperative immobilization on these changes. Twenty patients who underwent double-bundle ACL reconstruction using hamstring tendon autografts were included. We subcategorized patients into two groups: patients who underwent isolated ACL reconstruction and had three days of knee immobilization (Group A, n=10); and patients with concomitant meniscus injuries who underwent ACL reconstruction and meniscus repair simultaneously (Group B, n=10) had their knees immobilized for two weeks after surgery. Bone tunnel enlargement was evaluated using CT imaging at one to three days, two weeks, one month, three months and six months after surgery. The cross-sectional area of the femoral and tibial tunnels was measured, and enlargement rate was calculated. The tunnel center location at two weeks after surgery was also evaluated. The mean cross-sectional area adjacent to the joint space of the femoral and tibial tunnels significantly increased immediately after surgery, especially in the first month (P0.01). There was no significant difference in tunnel enlargement rate between group A and B. Tunnel center location changed even in the first two weeks. Bone tunnel enlargement following double-bundle ACL reconstruction occurred at an earlier time point after surgery than anticipated. Postoperative immobilization could not prevent bone tunnel enlargement, but might prevent tunnel migration. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Silicon spintronics with ferromagnetic tunnel devices

    Jansen, R; Sharma, S; Dash, S P; Min, B C

    2012-01-01

    In silicon spintronics, the unique qualities of ferromagnetic materials are combined with those of silicon, aiming at creating an alternative, energy-efficient information technology in which digital data are represented by the orientation of the electron spin. Here we review the cornerstones of silicon spintronics, namely the creation, detection and manipulation of spin polarization in silicon. Ferromagnetic tunnel contacts are the key elements and provide a robust and viable approach to induce and probe spins in silicon, at room temperature. We describe the basic physics of spin tunneling into silicon, the spin-transport devices, the materials aspects and engineering of the magnetic tunnel contacts, and discuss important quantities such as the magnitude of the spin accumulation and the spin lifetime in the silicon. We highlight key experimental achievements and recent progress in the development of a spin-based information technology. (topical review)

  1. Femoral head vitality after intracapsular hip fracture

    Stroemqvist, B.

    1983-01-01

    Femoral head vitality before, during and at various intervals from the operation was determined by tetracycline labeling and/or 99 sp (m)Tc-MDP scintimetry. In a three-year follow-up, healing prognosis could be determined by scintimetry 3 weeks from operation; deficient femoral head vitality predicting healing complications and retained vitality predicting uncomplicated healing. A comparison between pre- and postoperative scintimetry indicated that further impairment of the femoral head vitality could be caused by the operative procedure, and as tetracycline labeling prior to and after fracture reduction in 370 fractures proved equivalent, it was concluded that the procedure of osteosynthesis probably was responsible for capsular vessel injury, using a four-flanged nail. The four-flanged nail was compared with a low-traumatic method of osteosynthesis, two hook-pins, in a prospective randomized 14 month study, and the postoperative femoral head vitality was significantly better in the hook-pin group. This was also clearly demonstrated in a one-year follow-up for the fractures included in the study. Parallel to these investigations, the reliability of the methods of vitality determination was found satisfactory in methodologic studies. For clinical purpose, primary atraumatic osteosynthesis, postoperative prognostic scintimetry and early secondary arthroplasty when indicated, was concluded to be the appropriate approach to femoral neck fracture treatment. (Author)

  2. Avascular necrosis of the femoral head

    Kokubo, Takeshi; Takatori, Yoshio; Kamogawa, Morihide; Nakamura, Toshitaka; Ninomiya, Setsuo; Yoshikawa, Kohki; Itai, Yuji; Iio, Masahiro; Mitamura, Tadayuki

    1990-01-01

    T1-weighted MR images of thirty-six hips in 25 patients with avascular necrosis of the femoral head were obtained two to five times during the course of 2 to 26 months. We investigated these MR images in the light of the chronological change and compared them with plain radiographs. MR images changes in 16 femoral head; in general, the abnormal low intensity area in the femoral head reduced in extent and the internal high intensity area became smaller of disappeared. Thirteen femoral heads among them became more flattened on plain radiographs in the same period. It is noted that four different zones are defined in the femoral head after bone necrosis takes place: the dead bone marrow, the dead marrow which still contains fat, the reactive interface and the hyperemic bone marrow. In T1-weighted MR images, the dead bone marrow, the reactive interface and the hyperemic bone marrow are demonstrated as low intensity area, while the dead marrow containing fat may remain high in intensity. On the basis of this knowledge of histopathology and MR images of this disease, we suggest that reduction of the abnormal low intensity area and disappearance of the internal high intensity area on MR images can be regarded as diminution of hyperemia in the living bone marrow and loss of fat in the dead bone marrow, respectively. (author)

  3. Reliability of a semi-automated 3D-CT measuring method for tunnel diameters after anterior cruciate ligament reconstruction: A comparison between soft-tissue single-bundle allograft vs. autograft.

    Robbrecht, Cedric; Claes, Steven; Cromheecke, Michiel; Mahieu, Peter; Kakavelakis, Kyriakos; Victor, Jan; Bellemans, Johan; Verdonk, Peter

    2014-10-01

    Post-operative widening of tibial and/or femoral bone tunnels is a common observation after ACL reconstruction, especially with soft-tissue grafts. There are no studies comparing tunnel widening in hamstring autografts versus tibialis anterior allografts. The goal of this study was to observe the difference in tunnel widening after the use of allograft vs. autograft for ACL reconstruction, by measuring it with a novel 3-D computed tomography based method. Thirty-five ACL-deficient subjects were included, underwent anatomic single-bundle ACL reconstruction and were evaluated at one year after surgery with the use of 3-D CT imaging. Three independent observers semi-automatically delineated femoral and tibial tunnel outlines, after which a best-fit cylinder was derived and the tunnel diameter was determined. Finally, intra- and inter-observer reliability of this novel measurement protocol was defined. In femoral tunnels, the intra-observer ICC was 0.973 (95% CI: 0.922-0.991) and the inter-observer ICC was 0.992 (95% CI: 0.982-0.996). In tibial tunnels, the intra-observer ICC was 0.955 (95% CI: 0.875-0.985). The combined inter-observer ICC was 0.970 (95% CI: 0.987-0.917). Tunnel widening was significantly higher in allografts compared to autografts, in the tibial tunnels (p=0.013) as well as in the femoral tunnels (p=0.007). To our knowledge, this novel, semi-automated 3D-computed tomography image processing method has shown to yield highly reproducible results for the measurement of bone tunnel diameter and area. This series showed a significantly higher amount of tunnel widening observed in the allograft group at one-year follow-up. Level II, Prospective comparative study. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Quantum tunneling time

    Wang, Z.S.; Lai, C.H.; Oh, C.H.; Kwek, L.C.

    2004-01-01

    We present a calculation of quantum tunneling time based on the transition duration of wave peak from one side of a barrier to the other. In our formulation, the tunneling time comprises a real and an imaginary part. The real part is an extension of the phase tunneling time with quantum corrections whereas the imaginary time is associated with energy derivatives of the probability amplitudes

  5. Charge Islands Through Tunneling

    Robinson, Daryl C.

    2002-01-01

    It has been recently reported that the electrical charge in a semiconductive carbon nanotube is not evenly distributed, but rather it is divided into charge "islands." This paper links the aforementioned phenomenon to tunneling and provides further insight into the higher rate of tunneling processes, which makes tunneling devices attractive. This paper also provides a basis for calculating the charge profile over the length of the tube so that nanoscale devices' conductive properties may be fully exploited.

  6. Josephson tunneling and nanosystems

    Ovchinnikov, Yurii; Kresin, Vladimir

    2010-01-01

    Josephson tunneling between nanoclusters is analyzed. The discrete nature of the electronic energy spectra, including their shell ordering, is explicitly taken into account. The treatment considers the two distinct cases of resonant and non-resonant tunneling. It is demonstrated that the current density greatly exceeds the value discussed in the conventional theory. Nanoparticles are shown to be promising building blocks for nanomaterials-based tunneling networks.

  7. About tunnelling times

    Olkhovsky, V.S.; Recami, E.

    1991-08-01

    In this paper, first we critically analyse the main theoretical definitions and calculations of the sub-barrier tunnelling and reflection times. Secondly, we propose a new, physically sensible definition of such durations, on the basis of a recent general formalism (already tested for other types of quantum collisions). At last, we discuss some results regarding temporal evolution of the tunnelling processes, and in particular the ''particle'' speed during tunnelling. (author). 36 refs, 1 fig

  8. Selective arteriography in femoral head fractures

    Mannella, P; Galeotti, R; Borrelli, M; Benea, G; Massari, L; Chiarelli, G M

    1986-01-01

    The choice between conservative and radical operation in case of femoral neck fractures is very important because it is the determining factor for a successfull therapy. In case of epiphysial necrosis, an endoprosthesis as well as an osteosynthesis will be carried out. Selective arteriography of the medical circumflex artery represents the most reliable study to establish, immediately after the fractures, the possible presence of a post-traumatic ischemic necrosis. Angiography, as a reliable diagnostic tool, has to be carried out in the most selective way and needs the image subtraction technique. The authors report their preliminary results on the reliability of angiography in the femoral epiphyseal ischemic necrosis diagnosed by comparing the results of angiography with the wood light test carried out on the surgically removed femoral head. 18 refs.

  9. 99mTc-MDP scintigraphy of femoral head necrosis following femoral neck fracture

    Lee, Soon Jin; Lee, Jun Hyung; Kim, Eun Kyung; Lee, Sun Wha; Kim, Soon Yong

    1985-01-01

    Secondary ischemic necrosis of femoral head due to loss of blood supply following to femoral neck fracture is well known. The regional distribution of bone-seeking radiopharmaceuricals in the skeleton can depend on a number of factors, but bone blood flow is a major physiological determinant of regional skeletal uptake of Tc-99m polyphosphate and bone imaging may thus be used for the evaluation of vascularity of the femoral head. The authors made a comparative study of scintigraphic findings and operative findings of 28 cases of femoral neck fracture treated at Kyung Hee University Hospital from April 1980 to May 1984. The results were as follows: 1. In 16 cases of proven avascular necorsis of femoral head, scintigraphy showed absent or decreased activity in 14 cases (87.5%), while radiography showed increased density in 10 cases (62.5%). 2. In 12 cases of proven vital femoral head, scintigraphy showed increased activity in 9 cases (75%) and radiography showed decreased density in 9 cases (75%). 3. 99mTc-MDP scintigraphy was an excellent and useful method for assessing bone vitality of femoral head

  10. {sup 99m}Tc-MDP scintigraphy of femoral head necrosis following femoral neck fracture

    Lee, Soon Jin; Lee, Jun Hyung; Kim, Eun Kyung; Lee, Sun Wha; Kim, Soon Yong [Kyung Hee University School of Medicine, Seoul (Korea, Republic of)

    1985-02-15

    Secondary ischemic necrosis of femoral head due to loss of blood supply following to femoral neck fracture is well known. The regional distribution of bone-seeking radiopharmaceuricals in the skeleton can depend on a number of factors, but bone blood flow is a major physiological determinant of regional skeletal uptake of Tc-99m polyphosphate and bone imaging may thus be used for the evaluation of vascularity of the femoral head. The authors made a comparative study of scintigraphic findings and operative findings of 28 cases of femoral neck fracture treated at Kyung Hee University Hospital from April 1980 to May 1984. The results were as follows: 1. In 16 cases of proven avascular necorsis of femoral head, scintigraphy showed absent or decreased activity in 14 cases (87.5%), while radiography showed increased density in 10 cases (62.5%). 2. In 12 cases of proven vital femoral head, scintigraphy showed increased activity in 9 cases (75%) and radiography showed decreased density in 9 cases (75%). 3. 99mTc-MDP scintigraphy was an excellent and useful method for assessing bone vitality of femoral head.

  11. Microsystem Aeromechanics Wind Tunnel

    Federal Laboratory Consortium — The Microsystem Aeromechanics Wind Tunnel advances the study of fundamental flow physics relevant to micro air vehicle (MAV) flight and assesses vehicle performance...

  12. frequency of ipsilateral femoral neck fractures in patients

    Background: Ipsilateral associated femoral neck and shaft fractures are reported to occur in 2.5-6% of all femoral shaft ... nailing of the shaft fracture, which makes treatment of the neck ... chest, spine), while the other had maxillofacial injuries.

  13. Femoral component loosening after hip resurfacing arthroplasty

    Zustin, Jozef; Sauter, Guido; Hahn, Michael; Morlock, Michael M.; Ruether, Wolfgang; Amling, Michael

    2010-01-01

    Before the re-introduction of the current generation of total hip resurfacing arthroplasty, component loosening and osteolysis were of great concern to the orthopaedic community. Early, mid- and long-term clinical results are encouraging, but component loosening still exists. Macroscopic, contact radiographic and histopathological analyses after undecalcified preparation of bone tissue specimens were performed. To investigate the frequency and morphological patterns of the loosening of the femoral component, we analysed a series of 190 retrieved femoral remnants that were revised for aseptic failures. Thirty-five (18.4%) hips were revised for clinical and/or radiographic loosening of the femoral component. Pseudoarthrosis (n = 17; median in situ time: 16 weeks, interquartile range [IQR]: 9 to 34), collapsed osteonecrosis (n = 5; median in situ time: 79 weeks, IQR: 63 to 97), cement-socket debonding (n = 3; median in situ time: 89 weeks, IQR: 54 to 97) and at later follow-up bone-cement loosening (n = 10; median in situ time: 175 weeks; IQR 112 to 198; p =0.005) were distinct patterns of the femoral remnant-implant loosening. Fibrocartilaginous metaplasia of interface bone trabeculae (n = 38; median in situ time: 61 weeks, IQR: 32 to 138) was strongly associated with femoral component loosening (p = 0.009). Both the trabecular hyperosteoidosis (n = 32; median in situ time: 71 weeks, IQR 50 to 129) and excessive intraosseous lymphocyte infiltration (n = 12; median in situ time: 75 weeks, IQR 51 to 98) at the bone-cement interface correlated strongly with fibrocartilaginous metaplasia (p = 0.001 and p = 0.016 respectively) and all three lesions were associated with the female gender (p = 0.021, p = 0.009, and p = 0.051). Femoral component loosening at early follow-up was mostly caused by pathological changes of the femoral remnant bone tissue: pseudoarthrosis and collapsed osteonecrosis. Fibrocartilaginous metaplasia was frequently observed in hips with femoral

  14. A retrospective review of bone tunnel enlargement after anterior cruciate ligament reconstruction with hamstring tendons fixed with a metal round cannulated interference screw in the femur.

    Kobayashi, Masahiko; Nakagawa, Yasuaki; Suzuki, Takashi; Okudaira, Shuzo; Nakamura, Takashi

    2006-10-01

    To assess bone tunnel enlargement after anterior cruciate ligament (ACL) reconstruction with the use of hamstring tendons fixed with a round cannulated interference (RCI) screw in the femur. A consecutive series of 30 ACL reconstructions performed with hamstring tendons fixed with an RCI screw in the femur and with staples via Leeds-Keio ligament in the tibia was retrospectively reviewed. The clinical outcome was evaluated through the Lysholm score. Anterior instability was tested by Telos-SE (Telos Japan, Tokyo, Japan) measurement. The location and angle of each femoral and tibial tunnel were measured with the use of plain radiographs, and bone tunnel enlargement greater than 2 mm detected any time 3, 6, 12, and 24 months postoperatively was defined as positive. Each factor (location and angle of the tunnels, sex, affected side, age, Lysholm score, and Telos-SE measurement) was compared between enlarged and nonenlarged groups. Positive enlargement of the bone tunnel (>2.0 mm) was observed in 36.7% (11 of 30) on the femoral side and 33.3% (10 of 30) on the tibial side, and in 6 knees of both sides. Half of patients (15 of 30) had an enlarged tunnel on the femoral or the tibial side until 1 year postoperatively. In most cases, enlargement reached maximum at 6 months postoperatively. Female patients tended to have an enlarged tunnel, especially on the femoral side (P < .05). Tunnel enlargement was not correlated with location and angle of the tunnels. Moreover, no difference was found in Lysholm score and Telos-SE measurement between enlarged and nonenlarged groups, although the nonenlarged group tended to exhibit higher Lysholm score and lesser instability. Bone tunnel enlargement of the femoral or tibial side was observed in half of patients (6 in both sides, 5 only in the femur, and 4 only in the tibia) after ACL reconstruction was performed with a hamstring tendon fixed with an RCI screw. Female patients had a greater chance for enlargement of the femoral tunnel

  15. Inferior tendon graft to bone tunnel healing at the tibia compared to that at the femur after anterior cruciate ligament reconstruction

    Lui, P.P.Y.; Ho, G.; Shum, W.T.; Lee, Y.W.; Ho, P.Y.; Lo, W.N.; Lo, C.K.

    2010-01-01

    Tunnel widening after anterior cruciate ligament (ACL) reconstruction (ACLR) is commonly reported without a clear understanding of the mechanism. This study aimed to quantify the spatiotemporal change of the newly formed bone mass, bone tunnel diameter, and area along both bone tunnels using micro-computed tomography (μCT) and correlated the result with histology. ACLR was performed in 24 rabbits. At baseline and weeks 2, 6, and 12, the juxta-articular, middle, and exit segments of both tunnels were harvested for μCT and histological evaluation. μCT and histology revealed significant bone tunnel and graft-bone tunnel healing, respectively, only at week 6 after reconstruction. Despite this, the mean tunnel diameter and area remained relatively unchanged with time. The newly formed bone mass [new bone volume/total bone volume (BV/TV) ratio] and its bone mineral density (BMD) were both higher, whereas the mean tunnel diameter and area were significantly smaller at the femoral tunnel compared to those at the tibial tunnel at weeks 6 and 12 and at week 12, respectively. These were consistent with histological findings, which showed inferior graft remodeling and integration at the tibial tunnel at weeks 6 and 12. The BV/TV increased, whereas the mean tunnel diameter and area decreased toward the exit segment of both tunnels. However, whereas better histological healing occurred at the femoral exit segment, poorer graft remodeling and Sharpey's fiber formation occurred at the tibial exit segment. Poor healing was observed during the initial 6 weeks, particularly that of the tibia, after ACLR. Bone resorption was rapid during healing, resulting in unchanged tunnel diameter and area with time. (author)

  16. Scanning tunneling microscopy

    Binnig, G.; Rohrer, H.

    1983-01-01

    Based on vacuum tunneling, a novel type of microscope, the scanning tunneling microscope (STM) was developed. It has an unprecedented resolution in real space on an atomic scale. The authors review the important technical features, illustrate the power of the STM for surface topographies and discuss its potential in other areas of science and technology. (Auth.)

  17. Electron tunneling in chemistry

    Zamaraev, K.I.; Khajrutdinov, R.F.; Zhdanov, V.P.; Molin, Yu.N.

    1985-01-01

    Results of experimental and theoretical investigations are outlined systematically on electron tunnelling in chemical reactions. Mechanism of electron transport to great distances is shown to be characteristic to chemical compounds of a wide range. The function of tunnel reactions is discussed for various fields of chemistry, including radiation chemistry, electrochemistry, chemistry of solids, chemistry of surface and catalysis

  18. Angiographic analysis of avascular necrosis of a femoral head -selective angiography of medial femoral circumflex artery-

    Ryu, Kyung Nam; Yoon, Yup; Lee, Sun Wha; Lim, Jae Hoon [Kyung Hee University Hospital, Seoul (Korea, Republic of)

    1991-07-15

    The degree of anatomical revascularization of a necrotic femoral head and traumatic hip would provide information about treatment and prognosis. The authors analyzed the vascular changes of femoral head among unilateral avascular necrosis, bilateral avascular necrosis, and traumatic hips. Forty - four patients with avascular necrosis and 19 patients with traumatic hips were examined by selective angiography of the medial femoral circumflex artery. In the traumatic hip cases, 12 (63%) showed occlusion, 2 (11%) hypertrophy of the capsular branches, and 5 ( 26 % ) were normal . In the avascular necrosis cases, 15 (25%) showed occlusion, 39 (67%) had hypertrophy of the capsular branches, and 4 (7%) had normal findings. Hypertrophy of the superior capsular branch of the medial femoral circumflex artery is more frequently observed in avascular necrosis than in traumatic hip. Bilateral avascular necrosis reveals more frequent incidences than unilateral cases. Selective angiography could help in the therapy plan and also provide information about the contralateral side.

  19. Angiographic analysis of avascular necrosis of a femoral head -selective angiography of medial femoral circumflex artery-

    Ryu, Kyung Nam; Yoon, Yup; Lee, Sun Wha; Lim, Jae Hoon

    1991-01-01

    The degree of anatomical revascularization of a necrotic femoral head and traumatic hip would provide information about treatment and prognosis. The authors analyzed the vascular changes of femoral head among unilateral avascular necrosis, bilateral avascular necrosis, and traumatic hips. Forty - four patients with avascular necrosis and 19 patients with traumatic hips were examined by selective angiography of the medial femoral circumflex artery. In the traumatic hip cases, 12 (63%) showed occlusion, 2 (11%) hypertrophy of the capsular branches, and 5 ( 26 % ) were normal . In the avascular necrosis cases, 15 (25%) showed occlusion, 39 (67%) had hypertrophy of the capsular branches, and 4 (7%) had normal findings. Hypertrophy of the superior capsular branch of the medial femoral circumflex artery is more frequently observed in avascular necrosis than in traumatic hip. Bilateral avascular necrosis reveals more frequent incidences than unilateral cases. Selective angiography could help in the therapy plan and also provide information about the contralateral side

  20. Fibrous dysplasia of the femoral neck

    Savage, P.E.; Stoker, D.J.

    1984-01-01

    Fibrous dysplasia of the femur is usually observed in the intertrochanteric region. It is rarely confined to the femoral neck. We present four cases illustrating the radiographic appearance and spectrum of this condition which all showed the relatively lucent variety of fibrous dysplasia with varying degrees of expansion and surrounding sclerosis. The natural history of this condition is discussed. (orig.)

  1. Femoral Hernia At Mulago Hospital, Uganda

    user

    2004-12-02

    Dec 2, 2004 ... consecutive patients operated for femoral hernia over a period of twelve months. Results: There were ... The age ranged from 42 years to 70 years old with a mean of 54.6 years old. All the .... cholecystectomy. At this point in ...

  2. Radiation-induced femoral head necrosis

    2011-03-25

    Mar 25, 2011 ... had open medial menisectomy of the left knee following medial meniscal tear ... postoperative recovery and mobilised full weight-bearing immediately [Figure 6]. ... obtained from the oncologists at the time of this review), and there was a ... previous trauma such as femoral neck fracture, Gaucher's disease ...

  3. Transvenous liver biopsy via the femoral vein

    Khosa, F.; McNulty, J.G.; Hickey, N.; O'Brien, P.; Tobin, A.; Noonan, N.; Ryan, B.; Keeling, P.W.N.; Kelleher, D.P.; McDonald, G.S.A.

    2003-01-01

    AIM: To study the safety, effectiveness and diagnostic value of transvenous forceps biopsy of the liver in 54 patients with coagulopathy, gross ascites or morbid obesity and suspected liver disease in whom percutaneous liver biopsy was contraindicated. MATERIAL AND METHODS: Forceps biopsy of the liver via the femoral vein was attempted in 54 adult patients with advanced liver disease of unknown aetiology who had coagulation disorders (41 cases), gross ascites (11 cases) or morbid obesity (two cases). In each patient two to six biopsies (average four) were taken using a radial jaw forceps inserted via the right or left femoral vein. RESULTS: The procedure was successful in 53 cases. Hepatic vein catheterization failed in one patient. Adequate liver tissue for diagnosis was obtained in 84% of cases. One patient developed delayed haemorrhage at 12 h from a capsular leak that was undetected during the biopsy procedure. This patient required blood transfusions and laparotomy to control bleeding. There were no deaths in the 53 patients studied. Transient minor chest and shoulder pain was encountered during sheath insertion into a hepatic vein in 23 patients. Three patients developed a femoral vein haematoma, which resolved with conservative treatment. CONCLUSION: Transvenous liver biopsy via the femoral vein is another safe, effective, simple alternative technique of biopsy when the percutaneous route is contraindicated

  4. Postmortem Femoral Blood Concentrations of Risperidone

    Linnet, Kristian; Johansen, Sys Stybe

    2014-01-01

    Postmortem femoral blood concentrations of the antipsychotic drug risperidone and the active metabolite 9-hydroxyrisperidone were determined by an achiral LC-MS/MS method in 38 cases. The cause of death was classified as unrelated to risperidone in 30 cases, in which the sum of the concentration ...

  5. Femoral Prosthesis Infection by Rhodotorula mucilaginosa▿

    Savini, Vincenzo; Sozio, Federica; Catavitello, Chiara; Talia, Marzia; Manna, Assunta; Febbo, Fabio; Balbinot, Andrea; Di Bonaventura, Giovanni; Piccolomini, Raffaele; Parruti, Giustino; D'Antonio, Domenico

    2008-01-01

    This case report is a case history of a femoral prosthesis infection caused by Rhodotorula mucilaginosa in a human immunodeficiency virus patient. Though the pathogenicity of this organism for bone tissue has been previously reported, this is the first reported case of an orthopedic prosthesis infection by this species of the genus Rhodotorula. PMID:18753353

  6. Aseptic necrosis of femoral head complicating thalassemia

    Orzincolo, C.; Castaldi, G.; Scutellary, P.N.; Bariani, L.; Pinca, A.

    1986-01-01

    Aseptic necrosis of the femoral head is described in 4 patients, selected from 280 patients with homozygous β-thalassemia (Cooley anemia). The incidence of the complication appears to be very high (14.5per mille) in thalassemia, compared to the general population. The possible mechanism are discussed. (orig.)

  7. Tunnel fire dynamics

    Ingason, Haukur; Lönnermark, Anders

    2015-01-01

    This book covers a wide range of issues in fire safety engineering in tunnels, describes the phenomena related to tunnel fire dynamics, presents state-of-the-art research, and gives detailed solutions to these major issues. Examples for calculations are provided. The aim is to significantly improve the understanding of fire safety engineering in tunnels. Chapters on fuel and ventilation control, combustion products, gas temperatures, heat fluxes, smoke stratification, visibility, tenability, design fire curves, heat release, fire suppression and detection, CFD modeling, and scaling techniques all equip readers to create their own fire safety plans for tunnels. This book should be purchased by any engineer or public official with responsibility for tunnels. It would also be of interest to many fire protection engineers as an application of evolving technical principles of fire safety.

  8. Lateral femoral traction pin entry: risk to the femoral artery and other medial neurovascular structures

    Appleton Paul

    2010-01-01

    Full Text Available Abstract Background Femoral skeletal traction assists in the reduction and transient stabilization of pelvic, acetabular, hip, and femoral fractures when splinting is ineffective. Traditional teaching has recommended a medial entry site for insertion of the traction pin in order to minimize injury to the femoral artery as it passes through Hunter's canal. The present anatomical study evaluates the risk to the femoral artery and other medial neurovascular structures using a lateral entry approach. Methods Six embalmed cadavers (twelve femurs were obtained for dissection. Steinman pins were drilled from lateral to medial at the level of the superior pole of the patella, at 2 cm, and at 4 cm proximal to this point. Medial superficial dissection was then performed to identify the saphenous nerve, the superior medial geniculate artery, the adductor hiatus, the tendinous insertion of the adductor magnus and the femoral artery. Measurements localizing these anatomic structures relative to the pins were obtained. Results The femoral artery was relatively safe and was no closer than 29.6 mm (mean from any of the three Steinman pins. The superior medial geniculate artery was the medial structure at most risk. Conclusions Lateral femoral traction pin entry is a safe procedure with minimal risk to the saphenous nerve and femoral artery. Of the structures examined, only the superior medial geniculate artery is at a risk of iatrogenic injury due to its position. The incidence of such injury in clinical practice and its clinical significance is not known. Lateral insertion facilitates traction pin placement since it minimizes the need to move the contralateral extremity out of the way of the drilling equipment or the need to elevate or externally rotate the injured extremity relative to the contralateral extremity.

  9. Preoperative virtual reduction reduces femoral malrotation in the treatment of bilateral femoral shaft fractures.

    Omar, Mohamed; Suero, Eduardo M; Hawi, Nael; Decker, Sebastian; Krettek, Christian; Citak, Musa

    2015-10-01

    In bilateral femoral shaft fractures, significant malrotation (>15°) occurs in about 40 % of cases after intramedullary nailing. Most of the methods that provide rotational control during surgery are based on a comparison to the intact femur and, thus, not applicable for bilateral fractures. In this study, we evaluated if preoperative virtual reduction can help improving rotational alignment in patients with bilateral femoral shaft fractures. Seven patients with bilateral femoral shaft fractures were initially treated with external fixation of both femurs. After obtaining a CT scan of both legs, the fractures were reduced virtually using the software program VoXim®, and the amount and direction of rotational correction were calculated. Subsequently, the patients were treated by antegrade femoral nailing and rotation was corrected to the preoperatively calculated amount. After external fixation, the mean rotational difference between both legs was 15.0° ± 10.2°. Four out of seven patients had a significant malrotation over 15°. Following virtual reduction, the mean rotational difference between both legs was 2.1° ± 1.2°. After intramedullary nailing, no case of malrotation occurred and the mean rotational difference was 6.1° ± 2.8°. Preoperative virtual reduction allows determining the pretraumatic femoral antetorsion and provided useful information for the definitive treatment of bilateral femoral shaft fractures. We believe that this procedure is worth being implemented in the clinical workflow to avoid malrotation after intramedullary nailing.

  10. Femoral neck fracture following groin irradiation

    Grigsby, Perry W; Roberts, Heidi L; Perez, Carlos A

    1995-04-30

    Purpose: The incidence and risk factors are evaluated for femoral neck fracture following groin irradiation for gynecologic malignancies. Methods and Materials: The radiation therapy records of 1313 patients with advanced and recurrent cancer of the vagina, vulva, cervix, and endometrium, treated at the Mallinckrodt Institute of Radiology from 1954 to 1992, were reviewed. Median follow-up was 12.7 years. From this group, 207 patients were identified who received irradiation to the pelvis and groins with anterposterior-posterior anterior (AP-PA), 18 MV photons. Data were reviewed regarding irradiation dose to the femoral neck and other presumed risk factors including age, primary site, stage, groin node status, menopausal status, estrogen use, cigarette use, alcohol consumption, and osteoporosis. Results: The per-patient incidence of femoral neck fracture was 4.8% (10 out of 207). Four patients developed bilateral fractures. However, the cumulative actuarial incidence of fracture was 11% at 5 years and 15% at 10 years. Cox multivariate analysis of age, weight, and irradiation dose showed that only irradiation dose may be important to developing fracture. Step-wise logistic regression of presumed prognostic factors revealed that only cigarette use and x-ray evidence of osteoporosis prior to irradiation treatment were predictive of fracture. Conclusion: Femoral head fracture is a common complication of groin irradiation for gynecologic malignancies. Fracture in our database appears to be related to irradiation dose, cigarette use, and x-ray evidence of osteoporosis. Special attention should be given in treatment planning (i.e., shielding of femoral head/neck and use of appropriate electron beam energies for a portion of treatment) to reduce the incidence of this complication.

  11. Femoral neck fracture following groin irradiation

    Grigsby, Perry W.; Roberts, Heidi L.; Perez, Carlos A.

    1995-01-01

    Purpose: The incidence and risk factors are evaluated for femoral neck fracture following groin irradiation for gynecologic malignancies. Methods and Materials: The radiation therapy records of 1313 patients with advanced and recurrent cancer of the vagina, vulva, cervix, and endometrium, treated at the Mallinckrodt Institute of Radiology from 1954 to 1992, were reviewed. Median follow-up was 12.7 years. From this group, 207 patients were identified who received irradiation to the pelvis and groins with anterposterior-posterior anterior (AP-PA), 18 MV photons. Data were reviewed regarding irradiation dose to the femoral neck and other presumed risk factors including age, primary site, stage, groin node status, menopausal status, estrogen use, cigarette use, alcohol consumption, and osteoporosis. Results: The per-patient incidence of femoral neck fracture was 4.8% (10 out of 207). Four patients developed bilateral fractures. However, the cumulative actuarial incidence of fracture was 11% at 5 years and 15% at 10 years. Cox multivariate analysis of age, weight, and irradiation dose showed that only irradiation dose may be important to developing fracture. Step-wise logistic regression of presumed prognostic factors revealed that only cigarette use and x-ray evidence of osteoporosis prior to irradiation treatment were predictive of fracture. Conclusion: Femoral head fracture is a common complication of groin irradiation for gynecologic malignancies. Fracture in our database appears to be related to irradiation dose, cigarette use, and x-ray evidence of osteoporosis. Special attention should be given in treatment planning (i.e., shielding of femoral head/neck and use of appropriate electron beam energies for a portion of treatment) to reduce the incidence of this complication

  12. Review of evolution of tunnel position in anterior cruciate ligament reconstruction.

    Rayan, Faizal; Nanjayan, Shashi Kumar; Quah, Conal; Ramoutar, Darryl; Konan, Sujith; Haddad, Fares S

    2015-03-18

    Anterior cruciate ligament (ACL) rupture is one of the commonest knee sport injuries. The annual incidence of the ACL injury is between 100000-200000 in the United States. Worldwide around 400000 ACL reconstructions are performed in a year. The goal of ACL reconstruction is to restore the normal knee anatomy and kinesiology. The tibial and femoral tunnel placements are of primordial importance in achieving this outcome. Other factors that influence successful reconstruction are types of grafts, surgical techniques and rehabilitation programmes. A comprehensive understanding of ACL anatomy has led to the development of newer techniques supplemented by more robust biological and mechanical concepts. In this review we are mainly focussing on the evolution of tunnel placement in ACL reconstruction, focusing on three main categories, i.e., anatomical, biological and clinical outcomes. The importance of tunnel placement in the success of ACL reconstruction is well researched. Definite clinical and functional data is lacking to establish the superiority of the single or double bundle reconstruction technique. While there is a trend towards the use of anteromedial portals for femoral tunnel placement, their clinical superiority over trans-tibial tunnels is yet to be established.

  13. CT study of avascular necrosis of femoral head in adults

    Liu Jihua; Du Yuqing; Xu Aide

    2000-01-01

    Objective: To study the early and new CT signs of avascular necrosis of femoral head in adults. Methods: The CT scans of 127 cases with this condition were analyzed. Results: There were 90 hip joints with femoral head normal in shape, including 67 femoral heads with only high-density sclerosis and 23 ones with high-density and low-density areas. In 111 hip joints, the femoral head was depressed and manifested purely high-density sclerosis in 25 and mixed-density areas in 86. Air-filled cysts appeared in 43 femoral heads. In follow-up cases, the changes in shape and density of femoral head followed some rules. Conclusion: Purely high-density sclerosis is an early sign and is of great diagnostic value combined with its special shape. Air in femoral heads is also a sign of the disease

  14. Ultrafast scanning tunneling microscopy

    Botkin, D.A. [California Univ., Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley Lab., CA (United States)

    1995-09-01

    I have developed an ultrafast scanning tunneling microscope (USTM) based on uniting stroboscopic methods of ultrafast optics and scanned probe microscopy to obtain nanometer spatial resolution and sub-picosecond temporal resolution. USTM increases the achievable time resolution of a STM by more than 6 orders of magnitude; this should enable exploration of mesoscopic and nanometer size systems on time scales corresponding to the period or decay of fundamental excitations. USTM consists of a photoconductive switch with subpicosecond response time in series with the tip of a STM. An optical pulse from a modelocked laser activates the switch to create a gate for the tunneling current, while a second laser pulse on the sample initiates a dynamic process which affects the tunneling current. By sending a large sequence of identical pulse pairs and measuring the average tunnel current as a function of the relative time delay between the pulses in each pair, one can map the time evolution of the surface process. USTM was used to measure the broadband response of the STM`s atomic size tunnel barrier in frequencies from tens to hundreds of GHz. The USTM signal amplitude decays linearly with the tunnel junction conductance, so the spatial resolution of the time-resolved signal is comparable to that of a conventional STM. Geometrical capacitance of the junction does not appear to play an important role in the measurement, but a capacitive effect intimately related to tunneling contributes to the measured signals and may limit the ultimate resolution of the USTM.

  15. Tunnel magnetoresistance in alumina, magnesia and composite tunnel barrier magnetic tunnel junctions

    Schebaum, Oliver; Drewello, Volker; Auge, Alexander; Reiss, Guenter; Muenzenberg, Markus; Schuhmann, Henning; Seibt, Michael; Thomas, Andy

    2011-01-01

    Using magnetron sputtering, we have prepared Co-Fe-B/tunnel barrier/Co-Fe-B magnetic tunnel junctions with tunnel barriers consisting of alumina, magnesia, and magnesia-alumina bilayer systems. The highest tunnel magnetoresistance ratios we found were 73% for alumina and 323% for magnesia-based tunnel junctions. Additionally, tunnel junctions with a unified layer stack were prepared for the three different barriers. In these systems, the tunnel magnetoresistance ratios at optimum annealing temperatures were found to be 65% for alumina, 173% for magnesia, and 78% for the composite tunnel barriers. The similar tunnel magnetoresistance ratios of the tunnel junctions containing alumina provide evidence that coherent tunneling is suppressed by the alumina layer in the composite tunnel barrier. - Research highlights: → Transport properties of Co-Fe-B/tunnel barrier/Co-Fe-B magnetic tunnel junctions. → Tunnel barrier consists of MgO, Al-Ox, or MgO/Al-Ox bilayer systems. → Limitation of TMR-ratio in composite barrier tunnel junctions to Al-Ox values. → Limitation indicates that Al-Ox layer is causing incoherent tunneling.

  16. Tunneling current between graphene layers

    Poklonski, Nikolai A.; Siahlo, Andrei I.; Vyrko, Sergey A.; Popov, Andrey M.; Lozovik, Yurii E.

    2013-01-01

    The physical model that allows to calculate the values of the tunneling current be-tween graphene layers is proposed. The tunneling current according to the pro-posed model is proportional to the area of tunneling transition. The calculated value of tunneling conductivity is in qualitative agreement with experimental data.

  17. Vacuum phonon tunneling.

    Altfeder, Igor; Voevodin, Andrey A; Roy, Ajit K

    2010-10-15

    Field-induced phonon tunneling, a previously unknown mechanism of interfacial thermal transport, has been revealed by ultrahigh vacuum inelastic scanning tunneling microscopy (STM). Using thermally broadened Fermi-Dirac distribution in the STM tip as in situ atomic-scale thermometer we found that thermal vibrations of the last tip atom are effectively transmitted to sample surface despite few angstroms wide vacuum gap. We show that phonon tunneling is driven by interfacial electric field and thermally vibrating image charges, and its rate is enhanced by surface electron-phonon interaction.

  18. Quantum tunneling with friction

    Tokieda, M.; Hagino, K.

    2017-05-01

    Using the phenomenological quantum friction models introduced by P. Caldirola [Nuovo Cimento 18, 393 (1941), 10.1007/BF02960144] and E. Kanai [Prog. Theor. Phys. 3, 440 (1948), 10.1143/ptp/3.4.440], M. D. Kostin [J. Chem. Phys. 57, 3589 (1972), 10.1063/1.1678812], and K. Albrecht [Phys. Lett. B 56, 127 (1975), 10.1016/0370-2693(75)90283-X], we study quantum tunneling of a one-dimensional potential in the presence of energy dissipation. To this end, we calculate the tunneling probability using a time-dependent wave-packet method. The friction reduces the tunneling probability. We show that the three models provide similar penetrabilities to each other, among which the Caldirola-Kanai model requires the least numerical effort. We also discuss the effect of energy dissipation on quantum tunneling in terms of barrier distributions.

  19. Wind Tunnel Testing Facilities

    Federal Laboratory Consortium — NASA Ames Research Center is pleased to offer the services of our premier wind tunnel facilities that have a broad range of proven testing capabilities to customers...

  20. INCAS TRISONIC WIND TUNNEL

    Florin MUNTEANU

    2009-09-01

    Full Text Available The 1.2 m x 1.2 m Trisonic Blowdown Wind Tunnel is the largest of the experimental facilities at the National Institute for Aerospace Research - I.N.C.A.S. "Elie Carafoli", Bucharest, Romania. The tunnel has been designed by the Canadian company DSMA (now AIOLOS and since its commissioning in 1978 has performed high speed aerodynamic tests for more than 120 projects of aircraft, missiles and other objects among which the twin jet fighter IAR-93, the jet trainer IAR-99, the MIG-21 Lancer, the Polish jet fighter YRYDA and others. In the last years the wind tunnel has been used mostly for experimental research in European projects such as UFAST. The high flow quality parameters and the wide range of testing capabilities ensure the competitivity of the tunnel at an international level.

  1. The ISI Tunnel

    1993-10-01

    DP /etc/tunnelvisa p zephyr dark -star TCP /etc/tunnelvisa p zephyr dak’star ICMP /etc/tunnelvisa p zephyr quark MDP /etc/tunnelvisa p zephyr quark ...drax-net-yp 128.9.32.2 1 route add quark -net-yp 128.9.32.3 1 route add vlsi-net-yp 128.9.32.4 1 route add darkstar-net-yp 128.9.32.3 1 route add rocky...TCP /etc/tunnel-visa p zephyr quark ICMP /etc/tunnel-visa p zephyr drax tTI)P /etc/tunnel-visa p zephyr drax TCP /etc/tunnel_visa p zephyr drax ICMP

  2. Wind Tunnel Facility

    Federal Laboratory Consortium — This ARDEC facility consists of subsonic, transonic, and supersonic wind tunnels to acquire aerodynamic data. Full-scale and sub-scale models of munitions are fitted...

  3. Water Tunnel Facility

    Federal Laboratory Consortium — NETL’s High-Pressure Water Tunnel Facility in Pittsburgh, PA, re-creates the conditions found 3,000 meters beneath the ocean’s surface, allowing scientists to study...

  4. Computer tomographic determination of femoral anteversion

    Jend, H.H.

    1986-01-01

    Thirty-two macerated femora were examined by CT in order to determine the degree of anteversion and to relate this to the position of the femur and to the various reference lines quoted in the literature. The accuracy of CT is the same as that of the Rippstein method, provided the following conditions are met: 1. Position of the femur with its long axis perpendicular to the image plane. 2. Demonstration of the maximal configuration of the femoral condyles to enable one to construct a tangent to the dorsal aspect of the condyle. 3. Demonstration of the head and neck by a plane which divides the neck into approximately equal portions and sections the femoral head. These conditions are more easily met, even in immobile patients, than the requirements for the Rippstein method. (orig.) [de

  5. Intracorporeal knotting of a femoral nerve catheter

    Ghanem, Mohamed

    2015-01-01

    Full Text Available Peripheral nerve catheters are effective and well-established tools to provide postoperative analgesia to patients undergoing orthopedic surgery. The performance of these techniques is usually considered safe. However, placement of nerve catheters may be associated with a considerable number of side effects and major complications have repeatedly been published. In this work, we report on a patient who underwent total knee replacement with spinal anesthesia and preoperative insertion of femoral and sciatic nerve catheters for postoperative analgesia. During insertion of the femoral catheter, significant resistance was encountered upon retracting the catheter. This occurred due to knotting of the catheter. The catheter had to be removed by operative intervention which has to be considered a major complication. The postoperative course was uneventful. The principles for removal of entrapped peripheral catheters are not well established, may differ from those for neuroaxial catheters, and range from cautious manipulation up to surgical intervention.

  6. Femoral head fracture without hip dislocation

    Aggarwal Aditya K

    2013-10-01

    Full Text Available 【Abstract】Femoral head fractures without dislocation or subluxation are extremely rare injuries. We report a neglected case of isolated comminuted fracture of femoral head without hip dislocation or subluxation of one year duration in a 36-year-old patient who sustained a high en- ergy trauma due to road traffic accident. He presented with painful right hip and inability to bear full weight on right lower limb with Harris hip score of 39. He received cementless total hip replacement. At latest follow-up of 2.3 years, functional outcome was excellent with Harris hip score of 95. Such isolated injuries have been described only once in the literature and have not been classified till now. The purpose of this report is to highlight the extreme rarity, possible mechanism involved and a novel classification system to classify such injuries. Key words: Femur head; Hip dislocation; Classification; Arthroplasty, replacement, hip

  7. Spontaneous stress fractures of the femoral neck

    Dorne, H.L.; Lander, P.H.

    1985-01-01

    The diagnosis of spontaneous stress fractures of the femoral neck, a form of insufficiency stress fracture, can be missed easily. Patients present with unremitting hip pain without a history of significant trauma or unusual increase in daily activity. The initial radiographic features include osteoporosis, minor alterations of trabecular alignment, minimal extracortical or endosteal reaction, and lucent fracture lines. Initial scintigraphic examinations performed in three of four patients showed focal increased radionuclide uptake in two and no focal abnormality in one. Emphasis is placed on the paucity of early findings. Evaluation of patients with persistent hip pain requires a high degree of clinical suspicion and close follow-up; the sequelae of undetected spontaneous fractures are subcapital fracture with displacement, angular deformity, and a vascular necrosis of the femoral head

  8. Ipsilateral femoral neck and trochanter fracture

    Devdatta S Neogi

    2011-01-01

    Full Text Available Ipsilateral fractures in the neck and trochanteric region of the femur are very rare and seen in elderly osteoporotic patients. We present a case of a young man who presented with ipsilateral fracture of the femoral neck and a reverse oblique fracture in the trochanteric region following a motor vehicle accident. A possible mechanism, diagnostic challenge, and awareness required for identifying this injury are discussed.

  9. Proximal focal femoral deficiency: A case report

    Shashank Sharma

    2015-01-01

    Full Text Available Proximal focal femoral deficiency (PFFD is a rare congenital anomaly resulting in limb shortening and disability in young. The exact cause of the disease is not known and it may present as varying grades of affection involving the proximal femur and the acetabulum. Recognition of this rare abnormality on radiographs can help manage these cases better since early institution of therapy may help in achieving adequate growth of the femur.

  10. Radiofrequency ablation of two femoral head chondroblastomas

    Petsas, Theodore [Department of Radiology, University of Patras (Greece); Megas, Panagiotis [Department of Orthopaedic Surgery, University of Patras (Greece)]. E-mail: panmegas@med.upatras.gr; Papathanassiou, Zafiria [Department of Radiology, University of Patras (Greece)

    2007-07-15

    Chondroblastoma is a rare benign cartilaginous bone tumor. Surgical resection is the treatment of choice for pain relief and prevention of further growth. Open surgical techniques are associated with complications, particularly when the tumors are located in deep anatomical sites. The authors performed RF ablation in two cases of subarticular femoral head chondroblastomas and emphasize its positive impact. The clinical course, the radiological findings and the post treatment results are discussed.

  11. [Avascular necrosis of the femoral head].

    Porubský, Peter; Trč, Tomáš; Havlas, Vojtěch; Smetana, Pavel

    Avascular necrosis of the femoral head in adults is not common, but not too rare diseases. In orthopedic practice, it is one of the diseases that are causing implantation of hip replacement at a relatively early age. In the early detection and initiation of therapy can delay the implantation of prosthesis for several years, which is certainly more convenient for the patient and beneficial. This article is intended to acquaint the reader with the basic diagnostic procedures and therapy.

  12. The Beginner's Guide to Wind Tunnels with TunnelSim and TunnelSys

    Benson, Thomas J.; Galica, Carol A.; Vila, Anthony J.

    2010-01-01

    The Beginner's Guide to Wind Tunnels is a Web-based, on-line textbook that explains and demonstrates the history, physics, and mathematics involved with wind tunnels and wind tunnel testing. The Web site contains several interactive computer programs to demonstrate scientific principles. TunnelSim is an interactive, educational computer program that demonstrates basic wind tunnel design and operation. TunnelSim is a Java (Sun Microsystems Inc.) applet that solves the continuity and Bernoulli equations to determine the velocity and pressure throughout a tunnel design. TunnelSys is a group of Java applications that mimic wind tunnel testing techniques. Using TunnelSys, a team of students designs, tests, and post-processes the data for a virtual, low speed, and aircraft wing.

  13. Tunnelling of a molecule

    Jarvis, P.D.; Bulte, D.P.

    1998-01-01

    A quantum-mechanical description of tunnelling is presented for a one-dimensional system with internal oscillator degrees of freedom. The 'charged diatomic molecule' is frustrated on encountering a barrier potential by its centre of charge not being coincident with its centre of mass, resulting in transitions amongst internal states. In an adiabatic limit, the tunnelling of semiclassical coherent-like oscillator states is shown to exhibit the Hartman and Bueuttiker-Landauer times t H and t BL , with the time dependence of the coherent state parameter for the tunnelled state given by α(t) = α e -iω(t+Δt) , Δt = t H - it BL . A perturbation formalism is developed, whereby the exact transfer matrix can be expanded to any desired accuracy in a suitable limit. An 'intrinsic' time, based on the oscillator transition rate during tunnelling, transmission or reflection, is introduced. In simple situations the resulting intrinsic tunnelling time is shown to vanish to lowest order. In the general case a particular (nonzero) parametrisation is inferred, and its properties discussed in comparison with the literature on tunnelling times for both wavepackets and internal clocks. Copyright (1998) CSIRO Australia

  14. MYCOTIC FEMORAL PSEUDOANEURYSMS FROM INTRAVENOUS DRUG ABUSE

    Vojko Flis

    2004-04-01

    Full Text Available Background. Parenteral drug abuse is the most common cause of infected femoral artery pseudoaneurysms (IFAP. This complication of intravenous drug abuse is not only limb threatening but can also be life threatening. The management of the IFAP is difficult and controversial. Generally speaking, ligation and excision of the pseudoaneurysm without revascularization is accepted procedure in majority of the patients. However it is not regarded as an appropriate procedure for cases where the high probability of amputation is expected from acute interruption of the femoral artery flow.Patients, methods and results. We present three cases of young (average 20 years, range 18–24 patients with IFAP, in which a primary reconstruction was performed due to absence of doppler signal over pedal arteries after ligation of common femoral artery. In two of them complications in form of haemorrhage and repeated infection developed in late postoperative period. The first one, had an excision and ligation while the second one had a reconstruction made by means of a silver impregnated dacron prosthesis. None of the patients required an amputation.Conclusions. Overall prognosis and prognosis of the reconstruction in parenteral drug abuse patients is uncertain because there is a high incidence of postoperative drug injection despite aggressive drug rehabilitation.

  15. Radionuclide patterns of femoral head disease

    Webber, M M; Wagner, J; Cragin, M D [California Univ., Los Angeles (USA). Dept. of Radiological Sciences

    1977-12-01

    The pattern of uptake of bone marrow specific radio-sup(99m)Tc sulfur colloid and the pattern of uptake of bone mineral specific radio-sup(99m)Tc pryophosphate may be valuable in assessing bone vascularity in diseases suspected of causing impaired blood supply, or indicate the presence of reactive bone formation. The low energy of the technetium label has been shown to be superior to /sup 18/F and /sup 85/Sr, and leads to greater imaging detail on the scans. Femoral head scanning with mineral and/or marrow specific radionuclides offers the clinician a method of evaluating the status of the femoral head and possibly an early diagnosis of avascular necrosis before roentgenographic changes occur. This study, which reports on a 5-year experience using radionuclide scanning to assess femoral head vascularity, begins with baseline or normal studies followed by variations of the normal pattern. Typical scan patterns of hip pathology described above are also presented.

  16. German Orientalism

    Margaret Olin

    2011-01-01

    Review of: Suzanne L. Marchand, German Orientalism in the Age of Empire: Religion, Race and Scholarship, Cambridge and Washington, D.C.: Cambridge University Press, 2009. This analysis of Suzanne L. Marchand’s German Orientalism in the Age of Empire: Religion, Race and Scholarship reads her contribution in part against the background of Edward Said’s path breaking book Orientalism. Differences lie in her more expansive understanding of the term ‘Oriental’ to include the Far East and her conce...

  17. Incidence of Avascular Necrosis of the Femoral Head After Intramedullary Nailing of Femoral Shaft Fractures

    Kim, Ji Wan; Oh, Jong-Keon; Byun, Young-Soo; Shon, Oog-Jin; Park, Jai Hyung; Oh, Hyoung Keun; Shon, Hyun Chul; Park, Ki Chul; Kim, Jung Jae; Lim, Seung-Jae

    2016-01-01

    Abstract The goal of this study was to determine the incidence of avascular necrosis of the femoral head (AVNFH) after intramedullary nailing of femoral shaft fractures and to identify risk factors for developing AVNFH. We retrospectively reviewed all patients with femoral shaft fractures treated with antegrade intramedullary nailing at 10 institutions. Among the 703 patients enrolled, 161 patients were excluded leaving 542 patients in the study. Average age was 42.1 years with average follow-up of 26.3 months. Patient characteristics and fracture patterns as well as entry point of femoral nails were identified and the incidence of AVNFH was investigated. Patients were divided into 2 groups according to open versus closed physis, open versus closed fractures, and age (<20 versus ≥20 years). Overall incidence of AVNFH was 0.2% (1 of 542): the patient was 15-year-old boy. Of 25 patients with open physis, the incidence of AVNFH was 4%, whereas none of 517 patients with closed physis developed AVNFH (P < 0.001). The incidence of AVNFH in patients aged < 20 versus ≥20 years was 1.1% (1 of 93) and 0.0% (0 of 449), respectively (P = 0.172), which meant that the incidence of AVNFH was 0% in adult with femur shaft fracture. Of 61 patients with open fractures, the incidence of AVNFH was 0%. The number of cases with entry point at the trochanteric fossa or tip of the greater trochanter (GT) was 324 and 218, respectively, and the incidence of AVNFH was 0.3% and 0.0%, respectively (P = 0.412). In patients aged ≥20 years with isolated femoral shaft fracture, there was no case of AVNFH following antegrade intramedullary nailing regardless of the entry point. Therefore, our findings suggest that the risk of AVNFH following antegrade femoral nailing is extremely low in adult patients. PMID:26844518

  18. Structure factors for tunneling ionization rates of molecules

    Madsen, L.B.; Jensen, F.; Tolstikhin, O.I.

    2013-01-01

    Within the weak-field asymptotic theory, the dependence of the tunneling ionization rate of a molecule in a static electric field on its orientation with respect to the field is determined by the structure factor for the highest occupied molecular orbital (HOMO). An accurate determination...

  19. Ipsilateral femoral neck and shaft fractures: An overlooked association

    Daffner, R.H.; Riemer, B.L.; Butterfield, S.L.

    1991-01-01

    A total of 304 patients with injuries to the femoral shaft and ipsilateral hip presented between 1984 and 1990. Some 253 of them suffered fractures of the femoral shaft and dislocated hips or fractures of the acetabulum, and 51 of these sustained fractures of the femoral shaft and neck or trochanteric region. All of the trochanteric injuries were demonstrated on the initial radiographs. However, in 11 of the patients with combined femoral shaft and neck fractures, the diagnosis was delayed by as much as 4 weeks. This delay related to the fact that these fractures tended not to separate in the initial evaluation period and that there was external rotation of the proximal femoral fragment due to the femoral shaft fracture. (orig./GDG)

  20. Ipsilateral femoral neck and shaft fractures: An overlooked association

    Daffner, R.H. (Dept. of Diagnostic Radiology, Allegheny General Hospital, Pittsburgh, PA (USA) Medical Coll. of Pennsylvania, Pittsburgh, PA (USA)); Riemer, B.L.; Butterfield, S.L. (Dept. of Orthopedic Surgery, Allegheny General Hospital, Pittsburgh, PA (USA) Medical Coll. of Pennsylvania, Pittsburgh, PA (USA))

    1991-05-01

    A total of 304 patients with injuries to the femoral shaft and ipsilateral hip presented between 1984 and 1990. Some 253 of them suffered fractures of the femoral shaft and dislocated hips or fractures of the acetabulum, and 51 of these sustained fractures of the femoral shaft and neck or trochanteric region. All of the trochanteric injuries were demonstrated on the initial radiographs. However, in 11 of the patients with combined femoral shaft and neck fractures, the diagnosis was delayed by as much as 4 weeks. This delay related to the fact that these fractures tended not to separate in the initial evaluation period and that there was external rotation of the proximal femoral fragment due to the femoral shaft fracture. (orig./GDG).

  1. MR evaluation of femoral neck version and tibial torsion

    Koenig, James Karl; Dwek, Jerry R. [University of California, San Diego, Children' s Hospital and Health Center, Department of Radiology, San Diego, CA (United States); Pring, Maya E. [Rady Children' s Hospital, Department of Pediatric Orthopedic Surgery, San Diego, CA (United States)

    2012-01-15

    Abnormalities of femoral neck version have been associated with a number of hip abnormalities in children, including slipped capital femoral epiphysis, proximal femoral focal deficiency, coxa vara, a deep acetabulum and, rarely, developmental dysplasia of the hip. Orthopedic surgeons also are interested in quantifying the femoral neck anteversion or retroversion in children especially to plan derotational osteotomies. Historically, the angle of femoral version and tibial torsion has been measured with the use of radiography and later by CT. Both methods carry with them the risks associated with ionizing radiation. Techniques that utilize MR are used less often because of the associated lengthy imaging times. This article describes a technique using MRI to determine femoral neck version and tibial torsion with total scan times of approximately 10 min. (orig.)

  2. Computerized tomography in evaluation of decreased acetabular and femoral anteversion

    Toennis, D.; Skamel, H.J.

    2003-01-01

    Computerized tomography has received a new importance. It has been shown that decreased anteversion of femur and acetabulum, when both have decreased angles, are causing pain and osteoarthritis of the hip joint. Operative treatment should be performed before osteoarthritis develops. Exact measurements therefore are necessary. The investigation should be performed in prone position to have the pelvis lying in a defined and normal position. Femoral torsion is measured between the transverse axis of the knee and the femoral neck. The transverse axis for measurement of the femoral anteversion is defined by a rectangular line to the sagittal plane. For evaluation of the femoral anteversion in total the angle of the condyles has to be added to the femoral neck angle when the knee is found in internal rotation. Acetabular anteversion should be measured at the level where the femoral head is still in full contact and congruence with the anterior margin of the acetabulum. (orig.) [de

  3. Compartment Syndrome following Open Femoral Fracture with an Isolated Femoral Vein Injury Treated with Acute Repair

    David Walmsley

    2014-01-01

    Full Text Available Acute compartment syndrome is a surgical emergency and its diagnosis is more difficult in obtunded or insensate patients. We present the case of a 34-year-old woman who sustained a Gustilo-Anderson grade III open midshaft femur fracture with an isolated femoral vein injury treated with direct repair. She developed lower leg compartment syndrome at 48 hours postoperatively, necessitating fasciotomies. She was subsequently found to have a DVT in her femoral vein at the level of the repair and was started on therapeutic anticoagulation. This case highlights the importance of recognition of isolated venous injuries in a trauma setting as a risk factor for developing compartment syndrome.

  4. Delayed appearance of hypaesthesia and paralysis after femoral nerve block

    Stefan Landgraeber; Thomas Albrecht; Ulrich Reischuck; Marius von Knoch

    2012-01-01

    We report on a female patient who underwent an arthroscopy of the right knee and was given a continuous femoral nerve block catheter. The postoperative course was initially unremarkable, but when postoperative mobilisation was commenced, 18 hours after removal of the catheter, the patient noticed paralysis and hypaesthesia. Examination confirmed the diagnosis of femoral nerve dysfunction. Colour duplex sonography of the femoral artery and computed tomography of the lumbar spine and pelvis yie...

  5. Orienteering injuries

    Folan, Jean M.

    1982-01-01

    At the Irish National Orienteering Championships in 1981 a survey of the injuries occurring over the two days of competition was carried out. Of 285 individual competitors there was a percentage injury rate of 5.26%. The article discusses the injuries and aspects of safety in orienteering.

  6. Single Electron Tunneling

    Ruggiero, Steven T.

    2005-01-01

    Financial support for this project has led to advances in the science of single-electron phenomena. Our group reported the first observation of the so-called ''Coulomb Staircase'', which was produced by tunneling into ultra-small metal particles. This work showed well-defined tunneling voltage steps of width e/C and height e/RC, demonstrating tunneling quantized on the single-electron level. This work was published in a now well-cited Physical Review Letter. Single-electron physics is now a major sub-field of condensed-matter physics, and fundamental work in the area continues to be conducted by tunneling in ultra-small metal particles. In addition, there are now single-electron transistors that add a controlling gate to modulate the charge on ultra-small photolithographically defined capacitive elements. Single-electron transistors are now at the heart of at least one experimental quantum-computer element, and single-electron transistor pumps may soon be used to define fundamental quantities such as the farad (capacitance) and the ampere (current). Novel computer technology based on single-electron quantum dots is also being developed. In related work, our group played the leading role in the explanation of experimental results observed during the initial phases of tunneling experiments with the high-temperature superconductors. When so-called ''multiple-gap'' tunneling was reported, the phenomenon was correctly identified by our group as single-electron tunneling in small grains in the material. The main focus throughout this project has been to explore single electron phenomena both in traditional tunneling formats of the type metal/insulator/particles/insulator/metal and using scanning tunneling microscopy to probe few-particle systems. This has been done under varying conditions of temperature, applied magnetic field, and with different materials systems. These have included metals, semi-metals, and superconductors. Amongst a number of results, we have

  7. Resonant tunnel magnetoresistance in a double magnetic tunnel junction

    Useinov, Arthur; Useinov, Niazbeck Kh H; Tagirov, Lenar R.; Kosel, Jü rgen

    2011-01-01

    We present quasi-classical approach to calculate a spin-dependent current and tunnel magnetoresistance (TMR) in double magnetic tunnel junctions (DMTJ) FML/I/FMW/I/FMR, where the magnetization of the middle ferromagnetic metal layer FMW can

  8. Interaction between groundwater and TBM (Tunnel Boring Machine) excavated tunnels

    Font Capó, Jordi

    2012-01-01

    A number of problems, e.g. sudden inflows are encountered during tunneling under the piezometric level, especially when the excavation crosses high transmissivity areas. These inflows may drag materials when the tunnel crosses low competent layers, resulting in subsidence, chimney formation and collapses. Moreover, inflows can lead to a decrease in head level because of aquifer drainage. Tunnels can be drilled by a tunnel boring machine (TBM) to minimize inflows and groundwater impacts, restr...

  9. Seepage into PEP tunnel

    Weidner, H.

    1990-01-01

    The current rate of seepage into the PEP tunnel in the vicinity of IR-10 is very low compared to previous years. Adequate means of handling this low flow are in place. It is not clear whether the reduction in the flow is temporary, perhaps due to three consecutive dry years, or permanent due to drainage of a perched water table. During PEP construction a large amount of effort was expended in attempts to seal the tunnel, with no immediate effect. The efforts to ''manage'' the water flow are deemed to be successful. By covering equipment to protect it from dripping water and channeling seepage into the drainage gutters, the seepage has been reduced to a tolerable nuisance. There is no sure, safe procedure for sealing a leaky shotcreted tunnel

  10. Uncooled tunneling infrared sensor

    Kenny, Thomas W. (Inventor); Kaiser, William J. (Inventor); Podosek, Judith A. (Inventor); Vote, Erika C. (Inventor); Muller, Richard E. (Inventor); Maker, Paul D. (Inventor)

    1995-01-01

    An uncooled infrared tunneling sensor in which the only moving part is a diaphragm which is deflected into contact with a micromachined silicon tip electrode prepared by a novel lithographic process. Similarly prepared deflection electrodes employ electrostatic force to control the deflection of a silicon nitride, flat diaphragm membrane. The diaphragm exhibits a high resonant frequency which reduces the sensor's sensitivity to vibration. A high bandwidth feedback circuit controls the tunneling current by adjusting the deflection voltage to maintain a constant deflection of the membrane. The resulting infrared sensor can be miniaturized to pixel dimensions smaller than 100 .mu.m. An alternative embodiment is implemented using a corrugated membrane to permit large deflection without complicated clamping and high deflection voltages. The alternative embodiment also employs a pinhole aperture in a membrane to accommodate environmental temperature variation and a sealed chamber to eliminate environmental contamination of the tunneling electrodes and undesireable accoustic coupling to the sensor.

  11. To study the role of dynamic magnetic resonance imaging in assessing the femoral head vascularity in intracapsular femoral neck fractures

    Kaushik, Abhishek, E-mail: abhiortho27@gmail.co [Department of Orthopedics, 513, Thermal Colony, Sector-22, Faridabad 121005, Haryana (India); Sankaran, Balu; Varghese, Mathew [Department of Orthopedics, St Stephen' s Hospital, Tis hazari, Delhi, New Delhi 110054 (India)

    2010-09-15

    Intracapsular femoral neck fractures remain unsolved fractures even after improvement in techniques of diagnosis and internal fixation. Individuals who sustain displaced femoral neck fractures are at high risk of developing avascular necrosis and non-union. Although several methods for predicting the viability of femoral head have been reported, they are not effective or widely used because of unreliability, potential complications and technical difficulties. Dynamic MRI was introduced in the recent past as a simple, non-invasive technique to predict the femoral head viability after the femoral neck fractures. In this study role of dynamic MRI was studied in 30 patients with 31 intracapsular femoral neck fractures. Fractures were divided in to three types according to dynamic curve patterns on MRI evaluation and were followed up for 6 months to 2 years to observe the final outcome. Sensitivity, Specificity and the Accuracy of dynamic MRI in predicting vascularity after femoral neck fracture are 87%, 88% and 87%, respectively. Type A or Type B curve pattern is a positive factor to successful osteosynthesis with p value <0.0001 (Chi-square test). This is a statistically significant value. From this finding it can be suggested that the reliability of dynamic curves A and B in predicting maintained vascularity of femoral head is high. This investigation can be used to predict the vascularity of femoral head after intracapsular femoral neck fractures. There was a good correlation between the outcomes of fractures and dynamic MRI curves done within 48 h of injury. This signifies the role of dynamic MRI in predicting the vascularity of femoral head as early as 48 h. A treatment algorithm can be suggested on the basis of dynamic MRI curves. The fractures with Type C dynamic curve should be considered as fractures with poor vascularity of femoral head and measures to enhance the vascularity of femoral head along with rigid internal fixation should be undertaken to promote

  12. To study the role of dynamic magnetic resonance imaging in assessing the femoral head vascularity in intracapsular femoral neck fractures

    Kaushik, Abhishek; Sankaran, Balu; Varghese, Mathew

    2010-01-01

    Intracapsular femoral neck fractures remain unsolved fractures even after improvement in techniques of diagnosis and internal fixation. Individuals who sustain displaced femoral neck fractures are at high risk of developing avascular necrosis and non-union. Although several methods for predicting the viability of femoral head have been reported, they are not effective or widely used because of unreliability, potential complications and technical difficulties. Dynamic MRI was introduced in the recent past as a simple, non-invasive technique to predict the femoral head viability after the femoral neck fractures. In this study role of dynamic MRI was studied in 30 patients with 31 intracapsular femoral neck fractures. Fractures were divided in to three types according to dynamic curve patterns on MRI evaluation and were followed up for 6 months to 2 years to observe the final outcome. Sensitivity, Specificity and the Accuracy of dynamic MRI in predicting vascularity after femoral neck fracture are 87%, 88% and 87%, respectively. Type A or Type B curve pattern is a positive factor to successful osteosynthesis with p value <0.0001 (Chi-square test). This is a statistically significant value. From this finding it can be suggested that the reliability of dynamic curves A and B in predicting maintained vascularity of femoral head is high. This investigation can be used to predict the vascularity of femoral head after intracapsular femoral neck fractures. There was a good correlation between the outcomes of fractures and dynamic MRI curves done within 48 h of injury. This signifies the role of dynamic MRI in predicting the vascularity of femoral head as early as 48 h. A treatment algorithm can be suggested on the basis of dynamic MRI curves. The fractures with Type C dynamic curve should be considered as fractures with poor vascularity of femoral head and measures to enhance the vascularity of femoral head along with rigid internal fixation should be undertaken to promote

  13. Surgery for pathological proximal femoral fractures, excluding femoral head and neck fractures: resection vs. stabilisation.

    Zacherl, Max; Gruber, Gerald; Glehr, Mathias; Ofner-Kopeinig, Petra; Radl, Roman; Greitbauer, Manfred; Vecsei, Vilmos; Windhager, Reinhard

    2011-10-01

    Pathological femoral head and neck fractures are commonly treated by arthroplasty. Treatment options for the trochanteric region or below are not clearly defined. The purpose of this retrospective, comparative, double-centre study was to analyse survival and influences on outcome according to the surgical technique used to treat pathological proximal femoral fractures, excluding fractures of the femoral head and neck. Fifty-nine patients with 64 fractures were operated up on between 1998 and 2004 in two tertiary referral centres and divided into two groups. One group (S, n = 33) consisted of patients who underwent intramedullary nailing alone, and the other group (R, n = 31) consisted of patients treated by metastatic tissue resection and reconstruction by means of different implants. Median survival was 12.6 months with no difference between groups. Surgical complications were higher in the R group (n = 7) vs. the S group (n = 3), with no statistically significant difference. Patients with surgery-related complications had a higher survival rate (p = 0.049), as did patients with mechanical implant failure (p = 0.01). Survival scoring systems did not correlate with actual survival. Resection of metastases in patients with pathological fractures of the proximal femur, excluding femoral head and neck fractures, has no influence on survival. Patients with long postoperative survival prognosis are at risk of implant-related complications.

  14. Self-designed femoral neck guide pin locator for femoral neck fractures.

    Xia, Shengli; Wang, Ziping; Wang, Minghui; Wu, Zuming; Wang, Xiuhui

    2014-01-01

    Closed reduction and fixation with 3 cannulated screws is a widely accepted surgery for the treatment of femoral neck fractures. However, how to obtain optimal screw placement remains unclear. In the current study, the authors designed a guide pin positioning system for femoral neck fracture cannulated screw fixation and examined its application value by comparing it with freehand guide needle positioning and with general guide pin locator positioning provided by equipment manufacturers. The screw reset rate, screw parallelism, triangle area formed by the link line of the entry point of 3 guide pins, and maximum vertical load bearing of the femoral neck after internal fixation were recorded. As expected, the triangle area was largest in the self-designed positioning group, followed by the general positioning group and the freehand positioning group. The difference among the 3 groups was statistically significant (P.05). The authors’ self-designed guide pin positioning system has the potential to accurately insert cannulated screws in femoral neck fractures and may reduce bone loss and unnecessary radiation.

  15. Instabilities in thin tunnel junctions

    Konkin, M.K.; Adler, J.G.

    1978-01-01

    Tunnel junctions prepared for inelastic electron tunneling spectroscopy are often plagued by instabilities in the 0-500-meV range. This paper relates the bias at which the instability occurs to the barrier thickness

  16. Press-fit Femoral Fixation in ACL Reconstruction using Bone-Patellar Tendon-Bone Graft

    Kaseb Mohammad Hasan

    2009-05-01

    Full Text Available Bone-patellar tendon auto graft is probably the most widely used graft for ACL reconstruction. Several methods for graft fixation have been described. To avoid intra-articular hardware we adopt biological fixation with a femoral trapezoidal press-fit fixation. A prospective study was performed on 30 consecutive active people who underwent ACL reconstruction with this technique by two surgeons between september2004 and march2007 (mean follow-up 15.2 months. Results were evaluated by an independent examiner using radiography, subjective and objective evaluation. Assessment using the IKDC knee scoring revealed 92% of the patients with a normal or nearly normal knee joint. Lysholm's score was 63.6(40- 86 preoperatively and 91.88(73-100 at the latest follow up (P < 0.005. No patient complained of instability at latest follow up. The quadriceps muscle showed mild atrophy at 3 and 6 months and at final follow-up. Five Patients complained of anterior knee pain and had a positive kneeling test. We found no graft displacement on follow up radiographs. All cases showed radiological evidence of graft osteointegration at last follow up. Our results show that press-fit fixation of trapezoidal bone graft in femoral tunnel is a simple, reliable, and cost-effective alternative for ACL recon-struction using bone-patellar tendon-bone graft.

  17. Biogeometry of femoral neck for implant placement

    Patwa J

    2006-01-01

    Full Text Available Background : Treatment of fracture neck femur with three cannulated cancellous screws in an apex proximal configuration is practised in many parts of the world. Methods : Dimensions of femoral neck at the middle of transcervical neck using CT scan (live neck and vernier caliper (dry cadeveric neck in 20 subjects respectively were measured. Results : Inferior half of the neck is narrower than superior half. Conclusion : Biogeometry of the neck of femur does not accomodate two inferior screws and thus fixation of fracture neck femur with three canulated cancellous screws in an apex distal configuration is recommended.

  18. Superficial femoral artery: current treatment options

    Tepe, Gunnar; Schmehl, Joerg; Heller, Stephan; Wiesinger, Benjamin; Claussen, Claus D.; Duda, Stephan H.

    2006-01-01

    Treatment of the superficial femoral artery (SFA) has been among the least effective of all endovascular procedures in terms of long-term patency. The relatively small vessel lumen, in conjunction with a high plaque burden, slow flow, and a high frequency of primary occlusions, contributes to a considerable rate of acute technical failures. Because of these technical limitations a much effort has been made during the past years. This manuscript should summarize the hopes and limitations of different approaches such as brachytherapy, cutting balloons, stents and stent grafts, drug-eluting stents, and drug-coated balloons. (orig.)

  19. [Treatment of avascular necrosis of femoral head after femoral neck fracture with pedicled iliac bone graft].

    Wang, Benjie; Zhao, Dewei; Guo, Lin; Yang, Lei; Li, Zhigang; Cui, Daping; Tian, Fengde; Liu, Baoyi

    2011-05-01

    To explore the effectiveness of pedicled iliac bone graft transposition for treatment of avascular necrosis of femoral head (ANFH) after femoral neck fracture. Between June 2002 and December 2006, 22 cases (22 hips, 16 left hips and 6 right hips) of ANFH after femoral neck fracture were treated with iliac bone graft pedicled with ascending branch of the lateral femoral circumflex vessels. There were 18 males and 4 females with an age range from 28 to 48 years (mean, 37.5 years). The time from injury to internal fixation was 2-31 days, and all fractures healed within 12 months after internal fixation. The ANFH was diagnosed at 15-40 months (mean, 22 months) after internal fixation. The ANFH duration was 3-11 months (mean, 8 months). According to Association Research Circulation Osseous (ARCO) staging system, 2 hips were classified as stage IIa, 3 hips as stage IIb, 3 hips as stage IIc, 3 hips as stage IIIa, 7 hips as stage IIIb, and 4 hips as stage IIIc. The preoperative Harris hip score (HHS) was 64.10 +/- 5.95. All incisions healed by first intention and the patients had no complication of lung embolism, sciatic nerve injury, lower limb deep venous thrombosis, and numbness and pain of donor site. All patients were followed up 2.5 to 6.3 years (mean, 4.8 years). The fracture healing time was 8-12 months, and no femoral neck fracture recurred. The HHS was 90.20 +/- 5.35 at last follow-up, showing significant difference when compared with the preoperative value (t = -18.447, P = 0.000). The hip function were excellent in 11 hips, good in 10 hips, fair in 1 hip, and the excellent and good rate was 95.5%. Four hips were radiographically progressed in ARCO staging, 18 hips remained stable with a stable rate of 81.8%. Pedicled iliac bone graft transposition is an ideal option for treatment of ANFH after internal fixation of femoral neck fracture for the advantages of femoral head revascularization, sufficient cancellous bone supply, and relatively simple procedure.

  20. Tunneling in axion monodromy

    Brown, Jon; Cottrell, William; Shiu, Gary; Soler, Pablo [Department of Physics, University of Wisconsin,Madison, WI 53706 (United States)

    2016-10-06

    The Coleman formula for vacuum decay and bubble nucleation has been used to estimate the tunneling rate in models of axion monodromy in recent literature. However, several of Coleman’s original assumptions do not hold for such models. Here we derive a new estimate with this in mind using a similar Euclidean procedure. We find that there are significant regions of parameter space for which the tunneling rate in axion monodromy is not well approximated by the Coleman formula. However, there is also a regime relevant to large field inflation in which both estimates parametrically agree. We also briefly comment on the applications of our results to the relaxion scenario.

  1. LEP tunnel monorail

    1985-01-01

    A monorail from CERN's Large Electron Positron collider (LEP, for short). It ran around the 27km tunnel, transporting equipment and personnel. With its 27-kilometre circumference, LEP was the largest electron-positron accelerator ever built and ran from 1989 to 2000. During 11 years of research, LEP's experiments provided a detailed study of the electroweak interaction. Measurements performed at LEP also proved that there are three – and only three – generations of particles of matter. LEP was closed down on 2 November 2000 to make way for the construction of the Large Hadron Collider in the same tunnel.

  2. Excavating a transfer tunnel

    Laurent Guiraud

    2000-01-01

    The transfer tunnel being dug here will take the 450 GeV beam from the SPS and inject it into the LHC where the beam energies will be increased to 7 TeV. In order to transfer this beam from the SPS to the LHC, two transfer tunnels are used to circulate the beams in opposite directions. When excavated, the accelerator components, including magnets, beam pipes and cryogenics will be installed and connected to both the SPS and LHC ready for operation to begin in 2008.

  3. Gap anisotropy and tunneling currents. [MPS3

    Lazarides, N.; Sørensen, Mads Peter

    1996-01-01

    The tunneling Hamiltonian formalism is applied to calculate the tunnelingcurrents through a small superconducting tunnel junction. The formalism isextended to nonconstant tunneling matrix elements. The electrodes of thejunction are assumed to......The tunneling Hamiltonian formalism is applied to calculate the tunnelingcurrents through a small superconducting tunnel junction. The formalism isextended to nonconstant tunneling matrix elements. The electrodes of thejunction are assumed to...

  4. Breaking through the tranfer tunnel

    Laurent Guiraud

    2001-01-01

    This image shows the tunnel boring machine breaking through the transfer tunnel into the LHC tunnel. Proton beams will be transferred from the SPS pre-accelerator to the LHC at 450 GeV through two specially constructed transfer tunnels. From left to right: LHC Project Director, Lyn Evans; CERN Director-General (at the time), Luciano Maiani, and Director for Accelerators, Kurt Hubner.

  5. Control of tunneling in heterostructures

    Volokhov, V M; Tovstun, C A; Ivlev, B

    2007-01-01

    A tunneling current between two rectangular potential wells can be effectively controlled by applying an external ac field. A variation of the ac frequency by 10% may lead to the suppression of the tunneling current by two orders of magnitude, which is a result of quantum interference under the action of the ac field. This effect of destruction of tunneling can be used as a sensitive control of tunneling current across nanosize heterostructures

  6. Ivar Giaever, Tunneling, and Superconductors

    dropdown arrow Site Map A-Z Index Menu Synopsis Ivar Giaever, Tunneling, and Superconductors Resources with in Superconductors Measured by Electron Tunneling; Physical Review Letters, Vol. 5 Issue 4: 147 - 148 ; August 15, 1960 Electron Tunneling Between Two Superconductors; Physical Review Letters, Vol. 5 Issue 10

  7. Scanning tunneling microscope nanoetching method

    Li, Yun-Zhong; Reifenberger, Ronald G.; Andres, Ronald P.

    1990-01-01

    A method is described for forming uniform nanometer sized depressions on the surface of a conducting substrate. A tunneling tip is used to apply tunneling current density sufficient to vaporize a localized area of the substrate surface. The resulting depressions or craters in the substrate surface can be formed in information encoding patterns readable with a scanning tunneling microscope.

  8. Physics of optimal resonant tunneling

    Racec, P.N.; Stoica, T.; Popescu, C.; Lepsa, M.I.; Roer, van de T.G.

    1997-01-01

    The optimal resonant tunneling, or the complete tunneling transparence of a biased double-barrier resonant-tunneling (DBRT) structure, is discussed. It is shown that its physics does not rest on the departure from the constant potential within the barriers and well, due to the applied electric

  9. CT Assessment of the axial deviation of the femoral and tibial prosthetic components in total knee arthroplasty

    Rimondi, E.; Molinari, M.; Moio, A.; Busacca, M.; Trentani, F.; Trentani, P.; Tigani, D.; Nigrosoli, M.

    2000-01-01

    CT assessment of the axial deviation of the femoral and tibial prosthetic components in total knee arthroplasty. From January to July 1999, 17 patients, 10 males and 7 females, mean age 66 years (standard deviation plus or minus 4) were examined after total knee arthroplasty. Exclusion criteriawere prosthesis loosening and severe (equal or superior to 7'' varus o valgus deviation. All patients were examined with knee radiography in the standing position completed by axial projection of patella and by CT scanning. It was used a modification of Berger technique and carried out comparative CT scans extended lower limbs and acquisitions perpendicular to the mechanical axis of the knee, from the femoral supracondylar region down to the plane crossing the distal end of the tibial prosthetic component. Reference lines were then drawn electronically on given scanning planes to reckon the axial deviation of the femoral and tibial prosthetic components. Six patients, one female and 5 males with normal rotational values of femoral and tibial prosthetic components presented no clinical symptoms. Eight patients, 4 females and 4 males, with abnormal values presented the following clinical symptoms: medial impingement, (incomplete) dislocation patella, and lateral instability. One female patient with a normal rotational value of femoral prosthetic component and an altered value of tibial prosthetic component presented medial impingement. Finally two patients, one female and one male, were absolutely asymptomatic although the rotational values of the two prosthetic components were beyond the normal range. Total knee arthroplasty is presently a standard treatment for many conditions involving this joint. There are several possible postoperative complications, namely fractures, dislocations (a)septic losening and femoropatellar instability. The latter condition is the most frequent complication among implant failures and is caused by bad orientation of the femoral and tibial

  10. Comparison of Radial Access, Guided Femoral Access, and Non-Guided Femoral Access Among Women Undergoing Percutaneous Coronary Intervention.

    Koshy, Linda M; Aberle, Laura H; Krucoff, Mitchell W; Hess, Connie N; Mazzaferri, Ernest; Jolly, Sanjit S; Jacobs, Alice; Gibson, C Michael; Mehran, Roxana; Gilchrist, Ian C; Rao, Sunil V

    2018-01-01

    This study was conducted to determine the association between radial access, guided femoral access, and non-guided femoral access on postprocedural bleeding and vascular complications after percutaneous coronary intervention (PCI). Bleeding events and major vascular complications after PCI are associated with increased morbidity, mortality, and cost. While the radial approach has been shown to be superior to the femoral approach in reducing bleeding and vascular complications, whether the use of micropuncture, fluoroscopy, or ultrasound mitigates these differences is unknown. We conducted a post hoc analysis of women in the SAFE-PCI for Women trial who underwent PCI and had the access method identified (n = 643). The primary endpoint of postprocedure bleeding or vascular complications occurring within 72 hours or at discharge was adjudicated by an independent clinical events committee and was compared based on three categories of access technique: radial, guided femoral (fluoroscopy, micropuncture, ultrasound), or non-guided femoral (none of the aforementioned). Differences between the groups were determined using multivariate logistic regression using radial access as the reference. Of the PCI population, 330 underwent radial access, 228 underwent guided femoral access, and 85 underwent non-guided femoral access. There was a statistically significant lower incidence of the primary endpoint with radial access vs non-guided femoral access; however, there was no significant difference between radial approach and femoral access guided by fluoroscopy, micropuncture, or ultrasound. This post hoc analysis demonstrates that while radial access is safer than non-guided femoral access, guided femoral access appears to be associated with similar bleeding events or vascular complications as radial access.

  11. Current indications for open Kuntscher nailing of femoral shaft ...

    Current indications for open Kuntscher nailing of femoral shaft fractures. A S Bajwa FCS(SA)ORTH. E Schnaid FCS(SA)ORTH. M E B Sweet MD PhD(rned). University of Witwatersrand, Johannesburg, South Africa. Key Words: Kuntscher nail, intramedullary nail, femoral fracture. We retrospectively reviewed 32 patients with.

  12. Bilateral impacted femoral neck fracture in a renal disease patient ...

    Spontaneous bilateral femoral neck facture in a renal disease patient is not common. We report a case of 47-year-old female patient with chronic renal failure and on regular hemodialysis for the past 5 years who sustained bilateral impacted femoral neck fracture without history of trauma and injury and refused any surgical ...

  13. Slipped capital femoral epiphysis: A modern treatment protocol

    Slavković Nemanja

    2009-01-01

    Full Text Available The treatment of a patient with slipped capital femoral epiphysis begins with an early diagnosis and accurate classification. On the basis of symptom duration, clinical findings and radiographs, slipped capital femoral epiphysis is classified as pre-slip, acute, acute-on-chronic and chronic. The long-term outcome of slipped capital femoral epiphysis is directly related to severity and the presence or absence of avascular necrosis and/or chondrolysis. Therefore, the first priority in the treatment of slipped capital femoral epiphysis is to avoid complications while securing the epiphysis from further slippage. Medical treatment of patients with acute and acute-on-chronic slipped capital femoral epiphysis, as well as those presented in pre-slip stage, is the safest, although time-consuming. Manipulations, especially forced and repeated, are not recommended due to higher avascular necrosis risk. The use of intraoperative fluoroscopy to assist in the placement of internal fixation devices has markedly increased the success of surgical treatment. Controversy remains as to whether the proximal femoral epiphysis in severe, chronic slipped capital femoral epiphysis should be realigned by extracapsular osteotomies or just fixed in situ. The management protocol for slipped capital femoral epiphysis depends on the experience of the surgeon, motivation of the patient and technical facilities.

  14. Femoral neck fractures: A prospective assessment of the pattern ...

    OBJECTIVE: To review the pattern of femoral neck fractures, complications and outcome following fixation with Austin-Moore endoprosthesis. METHOD: A two year prospective study in patients who had fracture of the femoral neck based on strict inclusion criteria. All the patients were treated by Austin-Moore ...

  15. Femoral bifurcation with ipsilateral tibia hemimelia: Early outcome of ...

    Hereby, we present a case report of a 2-year-old boy who first presented in our orthopedic clinic as a 12-day-old neonate, with a grossly deformed right lower limb from a combination of complete tibia hemimelia and ipsilateral femoral bifurcation. Excision of femoral exostosis, knee disarticulation and prosthetic fitting gives ...

  16. Proximal Focal Femoral Deficiency in Ibadan a Developing ...

    The cultural aversion to amputation in our environment makes it difficult to employ that option of treatment. Proximal focal femoral deficiency in Ibadan a developing country's perspective and a review of the literature. Keywords: Proximal focal femoral deficiency , congenital malformations , limb malformations , lower limb ...

  17. [Treatment of femoral neck fracture--preference to internal fixation].

    Minato, Izumi

    2011-03-01

    In the guidelines for the treatment of femoral neck fracture, prosthetic replacement is recommended in displaced one and internal fixation is in undisplaced one. However, in the long view, survived femoral head after internal fixation can be superior to prosthesis which will deteriorate as time goes by. Surgical method should be considered not only by type of fracture but general status of the patient.

  18. Tunneling path toward spintronics

    Miao Guoxing; Moodera, Jagadeesh S; Muenzenberg, Markus

    2011-01-01

    The phenomenon of quantum tunneling, which was discovered almost a century ago, has led to many subsequent discoveries. One such discovery, spin polarized tunneling, was made 40 years ago by Robert Meservey and Paul Tedrow (Tedrow and Meservey 1971 Phys. Rev. Lett. 26 192), and it has resulted in many fundamental observations and opened up an entirely new field of study. Until the mid-1990s, this field developed at a steady, low rate, after which a huge increase in activity suddenly occurred as a result of the unraveling of successful spin tunneling between two ferromagnets. In the past 15 years, several thousands of papers related to spin polarized tunneling and transport have been published, making this topic one of the hottest areas in condensed matter physics from both fundamental science and applications viewpoints. Many review papers and book chapters have been written in the past decade on this subject. This paper is not exhaustive by any means; rather, the emphases are on recent progress, technological developments and informing the reader about the current direction in which this topic is moving.

  19. Magnetic Fluxtube Tunneling

    Dahlburg, Russell B.; Antiochos,, Spiro K.; Norton, D.

    1996-01-01

    We present numerical simulations of the collision and subsequent interaction of two initially orthogonal, twisted, force free field magnetic fluxtubes. The simulations were carried out using a new three dimensional explicit parallelized Fourier collocation algorithm for solving the viscoresistive equations of compressible magnetohydrodynamics. It is found that, under a wide range of conditions, the fluxtubes can 'tunnel' through each other. Two key conditions must be satisfied for tunneling to occur: the magnetic field must be highly twisted with a field line pitch much greater than 1, and the magnetic Lundquist number must be somewhat large, greater than or equal to 2880. This tunneling behavior has not been seen previously in studies of either vortex tube or magnetic fluxtube interactions. An examination of magnetic field lines shows that tunneling is due to a double reconnection mechanism. Initially orthogonal field lines reconnect at two specific locations, exchange interacting sections and 'pass' through each other. The implications of these results for solar and space plasmas are discussed.

  20. Tunnel nitrogen spill experiment

    Ageyev, A.I.; Alferov, V.N.; Mulholland, G.T.

    1983-01-01

    The Energy Saver Safety Analysis Report (SAR) found the tunnel oxygen deficiency considerations emphasized helium spills. These reports concluded the helium quickly warms and because of its low denisty, rises to the apex of the tunnel. The oxygen content below the apex and in all but the immediate vicinity of the helium spill is essentially unchanged and guarantees an undisturbed source of oxygen especially important to fallen personnel. In contrast nitrogen spills warm slower than helium due to the ratio of the enthalpy changes per unit volume spilled spread more uniformly across the tunnel cross-section when warmed because of the much smaller density difference with air, and generally provides a greater hazard than helium spills as a result. In particular there was concern that personnel that might fall to the floor for oxygen deficiency or other reasons might find less, and not more, oxygen with dire consequences. The SAR concluded tunnel nitrogen spills were under-investigated and led to this work

  1. The scanning tunneling microscope

    Salvan, F.

    1986-01-01

    A newly conceived microscope, based on a pure quantum phenomenon, is an ideal tool to study atom by atom the topography and properties of surfaces. Applications are presented: surface ''reconstruction'' of silicon, lamellar compound study, etc... Spectroscopy by tunnel effect will bring important information on electronic properties; it is presented with an application on silicon [fr

  2. Supramolecular tunneling junctions

    Wimbush, K.S.

    2012-01-01

    In this study a variety of supramolecular tunneling junctions were created. The basis of these junctions was a self-assembled monolayer of heptathioether functionalized ß-cyclodextrin (ßCD) formed on an ultra-flat Au surface, i.e., the bottom electrode. This gave a well-defined hexagonally packed

  3. Tunnelling determined superconducting energy gap of bulk single crystal aluminum

    Civiak, R.L.

    1974-01-01

    A procedure has been developed for fabricating Giaver tunnel junctions on bulk aluminum. Al-I-Ag junctions were prepared, where I is the naturally formed oxide on the polished, chemically treated aluminum surface. The aluminum energy gap was determined from tunneling conductance curves obtained from samples oriented in three different crystal directions, and as a function of magnetic field in each of these orientations. In contrast to the results of microwave absorption measurements on superconducting aluminum, no magnetic field dependence could be measured for either the average gap or the spread in gap values of the tunneling electrons. This is consistent with commonly accepted tunneling selection rules, and Garfunkel's interpretation of the microwave behavior which depended upon adjusting the energy spectrum of only the electrons traveling parallel to the surface in the presence of a magnetic field. The energy gaps measured for samples oriented in the 100, 110 and 111 directions are 3.52, 3.50 and 3.39 kT/sub c/, respectively. The trend in the anisotropy is the same as in the calculation of Leavens and Carbotte, however, the magnitude of the anisotropy is smaller than in their calculation and that which previous measurements have indicated

  4. Magnetic resonance imaging of the femoral head necrosis

    Narita, Shinya; Asada, Kanji; Yoshida, Kenjiro and others

    1986-06-01

    Ten patients with avascular femoral head necrosis and four normal adults were examined by magnetic resonance imaging (MRI). In addition, the relationship between MRI and pathophysiology of three operated-on avascular femoral heads was evaluated. The medullary cavities of the normal femoral heads had a strong signal intensity on the saturation recovery (SR) image due to fat marrow, and the T/sub 1/ relaxation time was 160 +- 11 msec. In avascular femoral head necrosis, the necrotic area had a low signal intensity on the SR image and a prolonged T/sub 1/ relaxation time, while the reactive fibrous area had more prolonged T/sub 1/ relaxation time. For these reasons, MRI was found to show the pathological changes of avascular femoral head necrosis and can be expected to be useful for making early diagnoses and operation planning.

  5. Magnetic resonance imaging of the femoral head necrosis

    Narita, Shinya; Asada, Kanji; Yoshida, Kenjiro

    1986-01-01

    Ten patients with avascular femoral head necrosis and four normal adults were examined by magnetic resonance imaging (MRI). In addition, the relationship between MRI and pathophysiology of three operated-on avascular femoral heads was evaluated. The medullary cavities of the normal femoral heads had a strong signal intensity on the saturation recovery (SR) image due to fat marrow, and the T 1 relaxation time was 160 ± 11 msec. In avascular femoral head necrosis, the necrotic area had a low signal intensity on the SR image and a prolonged T 1 relaxation time, while the reactive fibrous area had more prolonged T 1 relaxation time. For these reasons, MRI was found to show the pathological changes of avascular femoral head necrosis and can be expected to be useful for making early diagnoses and operation planning. (author)

  6. Monitoring pilot projects on bored tunnelling : The Second Heinenoord Tunnel and the Botlek Rail Tunnel

    Bakker, K.J.; De Boer, F.; Admiraal, J.B.M.; Van Jaarsveld, E.P.

    1999-01-01

    Two pilot projects for bored tunnelling in soft soil have been undertaken in the Netherlands. The monitoring was commissioned under the authority of the Centre for Underground Construction (COB). A description of the research related to the Second Heinenoord Tunnel and the Botlek Rail Tunnel will be

  7. Morpho-functional study of ionizing radiation effects on the rabbits` femoral vein; Avaliacao morfofuncional do efeito da radiacao ionizante sobre a veia femoral. Estudo experimental em coelhos

    Sakiyama, Mauro Yoshimitsu

    1996-12-31

    In this study we evaluate the effects of the ionizing radiation on the rabbits femoral vein. The samples of femoral vein were obtained from 56 New Zealand rabbits, male with ageing from 90 to 120 days, that were divided into 4 groups of 14 animals: one control group non-irradiated and three animal groups sacrificed 2 days, 14 days and 90 days after irradiation. In the three irradiated rabbits groups, each animal received the total dose 4000 cGy (rads) divided in 10 sessions of 400 cGy, a dose equivalent that utilized on clinical therapeutic. A morpho functional study of vein samples was carried out with: light microscopy: stained by hematoxin - eosin, Masson`s tricromic, and Verhoeff. Immunohistochemical: reactions of immunoperoxidase with monoclonal mouse anti-human endothelial cell factor CD-31 and anti-human Von Willebrand factor (factor VIII), to study the vein endothelium. Histomorphometry of elastic fiber system stained by Weigert`s resorcin-fuchsin with and without prior oxidation with oxone; for the study of mature, elaunin or pre-mature and oxytalan or young elastic fibers. Electronic microscopy: transmission and scanning. With the methodology utilized we observe changes in the femoral vein of the animals submitted to irradiation in relation to the control group, thus described: there is formation of vacuoles between the endothelium and the basal membrane, called sub endothelial vacuoles, in focal areas. The factor VIII and CD-31 endothelial antigens are preserved with no changes in their functions. Focal alterations are present in the endothelial surface with disorder in the setting and orientation of the endothelial cells. there is degeneration of the elastic fibers with significant decrease in their quantity in the stage, 2 days and 14 days after irradiation. There is increase in the quantity of elastic fibers in the late stage, 90 days after irradiation, tending to normality. In this present study, the changes described are not accompanied by venous

  8. Morpho-functional study of ionizing radiation effects on the rabbits` femoral vein; Avaliacao morfofuncional do efeito da radiacao ionizante sobre a veia femoral. Estudo experimental em coelhos

    Sakiyama, Mauro Yoshimitsu

    1995-12-31

    In this study we evaluate the effects of the ionizing radiation on the rabbits femoral vein. The samples of femoral vein were obtained from 56 New Zealand rabbits, male with ageing from 90 to 120 days, that were divided into 4 groups of 14 animals: one control group non-irradiated and three animal groups sacrificed 2 days, 14 days and 90 days after irradiation. In the three irradiated rabbits groups, each animal received the total dose 4000 cGy (rads) divided in 10 sessions of 400 cGy, a dose equivalent that utilized on clinical therapeutic. A morpho functional study of vein samples was carried out with: light microscopy: stained by hematoxin - eosin, Masson`s tricromic, and Verhoeff. Immunohistochemical: reactions of immunoperoxidase with monoclonal mouse anti-human endothelial cell factor CD-31 and anti-human Von Willebrand factor (factor VIII), to study the vein endothelium. Histomorphometry of elastic fiber system stained by Weigert`s resorcin-fuchsin with and without prior oxidation with oxone; for the study of mature, elaunin or pre-mature and oxytalan or young elastic fibers. Electronic microscopy: transmission and scanning. With the methodology utilized we observe changes in the femoral vein of the animals submitted to irradiation in relation to the control group, thus described: there is formation of vacuoles between the endothelium and the basal membrane, called sub endothelial vacuoles, in focal areas. The factor VIII and CD-31 endothelial antigens are preserved with no changes in their functions. Focal alterations are present in the endothelial surface with disorder in the setting and orientation of the endothelial cells. there is degeneration of the elastic fibers with significant decrease in their quantity in the stage, 2 days and 14 days after irradiation. There is increase in the quantity of elastic fibers in the late stage, 90 days after irradiation, tending to normality. In this present study, the changes described are not accompanied by venous

  9. Outcomes of trochanteric femoral fractures treated with proximal femoral nail: an analysis of 100 consecutive cases

    Korkmaz MF

    2014-04-01

    Full Text Available Mehmet Fatih Korkmaz,1 Mehmet Nuri Erdem,2 Zeliha Disli,3 Engin Burak Selcuk,4 Mustafa Karakaplan,1 Abdullah Gogus5 1Department of Orthopedics and Traumatology, Inonu University School of Medicine, Malatya, Turkey; 2Department of Orthopedics and Traumatology, Nisantasi University School of Medicine, Istanbul, Turkey; 3Department of Anesthesiology, Malatya Government Hospital, Malatya, Turkey; 4Department of Family Medicine, Inonu University School of Medicine, Malatya, Turkey; 5Department of Orthopedics and Traumatology, Florence Nightingale Hospital, Istanbul, Turkey Purpose: In this study, we aimed to report the results of a retrospective study carried out at our institute regarding cases of patients who had suffered proximal femoral fractures between January 2002 and February 2007, and who were treated with a proximal femoral nail. Materials and methods: One hundred consecutive cases were included in the study. A case documentation form was used to obtain intraoperative data including age, sex, mechanism of injury, type of fracture according to Association for Osteosynthesis/Association for the Study of Internal Fixation (AO/ASIF classification and the American Society of Anesthesiologists' (ASA physical status classification (ASA grade. Clinical and radiographic examinations were performed at the time of admission and at the 6th week; subsequent visits were organized on the 3rd month, 6th month, and 12th month, and in patients with longer follow-up and annually postoperatively. The Harris score of hip function was used, and any change in the position of the implants and the progress of the fracture union, which was determined radiologically, was noted. Results: The mean age of the patients was 77.66 years (range: 37–98 years, and the sex distribution was 32 males and 68 females. Seventy-three fractures were reduced by closed means, whereas 27 needed limited open reduction. The mean follow-up time for the study group was 31.3 months (range

  10. Macroscopic quantum tunneling in Mn12-acetat

    Beiter, J.; Reissner, M.; Hilscher, G.; Steiner, W.; Pajic, D.; Zadro, K.; Bartel, M.; Linert, W.

    2004-01-01

    Molecules provide the exciting opportunity to study magnetism on the passage from atomic to macroscopic level. One of the most interesting effects in such mesoscopic systems is the appearance of quantum tunnelling of magnetization (MQT) at low temperatures. In the last decade molecular chemistry has had a large impact in this field by providing new single molecule magnets. They consist of small clusters exhibiting superparamagnetic behavior, similar to that of conventional nanomagnetic particles. The advantage of these new materials is that they form macroscopic samples consisting of regularly arranged small identical high-spin clusters which are widely separated by organic molecules. The lack of distributions in size and shape of the magnetic clusters and the very weak intercluster interaction lead in principle to only one barrier for the spin reversal. We present detailed magnetic investigations on a Mn 12 -ac single crystal. In this compound the tetragonal ordered clusters consist of a central tetrahedron of four Mn 4+ (S = 3/2) atoms surrounded by eight Mn 3+ (S = 2) atoms with antiparallel oriented spins, leading to an overall spin moment of S = 10. In the hysteresis loops nine different jumps at regularly spaced fields are identified in the investigated temperature range (1.5 < T < 3 K). At these fields the relaxation of moment due to thermal activation is superimposed by strong quantum tunnelling. In lowering the temperature the time dependence changes from thermally activated to thermally assisted tunnelling. (author)

  11. Measuring fire size in tunnels

    Guo, Xiaoping; Zhang, Qihui

    2013-01-01

    A new measure of fire size Q′ has been introduced in longitudinally ventilated tunnel as the ratio of flame height to the height of tunnel. The analysis in this article has shown that Q′ controls both the critical velocity and the maximum ceiling temperature in the tunnel. Before the fire flame reaches tunnel ceiling (Q′ 1.0), Fr approaches a constant value. This is also a well-known phenomenon in large tunnel fires. Tunnel ceiling temperature shows the opposite trend. Before the fire flame reaches the ceiling, it increases very slowly with the fire size. Once the flame has hit the ceiling of tunnel, temperature rises rapidly with Q′. The good agreement between the current prediction and three different sets of experimental data has demonstrated that the theory has correctly modelled the relation among the heat release rate of fire, ventilation flow and the height of tunnel. From design point of view, the theoretical maximum of critical velocity for a given tunnel can help to prevent oversized ventilation system. -- Highlights: • Fire sizing is an important safety measure in tunnel design. • New measure of fire size a function of HRR of fire, tunnel height and ventilation. • The measure can identify large and small fires. • The characteristics of different fire are consistent with observation in real fires

  12. Coherent tunnelling conductance in normal-metal/d-wave superconductor/normal-metal double tunnel junctions

    Dong, Z C; Zheng, Z M; Xing, D Y

    2004-01-01

    Taking simultaneously into account the electron-injected current from one normal-metal (N) electrode and the hole-injected current from the other N electrode, we study the coherent tunnelling conductance and quantum interference effects in N/d-wave superconductor (S)/N double tunnel junctions. It is found that oscillations of all quasiparticle transport coefficients and the conductance spectrum with quasiparticle energy and thickness of the d-wave S depend to a great extent on the crystal orientation of the d-wave S. The zero-bias conductance peak is gradually lowered with increasing barrier strength and/or temperature, its magnitude exhibiting damped oscillatory behaviour with thickness of S

  13. Proximal tibial fracture following anterior cruciate ligament reconstruction surgery: a biomechanical analysis of the tibial tunnel as a stress riser.

    Aldebeyan, Wassim; Liddell, Antony; Steffen, Thomas; Beckman, Lorne; Martineau, Paul A

    2017-08-01

    This is the first biomechanical study to examine the potential stress riser effect of the tibial tunnel or tunnels after ACL reconstruction surgery. In keeping with literature, the primary hypothesis tested in this study was that the tibial tunnel acts as a stress riser for fracture propagation. Secondary hypotheses were that the stress riser effect increases with the size of the tunnel (8 vs. 10 mm), the orientation of the tunnel [standard (STT) vs. modified transtibial (MTT)], and with the number of tunnels (1 vs. 2). Tibial tunnels simulating both single bundle hamstring graft (8 mm) and bone-patellar tendon-bone graft (10 mm) either STT or MTT position, as well as tunnels simulating double bundle (DB) ACL reconstruction (7, 6 mm), were drilled in fourth-generation saw bones. These five experimental groups and a control group consisting of native saw bones without tunnels were loaded to failure on a Materials Testing System to simulate tibial plateau fracture. There were no statistically significant differences in peak load to failure between any of the groups, including the control group. The fracture occurred through the tibial tunnel in 100 % of the MTT tunnels (8 and 10 mm) and 80 % of the DB tunnels specimens; however, the fractures never (0 %) occurred through the tibial tunnel of the standard tunnels (8 or 10 mm) (P = 0.032). In the biomechanical model, the tibial tunnel does not appear to be a stress riser for fracture propagation, despite suggestions to the contrary in the literature. Use of a standard, more vertical tunnel decreases the risk of ACL graft compromise in the event of a fracture. This may help to inform surgical decision making on ACL reconstruction technique.

  14. The difference in centre position in the ACL femoral footprint inclusive and exclusive of the fan-like extension fibres.

    Iriuchishima, Takanori; Ryu, Keinosuke; Aizawa, Shin; Fu, Freddie H

    2016-01-01

    The purpose of this study was to compare the centre position of each anterior cruciate ligament bundle in its femoral footprint in measurements including and excluding the fan-like extension fibres. Fourteen non-paired human cadaver knees were used. All soft tissues around the knee were resected except the ligaments. The ACL was divided into antero-medial (AM) and postero-lateral (PL) bundles according to the difference in tension patterns. The ACL was carefully dissected, and two outlines were made of the periphery of each bundle insertion site: those which included and those which excluded the fan-like extension fibres. An accurate lateral view of the femoral condyle was photographed with a digital camera, and the images were downloaded to a personal computer. The centre position of each bundle, including and excluding the fan-like extension fibres, was measured with ImageJ software (National Institution of Health). Evaluation of the centre position was performed using the modified quadrant method. The centre of the femoral AM bundle including the fan-like extension was located at 28.8% in a shallow-deep direction and 37.2% in a high-low direction. When the AM bundle was evaluated without the fan-like extension, the centre was significantly different at 34.6% in a shallow-deep direction (p = 0.000) and 36% in a high-low direction. The centre of the PL bundle including the fan-like extension was found at 37.1% in a shallow-deep direction and 73.4% in a high-low direction. When the PL bundle was evaluated without the fan-like extension, the centre was significantly different at 42.7% in a shallow-deep direction (p = 0.000) and 69.3% in a high-low direction (p = 0.000). The centre position of the AM and PL bundles in the femoral ACL footprint was significantly different depending on the inclusion or exclusion of the fan-like extension fibres. For the clinical relevance, to reproduce the direct femoral insertion in the anatomical ACL reconstruction, tunnels should be

  15. Outcomes of trochanteric femoral fractures treated with proximal femoral nail: an analysis of 100 consecutive cases.

    Korkmaz, Mehmet Fatih; Erdem, Mehmet Nuri; Disli, Zeliha; Selcuk, Engin Burak; Karakaplan, Mustafa; Gogus, Abdullah

    2014-01-01

    In this study, we aimed to report the results of a retrospective study carried out at our institute regarding cases of patients who had suffered proximal femoral fractures between January 2002 and February 2007, and who were treated with a proximal femoral nail. One hundred consecutive cases were included in the study. A case documentation form was used to obtain intraoperative data including age, sex, mechanism of injury, type of fracture according to Association for Osteosynthesis/Association for the Study of Internal Fixation (AO/ASIF) classification and the American Society of Anesthesiologists' (ASA) physical status classification (ASA grade). Clinical and radiographic examinations were performed at the time of admission and at the 6th week; subsequent visits were organized on the 3rd month, 6th month, and 12th month, and in patients with longer follow-up and annually postoperatively. The Harris score of hip function was used, and any change in the position of the implants and the progress of the fracture union, which was determined radiologically, was noted. The mean age of the patients was 77.66 years (range: 37-98 years), and the sex distribution was 32 males and 68 females. Seventy-three fractures were reduced by closed means, whereas 27 needed limited open reduction. The mean follow-up time for the study group was 31.3 months (range: 12-75 months). Postoperative radiographs showed a near-anatomical fracture reduction in 78% of patients. The Harris hip score was negatively correlated with the ASA score and patient age. No cases of implant failure were observed. Three patients died before discharge (one due to pulmonary embolism, two due to cardiac arrest), and five patients died due to unrelated medical conditions within the first 3 months of the follow-up. Our study showed that proximal femoral nail is a reliable fixation with good fracture union, and it is not associated with major complications in any type of trochanteric femoral fracture.

  16. Avascular necrosis of the femoral head after osteosynthesis of femoral neck fracture.

    Min, Byung-Woo; Kim, Sung-Jin

    2011-05-18

    The reported incidence of avascular necrosis after femoral neck fracture fixation varies widely, and there is no consensus regarding its risk factors. We evaluated the incidence of avascular necrosis of the femoral head with the use of contemporary techniques for femoral neck fracture fixation. We then sought to determine what potential risk factors influenced the development of avascular necrosis.Between 1990 and 2005, one hundred sixty-three intracapsular femoral neck fractures in 163 patients were treated with internal fixation at our level-I trauma center. All patients were monitored until conversion to total hip arthroplasty or for a minimum of 2 years postoperatively. Ten patients (10 hips) died and 7 patients (7 hips) were lost to follow-up. The remaining 146 patients (146 hips) had a mean 5.2 years of follow-up (range, 3 months to 17 years). The incidence of avascular necrosis was 25.3% (37 hips). The average time to diagnosis of avascular necrosis was 18.8 months (range, 3-47 months). Patient sex, age, interval from injury to surgery, and mechanism of injury were statistically not associated with the development of avascular necrosis. The quality of fracture reduction, adequacy of fixation, degree of displacement, and comminution of the posterior cortex were significantly associated. After we controlled for patient and radiographic characteristics, multivariate analyses indicated that the important predictors for avascular necrosis are poor reduction (odds ratio=13.889) and initial displacement of the fracture (odds ratio=4.693). Copyright 2011, SLACK Incorporated.

  17. Analysis of slipped capital femoral epiphysis

    Magid, D.; Fishman, E.K.; Sponseller, P.D.; Griffin, P.P.

    1988-01-01

    CT with multiplanar reconstruction (CT/MPR) was used to assess 25 adolescents with known or suspected slipped capital femoral epiphysis (SCFE). CT/MPR localizes the epiphysis in three planes, establishing its relationship to the acetabulum and the metaphyseal neck. MPR facilitates measurements of head-neck angles, residusal head-neck contact, and relative retrovision. CT/MPR may establish the true age of the epiphyseal failure and can reveal subtle SCFE in the face of normal plain films. Patients often present with confusing histories; clues to the true age of failure include subtle signs of healing, remodeling, or new bone buttressing. Characterization of acute versus chronic conditions influences preoperative planning. Postoperatively, CT/MPR confirms early results and follows epiphyseal fusion and remodelling. It also detects complications, such as pin or graft migration avascular necrosis (AVN), or chondrolysis

  18. Femoral neck buttressing: a radiographic and histologic analysis

    Dixon, T.; Benjamin, J.; Lund, P.; Graham, A.; Krupinski, E.

    2000-01-01

    Objective. To examine the incidence, radiographic and histologic findings of medial femoral neck buttressing in a consecutive group of patients undergoing total hip arthroplasty.Design. Biomechanical parameters were evaluated on standard anteroposterior pelvic radiographs of 113 patients prior to hip replacement surgery. Demographic information on all patients was reviewed and histologic evaluation was performed on specimens obtained at the time of surgery.Results. The incidence of medial femoral neck buttressing was found to be 50% in a consecutive series of patients undergoing total hip arthroplasty. The incidence was slightly higher in women (56% vs 41%). Patients with buttressing had increased neck-shaft angles and smaller femoral neck diameters than were seen in patients without buttressing. Histologic evaluation demonstrated that the buttress resulted from deposition bone by the periosteum on the femoral neck in the absence of any evidence of femoral neck fracture.Conclusion. It would appear that femoral neck buttressing occurs in response to increased joint reactive forces seen at the hip being transmitted through the femoral neck. The increased joint reactive force can be related to the increased neck shaft angle seen in patients with buttressing. (orig.)

  19. Clinical study on 44 cases of femoral hernia

    Yamamoto, Ryo; Shinozaki, Hiroharu; Kase, Kenichi; Kobayashi, Kenji; Sasaki, Junichi

    2012-01-01

    Femoral hernia is a surgical disease that is frequently associated with incarceration and necessitates emergency surgery. However, there are only a few studies referred which have compared emergency and elective surgery for femoral hernias. We retrospectively reviewed the clinical characteristics of patients diagnosed as having femoral hernia between 2005 and 2009 in our institution. The clinical features of emergency repairs were compared with those of elective ones, and diagnostic values of preoperative diagnostic modalities were studied. The mean age of the patients was 73±12 years. Females comprised 68% of the cases, and right femoral hernias comprised 70% of the cases. Incarceration was associated with 66% of the cases (29 patients), and emergency surgery was performed in 52% of the patients (23 patients). Bowel resection was performed in 32% of the cases (14 patients). The mean age, body temperature, white blood cell (WBC) count, and LDH value were higher in the emergency repairs than in the elective one, and most of the hernias were repaired with McVay's procedure. CT scans had a high diagnostic value in detecting femoral hernias (44%) and incarceration (88%). It was confirmed that femoral hernias were frequently associated with incarceration and CT scan has a high diagnostic value in femoral hernias. (author)

  20. Simultaneous avascular necrosis of both medial and lateral femoral condyles

    Mansberg, R.

    2002-01-01

    Full text: Avascular necrosis (AVN) of a femoral condyle is a common orthopaedic condition. While both medial and lateral femoral condyles may be involved either singly or sequentially the simultaneous occurrence of AVN of both femoral condyles is extremely uncommon. A 57-year-old male is presented who developed the onset of severe left sided knee pain suddenly at rest. Plain and tomographic radiography was unremarkable and a bone scan was performed. Markedly increased vascularity was demonstrated in the left knee with intense osteoblastic activity in the left medial and femoral condyles more marked in the lateral femoral condyle. A diagnosis of AVN of both femoral condyles was made and a MRI exam was performed to confirm this unusual diagnosis. The MRI showed a diffuse increase in intensity bilaterally with subtle bony change in the subarticular bone consistent with AVN more marked in the left lateral femoral condyle. The patients' symptoms resolved with supportive treatment. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  1. Tunnel boring machine applications

    Bhattacharyya, K.K.; McDonald, R.; Saunders, R.S.

    1992-01-01

    This paper reports that characterization of Yucca Mountain for a potential repository requires construction of an underground Exploratory Studies Facility (ESF). Mechanical excavating methods have been proposed for construction of the ESF as they offer a number of advantages over drilling and blasting at the Yucca Mountain site, including; less ground disturbance and therefore a potential for less adverse effects on the integrity of the site, creation of a more stable excavation cross section requiring less ground support, and an inherently safer and cleaner working environment. The tunnel boring machine (TBM) provides a proven technology for excavating the welded and unwelded Yucca Mountain tuffs. The access ramps and main underground tunnels form the largest part of the ESF underground construction work, and have been designed for excavation by TBM

  2. Programmable ferroelectric tunnel memristor

    Andy eQuindeau

    2014-02-01

    Full Text Available We report an analogously programmable memristor based on genuine electronic resistive switching combining ferroelectric switching and electron tunneling. The tunnel current through an 8 unit cell thick epitaxial Pb(Zr[0.2]Ti[0.8]O[3] film sandwiched between La[0.7]Sr[0.3]MnO[3] and cobalt electrodes obeys the Kolmogorov-Avrami-Ishibashi model for bidimensional growth with a characteristic switching time in the order of 10^-7 seconds. The analytical description of switching kinetics allows us to develop a characteristic transfer function that has only one parameter viz. the characteristic switching time and fully predicts the resistive states of this type of memristor.

  3. Orienteering club

    Club d'orientation

    2015-01-01

    Course d'orientation La reprise des courses d’orientation était attendue dans la région puisque près de 150 coureurs ont participé à la première épreuve automnale organisée par le club d’orientation du CERN sur le site de La Faucille. Les circuits ont été remportés par Yann Locatelli du club d’Orientation Coeur de Savoie avec 56 secondes d’avance sur Damien Berguerre du club SOS Sallanches pour le parcours technique long, Marie Vuitton du club CO CERN (membre également de l’Equipe de France Jeune) pour le parcours technique moyen avec presque 4 minutes d’avance sur Jeremy Wichoud du club Lausanne-Jorat, Victor Dannecker pour le circuit technique court devant Alina Niggli, Elliot Dannecker pour le facile moyen et Alice Merat sur le facile court, tous membres du club O’Jura. Les résultats comp...

  4. Oriental cholangiohepatitis

    Scheible, F.W.; Davis, G.B.; California Univ., San Diego, La Jolla

    1981-01-01

    The recent influx of immigrants from Southeast Asia into the United States has increased the likelihood of encountering unusual diseases heretofore rarely seen in this country. Among these disorders is Oriental cholangiohepatitis, a potentially life-threatening process whose early diagnosis is facilitated by roentgenographic findings. Ultrasonography can also provide useful information, although potential pitfalls in diagnosis should be recognized. (orig.)

  5. Oriental cholangiohepatitis

    Scheible, F.W.; Davis, G.B.

    1981-07-15

    The recent influx of immigrants from Southeast Asia into the United States has increased the likelihood of encountering unusual diseases heretofore rarely seen in this country. Among these disorders is Oriental cholangiohepatitis, a potentially life-threatening process whose early diagnosis is facilitated by roentgenographic findings. Ultrasonography can also provide useful information, although potential pitfalls in diagnosis should be recognized.

  6. Hawking Radiation As Tunneling

    Parikh, Maulik K.; Wilczek, Frank

    2000-01-01

    We present a short and direct derivation of Hawking radiation as a tunneling process, based on particles in a dynamical geometry. The imaginary part of the action for the classically forbidden process is related to the Boltzmann factor for emission at the Hawking temperature. Because the derivation respects conservation laws, the exact spectrum is not precisely thermal. We compare and contrast the problem of spontaneous emission of charged particles from a charged conductor

  7. Tunnel blasting - recent developments

    White, T.E.

    1999-05-01

    While tunnelling machines are more efficient than previously, there are still areas where blasting is a more efficient method of advance. Drilling and design methods are increasingly sophisticated, as is choice of explosive. Explosive deployment must be carefully calculated so as to avoid desensitisation. Nitroglycerine may be used as slurries; bulk mixing on site of ANFO is also practised in mining in the UK. Electric detonators, Nonel tubes, and electronic detonators are also increasingly employed.

  8. The beam dump tunnels

    Patrice Loïez

    2002-01-01

    In these images workers are digging the tunnels that will be used to dump the counter-circulating beams. Travelling just a fraction under the speed of light, the beams at the LHC will each carry the energy of an aircraft carrier travelling at 12 knots. In order to dispose of these beams safely, a beam dump is used to extract the beam and diffuse it before it collides with a radiation shielded graphite target.

  9. Primary Tunnel Junction Thermometry

    Pekola, Jukka P.; Holmqvist, Tommy; Meschke, Matthias

    2008-01-01

    We describe the concept and experimental demonstration of primary thermometry based on a four-probe measurement of a single tunnel junction embedded within four arrays of junctions. We show that in this configuration random sample specific and environment-related errors can be avoided. This method relates temperature directly to Boltzmann constant, which will form the basis of the definition of temperature and realization of official temperature scales in the future

  10. Treatment of the femoral neck peudoarthrosis in childhood: Case report

    Vukašinović Zoran

    2013-01-01

    Full Text Available Introduction. Femoral neck fractures in children and adolescents are rare. However, their complications are frequent - avascular necrosis, femoral neck pseudoarthrosis, premature physeal closure with consequent growth disturbance and coxa vara deformity. Case Outline. A 9.5­year­old boy was injured in a car accident, and femoral neck fracture was diagnosed. Prior to admission at our hospital he was surgically treated several times. He was admitted at our hospital eight months following the accident. On the X­ray transcervical pseudoarthrosis of the femoral neck was found, as well as coxa vara deformity and metaphyseal avascular necrosis. He was operated at our hospital; all previously placed ostefixation material was removed, valgus osteotomy of 30 degrees was done as well as additional local osteoplasty using the commercial osteoindactive agent (Osteovit®. Postoperatively, we applied skin traction, bed rest and physical therapy. At the final follow­up, the patient was recovered completely. He is now painless, the legs are of equal length, range of movements in the left hip is full, life activity is normal. The X­ray shows that the femoral neck pseudoarthrosis is fully healed. Conclusion. This case is presented in order to encourage other colleagues to challenge the problematic situation such as this one. Also, we would like to remind them what one should think about and what should be taken into consideration in the primary treatment of femoral neck fractures in children. Valgus femoral osteotomy, as a part of the primary treatment of femoral neck fracture in children (identically as in the adults can prevent the occurrence of femoral neck pseudoarthrosis.

  11. Hydrodynamic optical soliton tunneling

    Sprenger, P.; Hoefer, M. A.; El, G. A.

    2018-03-01

    A notion of hydrodynamic optical soliton tunneling is introduced in which a dark soliton is incident upon an evolving, broad potential barrier that arises from an appropriate variation of the input signal. The barriers considered include smooth rarefaction waves and highly oscillatory dispersive shock waves. Both the soliton and the barrier satisfy the same one-dimensional defocusing nonlinear Schrödinger (NLS) equation, which admits a convenient dispersive hydrodynamic interpretation. Under the scale separation assumption of nonlinear wave (Whitham) modulation theory, the highly nontrivial nonlinear interaction between the soliton and the evolving hydrodynamic barrier is described in terms of self-similar, simple wave solutions to an asymptotic reduction of the Whitham-NLS partial differential equations. One of the Riemann invariants of the reduced modulation system determines the characteristics of a soliton interacting with a mean flow that results in soliton tunneling or trapping. Another Riemann invariant yields the tunneled soliton's phase shift due to hydrodynamic interaction. Soliton interaction with hydrodynamic barriers gives rise to effects that include reversal of the soliton propagation direction and spontaneous soliton cavitation, which further suggest possible methods of dark soliton control in optical fibers.

  12. Resonant Tunneling Spin Pump

    Ting, David Z.

    2007-01-01

    The resonant tunneling spin pump is a proposed semiconductor device that would generate spin-polarized electron currents. The resonant tunneling spin pump would be a purely electrical device in the sense that it would not contain any magnetic material and would not rely on an applied magnetic field. Also, unlike prior sources of spin-polarized electron currents, the proposed device would not depend on a source of circularly polarized light. The proposed semiconductor electron-spin filters would exploit the Rashba effect, which can induce energy splitting in what would otherwise be degenerate quantum states, caused by a spin-orbit interaction in conjunction with a structural-inversion asymmetry in the presence of interfacial electric fields in a semiconductor heterostructure. The magnitude of the energy split is proportional to the electron wave number. Theoretical studies have suggested the possibility of devices in which electron energy states would be split by the Rashba effect and spin-polarized currents would be extracted by resonant quantum-mechanical tunneling.

  13. Ipsilateral femoral shaft and vertical patella fracture: a case report

    Ozkan, Korhan; Eceviz, Engin; Sahin, Adem; Ugutmen, Ender

    2009-01-01

    Introduction A femoral shaft fracture with an ipsilateral patella fracture has been, to our knowledge, given only cursory attention in English-speaking literature. Case presentation A 15 year old male patient had hitten by a car to his motorcycle came to emergency room and he had been operated for his femoral shaft freacture and vertical patellar fracture which was iniatally missed. Conclusion To us it is vital to obtain CT scan of the patient’s knee if there is an ipsilateral femoral fracture with an ipsilateral knee effusion and a punction which reveals hematoma even in the absence of a fracture line seen in AP and lateral projections. PMID:19829933

  14. Aneurysm of the superficial femoral artery in an infant

    Watanabe, M.; Komuro, H.; Matoba, K.; Kaneko, M. [Dept. of Paediatric Surgery, Inst. of Clinical Medicine, Univ. of Tsukuba, Ibaraki (Japan); Niitsu, M.; Itai, Y. [Dept. of Radiology, Inst. of Clinical Medicine, Univ. of Tsukuba, Ibaraki (Japan)

    2003-04-01

    An isolated arterial aneurysm in childhood is extremely rare. We report a 1-year-old girl with an aneurysm of the right superficial femoral artery, presenting as an asymptomatic mass of the thigh. The aneurysm involved the whole superficial femoral artery (9 cm in length), and surgical treatment would have required replacement of the affected artery. Conservative treatment was chosen, influenced by the patient's rapid growth at that time. Non-invasive, 3-D contrast-enhanced magnetic resonance angiography (MRA) was useful as an alternative to conventional angiography for detailed evaluation of the femoral arteries, including the aneurysm. (orig.)

  15. Avascular osteonecrosis of the femoral condyle after arthroscopic surgery

    Al-Kaar, M.; Garcia, J.; Fritschy, D.; Bonvin, J.C.

    1997-01-01

    Avascular osteonecrosis of the femoral condyle after arthroscopic surgery. Retrospective review of 10 patients who presented with avascular necrosis of the ipsilateral femoral condyle following arthroscopic meniscectomy (9 medial, 1 lateral). The bone lesions were evaluated by radiography and MRI, which were repeated for few patients. MRI allows earlier diagnosis of avascular necrosis of the femoral condyle and offers an evaluation of extent of the lesions whose evolution is variable: 3 patients required a knee prosthesis, the other 7 patients were treated medically. (authors)

  16. Femoral artery pseudoaneurysm as a complication of angioplasty. How can it be prevented?

    Gupta, Prabha Nini; Salam Basheer, Abdul; Sukumaran, Gireesh Gomaty; Padmajan, Sabin; Praveen, Satheesan; Velappan, Praveen; Nair, Bigesh Unnikrishnan; Nair, Sandeep Govindan; Kunjuraman, Usha Kumari; Madthipat, Unnikrishnan; R, Jayadevan

    2013-01-01

    Femoral pseudoaneurysm is a common complication of repeated femoral puncture during cardiac catheterisation. We describe here the development of femoral pseudoaneurysms in a patient with Takayasu's arteritis, which healed in response to conservative treatment, and review the literature on the prevention and treatment of femoral pseudoaneurysm. PMID:27326111

  17. ONKALO 3D tunnel seismic investigations at Olkiluoto in 2009

    Cosma, C.; Enescu, N.; Balu, L.; Jacome, M.

    2011-02-01

    POSIVA Oy conducts bedrock investigations at the spent nuclear fuel final disposal site at Olkiluoto, in western Finland. The excavation of the access tunnel to the repository hosts the ONKALO underground rock characterization facility. The investigations carried out at ONKALO focus on the bedrock and groundwater conditions prevailing on the final disposal site and how construction work affects them. Tunnel seismic investigations were carried out in July 2009, as an extension of similar work performed in December 2007. The main objective of the tunnel seismic investigations have been to demonstrate the possibility to detect, locate and image cost effectively steeply and gently dipping fractures, at the side and/or below the tunnel and to characterize the volume of rock surrounding a 250 m long segment of the ONKALO tunnel. The survey was conducted at a depth of 350 m, over a 240 m long line of 3-components receivers, spaced at 3m intervals. Seismic signals were produced along two lines, on the tunnel wall and floor, with source points spaced at 1m. A timedistributed swept-impact, the Vibsist-250 hydraulic source, was used. The source was hosted on a mini excavator. Receiver holes approximately 0.4 m deep were drilled prior to the survey, horizontally into the tunnel wall. One of the procedures used for data stacking and migration is based on a proprietary method combining the DMO (Dip Move Out) correction and an expression of the Radon Transform. Horizontal and vertical migrated profiles were computed both for the P wave and S wave reflected wave fields. A true 3D migration technique (Image Point migration) was used to create 3D migrated sections oriented to incremental azimuths around the tunnel, the result being a cylindrical imaging volume. A general conclusion is that seismic surveys along the tunnel can economically be used for rock mass characterization. High quality results can be obtained by operations in tunnel working conditions, provided that due

  18. Submucosal tunneling techniques: current perspectives.

    Kobara, Hideki; Mori, Hirohito; Rafiq, Kazi; Fujihara, Shintaro; Nishiyama, Noriko; Ayaki, Maki; Yachida, Tatsuo; Matsunaga, Tae; Tani, Johji; Miyoshi, Hisaaki; Yoneyama, Hirohito; Morishita, Asahiro; Oryu, Makoto; Iwama, Hisakazu; Masaki, Tsutomu

    2014-01-01

    Advances in endoscopic submucosal dissection include a submucosal tunneling technique, involving the introduction of tunnels into the submucosa. These tunnels permit safer offset entry into the peritoneal cavity for natural orifice transluminal endoscopic surgery. Technical advantages include the visual identification of the layers of the gut, blood vessels, and subepithelial tumors. The creation of a mucosal flap that minimizes air and fluid leakage into the extraluminal cavity can enhance the safety and efficacy of surgery. This submucosal tunneling technique was adapted for esophageal myotomy, culminating in its application to patients with achalasia. This method, known as per oral endoscopic myotomy, has opened up the new discipline of submucosal endoscopic surgery. Other clinical applications of the submucosal tunneling technique include its use in the removal of gastrointestinal subepithelial tumors and endomicroscopy for the diagnosis of functional and motility disorders. This review suggests that the submucosal tunneling technique, involving a mucosal safety flap, can have potential values for future endoscopic developments.

  19. Avascular osteonecrosis of the femoral condyle after arthroscopic surgery; Osteonecrose aseptique du condyle femoral apres meniscectomie par voie arthroscopique

    Al-Kaar, M.; Garcia, J. [Hopital Cantonal Geneve, Geneva (Switzerland); Fritschy, D.; Bonvin, J.C. [Policlinique de Chirurgie, Hopital Cantonal Universitaire, Geneve (Switzerland)

    1997-04-01

    Avascular osteonecrosis of the femoral condyle after arthroscopic surgery. Retrospective review of 10 patients who presented with avascular necrosis of the ipsilateral femoral condyle following arthroscopic meniscectomy (9 medial, 1 lateral). The bone lesions were evaluated by radiography and MRI, which were repeated for few patients. MRI allows earlier diagnosis of avascular necrosis of the femoral condyle and offers an evaluation of extent of the lesions whose evolution is variable: 3 patients required a knee prosthesis, the other 7 patients were treated medically. (authors). 21 refs.

  20. Semiclassical description of resonant tunneling

    Bogomolny, E.B.; Rouben, D.C.

    1996-01-01

    A semiclassical formula is calculated for the tunneling current of electrons trapped in a potential well which can tunnel into and across a wide quantum well. The tunneling current is measured at the second interface of this well and the calculations idealized an experimental situation where a strong magnetic field tilted with respect to an electric field was used. It is shown that the contribution to the tunneling current, due to trajectories which begin at the first interface and end on the second, is dominant for periodic orbits which hit both walls of the quantum well. (author)

  1. Orientation Club

    Club d'orientation

    2014-01-01

    COURSE ORIENTATION Résultats de samedi 10 mai    C’est sur une carte entièrement réactualisée dans les bois de Versoix, que plus de 100 coureurs sont venus participer à la course d’orientation, type longue distance, préparée par des membres du club du CERN. Le terrain plutôt plat nécessitait une orientation à grande vitesse, ce qui a donné les podiums suivants :  Technique long avec 17 postes : 1er Jurg Niggli, O’Jura en 52:48, 2e Beat Muller, COLJ Lausanne-Jorat en 58:02, 3e Christophe Vuitton, CO CERN en 58:19 Technique moyen avec 13 postes : 1er Jean-Bernard Zosso, CO CERN, en 46:05 ; 2e Yves Rousselot, Balise 25 Besançon, en 55:11 ; 3e Laurent Merat, O'Jura, en 55:13 Technique court avec 13 postes : 1er Julien Vuitton, CO CERN en 40:59, 2e Marc Baumgartner, CO CERN en 43:18, 3e Yaelle Mathieu en 51:42 Su...

  2. Orienteering Club

    Club d'orientation

    2013-01-01

    Courses d’orientation ce printemps Le Club d’orientation du CERN vous invite à venir découvrir la course d’orientation et vous propose, en partenariat avec d’autres clubs de la région, une dizaine de courses populaires. Celles-ci ont lieu les samedis après-midi, elles sont ouvertes à tous, quel que soit le niveau, du débutant au sportif confirmé, en famille ou en individuel, en promenade ou en course. Si vous êtes débutant vous pouvez profiter d’une petite initiation offerte par l’organisateur avant de vous lancer sur un parcours. Divers types de parcours sont à votre choix lors de chaque épreuve : facile court (2-3 km), facile moyen (3-5 km), technique court (3-4 km), technique moyen (4-5 km) et technique long (5-7 km). Les dates à retenir sont les suivantes : Samedi 23 mars: Pully (Vd) Samedi 13 avril: Pougny...

  3. Topography-specific isotropic tunneling in nanoparticle monolayer with sub-nm scale crevices.

    Wang, Guisheng; Jiao, Weihong; Yi, Lizhi; Zhang, Yuejiao; Wu, Ke; Zhang, Chao; Lv, Xianglong; Qian, Lihua; Li, Jianfeng; Yuan, Songliu; Chen, Liang

    2016-10-07

    Material used in flexible devices may experience anisotropic strain with identical magnitude, outputting coherent signals that tend to have a serious impact on device reliability. In this work, the surface topography of the nanoparticles (NPs) is proposed to be a parameter to control the performance of strain gauge based on tunneling behavior. In contrast to anisotropic tunneling in a monolayer of spherical NPs, electron tunneling in a monolayer of urchin-like NPs actually exhibits a nearly isotropic response to strain with different loading orientations. Isotropic tunneling of the urchin-like NPs is caused by the interlocked pikes of these urchin-like NPs in a random manner during external mechanical stimulus. Topography-dependent isotropic tunneling in two dimensions reported here opens a new opportunity to create highly reliable electronics with superior performance.

  4. early functional outcome of distal femoral fractures at kenyatta

    The leading cause was RTA, followed by falls from a height. ... Distal femoral fractures cause considerable morbidity .... as means and standard deviations. .... Anaesthesia. Spinal. 37 (80). General Anaesthesia (GA). 9 (20). Transfusion.

  5. Femoral neck fractures complicating gaucher disease in children

    Goldman, A.B.; Jacobs, B.

    1984-09-01

    In normal children, fractures of the femoral neck are uncommon and accompany severe trauma and multiple injuries elsewhere in the skeleton. In children with Gaucher disease, a rare hereditary disorder of lipid metabolism, midcervical or basicervical fractures can occur with minor or no trauma and without other injury to the skeleton. Three children with Gaucher disease who developed pathologic fractures of the femoral neck are described. In all three, the fractures occurred between five and nine years of age, and the fracture lines passed through areas of abnormal bone characterized by poorly defined patches of increased and decreased density and cortical thinning along the medial femoral necks. In the affected hips, there was no evidence of avascular necrosis of the femoral heads at the time of injury. One child's fracture was preceeded by multiple bone 'crisis' localized to the proximal femora.

  6. Femoral neck fractures complicating gaucher disease in children

    Goldman, A.B.; Jacobs, B.

    1984-01-01

    In normal children, fractures of the femoral neck are uncommon and accompany severe trauma and multiple injuries elsewhere in the skeleton. In children with Gaucher disease, a rare hereditary disorder of lipid metabolism, midcervical or basicervical fractures can occur with minor or no trauma and without other injury to the skeleton. Three children with Gaucher disease who developed pathologic fractures of the femoral neck are described. In all three, the fractures occurred between five and nine years of age, and the fracture lines passed through areas of abnormal bone characterized by poorly defined patches of increased and decreased density and cortical thinning along the medial femoral necks. In the affected hips, there was no evidence of avascular necrosis of the femoral heads at the time of injury. One child's fracture was preceeded by multiple bone 'crisis' localized to the proximal femora. (orig.)

  7. Effectiveness of plate augmentation for femoral shaft nonunion after nailing

    Chin-Jung Lin

    2012-08-01

    Conclusion: Plate augmentation with retention of the nail with autologous bone grafting may be an effective and reliable alternative in treating nonunion of the femoral shaft fracture after open reduction and internal fixation with intramedullary nail.

  8. 'Femoral head necrosis' in metabolic and hormonal osteopathies

    Heuck, F.H.W.; Treugut, H.

    1984-01-01

    The pathogenesis of bone necrosis is discussed with special attention and with respect to metabolic, hormonal, and vascular factors. The influence of statics and dynamics of the hip joint bones for the development of aseptic necrosis are discussed. 45 patients with ''idiopathic femoral head necroses'' were observed, including 6 cases of renal osteopathy following renal transplantation and immune suppression therapy, 14 cases of long term corticoid therapy, and 11 cases of liver diseases of different genesis. The femoral head necrosis understood as complication of an osteopathy. In our patients there were 31 males and 14 females - which means higher involvement of males. Plain radiological findings and CT-findings of changes of the femoral heat structure in different stages of the disease are described. Early diagnosis of metabolic and hormonal osteopathies is demanded for a joint keeping therapy of the beginning femoral head necrosis. (orig.) [de

  9. Short-term outcome of patients with closed comminuted femoral ...

    Short-term outcome of patients with closed comminuted femoral shaft fracture treated with locking intramedullary sign nail at Muhimbili Orthopaedic Institute in Tanzania. Billy T. Haonga, Felix S. Mrita, Edmundo E. Ndalama, Jackline E. Makupa ...

  10. Delayed appearance of hypaesthesia and paralysis after femoral nerve block

    Stefan Landgraeber

    2012-03-01

    Full Text Available We report on a female patient who underwent an arthroscopy of the right knee and was given a continuous femoral nerve block catheter. The postoperative course was initially unremarkable, but when postoperative mobilisation was commenced, 18 hours after removal of the catheter, the patient noticed paralysis and hypaesthesia. Examination confirmed the diagnosis of femoral nerve dysfunction. Colour duplex sonography of the femoral artery and computed tomography of the lumbar spine and pelvis yielded no pathological findings. Overnight the neurological deficits decreased without therapy and were finally no longer detectable. We speculate that during the administration of the local anaesthetic a depot formed, localised in the medial femoral intermuscular septa, which was leaked after first mobilisation. To our knowledge no similar case has been published up to now. We conclude that patients who are treated with a nerve block should be informed and physician should be aware that delayed neurological deficits are possible.

  11. Incidence and predictors of post-catheterization femoral artery pseudoaneurysms

    Hussein Heshmat Kassem

    2013-09-01

    Conclusion: Femoral artery pseudoaneurysms are not uncommon. Female gender, obesity, hypertension, the use of antiplatelet and/or anticoagulant therapy and faulty puncture techniques are independent risk factors for FAPs.

  12. Delayed appearance of hypaesthesia and paralysis after femoral nerve block

    Landgraeber, Stefan; Albrecht, Thomas; Reischuck, Ulrich; von Knoch, Marius

    2012-01-01

    We report on a female patient who underwent an arthroscopy of the right knee and was given a continuous femoral nerve block catheter. The postoperative course was initially unremarkable, but when postoperative mobilisation was commenced, 18 hours after removal of the catheter, the patient noticed paralysis and hypaesthesia. Examination confirmed the diagnosis of femoral nerve dysfunction. Colour duplex sonography of the femoral artery and computed tomography of the lumbar spine and pelvis yielded no pathological findings. Overnight the neurological deficits decreased without therapy and were finally no longer detectable. We speculate that during the administration of the local anaesthetic a depot formed, localised in the medial femoral intermuscular septa, which was leaked after first mobilisation. To our knowledge no similar case has been published up to now. We conclude that patients who are treated with a nerve block should be informed and physician should be aware that delayed neurological deficits are possible. PMID:22577509

  13. Femoral neck fractures complicating gaucher disease in children

    Goldman, A B; Jacobs, B

    1984-09-01

    In normal children, fractures of the femoral neck are uncommon and accompany severe trauma and multiple injuries elsewhere in the skeleton. In children with Gaucher disease, a rare hereditary disorder of lipid metabolism, midcervical or basicervical fractures can occur with minor or no trauma and without other injury to the skeleton. Three children with Gaucher disease who developed pathologic fractures of the femoral neck are described. In all three, the fractures occurred between five and nine years of age, and the fracture lines passed through areas of abnormal bone characterized by poorly defined patches of increased and decreased density and cortical thinning along the medial femoral necks. In the affected hips, there was no evidence of avascular necrosis of the femoral heads at the time of injury. One child's fracture was preceeded by multiple bone 'crisis' localized to the proximal femora.

  14. Tunnelling anomalous and planar Hall effects (Conference Presentation)

    Matos-Abiague, Alex; Scharf, Benedikt; Han, Jong E.; Hankiewicz, Ewelina M.; Zutic, Igor

    2016-10-01

    We theoretically show how the interplay between spin-orbit coupling (SOC) and magnetism can result in a finite tunneling Hall conductance, transverse to the applied bias. For two-dimensional tunnel junctions with a ferromagnetic lead and magnetization perpendicular to the current flow, the detected anomalous Hall voltage can be used to extract information not only about the spin polarization but also about the strength of the interfacial SOC. In contrast, a tunneling current across a ferromagnetic barrier on the surface of a three-dimensional topological insulator (TI) can induce a planar Hall response even when the magnetization is oriented along the current flow[1]. The tunneling nature of the states contributing to the planar Hall conductance can be switched from the ordinary to the Klein regimes by the electrostatic control of the barrier strength. This allows for an enhancement of the transverse response and a giant Hall angle, with the tunneling planar Hall conductance exceeding the longitudinal component. Despite the simplicity of a single ferromagnetic region, the TI/ferromagnet system exhibits a variety of functionalities. In addition to a spin-valve operation for magnetic sensing and storing information, positive, negative, and negative differential conductances can be tuned by properly adjusting the barrier potential and/or varying the magnetization direction. Such different resistive behaviors in the same system are attractive for potential applications in reconfigurable spintronic devices. [1] B. Scharf, A. Matos-Abiague, J. E. Han, E. M. Hankiewicz, and I. Zutic, arXiv:1601.01009 (2016).

  15. Validation of a new classification system for interprosthetic femoral fractures.

    Pires, Robinson Esteves Santos; Silveira, Marcelo Peixoto Sena; Resende, Alessandra Regina da Silva; Junior, Egidio Oliveira Santana; Campos, Tulio Vinicius Oliveira; Santos, Leandro Emilio Nascimento; Balbachevsky, Daniel; Andrade, Marco Antônio Percope de

    2017-07-01

    Interprosthetic femoral fracture (IFF) incidence is gradually increasing as the population is progressively ageing. However, treatment remains challenging due to several contributing factors, such as poor bone quality, patient comorbidities, small interprosthetic fragment, and prostheses instability. An effective and specific classification system is essential to optimize treatment management, therefore diminishing complication rates. This study aims to validate a previously described classification system for interprosthetic femoral fractures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Incidence and predictors of post-catheterization femoral artery pseudoaneurysms

    Kassem, Hussein Heshmat; Elmahdy, Mahmoud Farouk; Ewis, Essam Baligh; Mahdy, Soilman Ghareeb

    2013-01-01

    Background: Femoral artery pseudoaneurysm (FAP) is a troublesome complication after transfemoral catheter procedures. The incidence and predictors of FAP as a separate entity have not been extensively studied. Aim: Detect prospectively the incidence and predictors of post catheterization FAP. Methods: From June 2009 till June 2011, we prospectively included all patients who underwent catheterization from the femoral approach. Duplex ultrasound was performed in cases with clinical suspic...

  17. Mechanical Characterization of Femoral Cartilage Under Unicompartimental Osteoarthritis

    Vidal-Lesso, A.; Ledesma-Orozco, E.; Daza-Benítez, L.; Lesso-Arroyo, R.

    2014-01-01

    The aim of this study was to determine the mechanical properties and thickness of articular cartilage in the unaffected femoral regions in cases of unicompartimental osteoarthritis on the knees. The specimens were tested using a 3mm plane-ended cylindrical indenter and a displacement of 0.5mm was applied at specific points in seven femoral knee cartilages with unicompartimental osteoarthritis. The thickness, stiffness, elastic modulus, shear modulus and bulk modulus were obtained. These prope...

  18. Engineers win award for Swiss tunnel

    2003-01-01

    A Derby engineering consultancy has won the Tunnelling Industry Award 2003 for Excellence in Tunnel Design, offered by the British Tunnelling Society, for its work on the LHC in Geneva, Switzerland (1/2 page).

  19. Thermovoltages in vacuum tunneling investigated by scanning tunneling microscopy

    Hoffmann, D. H.; Rettenberger, Armin; Grand, Jean Yves; Läuger, K.; Leiderer, Paul; Dransfeld, Klaus; Möller, Rolf

    1995-01-01

    By heating the tunneling tip of a scanning tunneling microscope the thermoelectric properties of a variable vacuum barrier have been investigated. The lateral variation of the observed thermovoltage will be discussed for polycrystalline gold, stepped surfaces of silver, as well as for copper islands on silver.

  20. OUTCOME OF INTERTROCHANTERIC FRACTURES TREATED WITH SHORT FEMORAL NAIL

    Yadkikar Shriniwas V, Yadkikar Vishnu S, Patel Mayank, Dhruvilkumar Gandhi, Kunkulol Rahul

    2015-07-01

    Full Text Available Aim: To study the functional and anatomical outcome of Inter trochanteric fractures of femur treated with Short femoral nail. Method: This was retrospective study carried out in which 60 patients (50 Male & 10 Female of 5th to 8th decade of life who underwent Short femoral nail fixation for both Stable & unstable Inter Trochanteric fractures. From the records each patient data was assessed for time required for mobilization, average fracture healing time, degree and grade of hip range of movements, complications, anatomical reduction achieved using Short femoral nail fixation. Results: 55 cases achieved Anatomical reduction. Good to Excellent Hip range of Motion was in 55 (90 % cases. Fracture union was seen in all cases. No evidence of Z Effect, AVN of femoral head, Implant failure, Fracture of femoral shaft below the Nail tip was seen in any case, However Reverse Z Effect was seen in 4 & shortening of less than 2 cm was seen in 2 cases, External rotation of 10 degree was seen in1 case. Average fracture Union time was 14 weeks. Conclusion: Short femoral nail appears to be better implant for fixation of both Stable & unstable Inter Trochanteric fractures as it fulfills the biomechanical demands being minimally invasive, less blood loss , it prevents excessive varus collapse at fracture site, produces less stress riser effect below the nail tip, Short operative time, Facilitates early mobilization & functional recovery of patients. But Anatomical fracture reduction & optimal implant placement are absolutely must for better results.

  1. Femoral Neck Shaft Angle in Men with Fragility Fractures

    S. P. Tuck

    2011-01-01

    Full Text Available Introduction. Femoral neck shaft angle (NSA has been reported to be an independent predictor of hip fracture risk in men. We aimed to assess the role of NSA in UK men. Methods. The NSA was measured manually from the DXA scan printout in men with hip (62, 31 femoral neck and 31 trochanteric, symptomatic vertebral (91, and distal forearm (67 fractures and 389 age-matched control subjects. Age, height, weight, and BMD (g/cm2: lumbar spine, femoral neck, and total femur measurements were performed. Results. There was no significant difference in mean NSA between men with femoral neck and trochanteric hip fractures, so all further analyses of hip fractures utilised the combined data. There was no difference in NSA between those with hip fractures and those without (either using the combined data or analysing trochanteric and femoral neck shaft fractures separately, nor between fracture subjects as a whole and controls. Mean NSA was smaller in those with vertebral fractures (129.2° versus 131°: P=0.001, but larger in those with distal forearm fractures (129.8° versus 128.5°: P=0.01. Conclusions. The conflicting results suggest that femoral NSA is not an important determinant of hip fracture risk in UK men.

  2. Morpho-functional study of ionizing radiation effects on the rabbits' femoral vein

    Sakiyama, Mauro Yoshimitsu

    1995-01-01

    In this study we evaluate the effects of the ionizing radiation on the rabbits femoral vein. The samples of femoral vein were obtained from 56 New Zealand rabbits, male with ageing from 90 to 120 days, that were divided into 4 groups of 14 animals: one control group non-irradiated and three animal groups sacrificed 2 days, 14 days and 90 days after irradiation. In the three irradiated rabbits groups, each animal received the total dose 4000 cGy (rads) divided in 10 sessions of 400 cGy, a dose equivalent that utilized on clinical therapeutic. A morpho functional study of vein samples was carried out with: light microscopy: stained by hematoxin - eosin, Masson's tricromic, and Verhoeff. Immunohistochemical: reactions of immunoperoxidase with monoclonal mouse anti-human endothelial cell factor CD-31 and anti-human Von Willebrand factor (factor VIII), to study the vein endothelium. Histomorphometry of elastic fiber system stained by Weigert's resorcin-fuchsin with and without prior oxidation with oxone; for the study of mature, elaunin or pre-mature and oxytalan or young elastic fibers. Electronic microscopy: transmission and scanning. With the methodology utilized we observe changes in the femoral vein of the animals submitted to irradiation in relation to the control group, thus described: there is formation of vacuoles between the endothelium and the basal membrane, called sub endothelial vacuoles, in focal areas. The factor VIII and CD-31 endothelial antigens are preserved with no changes in their functions. Focal alterations are present in the endothelial surface with disorder in the setting and orientation of the endothelial cells. there is degeneration of the elastic fibers with significant decrease in their quantity in the stage, 2 days and 14 days after irradiation. There is increase in the quantity of elastic fibers in the late stage, 90 days after irradiation, tending to normality. In this present study, the changes described are not accompanied by venous

  3. Magnetic tunnel junctions with monolayer hexagonal boron nitride tunnel barriers

    Piquemal-Banci, M.; Galceran, R.; Bouzehouane, K.; Anane, A.; Petroff, F.; Fert, A.; Dlubak, B.; Seneor, P. [Unité Mixte de Physique, CNRS, Thales, Univ. Paris-Sud, Université Paris-Saclay, Palaiseau 91767 (France); Caneva, S.; Martin, M.-B.; Weatherup, R. S.; Kidambi, P. R.; Robertson, J.; Hofmann, S. [Department of Engineering, University of Cambridge, Cambridge CB21PZ (United Kingdom); Xavier, S. [Thales Research and Technology, 1 avenue Augustin Fresnel, Palaiseau 91767 (France)

    2016-03-07

    We report on the integration of atomically thin 2D insulating hexagonal boron nitride (h-BN) tunnel barriers into Co/h-BN/Fe magnetic tunnel junctions (MTJs). The h-BN monolayer is directly grown by chemical vapor deposition on Fe. The Conductive Tip Atomic Force Microscopy (CT-AFM) measurements reveal the homogeneity of the tunnel behavior of our h-BN layers. As expected for tunneling, the resistance depends exponentially on the number of h-BN layers. The h-BN monolayer properties are also characterized through integration into complete MTJ devices. A Tunnel Magnetoresistance of up to 6% is observed for a MTJ based on a single atomically thin h-BN layer.

  4. Necrosis de la cabeza femoral tras fractura del cuello femoral tratada mediante osteosíntesis

    Martínez Martín, Angel Antonio; Panisello Sebastiá, Juan José; Lallana Duplá, J.; Herrera Rodríguez, Antonio

    2000-01-01

    Se presenta un análisis retrospectivo de las necrosis aparecidas en 233 pacientes con fractura de cuello femoral fijada con tornillos de esponjosa. La edad media fue de 80,6 años. Setenta y un pacientes (26%) tuvieron una fractura no desplazada (Garden I o II) y 172 (74%) una fractura desplazada (Garden III o IV). Seis meses tras la cirugía 170 pacientes sobrevivían (72,9%). Treinta y cuatro de ellos (20%) habían desarrollado necrosis y 10 (5,9%) colapso. Tras un seguimiento de 12 meses 114 p...

  5. Femoral loading mechanics in the Virginia opossum, Didelphis virginiana: torsion and mediolateral bending in mammalian locomotion.

    Gosnell, W Casey; Butcher, Michael T; Maie, Takashi; Blob, Richard W

    2011-10-15

    Studies of limb bone loading in terrestrial mammals have typically found anteroposterior bending to be the primary loading regime, with torsion contributing minimally. However, previous studies have focused on large, cursorial eutherian species in which the limbs are held essentially upright. Recent in vivo strain data from the Virginia opossum (Didelphis virginiana), a marsupial that uses a crouched rather than an upright limb posture, have indicated that its femur experiences appreciable torsion during locomotion as well as strong mediolateral bending. The elevated femoral torsion and strong mediolateral bending observed in D. virginiana might result from external forces such as a medial inclination of the ground reaction force (GRF), internal forces deriving from a crouched limb posture, or a combination of these factors. To evaluate the mechanism underlying the loading regime of opossum femora, we filmed D. virginiana running over a force platform, allowing us to measure the magnitude of the GRF and its three-dimensional orientation relative to the limb, facilitating estimates of limb bone stresses. This three-dimensional analysis also allows evaluations of muscular forces, particularly those of hip adductor muscles, in the appropriate anatomical plane to a greater degree than previous two-dimensional analyses. At peak GRF and stress magnitudes, the GRF is oriented nearly vertically, inducing a strong abductor moment at the hip that is countered by adductor muscles on the medial aspect of the femur that place this surface in compression and induce mediolateral bending, corroborating and explaining loading patterns that were identified in strain analyses. The crouched orientation of the femur during stance in opossums also contributes to levels of femoral torsion as high as those seen in many reptilian taxa. Femoral safety factors were as high as those of non-avian reptiles and greater than those of upright, cursorial mammals, primarily because the load

  6. Combined Radial and Femoral Access Strategy and Radial-Femoral Rendezvous in Patients With Long and Complex Iliac Occlusions.

    Hanna, Elias B; Mogabgab, Owen N; Baydoun, Hassan

    2018-01-01

    We present cases of complex, calcified iliac occlusive disease revascularized via a combined radial-femoral access strategy. Through a 6-French, 125-cm transradial guiding catheter, antegrade guidewires and catheters are advanced into the iliac occlusion, while retrograde devices are advanced transfemorally. The transradial and transfemoral channels communicate, allowing the devices to cross the occlusion into the true lumen (radial-femoral antegrade-retrograde rendezvous).

  7. Estimated carotid-femoral pulse wave velocity has similar predictive value as measured carotid-femoral pulse wave velocity

    Greve, Sara V; Blicher, Marie K; Kruger, Ruan

    2016-01-01

    BACKGROUND: Carotid-femoral pulse wave velocity (cfPWV) adds significantly to traditional cardiovascular risk prediction, but is not widely available. Therefore, it would be helpful if cfPWV could be replaced by an estimated carotid-femoral pulse wave velocity (ePWV) using age and mean blood pres...... that these traditional risk scores have underestimated the complicated impact of age and blood pressure on arterial stiffness and cardiovascular risk....

  8. Perpendicular magnetic tunnel junction with tunneling magnetoresistance ratio of 64% using MgO (100) barrier layer prepared at room temperature

    Ohmori, Hideto; Hatori, Tomoya; Nakagawa, Shigeki

    2008-01-01

    MgO (100) textured films can be prepared by reactive facing targets sputtering at room temperature without postdeposition annealing process when they were deposited on (100) oriented Fe buffer layers. This method allows fabrication of perpendicular magnetic tunnel junction (p-MTJ) with MgO (100) tunneling barrier layer and rare-earth transition metal (RE-TM) alloy thin films as perpendicularly magnetized free and pinned layers. The 3-nm-thick MgO tunneling barrier layer in p-MTJ multilayer prepared on glass substrate revealed (100) crystalline orientation. Extraordinary Hall effect measurement clarified that the perpendicular magnetic components of 3-nm-thick Fe buffer layers on the two ends of MgO tunneling barrier layer were increased by exchange coupling with RE-TM alloy layers. The RA of 35 kΩ μm 2 and tunneling magnetoresistance ratio of 64% was observed in the multilayered p-MTJ element by current-in-plane-tunneling

  9. Spin tunnelling in mesoscopic systems

    We study spin tunnelling in molecular magnets as an instance of a mesoscopic phenomenon, with special emphasis on the molecule Fe8. We show that the tunnel splitting between various pairs of Zeeman levels in this molecule oscillates as a function of applied magnetic field, vanishing completely at special points in the ...

  10. Hawking temperature from tunnelling formalism

    Mitra, P.

    2007-01-01

    It has recently been suggested that the attempt to understand Hawking radiation as tunnelling across black hole horizons produces a Hawking temperature double the standard value. It is explained here how one can obtain the standard value in the same tunnelling approach.

  11. Relationship between Widening and Position of the Tunnels and Clinical Results of Anterior Cruciate Ligament Reconstruction to Knee Osteoarthritis: 30 Patients at a Minimum Follow-Up of 10 Years.

    Ayala-Mejias, Juan Diego; Garcia-Gonzalez, Benjamin; Alcocer-Perez-España, Luis; Villafañe, Jorge Hugo; Berjano, Pedro

    2017-07-01

    To evaluate the relationship between tunnel position and widening and long-term clinical results in anterior cruciate ligament (ACL) reconstruction, a retrospective cohort of 30 patients undergoing ACL reconstruction with double semitendinous plus double gracilis (SAC technique) with longer than 10-year follow-up was selected. CT scans in the first 3 months and at final follow-up was evaluated. Position, angle, and widening of tunnels including Nebelung criteria were recorded in all CT scans. Physical, KT-1000, and clinical evaluation were performed at final follow-up. Outcomes and knee arthritis severity were evaluated at final follow-up. Mean follow-up was 11.2 ± 1.2. At final follow-up, 85 and 57% of tibial and femoral tunnels, respectively, developed some degree of enlargement. Frontal tibial angle (mean) was 72°, sagittal tibial angle 63°, frontal femoral angle 47°, sagittal femoral angle 20°, and tunnels divergence angle 36°. Preoperatively, KT-1000 30L and Lachman test scores were 5.52 and 5.79 respectively. In the last follow-up, 30L and manual Lachman test scores were 0.97 and 1.13, respectively ( p  verticalization. Tibial tunnel dilation was associated with long-term degenerative changes but not with final knee instability. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  12. Femoral neck-shaft angle in extra-capsular proximal femoral fracture fixation; does it make a TAD of difference?

    Walton, N P; Wynn-Jones, H; Ward, M S; Wimhurst, J A

    2005-11-01

    The effect of femoral neck-shaft angle and implant type on the accuracy of lag screw placement in extra-capsular proximal femoral fracture fixation was investigated. Radiographs of all extra-capsular proximal femoral fractures seen in one unit over 18 months were reviewed. Of 399 cases, 307 (237 female, 70 male) were included in the study as they had no contra-lateral proximal femoral metal work. Femoral neck-shaft angle (NSA) of the uninjured hip and magnification adjusted tip-apex distance (TAD) of femoral head lag screw were measured. Type of fixation implant was 135 degrees classic hip screw (CHS) (n=144) or 130 degrees intra-medullary hip screw (IMHS) (n=163). Mean contra-lateral NSA was 130.2 degrees (112.9--148 degrees ) and 64 patients (58 female, 6 male) had a NSA TAD was 18.7 mm (5.8--43.8mm) and 88.9% of cases had a TAD of less than 25 mm. TAD values were significantly greater using an IMHS if NSA was 125 degrees (p=0.028). This was not the case with the CHS. The use of the 130 degrees -IMHS in patients with a NSA 125 degrees and caution is advocated when using this device in such cases.

  13. Tunneling Ionization of Diatomic Molecules

    Svensmark, Jens Søren Sieg

    2016-01-01

    When a molecule is subject to a strong laser field, there is a probability that an electron can escape, even though the electrons are bound by a large potential barrier. This is possible because electrons are quantum mechanical in nature, and they are therefore able to tunnel through potential...... barriers, an ability classical particles do not possess. Tunnelling is a fundamental quantum mechanical process, a process that is distinctly non-classical, so solving this tunnelling problem is not only relevant for molecular physics, but also for quantum theory in general. In this dissertation the theory...... of tunneling ionizaion of molecules is presented and the results of numerical calculations are shown. One perhaps surprising result is, that the frequently used Born-Oppenheimer approximation breaks down for weak fields when describing tunneling ionization. An analytic theory applicable in the weak-field limit...

  14. Tunneling from the past horizon

    Kang, Subeom; Yeom, Dong-han

    2018-04-01

    We investigate a tunneling and emission process of a thin-shell from a Schwarzschild black hole, where the shell was initially located beyond the Einstein-Rosen bridge and finally appears at the right side of the Penrose diagram. In order to obtain such a solution, we should assume that the areal radius of the black hole horizon increases after the tunneling. Hence, there is a parameter range such that the tunneling rate is exponentially enhanced, rather than suppressed. We may have two interpretations regarding this. First, such a tunneling process from the past horizon is improbable by physical reasons; second, such a tunneling is possible in principle, but in order to obtain a stable Einstein-Rosen bridge, one needs to restrict the parameter spaces. If such a process is allowed, this can be a nonperturbative contribution to Einstein-Rosen bridges as well as eternal black holes.

  15. Orienteering club

    Club d'orientation

    2013-01-01

    Courses d’orientation Le soleil enfin de retour a incité nombre de sportifs et promeneurs à nous rejoindre dans la belle forêt de Challex /Pougny pour la deuxième étape de notre coupe de printemps 2013. Certains sont revenus crottés et fourbus alors que d’autres avaient les joues bien roses après un grand bol d’air frais. Mais tous avaient passé un agréable moment dans la nature. Nous rappelons que nos activités sont ouvertes à tous, jeunes, moins jeunes, sportifs, familles, du CERN ou d’ailleurs, et que le seul inconvénient est que si vous goûtez à la course d’orientation, il vous sera difficile de ne pas y revenir ! Samedi 20 avril 2013, nous serons sur le Mont Mourex (entre Gex et Divonne) pour notre prochaine épreuve et vous y serez les bienvenus. Les inscriptions et les départ...

  16. Orienteering club

    Club d’Orientation du CERN

    2015-01-01

    Courses d’orientation Nouvelle saison nouveau programme Le Club d’orientation du CERN, en partenariat avec d’autres clubs de la région, vous propose une dizaine de courses populaires comptant pour la coupe Genevoise de printemps: samedi 28 mars: Vernand Dessus samedi 18 avril: Pougny/Challex samedi 25 avril: Chancy/Valleiry samedi 2 mai: Mauvernay samedi 9 mai: Longchaumois samedi 16 mai: Genolier samedi 30 mai: Prevondavaux samedi 6 juin: Biere-Ballens samedi 13 juin: Haut-Jura samedi 20 juin: Bonmont - Finale Ces courses sont ouvertes à tous, quel que soit le niveau, du débutant au sportif confirmé, en famille ou en individuel, en promenade ou en course. Les inscriptions se font sur place le jour de l’épreuve. Si vous êtes débutant, vous pouvez profiter d’une initiation offerte par l’organisateur avant de vous lancer sur un parcours. Le club propose aussi...

  17. Orienteering club

    Orienteering Club

    2016-01-01

    Course d'orientation Calendrier des courses d’orientation Coupe genevoise d’automne 2016 Samedi 3 septembre : La Faucille (01) Samedi 10 septembre : Prémanon (39) Samedi 17 septembre : Saint-Cergue (VD) Samedi 24 septembre : Jorat / Corcelles (VD) Samedi 1 octobre: Bière - Ballens (VD) -relais Vendredi 14 octobre : Parc Mon Repos (GE) - nocturne Samedi 15 octobre : Terrasse de Genève (74) Samedi 29 octobre : Bonmont (VD) Samedi 5 novembre : Pomier (74) – one-man-relay - Finale   Courses ouvertes à toutes et à tous, sportifs, familles, débutants ou confirmés, du CERN ou d’ailleurs. Cinq circuits disponibles, ceci va du facile court (2 km) adapté aux débutants et aux enfants jusqu’au parcours technique long de 6 km pour les chevronnés en passant par les parcours facile moyen (4&am...

  18. COURSE ORIENTATION

    Club d'orientation du CERN

    2015-01-01

      Les coureurs d’orientation de la région se sont donné rendez-vous samedi dernier dans les bois de Pougny/Challex lors de l’épreuve organisée par le club d’orientation du CERN. La carte proposée pour les 5 circuits offrait aussi bien un coté très technique avec un relief pentu qu’un coté avec de grandes zones plates à forêt claire. Le parcours technique long comportant 20 postes a été remporté par Beat Muller du COLJ Lausanne en 56:26 devançant Denis Komarov, CO CERN en 57:30 et Yvan Balliot, ASO Annecy en 57:46. Pour les autres circuits les résultats sont les suivants: Technique moyen (13 postes): 1er Joël Mathieu en 52:32 à une seconde du 2e Vladimir Kuznetsov, COLJ Lausanne-Jorat, 3e Jean-Bernard Zosso, CO CERN, en 54:01 Technique court (12 postes): 1er Lennart Jirden, ...

  19. Orienteering Club

    Club d'Orientation

    2013-01-01

    Course d’orientation Face aux Championnats de France des Clubs à Poitiers, et à une météo hivernale (vent glaciale et pluie), il ne restait qu’une cinquantaine d’orienteurs pour participer à l’épreuve organisée le samedi 25 mai à Grange-Malval. Les participants ont tout de même bien apprécié les 5 circuits proposés par le Satus Genève. Les résultats sont disponibles sur notre site http://cern.ch/club-orientation. En plus des résultats, vous pourrez noter des informations sur la nouvelle école de CO encadrée par B. Barge, Prof. EPS à Ferney-Voltaire pour les jeunes à partir de 6 ans. La prochaine étape de la coupe genevoise se déroulera samedi 1er juin à Morez (39). Epreuve organisée par le club O’Jura&nb...

  20. Orienteering Club

    Le Club d’orientation du CERN

    2017-01-01

    COURSE ORIENTATION Finale de la coupe d’automne Le club d’orientation du CERN (COC Genève) a organisé sa dernière course populaire de la saison samedi 4 novembre au lieu-dit Les Terrasses de Genève (74). Cette 9e épreuve qui se courait sous la forme d’un One-Man-Relay, clôturait ainsi la coupe genevoise d’automne dont les lauréats sont : Circuit technique long : 1. Julien Vuitton (COC Genève), 2. Berni Wehrle (COC Genève), 3. Christophe Vuitton (COC Genève). Circuit technique moyen : 1. Vladimir Kuznetsov (Lausanne-Jorat), 2. J.-Bernard Zosso (COC Genève), 3. Laurent Merat (O’Jura). Circuit technique court : 1. Thibault Rouiller (COC Genève), 2. exæquo Lennart Jirden (COC Genève) et Katya Kuznetsova (Lausanne-Jorat). Circuit facile moyen : 1. Tituan Barge ...

  1. Orienteering Club

    Le Club d’orientation du CERN

    2017-01-01

    COURSE ORIENTATION Finale de la coupe d’automne Le club d’orientation du CERN (COC Genève) a organisé sa dernière course populaire de la saison samedi 4 novembre au lieu-dit Les Terrasses de Genève (74). Cette 9e épreuve qui se courait sous la forme d’un One-Man-Relay, clôturait ainsi la coupe genevoise d’automne dont les lauréats sont : Circuit technique long : 1. Julien Vuitton (COC Genève), 2. Berni Wehrle (COC Genève), 3. Christophe Vuitton (COC Genève). Circuit technique moyen : 1. Vladimir Kuznetsov (Lausanne-Jorat), 2. J.-Bernard Zosso (COC Genève), 3. Laurent Merat (O’Jura). Circuit technique court : 1. Thibault Rouiller (COC Genève), 2. exæquo Lennart Jirden (COC Genève) et Katya Kuznetsova (Lausanne-Jorat). Circuit facile moyen : 1. Tituan Barge...

  2. Orienteering Club

    Club d'Orientation

    2015-01-01

    Course orientation C’est au pied du Salève, proche du Golf de Bosset, que le club d’orientation du CERN (CO CERN) a organisé samedi 19 septembre une nouvelle épreuve comptant pour la Coupe Genevoise d’automne. La zone « des Terrasses de Genève » avait été cartographiée et mise en service l’année dernière. Les participants ont pu apprécier un terrain ludique avec beaucoup de microreliefs, de points d’eau et de gros rochers, le tout au milieu d’une forêt assez claire et agréable à courir. Sur le parcours technique long, le résultat a été très serré puisque Pierrick Merino du club d’Annecy a gagné avec seulement 9 secondes d’avance sur Gaëtan Vuitton (CO CERN) qui confiait avoir perdu beaucoup du te...

  3. Orienteering Club

    Le Club d’orientation du CERN

    2017-01-01

    Course orientation Les courses d’orientation comptant pour la coupe genevoise de printemps s’enchainent dans la région franco-suisse. Samedi dernier, une bonne centaine de coureurs se sont retrouvés au Mont Mourex où le club du CERN avait préparé la sixième épreuve. A l’issue de la course, les participants confirmaient l’exigence des circuits, à savoir la condition physique et le côté technique du traçage. Le parcours technique long comportant 20 postes a été remporté par Darrell High du Care Vevey en 1:22:38 devançant Beat Muller du COLJ Lausanne-Jorat en 1:25:25 et Alison High également du Care Vevey en 1:28:51. Le circuit technique moyen a été remporté par Christophe Vuitton du CO CERN et le circuit technique court par Claire-Lise Rouiller, CO CERN. Les trois pr...

  4. Orienteering Club

    Club d'orientation

    2010-01-01

    COURSE D’ORIENTATION La finale de la coupe de printemps Après avoir remporté le challenge club, samedi 29 juin lors du relais inter-club à Lausanne, le Club d’orientation du CERN organisait la dernière étape de la coupe genevoise de printemps samedi 5 juin à Saint-Cergue dans les bois de Monteret (Canton de Vaud). Plus de 100 participants se sont déplacés pour venir participer à la finale et découvrir une toute nouvelle carte dans une forêt vallonnée. Les résultats pour chaque circuit de cette étape sont : Technique long : 1. Jurg Niggli du club O’Jura, 2. Clément Poncet, 3. Oystein Midttun. Technique moyen : 1. Zoltan Trocsanyi CO CERN, 2. Christophe Ingold, 3. Christina Falga. Technique court : 1. Pierre-Andre Baum, CARE Vevey, 2. Emese Szunyog, 3. Solène Balay. Facile moyen : 1. Elisa P...

  5. Club Orientation

    Club d'orientation

    2014-01-01

      COURSE ORIENTATION   Pas moins de 100 concurrents sont venus s’affronter sur les parcours proposés par le club d’orientation du CERN ce samedi 26 avril lors de la 4e étape de la coupe genevoise de printemps. Les podiums ont été attribués à :  Technique long avec 19 postes : 1er Yvan Balliot, ASO Annecy en 1:01:39 ; 2e Dominique Fleurent, ASO Annecy, en 1:05:12 ; 3e Rémi Fournier, SOS Sallanches, en 1:05:40. Technique moyen avec 14 postes : 1er Jean-Bernard Zosso, CO CERN, en 46:42 ; 2e Céline Zosso, CO CERN, en 50:51 ; 3e Clément Poncet, O’Jura Prémanon, en 51:27. Technique court avec 13 postes : 1er Jaakko Murtomaki, YKV Seinaejoki, en 36:04 ; 2e Marc Baumgartner en 41:27 ; 3e Natalia Niggli, O’Jura Prémanon, en 52:43. Sur les parcours facile moyen et facile court, victoire respectivement de Stéphanie...

  6. Orienteering Club

    Le Club d’orientation du CERN

    2017-01-01

    Calendrier des courses de la Coupe Genevoise – printemps 2017 Club d'orientation - Julien,  jeune membre du club. Le Club d’orientation du CERN, en partenariat avec d’autres clubs de la région, vous propose une série de courses populaires, qui se dérouleront des deux côtés de la frontière franco-suisse, à savoir : Samedi 1 avril : Pougny/Challex (01) Samedi 8 avril: Ballens (VD) Samedi 22 avril: Apples (VD) Samedi 29 avril: Mont Mussy (01) Samedi 6 mai: Prémanon (39) Samedi 13 mai: Mont Mourex (01) Samedi 20 mai: Prévondavaux (VD) Samedi 10 juin: Chancy/Valleiry (74) Samedi 17 juin: Trélex - Finale (VD) Ces courses sont ouvertes à tous, quel que soit le niveau, du débutant au sportif confirmé, en famille ou en individuel. Les inscriptions sur un des 5 parcours proposés se font sur place le jour de l...

  7. Herniation pits in the femoral neck: a radiographic indicator of femoroacetabular impingement?

    Kim, Jin Ah; Park, Ji Seon; Ryu, Kyungnam; Jin, Wook

    2011-01-01

    The purpose was to assess the significance of herniation pits in the femoral neck for radiographic diagnosis of femoroacetabular impingement (FAI). Eighty hips in 62 patients (bilateral in 18) with neutral pelvic orientation were enrolled. Herniation pits were diagnosed when they were located at the anterosuperior femoral neck, close to the physis, and with a diameter of >3 mm. The five radiographic signs of FAI were used: lateral center edge angle (LCE) >39 , acetabular index (AI) ≤0, extrusion index (EI) <25%, acetabular retroversion, and pistol-grip deformity. Patients with radiographs suggesting FAI were retrospectively correlated with their clinical symptoms. Positive radiographic signs were observed in 7 hips with LCE, 7 with AI, and 80 with EI criteria. Only 3 hips out of 80 (3.8%) showed all of the signs. The acetabular retroversion and pistol-grip deformity were seen in 12/80 and 3/80 hips, respectively. The total number of hips that met radiographic criteria for FAI, including pincer type and cam type, was 18 (23%). However, none of these hips were clinically diagnosed with FAI. All symptomatic hips (11/80) presented only with nonspecific pain, and 2 hips out of 11 showed radiographic signs of FAI. The low frequency of positive radiographic signs suggesting FAI with related symptoms among patients with herniation pits suggests that herniation pits have limited significance in the diagnosis of FAI. Therefore it can be concluded that an incidental finding of herniation pits does not necessarily imply a correlation with FAI. (orig.)

  8. Prevention of excessive postoperative sliding of the short femoral nail in femoral trochanteric fractures.

    Ito, Juji; Takakubo, Yuya; Sasaki, Kan; Sasaki, Junya; Owashi, Kazuya; Takagi, Michiaki

    2015-05-01

    Lag screw cut-out is one of the major postoperative complications on femoral trochanteric fractures. However, precise analyses of excessive sliding and lag screw cut-out were limited. The purpose of this study was to investigate the factors that induce this unfavorable event. From April 2010 to April 2013, 226 patients were operated in our institute using a short femoral nail. Among them, 177 patients (29 males and 148 females) with a mean age of 84 years (60-97 years), who were followed up >3 months, were included in this study. The postoperative sliding distance, fracture type (AO/OTA classification), tip-apex distance (TAD), reduction pattern in the postoperative X-ray (antero-posterior and lateral views), bone quality (canal flare and cortical indices), walking ability at the time of pre-injury and final follow-up, and complications were investigated retrospectively. The mean sliding distance was 3.7 mm, and one cut-out case (0.6 %) was observed. The sliding distance of the AO/OTA 31-A2 fractures was significantly longer than that of the A1 fractures (p fractures, an accurate reduction in the lateral view at surgery is important, particularly in unstable fractures.

  9. Multiplanar CT assessment of femoral head displacement in slipped capital femoral epiphysis

    Monazzam, Shafagh [Rady Children' s Hospital and Health Center, Department of Orthopedics, San Diego, CA (United States); Dwek, Jerry R. [Rady Children' s Hospital and Health Center, Department of Radiology, San Diego, CA (United States); Hosalkar, Harish S. [Center for Hip Preservation, Department of Orthopedic Surgery, TriCity Medical Center, Oceanside, CA (United States)

    2013-12-15

    With recent changing approaches to the management of slipped capital femoral epiphysis (SCFE), the accurate radiographic assessment of maximum extent of displacement is crucial for planning surgical treatment. To determine what plane best represents the maximum SCFE displacement as quantified by the head-neck angle difference (HNAD), whether HNAD can quantitatively differentiate the SCFE cohort from the normal cohort, based on CT, and how Southwick slip angle (SSA) compares to HNAD. We reviewed 19 children with SCFE (23 affected hips) with preoperative CT scans and 27 age- and sex-matched children undergoing abdominal CT for non-orthopedic problems. Head-neck angle (HNA), the angle between the femoral epiphysis and the neck axis, was measured in three planes on each hip and the HNAD (affected - unaffected hip) was determined. SSA was measured on radiographs. The coronal HNAD (mean 8.7 ) was less than both the axial-oblique (mean 30.7 ) and sagittal (mean 37.4 ) HNADs, which were also greater than the HNADs of the normal cohort. Grouping HNAD measurements by SSA severity classification did not consistently distinguish between SCFE severity levels. Axial-oblique and sagittal planes best represent the maximum SCFE displacement while biplanar radiograph may underestimate the extent of the displacement, thereby potentially altering the management between in situ pinning and capital realignment. (orig.)

  10. Varus femoral osteotomy improves sphericity of the femoral head in older children with severe form of Legg-Calvé-Perthes disease.

    Terjesen, Terje; Wiig, Ola; Svenningsen, Svein

    2012-09-01

    In the Norwegian prospective study on Legg-Calvé-Perthes disease (LCPD), we found varus femoral osteotomy gave better femoral head sphericity at a mean of 5 years postoperative than physiotherapy in children older than 6.0 years at diagnosis with femoral head necrosis of more than 50%. That study did not include separate analyses for hips with 100% necrosis and those with a percentage of necrosis between 50% and 100%. We asked whether (1) femoral osteotomy improves femoral head sphericity at followup in all patients with more than 50% femoral head necrosis or in selected groups only and (2) there is a critical age between 6.0 and 10.0 years over which femoral osteotomy does not improve the prognosis. We treated 70 patients with unilateral LCPD, age at diagnosis of more than 6.0 years, and femoral head necrosis of more than 50% with varus femoral osteotomy between 1996 and 2000. We classified necrosis using the Catterall classification. We established a control group of 51 similar children who received physiotherapy. At the 5-year followup visit, the hips were graded according to femoral head shape: spherical, ovoid, or flat. At 5-year followup, there was no difference between the treatment groups in radiographic outcome in Catterall Group 3 hips. In Catterall Group 4 hips, femoral head sphericity was better in the osteotomy group, with flat femoral heads in 14% compared to 75% after physiotherapy. The same trend toward better head sphericity occurred when the lateral pillar classification was used. In children aged 6.0 to 10.0 years, in whom the whole femoral head is affected, femoral head sphericity 5 years after femoral osteotomy was better than that after physiotherapy.

  11. [Femoral artery pseudoaneurysms encountered in orthopedics and traumatology].

    Raherinantenaina, F; Rajaonanahary, T M A; Rakoto Ratsimba, H N

    2015-12-01

    Most published articles regarding orthopedic- and trauma-related femoral artery pseudoaneurysms (FAPs) are case reports in English. Reported cases are often associated with a literature review but actually provide little robust data. We wanted to summarize the current knowledge on diagnostic and therapeutic features of these FAPs. A new case of superficial FAP is described followed by a review of the literature. A bibliographic search was performed online (PubMed, ScinceDirect) from 1964 to 2015 using the descriptors "traumatic femoral pseudoaneurysm, orthopedic surgery, osteochondroma". A total of 64 cases of FAPs was analyzed. There were 50 men with an average age of 40.72±26.45 years old. The most common clinical presentation was painful swelling (34%). Arteriography was the commonest radiological investigation used (63%). The main etiologies were orthopedic injuries (47%), surgery of the upper thigh (30%) and femoral osteochondromas (23%). Arterial injuries included superficial femoral (47%) and profunda femoris artery (50%). The treatment was open surgery (56%) or endovascular repair (36%). Deep femoral artery and its branches were embolized (47%) or ligated (38%). Endovascular stenting was performed in 30% of posttraumatic FAPs. All FAPs relating to osteochondromas were repaired surgically. Postoperative courses were uneventful in 95% of patients. Endovascular embolization is preferred in management of postsurgical FAPs which have usually involved the deep femoral artery. Endovascular stenting graft may be proposed for posttraumatic FAPs, for which the superficial femoral trunk is the most often involved vessel. Surgical repair should be performed when endovascular stenting graft is not feasible. Surgical repair is mandatory for all FAPs secondary to traumatic exostoses. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  12. Structural and functional studies of bioobjects prepared from femoral heads

    Kirilova, I. A., E-mail: IKirilova@niito.ru; Podorozhnaya, V. T., E-mail: VPodorognaya@niito.ru [Research Institute of Traumatology and Orthopedics n.a. Ya.L. Tsivyan, 17, Frunze, Novosibirsk, 630091 (Russian Federation); Sharkeev, Yu. P., E-mail: sharkeev@ispms.tsc.ru [Institute of Strength Physics and Materials Science SB RAS, 2/4, pr. Akademicheskii, Tomsk, 634021 (Russian Federation); National Research Tomsk Polytechnic University, 30, Lenin Avenue, Tomsk, 634050 (Russian Federation); Popova, K. S., E-mail: kseniya@ispms.tsc.ru; Uvarkin, P. V., E-mail: uvarkin@ispms.tsc.ru [Institute of Strength Physics and Materials Science SB RAS, 2/4, pr. Akademicheskii, Tomsk, 634021 (Russian Federation)

    2015-11-17

    Results of examination of physicomechanical characteristics of samples of medial femoral head cuts are presented. The samples of medial femoral head cuts resected in 6 patients with coxarthrosis in primary endoprosthetic replacement of a coxofemoral joint have been tested for micro- and nanohardness. Young’s modulus and elemental composition of bone tissue have been investigated. To estimate the architectonics of cancellous tissue of the femoral head, adjacent cuts of the same patient have been analyzed. The porosity of bone tissue was estimated from macroscopic images obtained using macrophotography. The total porosity is calculated as the ratio of the total length of straight line segments overlapping pores to the total length of secants. A three-point bending test of the samples has shown that their strength changed from 0.187 to 1.650 MPa and their elasticity modulus changes from 1.69 to 8.15 MPa. The microhardness of the samples changes in the range 220–265 MPa and the average microhardness of medial femoral head cuts is 240 MPa. The elemental composition of medial femoral head cuts is represented by basic Ca, P, O, Na and Mg elements as well as by Sn, S, Fe, Cr, and C in microamounts. The atomic Ca to P ratio for bone tissue is 1.55. It is revealed that pores of the upper part of the femoral head have a more regular shape and in the lower part they are more elongated along the cut and occupy a larger volume. The lower part of the femoral head has a higher porosity (39 and 33%) than the upper part (34 and 30%). The total porosity of all samples does not exceed 37%.

  13. Radiological assessment of the femoral bowing in Japanese population

    Abdelaal Ahmed Hamed Kassem

    2016-01-01

    Full Text Available Introduction: Differences in the magnitude of bowing between races are well-known characteristics of the femur. Asian races have an increased magnitude of femoral bowing but most of the orthopedic implants designed for the femur do not match this exaggerated bowing. We calculated the sagittal and coronal femoral bowing in the Japanese population at different levels of the femur and addressed its surgical significance. Material and methods: We calculated the sagittal and coronal bowing of 132 Japanese femora using CT scan of the femur. A mathematical calculation of the radius of curvature at proximal, middle, and distal regions of the femur was used to determine the degree of femoral bowing. Results: Mean sagittal bowing of the femur was 581, 188, and 161 mm for the proximal, middle, and distal thirds of the femur and mean lateral bowing was 528, 5092, and 876 mm, respectively. Mean sagittal and coronal bowing for the whole femur was 175 and 2640 mm, respectively. No correlation was found between age, gender, length of femur, and the degree of bowing. Conclusion: Our study reveals that femoral bowing in the Japanese population is 175 mm in the sagittal plane and 2640 mm in the coronal plane; these values are greater than the femoral bowing in other ethnic groups studied in the literature. This may result in varying degrees of mismatch between the western-manufactured femoral intramedullary implants and the Japanese femur. We recommend that orthopedic surgeons to accurately perform preoperative evaluation of the femoral bowing to avoid potential malalignment, rotation, and abnormal stresses between the femur and implant.

  14. Fluctuation Dominated Josephson Tunneling with a Scanning Tunneling Microscope

    Naaman, O.; Teizer, W.; Dynes, R. C.

    2001-01-01

    We demonstrate Josephson tunneling in vacuum tunnel junctions formed between a superconducting scanning tunneling microscope tip and a Pb film, for junction resistances in the range 50--300 k Omega. We show that the superconducting phase dynamics is dominated by thermal fluctuations, and that the Josephson current appears as a peak centered at small finite voltage. In the presence of microwave fields (f=15.0 GHz) the peak decreases in magnitude and shifts to higher voltages with increasing rf power, in agreement with theory

  15. Tunneling junction as an open system. Normal tunneling

    Ono, Y.

    1978-01-01

    The method of the tunneling Hamiltonian is reformulated in the case of normal tunneling by introducing two independent particle baths. Due to the baths, it becomes possible to realize a final stationary state where the electron numbers of the two electrodes in the tunneling system are maintained constant and where there exists a stationary current. The effect of the bath-system couplings on the current-voltage characteristics of the junction is discussed in relation to the usual expression of the current as a function of voltage. (Auth.)

  16. Frequency driven inversion of tunnel magnetoimpedance and observation of positive tunnel magnetocapacitance in magnetic tunnel junctions

    Parui, Subir; Ribeiro, Mário; Atxabal, Ainhoa; Llopis, Roger; Bedoya-Pinto, Amilcar; Sun, Xiangnan; Casanova, Fèlix; Hueso, Luis E.

    2016-01-01

    The relevance for modern computation of non-volatile high-frequency memories makes ac-transport measurements of magnetic tunnel junctions (MTJs) crucial for exploring this regime. Here, we demonstrate a frequency-mediated effect in which the tunnel magnetoimpedance reverses its sign in a classical Co/Al 2 O 3 /NiFe MTJ, whereas we only observe a gradual decrease in the tunnel magnetophase. Such effects are explained by the capacitive coupling of a parallel resistor and capacitor in the equivalent circuit model of the MTJ. Furthermore, we report a positive tunnel magnetocapacitance effect, suggesting the presence of a spin-capacitance at the two ferromagnet/tunnel-barrier interfaces. Our results are important for understanding spin transport phenomena at the high frequency regime in which the spin-polarized charge accumulation due to spin-dependent penetration depth at the two interfaces plays a crucial role.

  17. Frequency driven inversion of tunnel magnetoimpedance and observation of positive tunnel magnetocapacitance in magnetic tunnel junctions

    Parui, Subir, E-mail: s.parui@nanogune.eu, E-mail: l.hueso@nanogune.eu; Ribeiro, Mário; Atxabal, Ainhoa; Llopis, Roger [CIC nanoGUNE, 20018 Donostia-San Sebastian (Spain); Bedoya-Pinto, Amilcar [CIC nanoGUNE, 20018 Donostia-San Sebastian (Spain); Max Planck Institute of Microstructure Physics, D-06120 Halle (Germany); Sun, Xiangnan [CIC nanoGUNE, 20018 Donostia-San Sebastian (Spain); National Center for Nanoscience and Technology, 100190 Beijing (China); Casanova, Fèlix; Hueso, Luis E., E-mail: s.parui@nanogune.eu, E-mail: l.hueso@nanogune.eu [CIC nanoGUNE, 20018 Donostia-San Sebastian (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain)

    2016-08-01

    The relevance for modern computation of non-volatile high-frequency memories makes ac-transport measurements of magnetic tunnel junctions (MTJs) crucial for exploring this regime. Here, we demonstrate a frequency-mediated effect in which the tunnel magnetoimpedance reverses its sign in a classical Co/Al{sub 2}O{sub 3}/NiFe MTJ, whereas we only observe a gradual decrease in the tunnel magnetophase. Such effects are explained by the capacitive coupling of a parallel resistor and capacitor in the equivalent circuit model of the MTJ. Furthermore, we report a positive tunnel magnetocapacitance effect, suggesting the presence of a spin-capacitance at the two ferromagnet/tunnel-barrier interfaces. Our results are important for understanding spin transport phenomena at the high frequency regime in which the spin-polarized charge accumulation due to spin-dependent penetration depth at the two interfaces plays a crucial role.

  18. Fracturing of revision of a cobalt-chrome femoral head after fracturing of a ceramic femoral head, with diffuse metallosis. Case report

    Pedro Miguel Dantas Costa Marques

    2013-04-01

    Full Text Available We presente a case of a fracture of a cobalt-chrome femoral head after revision of a hip total prosthesis with ceramic femoral head fracture. During surgery we found the cobalt-chrome femoral head fracture, wear of the polyethylene and massive metallosis in muscular and cartilaginous tissue. Both femoral stem and acetabular cup were stable and without apparent wearing. After surgical debridement, we promoted the substitution of the femoral head and the acetabular polyethylene by similar ones. After 12 months of follow-up, the patient has no pain complaints, function limit or systemic signs associated with malign metallosis

  19. Femoral shaft bowing in the coronal plane has more significant effect on the coronal alignment of TKA than proximal or distal variations of femoral shape.

    Kim, Jong-Min; Hong, Soo-Heon; Kim, Jong-Min; Lee, Bum-Sik; Kim, Dong-Eun; Kim, Kyung-Ah; Bin, Seong-Il

    2015-07-01

    The aim of this study was to determine (1) variations in the shape of the proximal, middle, and distal femur in a series of Korean patients who had undergone total knee arthroplasty (TKA), (2) the preoperative relationship between these three parameters and the distal valgus cutting angle referenced off the femoral intramedullary guide, and (3) whether there was any relationship between femoral bowing and variations in the shape of the proximal or distal femur in the coronal plane. The preoperative long-standing anteroposterior radiographs of 316 consecutive osteoarthritis patients who underwent primary TKA from 2009 to 2011 were examined. The femoral neck shaft angle, the femoral shaft bowing angle, and the mechanical lateral distal femoral angle were measured to assess the shape of the proximal, middle, and distal femur, respectively. The valgus cutting angle of the femur was defined as the angle between the distal anatomical and mechanical axes of the femur. The study population showed large variations in femoral shape. The mean femoral intramedullary guide angle was 6.5° ± 1.3° (range: 4°-13°). The femoral shaft bowing angle was the factor that showed the strongest correlation with this angle (P shaft angle showed no correlation (n.s.). The femoral shaft bowing angle showed a weak correlation with the mechanical lateral distal femoral angle (P = 0.001), but was not significantly correlated with the femoral neck shaft angle (n.s.). Apparent femoral bowing (>3° of lateral or medial bowing) was found in 42 (13.3 %) of cases (37 cases of lateral bowing and five of medial bowing). Cases with lateral apparent femoral bowing >3° had a distal cutting angle of 8.6° ± 2.2° relative to the femoral intramedullary guide. The femoral intramedullary guide angle was mainly influenced by femoral shaft bowing among femoral deformities in the coronal plane. Therefore, to increase the accuracy of distal femoral cut during TKA, it is necessary to confirm femoral

  20. Orienting hypnosis.

    Hope, Anna E; Sugarman, Laurence I

    2015-01-01

    This article presents a new frame for understanding hypnosis and its clinical applications. Despite great potential to transform health and care, hypnosis research and clinical integration is impaired in part by centuries of misrepresentation and ignorance about its demonstrated efficacy. The authors contend that advances in the field are primarily encumbered by the lack of distinct boundaries and definitions. Here, hypnosis, trance, and mind are all redefined and grounded in biological, neurological, and psychological phenomena. Solutions are proposed for boundary and language problems associated with hypnosis. The biological role of novelty stimulating an orienting response that, in turn, potentiates systemic plasticity forms the basis for trance. Hypnosis is merely the skill set that perpetuates and influences trance. This formulation meshes with many aspects of Milton Erickson's legacy and Ernest Rossi's recent theory of mind and health. Implications of this hypothesis for clinical skills, professional training, and research are discussed.

  1. Oriented Approach

    Seyed Mohammad Moghimi

    2013-12-01

    Full Text Available Promoting productivity is one of the goals of usinginformation technology in organizations. The purpose of this research isexamining the impact of IT on organizational productivity andrecognizing its mechanisms based on process-oriented approach. For thisend, by reviewing the literature of the subject a number of impacts of ITon organizational processes were identified. Then, through interviewswith IT experts, seven main factors were selected and presented in aconceptual model. This model was tested through a questionnaire in 148industrial companies. Data analysis shows that impact of IT onproductivity can be included in the eight major categories: Increasing ofthe Automation, Tracking, Communication, Improvement, Flexibility,Analytic, Coordination and Monitoring in organizational processes.Finally, to improve the impact of information technology onorganizational productivity, some suggestions are presented.

  2. A biomechanical comparison of proximal femoral nails and locking proximal anatomic femoral plates in femoral fracture fixation A study on synthetic bones

    Korhan Ozkan

    2015-01-01

    Conclusion: The proximal femoral intramedullary nail provides more stability and allows for earlier weight bearing than the locking plate when used for the treatment of unstable intertrochanteric fractures of the femur. Clinicians should be cautious for early weight bearing with locking plate for unstable intertrochanteric femur fractures.

  3. Disparities in correlating microstructural to nanostructural preservation of dinosaur femoral bones

    Kim, Jung-Kyun; Kwon, Yong-Eun; Lee, Sang-Gil; Lee, Ji-Hyun; Kim, Jin-Gyu; Huh, Min; Lee, Eunji; Kim, Youn-Joong

    2017-03-01

    Osteohistological researches on dinosaurs are well documented, but descriptions of direct correlations between the bone microstructure and corresponding nanostructure are currently lacking. By applying correlative microscopy, we aimed to verify that well-preserved osteohistological features correlate with pristine fossil bone nanostructures from the femoral bones of Koreanosaurus boseongensis. The quality of nanostructural preservation was evaluated based on the preferred orientation level of apatite crystals obtained from selected area electron diffraction (SAED) patterns and by measuring the “arcs” from the {100} and {002} diffraction rings. Unlike our expectations, our results revealed that well-preserved microstructures do not guarantee pristine nanostructures and vice versa. Structural preservation of bone from macro- to nanoscale primarily depends on original bioapatite density, and subsequent taphonomical factors such as effects from burial, pressure, influx of external elements and the rate of diagenetic alteration of apatite crystals. Our findings suggest that the efficient application of SAED analysis opens the opportunity for comprehensive nanostructural investigations of bone.

  4. Morphometric analysis of rat femoral vessels under a video magnification system

    Rui Sergio Monteiro de Barros

    Full Text Available Abstract The right femoral vessels of 80 rats were identified and dissected. External lengths and diameters of femoral arteries and femoral veins were measured using either a microscope or a video magnification system. Findings were correlated to animals’ weights. Mean length was 14.33 mm for both femoral arteries and femoral veins, mean diameter of arteries was 0.65 mm and diameter of veins was 0.81 mm. In our sample, rats’ body weights were only correlated with the diameter of their femoral veins.

  5. EDITORIAL: Optical orientation Optical orientation

    SAME ADDRESS *, Yuri; Landwehr, Gottfried

    2008-11-01

    priority of the discovery in the literature, which was partly caused by the existence of the Iron Curtain. I had already enjoyed contact with Boris in the 1980s when the two volumes of Landau Level Spectroscopy were being prepared [2]. He was one of the pioneers of magneto-optics in semiconductors. In the 1950s the band structure of germanium and silicon was investigated by magneto-optical methods, mainly in the United States. No excitonic effects were observed and the band structure parameters were determined without taking account of excitons. However, working with cuprous oxide, which is a direct semiconductor with a relative large energy gap, Zakharchenya and his co-worker Seysan showed that in order to obtain correct band structure parameters, it is necessary to take excitons into account [3]. About 1970 Boris started work on optical orientation. Early work by Hanle in Germany in the 1920s on the depolarization of luminescence in mercury vapour by a transverse magnetic field was not appreciated for a long time. Only in the late 1940s did Kastler and co-workers in Paris begin a systematic study of optical pumping, which led to the award of a Nobel prize. The ideas of optical pumping were first applied by Georges Lampel to solid state physics in 1968. He demonstrated optical orientation of free carriers in silicon. The detection method was nuclear magnetic resonance; optically oriented free electrons dynamically polarized the 29Si nuclei of the host lattice. The first optical detection of spin orientation was demonstrated by with the III-V semiconductor GaSb by Parsons. Due to the various interaction mechanisms of spins with their environment, the effects occurring in semiconductors are naturally more complex than those in atoms. Optical detection is now the preferred method to detect spin alignment in semiconductors. The orientation of spins in crystals pumped with circularly polarized light is deduced from the degree of circular polarization of the recombination

  6. Trochanteric entry femoral nails yield better femoral version and lower revision rates-A large cohort multivariate regression analysis.

    Yoon, Richard S; Gage, Mark J; Galos, David K; Donegan, Derek J; Liporace, Frank A

    2017-06-01

    Intramedullary nailing (IMN) has become the standard of care for the treatment of most femoral shaft fractures. Different IMN options include trochanteric and piriformis entry as well as retrograde nails, which may result in varying degrees of femoral rotation. The objective of this study was to analyze postoperative femoral version between three types of nails and to delineate any significant differences in femoral version (DFV) and revision rates. Over a 10-year period, 417 patients underwent IMN of a diaphyseal femur fracture (AO/OTA 32A-C). Of these patients, 316 met inclusion criteria and obtained postoperative computed tomography (CT) scanograms to calculate femoral version and were thus included in the study. In this study, our main outcome measure was the difference in femoral version (DFV) between the uninjured limb and the injured limb. The effect of the following variables on DFV and revision rates were determined via univariate, multivariate, and ordinal regression analyses: gender, age, BMI, ethnicity, mechanism of injury, operative side, open fracture, and table type/position. Statistical significance was set at pregression analysis revealed that a lower BMI was significantly associated with a lower DFV (p=0.006). Controlling for possible covariables, multivariate analysis yielded a significantly lower DFV for trochanteric entry nails than piriformis or retrograde nails (7.9±6.10 vs. 9.5±7.4 vs. 9.4±7.8°, pregression analysis. However, this is not to state that the other nail types exhibited abnormal DFV. Translation to the clinical impact of a few degrees of DFV is also unknown. Future studies to more in-depth study the intricacies of femoral version may lead to improved technology in addition to potentially improved clinical outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Case report: AVN of the femoral head five year follow-up of the combination of ipsilateral femoral neck and sub-trochanteric fracture.

    Zhang, Wei; Zhu, Feng; Dong, Hanqing; Xu, Yaozeng

    2016-04-01

    To our knowledge, the type of combination of ipsilateral femoral neck and sub-trochanteric fracture is rare. And the long term follow-up is seldom been reported. A 60 year old woman suffered from a traffic accident. We gave her the intramedullary nail treatment for the combination of ipsilateral femoral neck and sub-trochanteric fracture, and the fracture indeed cured after one year and there is no clue of necrosis of the femoral head, but after 5 years, there is an evidence of necrosis of the femoral head. Combination of ipsilateral femoral neck and sub-trochanteric fracture should be kept in mind. Patients with this unusual fracture should be kept under surveillance for longer than might be thought currently to be necessary for there is a possibility of necrosis of the femoral head, even a nondisplaced femoral neck fracture.

  8. Femoral neck radiography: effect of flexion on visualization

    Garry, S.C.; Jhangri, G.S.; Lambert, R.G.W.

    2005-01-01

    To determine whether flexion improves radiographic visualization of the femoral neck when the femur is externally rotated. Five human femora, with varying neck-shaft and anteversion angles, were measured and immobilized. Degree of flexion required to bring the femoral neck horizontal was measured, varying the rotation. Next, one bone was radiographed in 16 positions, varying rotation in 15 o and flexion in 10 o increments. Radiographs were presented in randomized blinded fashion to 15 staff radiologists for scoring of femoral neck visualization. Following this, all 5 bones were radiographed in 4 positions of rotation and at 0 o and 20 o flexion, and blinded randomized review of radiographs was repeated. Comparisons between angles and rotations were made using the Mann-Whitney test. The flexion angle required to bring the long axis of the femoral neck horizontal correlated directly with the degree of external rotation (ρ o internal rotation to 30 o external rotation (ρ o flexion was applied to bones in external rotation, visualization significantly improved at 15 o (ρ o (ρ o ) of flexion can significantly improve radiographic visualization. This manoeuvre could be useful for radiography of the femoral neck when initial radiographs are inadequate because of external rotation of the leg. (author)

  9. Avascular necrosis of the femoral head in HIV infected patients

    Marcos Almeida Matos

    Full Text Available Avascular necrosis (AVN of the femoral head is an emerging complication in HIV infected patients. It has been suggested that the increased incidence of AVN in this population may be caused by an increased prevalence of predisposing factors for osteonecrosis, including protease inhibitors, hyperlipidemia, corticosteroid use, alcohol and intravenous drug abuse. The aim of this study was to assess the risk factors for avascular necrosis developing in the femoral head of HIV infected individuals. This study consisted of meta-analysis of the secondary data extracted from current literature. The selected articles allowed two study groups to be drawn up for comparison. Group 1 comprised 324 individuals infected by the HIV virus, who did not present femoral head AVN. Group 2 comprised 32 HIV positive patients, who presented femoral head AVN. The parameters used for analysis were as follows: age, gender, sexual preference, use of intravenous drugs, time of diagnosis, CD4+ cell count, use of antiretroviral agents and duration, serum cholesterol and serum triglycerides. The present study found a statistically significant association between hypertriglyceridemia, hypercholesterolemia, sexual preference and intravenous drug abuse. The authors concluded that femoral head osteonecrosis is associated with hyperlipidemia (hypercholesterolemia and hypertriglyceridemia and intravenous drug abuse. This study supports the hypothesis that protease inhibitors play a role in the development of osteonecrosis through a tendency to cause hyperlipidemia.

  10. Valgus Slipped Capital Femoral Epiphysis in Patient with Hypopituitarism

    Yoshihiro Kotoura

    2017-01-01

    Full Text Available Slipped capital femoral epiphysis (SCFE is a common disease of adolescent and the epiphysis is positioned more posteromedially in relation to the femoral neck shaft with varus SCFE; however, posterolateral displacement of the capital epiphysis, valgus SCFE, occurs less frequently. We report a case of valgus SCFE in a 17-year-old boy with hypopituitarism. After falling down, he experienced difficulty in walking. The radiographs were inconclusive; however three-dimensional computed tomography images showed lateral displacement of the epiphysis on the right femoral head. Valgus SCFE was diagnosed. The patient underwent in situ pinning of both sides. In situ pinning on the left side was performed as a prophylactic pinning because of endocrine abnormalities. At the 1-year follow-up, he could walk without any difficulty and there were no signs of pain. The epiphysis is commonly positioned more posteromedially in relation to the femoral neck shaft with most SCFE, but, in this case, the epiphysis slipped laterally. Differential diagnosis included femoral neck fracture (Delbet-Colonna type 1; however, this was less likely due to the absence of other clinical signs. Therefore, we diagnosed the patient as SCFE. When children complain of leg pain and limp, valgus SCFE that may not be visualized on anteroposterior radiographs needs to be considered.

  11. Clinical use of femoral artery hemostasis sticking after interventional procedure via femoral artery access

    Zhu Zhongsheng; Chen Shaoliang; Ye Fei; Zhang Junjie; Zhou Jie; Tian Nailiang; Lin Song; Liu Zhizhong; Xiao Pingxi; Qu Hong

    2010-01-01

    Objective: To observe the clinical effect of the use of femoral artery hemostasis sticking V+PAD after the interventional procedure via femoral artery access. Methods: By using random permutation list 80 patients, who decided to receive coronary angiography and percutaneous transluminal coronary angioplasty, were randomly selected. Of the 80 patients, hemostasis sticking V + PAD was employed in 40 patients with even numbers (trial group), only manual compression was adopted to stop bleeding in another 40 patients with odd numbers (control group). All the patients were informed about this trial and had to sign a consent letter. The pressure time, the treatment method of access site after hemostasis, the posture in bed, the immobilization time, the comfort degree of patients, the complications of access site prior to discharge, etc. were observed and the results were compared between two groups. Results: There was no significant difference between two groups as respect to age, gender ratios,activated clotting time (ACT) value and blood pressure. However, significantly difference in the compression time and bed rest time existed between the two groups. The compression time in trial group and control group was (7.9 ± 0.5) min and (19.8 ± 5.1) min respectively (P<0.01), while the bed rest time in trial group and control group was (6.1 ± 5.0) hours and (23.9 ± 0.2) hours respectively (P<0.01). All patients in trial group was supine in bed with the head side of the bed raised at 30 degree immediately after the procedure, and the head side of the bed was further raised to 90 degree one hour later. The puncture site was bandaged with conventional compression and immobilization was not employed. Patients could lie in bed with free posture and the patient's comfort degree was greatly improved. During hospitalization no complications related to puncture site occurred in all patients except one obese woman in trial group who developed pseudoaneurysm. Conclusion: Femoral

  12. Tunneling of Atoms, Nuclei and Molecules

    Bertulani, C.A.

    2015-01-01

    This is a brief review of few relevant topics on tunneling of composite particles and how the coupling to intrinsic and external degrees of freedom affects tunneling probabilities. I discuss the phenomena of resonant tunneling, different barriers seen by subsystems, damping of resonant tunneling by level bunching and continuum effects due to particle dissociation. (author)

  13. Computational Multiqubit Tunnelling in Programmable Quantum Annealers

    2016-08-25

    ARTICLE Received 3 Jun 2015 | Accepted 26 Nov 2015 | Published 7 Jan 2016 Computational multiqubit tunnelling in programmable quantum annealers...state itself. Quantum tunnelling has been hypothesized as an advantageous physical resource for optimization in quantum annealing. However, computational ...qubit tunnelling plays a computational role in a currently available programmable quantum annealer. We devise a probe for tunnelling, a computational

  14. 78 FR 46117 - National Tunnel Inspection Standards

    2013-07-30

    ... busiest vehicular tunnel in the world. The Fort McHenry Tunnel handles a daily traffic volume of more than... vehicular, transit, and rail tunnels in the New York City metropolitan area. Although it is still too early... congestion along alternative routes, and save users both dollars and fuel. If these tunnels were closed due...

  15. Een systeem voor classificatie van korte tunnels.

    Schreuder, D.A.

    1985-01-01

    The most difficult problems in the lighting of tunnels occur in daylight and in particular in the entrance of the tunnel, while drivers approaching the tunnel must be able to look into the tunnel from the outside to detect the road course and eventual obstacles. A classification should The made on

  16. Tunnel fire testing and modeling the Morgex North tunnel experiment

    Borghetti, Fabio; Gandini, Paolo; Frassoldati, Alessio; Tavelli, Silvia

    2017-01-01

    This book aims to cast light on all aspects of tunnel fires, based on experimental activities and theoretical and computational fluid dynamics (CFD) analyses. In particular, the authors describe a transient full-scale fire test (~15 MW), explaining how they designed and performed the experimental activity inside the Morgex North tunnel in Italy. The entire organization of the experiment is described, from preliminary evaluations to the solutions found for management of operational difficulties and safety issues. This fire test allowed the collection of different measurements (temperature, air velocity, smoke composition, pollutant species) useful for validating and improving CFD codes and for testing the real behavior of the tunnel and its safety systems during a diesel oil fire with a significant heat release rate. Finally, the fire dynamics are compared with empirical correlations, CFD simulations, and literature measurements obtained in other similar tunnel fire tests. This book will be of interest to all ...

  17. Apparent tunneling in chemical reactions

    Henriksen, Niels Engholm; Hansen, Flemming Yssing; Billing, G. D.

    2000-01-01

    A necessary condition for tunneling in a chemical reaction is that the probability of crossing a barrier is non-zero, when the energy of the reactants is below the potential energy of the barrier. Due to the non-classical nature (i.e, momentum uncertainty) of vibrational states this is, however......, not a sufficient condition in order to establish genuine tunneling as a result of quantum dynamics. This proposition is illustrated for a two-dimensional model potential describing dissociative sticking of N-2 on Ru(s). It is suggested that the remarkable heavy atom tunneling, found in this system, is related...

  18. A new angle and its relationship with early fixation failure of femoral neck fractures treated with three cannulated compression screws.

    Zhang, Y L; Zhang, W; Zhang, C Q

    2017-04-01

    The Pauwels angle has been used widely, however an accurate evaluation of this angle is difficult because of deformity of the affected lower extremity. Therefore we designed a new measurement of the orientation of femoral neck fracture and applied this in a retrospective study to assess: (1) its reproducibility, (2) its advantages compared with the Pauwels angle, (3) its relationship with the short-term prognosis treated with three cannulated compression screws. This new measurement is reproducible and has some reference meaning for the treatment of femoral neck fractures. Two hundred and twenty-eight patients with femoral neck fractures treated with three cannulated compression screws were retrospectively analyzed. The VN angle, which was the angle between the fracture line and the vertical of the neck axis, and the Pauwels angle were measured respectively. The method of ICC was performed to assess the reproducibility of the two angles, and the absolute value of difference in pre-operative and post-operative radiographs was used to evaluate the uniformity of the two angles. These fractures were divided into four groups according to VN angle (VN50°) were respectively 0%, 1.46% (95% CI: 1.42-1.50) and 36.24% (95% CI: 34.93-37.54). The VN angle has a good inter-rater reproducibility, a higher reliability than the Pauwels angle and is closely related to the short-term prognosis of femoral neck fractures treated with cannulated compression screws. Level IV, retrospective diagnostic study. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  19. Tunneling progress on the Yucca Mountain Project

    Hansmire, W.H.; Munzer, R.J.

    1996-01-01

    The current status of tunneling progress on the Yucca Mountain Project (YMP) is presented in this paper. The Exploratory Studies Facility (ESF), a key part of the YMP, has been long in development and construction is ongoing. This is a progress report on the tunneling aspects of the ESF as of January 1, 1996. For purposes of discussion in this summary, the tunneling has progressed in four general phases. The paper describes: tunneling in jointed rock under low stress; tunneling through the Bow Ridge Fault and soft rock; tunneling through the Imbricate Fault Zone; and Tunneling into the candidate repository formation

  20. Tunnel magnetoresistance in asymmetric double-barrier magnetic tunnel junctions

    Useinov, N.Kh.; Petukhov, D.A.; Tagirov, L.R.

    2015-01-01

    The spin-polarized tunnel conductance and tunnel magnetoresistance (TMR) through a planar asymmetric double-barrier magnetic tunnel junction (DBMTJ) have been calculated using quasi-classical model. In DBMTJ nanostructure the magnetization of middle ferromagnetic metal layer can be aligned parallel or antiparallel with respect to the fixed magnetizations of the top and bottom ferromagnetic electrodes. The transmission coefficients of an electron to pass through the barriers have been calculated in terms of quantum mechanics. The dependencies of tunnel conductance and TMR on the applied voltage have been calculated in case of non-resonant transmission. Estimated in the framework of our model, the difference between the spin-channels conductances at low voltages was found relatively large. This gives rise to very high magnitude of TMR. - Highlights: • The spin-polarized conductance through the junction is calculated. • Dependencies of the tunnel conductance vs applied bias are shown. • Bias voltage dependence of tunnel magnetoresistance for the structure is shown

  1. Tunneling through landsliding zone; Jisuberi chitainai no tunnel seko

    Konbu, A; Hatabu, K; Kano, T [Tekken Corp., Tokyo (Japan)

    1994-08-01

    At the new tunnel construction site of the Shirakata tunnel on the Obama line in Yamaguchi Prefecture, a landsliding occurred at about 60 meters to the upper portion obliquely to the right hand side of the shaft when the excavation progressed to about 10 meters from the starting side. The landslide caused displacement at the shaft opening and change in the supports. As a result of the re-investigation, it was confirmed that the slide face went through the tunnel cross section. The measures taken were removal of the upper soil and an adoption of the all ground fastening (AGF) method (injection type long tip fastening method) as an auxiliary construction to stop loosening of the natural ground associated with the tunnel excavation. The result was a completion of tunneling the landsliding zone without a problem. This paper reports the AGF method adopted in the above construction, together with the construction works and natural ground conditions. The AGF method is about the same as the pipe roof method with regard to the natural ground accepting mechanism and the materials used. The difference is building an improved body in a limited area in the natural ground around the steel pipes by injecting the fixing material. The use of this method caused no problems in subsidence and displacement in the surrounding ground, and completed the tunneling construction without an unusual event. 1 ref., 7 figs., 2 tabs.

  2. A STUDY OF UNSTABLE INTERTROCHANTERIC FEMORAL FRACTURES TREATED BY TROCHANTERIC FEMORAL NAIL

    Sreenivasa Neikar

    2017-11-01

    Full Text Available BACKGROUND Intertrochanteric fracture is one of the most common fracture of the hip especially in the elderly. The incidence of intertrochanteric fracture is rising because of the increase in number of elderly population along with superadded osteoporosis. MATERIALS AND METHODS Study included cases of unstable intertrochanteric fractures (AO and OTA Classification 31-A2 and 31-A3 fracture patterns that were operated with the short trochanteric femoral nail, which fitted into the inclusion criteria done in medical college hospital, Vijayanagara Institute of Medical Sciences, Bellary, from February 2015 to September 2016. RESULTS The age distribution was from 40 to 80 years. The largest group of patients were from 61 to 70 years. The average age was 60.5 years. The number of male patients in our series was 20 (66.7% and female was 10 (33.3%. Right side was affected in 11 cases (36.7% and left side in 19 cases (63.3%. Good reduction was achieved in 23 patients (76.7%. Acceptable reduction was achieved in 7 (23.3% patients due to severe comminution. In our study, 25 patients (83.33% had no complications. We encountered one intraoperative complication in the form of greater trochanter splintering, while inserting the nail. In our study, we encountered following postoperative complications. We noticed one case of delayed union, one case of Z effect and 2 cases of varus malunion. CONCLUSION We conclude that short trochanteric femoral nail provides good fixation for unstable intertrochanteric fractures if proper preoperative planning, good reduction and surgical technique are followed leading to high rate of bone union and minimal soft tissue damage especially for Asian patients with relatively small femora.

  3. A Case of Late Femoral Pseudoaneurysm Caused by Stent Disconnection

    Rivolta, Nicola; Fontana, Federico; Piffaretti, Gabriele; Tozzi, Matteo; Carrafiello, Gianpaolo

    2010-01-01

    We present the case of a late superficial femoral artery stent disconnection causing an asymptomatic pseudoaneurysm successfully treated with a stent-graft. A 67-year-old female was referred to our department for evaluation of claudication of the left lower limb and was diagnosed to have a total occlusion of the superficial femoral artery. Three nitinol stents were used to revascularize this artery. At 48 months, duplex-ultrasonography control revealed the presence of a 45-mm saccular femoral dilatation; X-rays and CT angiography showed fractures of the proximal stents and the presence of a pseudoaneurysm at the site of the distal stents disconnection. The pseudoaneurysm was excluded using two stent-grafts. We conclude that patients and surgeons should be aware of structural complications with all stents. Rigorous follow-up controls should be mandatory. Endovascular repair proved to be feasible and durable to manage a previous endovascular procedure.

  4. Femoral arteriographic finding in acute ergotism: Report of A Case

    Rhee, H S; Lee, K N; Cha, S B [St. Mary' s Hospital, Catholic Medical College, Seoul (Korea, Republic of)

    1971-10-15

    A case of acute ergotism with angiographic demonstration of bilateral femoral artery involvement is reported. A 27-year-old married woman was admitted because of sudden onset of severe pain in both flanks and lower legs, followed by numbness and coldness of the skin on both legs. The attack occurred after the administration of ergot tartrate as postpartum care. Femoral arteriography was performed on 10th day of illness with the Seldinger technic. The femoral arteries were generally smaller in caliber than normal. There was no definite evidence of occlusive disease. Findings were more or less symmetrical and extended to lower legs where only fine branches were visualized. The final diagnosis was diffuse vasospasm due to acute ergotism with secondary occlusion of the arteries of lower leg bilaterally.

  5. Emergency Stenting of a Ruptured Infected Anastomotic Femoral Pseudoaneurysm

    Klonaris, Chris; Katsargyris, Athanasios; Matthaiou, Alexandros; Giannopoulos, Athanasios; Tsigris, Chris; Papadopouli, Katerina; Tsiodras, Sotiris; Bastounis, Elias

    2007-01-01

    A 74-year-old man presented with a ruptured infected anastomotic femoral pseudoaneurysm. Due to severe medical comorbidities he was considered unsuitable for conventional surgical management and underwent an emergency endovascular repair with a balloon-expandable covered stent. The pseudoaneurysm was excluded successfully and the patient had an uneventful postoperative recovery with long-term suppressive antimicrobials. He remained well for 10 months after the procedure with no signs of recurrent local or systemic infection and finally died from an acute myocardial infarction. To our knowledge, emergency endovascular treatment of a free ruptured bleeding femoral artery pseudoaneurysm has not been documented before in the English literature. This case illustrates that endovascular therapy may be a safe and efficient alternative in the emergent management of ruptured infected anastomotic femoral artery pseudoaneurysms when traditional open surgery is contraindicated

  6. Femoral arteriographic finding in acute ergotism: Report of A Case

    Rhee, H. S.; Lee, K. N.; Cha, S. B.

    1971-01-01

    A case of acute ergotism with angiographic demonstration of bilateral femoral artery involvement is reported. A 27-year-old married woman was admitted because of sudden onset of severe pain in both flanks and lower legs, followed by numbness and coldness of the skin on both legs. The attack occurred after the administration of ergot tartrate as postpartum care. Femoral arteriography was performed on 10th day of illness with the Seldinger technic. The femoral arteries were generally smaller in caliber than normal. There was no definite evidence of occlusive disease. Findings were more or less symmetrical and extended to lower legs where only fine branches were visualized. The final diagnosis was diffuse vasospasm due to acute ergotism with secondary occlusion of the arteries of lower leg bilaterally

  7. Avascular Necrosis of the Femoral Head: Are Any Genes Involved?

    Pouya, Farzaneh; Kerachian, Mohammad Amin

    2015-01-01

    Avascular necrosis of the femoral head (ANFH) is a pathologic process that results from interruption of blood supply to the femur bone resulting in the death of bone cells and collapse of the femoral head. Nontraumatic ANFH continues to be a significant challenge to orthopedic surgeons. While the exact mechanisms remain elusive, many new insights have emerged from research in the last decade that has given us a clearer picture of the pathogenesis of nontraumatic ANFH. Progression to the end stage of ANFH appears to be related to five main mechanisms: hypercoagulable conditions, angiogenesis suppressions, hyperadipogenesis, heritable states, and switching the bone remodelling into bone resorption. Researchers have been examining the pathogenic mechanisms of ANFH but none of these theories have been firmly confirmed although some appear more plausible than the others. All of these factors can switch bone remodelling into bone resorption, which can further lead to ANFH progression ending up to femoral head collapse. PMID:26213697

  8. Assessment of femoral head perfusion by dynamic MR imaging

    Ochi, Ryuya; Nakano, Tetsuo; Miyazono, Kazuki; Tsurugami, Hiroshi; Fukuda, Tomohiro; Inaba, Daisuke; Takada, Koji

    2004-01-01

    We studied femoral head perfusion in 21 femoral neck fractures using dynamic MR imaging (MRI) between November 2001 and July 2002. MRI patterns divided into four groups when the results between the fractured side and unaffected side were compared. Femoral head perfusion at the fractured side was normal in Type A, about half in Type B, and absent in Type C. When perfusion at both the fractured side and unaffected side was absent, Exceptional Type was suspected. The Garden I group consisted of one Type B. The Garden II group consisted of one Type A, six Type B, one Type C, and two Exceptional Type. The Garden III group consisted of two Type B and one Type C, and the Garden IV group consisted of six Type C and one Exceptional Type. Post operations of by internal fixation confirmed the incidence of aseptic necrosis using MRI. (author)

  9. A cementless, proximally fixed anatomic femoral stem induces high micromotion with nontraumatic femoral avascular necrosis: A finite element study

    Wen-Chuan Chen

    2014-07-01

    Full Text Available Decrease in bone mineral density of metaphysis in patients with nontraumatic avascular necrosis of the femoral head (AVN is considered the main factor leading to aseptic loosening of the femoral component. Researchers have hypothesized that a cementless, anatomic stem fixed proximally to the metaphysis has a higher risk for aseptic loosening than a straight stem that is fixed at the diaphysis in patients with nontraumatic AVN. The purpose of the current study was to evaluate the effects of cancellous bone stiffness at the metaphysis and stem geometry on the micromotion of the femoral stem relative to the femur. The VerSys (straight and ABG (anatomic femoral stems were enrolled in this finite element study to determine the performance of prosthetic micromotion. The simulated load to the hip joint during heel strike was assigned. Results showed that the VerSys model represented better resistance in micromotion between the bone/stem interface than the ABG model in either normal or poor cancellous bone stiffness at the metaphysis. The bone quality at the metaphysis of patients with nontraumatic AVN should be considered prior to selecting a femoral stem. In consideration of initial stability, acementless, straight stem that fits the isthmus is more favourable than an anatomic stem that is fixed to the proximal area of the canal.

  10. A micro-architectural evaluation of osteoporotic human femoral heads to guide implant placement in proximal femoral fractures.

    Jenkins, Paul J; Ramaesh, Rishikesan; Pankaj, Pankaj; Patton, James T; Howie, Colin R; Goffin, Jérôme M; Merwe, Andrew van der; Wallace, Robert J; Porter, Daniel E; Simpson, A Hamish

    2013-10-01

    The micro-architecture of bone has been increasingly recognized as an important determinant of bone strength. Successful operative stabilization of fractures depends on bone strength. We evaluated the osseous micro-architecture and strength of the osteoporotic human femoral head. 6 femoral heads, obtained during arthroplasty surgery for femoral neck fracture, underwent micro-computed tomography (microCT) scanning at 30 μm, and bone volume ratio (BV/TV), trabecular thickness, structural model index, connection density, and degree of anisotropy for volumes of interest throughout the head were derived. A further 15 femoral heads underwent mechanical testing of compressive failure stress of cubes of trabecular bone from different regions of the head. The greatest density and trabecular thickness was found in the central core that extended from the medial calcar to the physeal scar. This region also correlated with the greatest degree of anisotropy and proportion of plate-like trabeculae. In the epiphyseal region, the trabeculae were organized radially from the physeal scar. The weakest area was found at the apex and peripheral areas of the head. The strongest region was at the center of the head. The center of the femoral head contained the strongest trabecular bone, with the thickest, most dense trabeculae. The apical region was weaker. From an anatomical and mechanical point of view, implants that achieve fixation in or below this central core may achieve the most stable fixation during fracture healing.

  11. Orienteering Club

    Club d'orientation

    2013-01-01

    Course d'orientation Le coup d’envoi de la coupe genevoise a été donné samedi 31 août dans les bois de Combe Froide à Prémanon. Plus de 150 coureurs avaient fait le déplacement. Les parcours facile court, facile moyen et technique court ont été remportés par des coureurs du club O’Jura - Ulysse Dannecker, Léo Lonchampt, Franck Lonchampt, le technique moyen par Pekka Marti du club Ol Biel Seeland et le technique long par Térence Risse du CA Rosé – également membre de l’équipe nationale suisse des moins de 20 ans. Pour le club du CERN, les meilleures résultats ont été obtenus pas Emese Szunyog sur technique court et Marie Vuitton sur technique moyen avec une 4e place. La prochaine course aura lieu samedi 14 septembre à La Faucille. Le club propose aussi...

  12. Orienteering club

    Club d'orientation

    2014-01-01

    Course d'orientation Finale de la coupe d’automne La dernière épreuve de la coupe d’automne organisée par le club s’est déroulée ce samedi 1er novembre avec une course type «one-man-relay» dans la forêt de Trelex (Vd). Les concurrents des circuits techniques devaient parcourir trois boucles et ceux des circuits «faciles» deux boucles, avec changements de carte. Le parcours technique long a été remporté par un membre du club, Berni Wehrle. A l’issue de cette course, le Président du club, L. Jirden annonçait le classement général de la coupe d’automne, basé sur les 6 meilleurs résultats de la saison : Circuit technique long : 1er Juerg Niggli (O’Jura), 2e Berni Wehrle, 3e Beat Mueller. Circuit technique moyen : 1er Laurent Merat (O&r...

  13. Orienteering club

    Club d'orientation

    2013-01-01

    Course d'orientation Finale de la coupe genevoise Rapide et méthodique, voilà les qualités dont il fallait faire preuve pour remporter la dernière étape de la coupe organisée par le club du CERN dans les bois de Monteret. Il s’agissait d’une course au score où chaque concurrent disposait d’un temps imparti pour poinçonner le maximum de balises. Le parcours technique a été remporté par Tomas Shellman et le parcours facile par Victor Dannecker. Cette dernière étape était aussi décisive pour la désignation des lauréats de la coupe genevoise de printemps. Les résultats officiels étaient donnés par le président du club, L. Jirden : Circuit Technique Long : Berni Wehrle, Bruno Barge, Edvins Reisons Circuit Technique Moyen : J.-Bernard Zosso, ...

  14. Orienteering Club

    Club d'Orientation

    2011-01-01

    Course d'orientation Avec la CO en nocturne organisée par le club du CERN vendredi 14 octobre au stade des Eveaux (Ge), et la CO à Savigny (Vd) proposée par le club de Lausanne-Jorat le lendemain, les étapes de la coupe genevoise d’automne s’enchainent rapidement. Il ne reste plus que 3 rendez-vous pour boucler la saison. Les premières places devraient certainement se jouer entre des membres du club du CERN, du O’Jura ou de Lausanne-Jorat. La prochaine course du club est programmée pour samedi 22 octobre à Pomier, près de Cruseilles. L’accueil se fera à partir de 12h30 et les départs s’échelonneront de 13h à 15h. * * * * * * * Nouvelle belle victoire samedi 8 octobre à Saint Cergue du jeune finlandais Ville Keskisaari (COLJ) en 50:56 devant Jürg Niggli (O’Jura) en 1:03:32, et Alexandre...

  15. Orienteering Club

    Club d'orientation

    2013-01-01

    De jour comme de nuit Les amateurs de course d’orientation ont pu s’en donner à cœur joie ce week-end puisqu’ils avaient la possibilité de courir sur deux épreuves en moins de 24 heures. En effet, le club du CERN organisait une course de nuit aux Evaux et la 7e étape de la coupe genevoise se tenait samedi après-midi dans les bois du Grand Jorat à Savigny. Les vainqueurs pour chaque course sont : Technique long CO de nuit: Julien Charlemagne, SOS Sallanches CO samedi: Philipp Khlebnikov, ANCO   Technique moyen CO de nuit: Céline Zosso, CO CERN CO samedi: Pavel Khlebnikov, ANCO Technique court CO de nuit: Colas Ginztburger, SOS Sallanches CO samedi: Victor Kuznetsov, COLJ Lausannne Facile moyen CO de nuit: Gaëtan Rickenbacher, CO CERN CO samedi: Tamas Szoke   Facile court CO de nuit:Oriane Rickenbacher, CO CERN CO samedi: Katya Kuznetsov...

  16. Orienteering Club

    Club d'Orientation

    2015-01-01

    Course orientation Finale de la coupe genevoise La série des courses de printemps s’est achevée samedi dernier dans les bois de Bonmont (Vaud) avec une épreuve «one-man-relay» organisée par le club. Le vainqueur du parcours technique  long, Yann Locatelli (Club de Chambéry Savoie) a réalisé les deux boucles comportant 24 balises avec presque 6 minutes d’avance sur le second concurrent Domenico Lepori (Club CARE Vevey). Cette dernière étape était aussi décisive pour la désignation des lauréats de la coupe genevoise de printemps, en comptabilisant les 6 meilleurs résultats sur les 10 épreuves. Le podium officiel était donné par le président du club, L. Jirden, qui profitait de l’occasion pour remercier tous les participants et également tous les...

  17. Orienteering Club

    CLUB D'ORIENTATION

    2013-01-01

    Calendrier de la coupe d’automne Le Club d’orientation du CERN, en partenariat avec d’autres clubs de la région, vous propose, pour cette nouvelle coupe d’automne genevoise, une série de 10 courses. Le club du O’Jura donnera le coup d’envoi le samedi 31 août. Les courses s’enchaîneront selon le calendrier suivant : Samedi 31 août : Prémanon (39) - longue distance Samedi 14 septembre : La Faucille (01) - longue distance Samedi 21 septembre : Saint Cergue (VD) - longue distance Samedi 28 septembre : Ballens (VD) - relais Samedi 5 octobre : La Pile (VD) - longue distance Vendredi 11 octobre : Les Evaux (GE) - nocturne Samedi 12 octobre : Grand Jorat, Savigny (VD) - longue distance Samedi 19 octobre : Terrasses de Genève (74) - longue distance Samedi 26 octobre : Prémanon (39) - longue distance Samedi 2 novembre : Bois Tollot (GE) - score - Finale Les &a...

  18. Orienteering club

    Club d'orientation

    2014-01-01

    Course d'orientation C’est sous un beau soleil samedi 4 octobre que s’est déroulée la 6e étape de la Coupe genevoise d’automne organisée par le club. Plus d’une centaine de concurrents provenant de 7 clubs de CO avaient fait le déplacement pour courir sur un des cinq parcours proposés dans les bois de Trélex-Génolier (VD). Le podium est le suivant : Technique long (5,9 km, 19 postes) : 1er Jurg Niggli, O’Jura (1:00:02); 2e Berni Wehrle, CO CERN (1:06:44); 3e Konrad Ehrbar, COLJ (1:07:08) Technique moyen (4,8 km, 18 postes) : 1er Christophe Vuitton, CO CERN (54:25); 2e J.B. Zosso, CO CERN (1:01:19); 3e Jeremy Wichoud, COLJ (1:06:21) Technique court (3,8 km, 14 postes) : 1er Julien Vuitton, CO CERN (36:19); 2e Vladimir Kuznetsov, COLJ (48:47); 3e Natalia Niggli, O’Jura (50:38) Facile moyen (3,2 km, 11 postes) : 1ère Alina Niggli, O&...

  19. Orienteering Club

    Club d'Orientation

    2012-01-01

    Relais inter-club/Challenge Carlo Milan Samedi dernier, lors de l’épreuve de course d’orientation organisée par le club du O’Jura, le moteur de la discipline était l’esprit d’équipe, puisqu’il était question d’un relais inter-club avec le Challenge Carlo Milan. Les clubs avaient aligné leurs coureurs soit sur le relais technique (trois participants) soit sur le relais facile (deux participants). Côté O’Jura, il fallait noter la participation de François Gonon, champion du monde 2011, côté club du CERN, Marie et Gaëtan Vuitton, jeunes espoirs du club, devaient préparer la piste pour lancer le dernier relayeur. Côté Lausanne-Jorat, il fallait compter sur le très jeune Viktor Kuznetsov. Les 31 équipes engagées n’ont pas m&ea...

  20. Orienteering Club

    Club d'Orientation

    2012-01-01

     Finale de la coupe de printemps   La dernière course d’orientation comptant pour la Coupe de printemps a eu lieu samedi dernier dans le village des Rousses et vers le Fort. Il s’agissait d’un sprint organisé par le club O’Jura. Les temps de course ont avoisiné les 20 minutes que ce soit pour le parcours technique moyen ou technique long. Tous les habitués étaient au rendez-vous pour venir consolider ou améliorer leur place au classement. A l’issue de cette course, le classement général de la Coupe de printemps prenant en compte les 6 meilleurs résultats des 9 courses était établi et les lauréats de chaque catégorie sont les suivants: Circuit technique long : 1er Berni Wehrle, 2e Bruno Barge, 3e Edvins Reisons. Circuit technique moyen : 1er Jean-Bernard Zosso, 2e Cédric Wehrl&...

  1. Orienteering club

    Club d'orientation

    2010-01-01

    COURSE D’ORIENTATION  De La Rippe à Sauvabellin, la coupe genevoise continue ! Le rendez-vous était donné samedi 8 mai aux amateurs de course d’orientation dans les bois de La Rippe (Canton de Vaud). Cette 6e épreuve était organisée par le Club Satus Grutli de Genève. Il est dommage que les participants n’aient pas été aussi nombreux que lors des dernières courses, les Championnats de France des clubs à Dijon ayant certainement retenus plus d’un compétiteur. La première place est revenue à : – Technique long : Berni Wehrle – Technique moyen : Jean-Bernard Zosso – Technique court : Berni Wehrle – Facile moyen : Peter Troscanyi – Facile court : Claire Droz. Il ne restera plus que deux épreuves ...

  2. Orienteering club

    Club d'orientation

    2013-01-01

    Courses d’orientation Samedi 20 avril, les organisateurs du Club de CO du CERN ont accueilli au Mont Mourex 70 participants qui n’ont pas hésité à venir malgré la forte bise. Berni Wehrle du CO CERN s’est octroyé la première place en 1:04:49 sur le parcours technique long devant Pyry Kettunen du Saynso Juankoski en 1:06:52, la 3e place revenant à Bruno Barge, CO CERN, à 7 secondes. Les autres parcours ont été remportés par : Technique moyen : 1er Jacques Moisset, Chamonix (47:44), 2e Yves Rousselot, Balise 25 Besançon (57:16), 3e Jean-Bernard Zosso, CO CERN (59:28). Technique court : 1er Victor Kuznetsov, COLJ (51:53), 2e Pierrick Collet, CO CERN (1:12:52), 3e Dominique Balay, CO CERN (1:16:04). Pour les parcours facile moyen et facile court, Ralf Nardini et Léa Nicolas, tous deux du CO CERN, terminaient respectivement premier. Voi...

  3. FUNDAMENTAL TUNNELING PROCESSES IN MOSa SOLAR CELLS

    Balberg , I.; Hanak , J.; Weakliem , H.; Gal , E.

    1981-01-01

    In previous studies of tunneling through a MOSa tunnel junction, where Sa was a-Si : H, it was shown that their characteristics resemble those of MOSc devices where Sc was crystalline silicon. In the present work we would like to report a demonstration of fundamental tunneling processes in such tunnel junctions. In particular, the transition from semiconductor controlled regime to tunneling controlled regime can be clearly distinguished. The present results represent one of the rare cases whe...

  4. Destructive quantum interference in spin tunneling problems

    von Delft, Jan; Henley, Christopher L.

    1992-01-01

    In some spin tunneling problems, there are several different but symmetry-related tunneling paths that connect the same initial and final configurations. The topological phase factors of the corresponding tunneling amplitudes can lead to destructive interference between the different paths, so that the total tunneling amplitude is zero. In the study of tunneling between different ground state configurations of the Kagom\\'{e}-lattice quantum Heisenberg antiferromagnet, this occurs when the spi...

  5. 13th Australian tunnelling conference. Proceedings

    NONE

    2008-07-01

    The theme of the conference was 'Engineering in a changing environment'. Topics covered include Australian tunnelling projects, design and development of ground support, tunnelling, international projects, fire and life safety, mining projects, risk management in tunnelling, and tunnel boring machine tunnelling. Papers of particular interest to the coal industry are: improving roadway development in underground coal mine (G. Lewis and G. Gibson), and polymer-based alternative to steel mesh for coal mine strata reinforcement (C. Lukey and others).

  6. Tunnelling instability via perturbation theory

    Graffi, S. (Bologna Univ. (Italy). Dip. di Matematica); Grecchi, V. (Moderna Univ. (Italy). Dip. di Matematica); Jona-Lasinio, G. (Paris-11 Univ., 91 - Orsay (France). Lab. de Physique Theorique et Hautes Energies)

    1984-10-21

    The semiclassical limit of low lying states in a multiwell potential is studied by rigorous perturbative techniques. In particular tunnelling instability and localisation of wave functions is obtained in a simple way under small deformations of symmetric potentials.

  7. Scanning Tunneling Microscopy - image interpretation

    Maca, F.

    1998-01-01

    The basic ideas of image interpretation in Scanning Tunneling Microscopy are presented using simple quantum-mechanical models and supplied with examples of successful application. The importance is stressed of a correct interpretation of this brilliant experimental surface technique

  8. Electron tunneling in proteins program.

    Hagras, Muhammad A; Stuchebrukhov, Alexei A

    2016-06-05

    We developed a unique integrated software package (called Electron Tunneling in Proteins Program or ETP) which provides an environment with different capabilities such as tunneling current calculation, semi-empirical quantum mechanical calculation, and molecular modeling simulation for calculation and analysis of electron transfer reactions in proteins. ETP program is developed as a cross-platform client-server program in which all the different calculations are conducted at the server side while only the client terminal displays the resulting calculation outputs in the different supported representations. ETP program is integrated with a set of well-known computational software packages including Gaussian, BALLVIEW, Dowser, pKip, and APBS. In addition, ETP program supports various visualization methods for the tunneling calculation results that assist in a more comprehensive understanding of the tunneling process. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  9. Tunneling Plasmonics in Bilayer Graphene.

    Fei, Z; Iwinski, E G; Ni, G X; Zhang, L M; Bao, W; Rodin, A S; Lee, Y; Wagner, M; Liu, M K; Dai, S; Goldflam, M D; Thiemens, M; Keilmann, F; Lau, C N; Castro-Neto, A H; Fogler, M M; Basov, D N

    2015-08-12

    We report experimental signatures of plasmonic effects due to electron tunneling between adjacent graphene layers. At subnanometer separation, such layers can form either a strongly coupled bilayer graphene with a Bernal stacking or a weakly coupled double-layer graphene with a random stacking order. Effects due to interlayer tunneling dominate in the former case but are negligible in the latter. We found through infrared nanoimaging that bilayer graphene supports plasmons with a higher degree of confinement compared to single- and double-layer graphene, a direct consequence of interlayer tunneling. Moreover, we were able to shut off plasmons in bilayer graphene through gating within a wide voltage range. Theoretical modeling indicates that such a plasmon-off region is directly linked to a gapped insulating state of bilayer graphene, yet another implication of interlayer tunneling. Our work uncovers essential plasmonic properties in bilayer graphene and suggests a possibility to achieve novel plasmonic functionalities in graphene few-layers.

  10. Shaft and tunnel sealing considerations

    Kelsall, P.C.; Shukla, D.K.

    1980-01-01

    Much of the emphasis of previous repository sealing research has been placed on plugging small diameter boreholes. It is increasingly evident that equal emphasis should now be given to shafts and tunnels which constitute more significant pathways between a repository and the biosphere. The paper discusses differences in requirements for sealing shafts and tunnels as compared with boreholes and the implications for seal design. Consideration is given to a design approach for shaft and tunnel seals based on a multiple component design concept, taking into account the requirements for retrievability of the waste. A work plan is developed for the future studies required to advance shaft and tunnel sealing technology to a level comparable with the existing technology for borehole sealing

  11. Organic tunnel field effect transistors

    Tietze, Max Lutz; Lussem, Bjorn; Liu, Shiyi

    2017-01-01

    Various examples are provided for organic tunnel field effect transistors (OTFET), and methods thereof. In one example, an OTFET includes a first intrinsic layer (i-layer) of organic semiconductor material disposed over a gate insulating layer

  12. Bijzondere belastingen in tunnels : Eindrapport

    Molenaar, D.J.; Weerheijm, J.; Vervuurt, A.; Burggraaf, H.; Roekaerts, D.; Meijers, P.

    2009-01-01

    Verkeerstunnels en overkapte wegen (landtunnels) komen de milieukundige en stedenbouwkundige inpassing ten goede en maken meervoudig ruimtegebruik in de stad mogelijk. Het aantal tunnels en overkappingen groeit dan ook. Dit maakt het vervoer van explosiegevaarlijke stoffen en onder hoge druk

  13. Free Surface Water Tunnel (FSWT)

    Federal Laboratory Consortium — Description: The Free Surface Water Tunnel consists of the intake plenum, the test section and the exit plenum. The intake plenum starts with a perforated pipe that...

  14. Image features of herniation pit of the femoral neck

    Zhang Xuezhe; Li Guangming; Wang Cunli; Wang Guimin

    2008-01-01

    Objective: To evaluate imaging appearances of herniation pit of the femoral neck. Methods: We retrospectively analyzed the X-ray, CT and MRI findings of 9 patients with herniation pit of the femoral neck. All nine patients were male with the age ranging from 21 to 73 years. They had pain in the hip from two months to two years duration. Results: The bilateral hips were affected in six patients, the right hips in the other 3 patients. Of the nine patients, X-ray plain films (2 cases), CT scanning(6 cases), and MR scanning (5 cases ) were performed. The size of the lesions ranged from 0.5 cm x 0.6 cm to 1.0 cm x 1.5 cm, located in the anterosuperior portion of the femoral neck (n=7) or anteroinferior portion (n=2). X-ray plain films showed an osteolytic lesion surrounded by a sclerotic rim. CT scanning showed the lesion just below the cortex of the femoral neck surrounded by a rim of sclerosis or associated with a small cortical break in two patients. MR scanning showed low signal intensity in five patients on T 1 WI and high signal intensity surrounded by a rim of low signal intensity (n=3) or low signal intensity (n=2) on T 2 WI, and high signal intensity on fat suppression MR image. A small joint effusion was observed in two cases on T 2 WI. Conclusion: The CT and MRI findings of herniation pit of the femoral neck are characteristic, it is useful in defining the diagnosis of the herniation pit of the femoral neck. (authors)

  15. Biophysical stimulation in osteonecrosis of the femoral head

    Massari Leo

    2009-01-01

    Full Text Available Osteonecrosis of the femoral head is the endpoint of a disease process that results from insufficient blood flow and bone-tissue necrosis, leading to joint instability, collapse of the femoral head, arthritis of the joint, and total hip replacement. Pain is the most frequent clinical symptom. Both bone tissue and cartilage suffer when osteonecrosis of the femoral head develops. Stimulation with pulsed electromagnetic fields (PEMFs has been shown to be useful for enhancing bone repair and for exerting a chondroprotective effect on articular cartilage. Two Italian studies on the treatment of avascular necrosis of the femoral head with PEMFs were presented in this review. In the first study, 68 patients suffering from avascular necrosis of the femoral head were treated with PEMFs in combination with core decompression and autologous bone grafts. The second one is a retrospective analysis of the results of treatment with PEMFs of 76 hips in 66 patients with osteonecrosis of the femoral head. In both studies clinical information and diagnostic imaging were collected at the beginning of the treatment and at the time of follow up. Statistical analysis was performed using chi-square test. Both authors hypothesize that the short-term effect of PEMF stimulation may be to protect the articular cartilage from the catabolic effect of inflammation and subchondral bone-marrow edema. The long-term effect of PEMF stimulation may be to promote osteogenic activity at the necrotic area and prevent trabecular fracture and subchondral bone collapse. PEMF stimulation represents an important therapeutic opportunity to resolve the Ficat stage-I or II disease or at least to delay the time until joint replacement becomes necessary.

  16. Direct, coherent and incoherent intermediate state tunneling and scanning tunnel microscopy (STM)

    Halbritter, J.

    1997-01-01

    Theory and experiment in tunneling are still qualitative in nature, which hold true also for the latest developments in direct-, resonant-, coherent- and incoherent-tunneling. Those tunnel processes have recently branched out of the field of ''solid state tunnel junctions'' into the fields of scanning tunnel microscopy (STM), single electron tunneling (SET) and semiconducting resonant tunnel structures (RTS). All these fields have promoted the understanding of tunneling in different ways reaching from the effect of coherence, of incoherence and of charging in tunneling, to spin flip or inelastic effects. STM allows not only the accurate measurements of the tunnel current and its voltage dependence but, more importantly, the easy quantification via the (quantum) tunnel channel conductance and the distance dependence. This new degree of freedom entering exponentially the tunnel current allows an unique identification of individual tunnel channels and their quantification. In STM measurements large tunnel currents are observed for large distances d > 1 nm explainable by intermediate state tunneling. Direct tunneling with its reduced tunnel time and reduced off-site Coulomb charging bridges distances below 1 nm, only. The effective charge transfer process with its larger off-site and on-site charging at intermediate states dominates tunnel transfer in STM, biology and chemistry over distances in the nm-range. Intermediates state tunneling becomes variable range hopping conduction for distances larger than d > 2 nm, for larger densities of intermediate states n 1 (ε) and for larger temperatures T or voltages U, still allowing high resolution imaging

  17. Quantum resonances in physical tunneling

    Nieto, M.M.; Truax, D.R.

    1985-01-01

    It has recently been emphasized that the probability of quantum tunneling is a critical function of the shape of the potential. Applying this observation to physical systems, we point out that in principal information on potential surfaces can be obtained by studying tunneling rates. This is especially true in cases where only spectral data is known, since many potentials yield the same spectrum. 13 refs., 10 figs., 1 tab

  18. Stress fracture of the femoral neck in a child (stress fracture)

    Coldwell, D.; Gross, G.W.; Boal, D.K.

    1984-01-01

    Femoral neck stress fracture is extremely rare in childhood. We report a case of femoral neck stress fracture in an 11-year-old girl. Differentials diagnosis and a brief review of the literature follow. (orig.)

  19. The treatment of nonisthmal femoral shaft nonunions with im nail exchange versus augmentation plating.

    Park, Jin; Kim, Sul Gee; Yoon, Han Kook; Yang, Kyu Hyun

    2010-02-01

    The purpose of this study was to compare the results between exchange nailing (EN) and augmentation plating (AP) with a nail left in situ for nonisthmal femoral shaft nonunion after femoral nailing. : Retrospective data analysis, November 1996-March 2006. A level I trauma center. Eighteen patients with 18 nonisthmal femoral nonunions. Seven patients with 7 fractures treated for nonisthmal femoral shaft nonunions after femoral nailing with EN and 11 patients with 11 fractures treated for nonisthmal femoral shaft nonunions after nailing with AP combined with bone grafting. Union and complications. Five nonunions in the EN group failed to achieve union (72% failure rate), whereas all 11 pseudarthroses in the AP group obtained osseous union. Fisher exact test showed a higher nonunion rate of EN compared with AP for nonisthmal femoral shaft nonunion (odds ratio, 6.5; P = 0.002). AP with autogenous bone grafting may be a better option than EN for nonisthmal femoral nonunions.

  20. Automatic quantification of tibio-femoral contact area and congruity

    Tummala, Sudhakar; Nielsen, Mads; Lillholm, Martin

    2012-01-01

    We present methods to quantify the medial tibio- femoral (MTF) joint contact area (CA) and congruity index (CI) from low-field magnetic resonance imaging (MRI). Firstly, based on the segmented MTF cartilage compartments, we computed the contact area using the Euclidian distance transformation....... The CA was defined as the area of the tibial superior surface and the femoral inferior surface that are less than a voxel width apart. Furthermore, the CI is computed point-by-point by assessing the first- and second-order general surface features over the contact area. Mathematically, it is the inverse...

  1. Morfología femoral proximal en fracturas de cadera

    Calvo de Mora Rebollo, María Jesús; Albareda Albareda, Jorge Cruz; Seral García, Belén; Martín Ruiz, G.; Lasierra Sanromán, José Manuel; Seral Iñigo, Fernando

    2003-01-01

    Es frecuente observar como pacientes que han sufrido una fractura de cadera, si se fracturan posteriormente la cadera contralateral, es del mismo tipo que la primera fractura. El objetivo de este trabajo es tratar de relacional la morfología femoral proximal con la producción de un tipo determinado de fractura. Para ello hemos realizado un estudio prospectivo en 50 pacientes mayores de 65 años, sin distinción de sexo, que han ingresado en nuestro servicio por fractura femoral proximal, 25 ...

  2. Repair of femoral trochanteric osteotomy in the dog

    Whitelock, R.G.; Dyce, J.; Houlton, J.E.F.

    1997-01-01

    The records and radiographs of 24 dogs that underwent femoral trochanteric osteotomy repair were reviewed. Osteotomy repair was performed with either a pin and tension band wire or a lag screw technique. Significant clinical complications associated with the osteotomy were identified in one dog (4 per cent) six weeks after surgery, although abnormal radiographic changes were evident in 15 dogs (62 per cent). The method of repair did not influence healing and there were comparable radiographic complication rates. It is concluded that femoral trochanteric osteotomy is not associated with significant clinical problems, despite a high incidence of abnormal radiographic findings

  3. [SURGICAL HIP DISLOCATION APPROACH FOR TREATMENT OF FEMORAL HEAD FRACTURE].

    Tang, Yanfeng; Liu, Youwen; Zhu, Yingjie; Li, Jianming; Li, Wuyin; Li, Qiyi; Jia, Yudong

    2015-11-01

    To discuss the value of surgical hip dislocation approach in the treatment of femoral head fracture. A retrospectively analysis was made on the clinical data of 15 patients with femoral head fractures treated through surgical hip dislocation approach between January 2010 and February 2013. There were 11 men and 4 women with an average age of 30.8 years (range, 15-63 years). The causes included traffic accident injury in 9 cases, falling injury from height in 5 cases, and sports injury in 1 case. According to Pipkin typing, 2 cases were rated as type I, 7 cases as type II, 1 case as type III, and 5 cases as type IV. The interval of injury and operation was 2-10 days (mean, 4.1 days). Reduction was performed in 10 patients within 6 hours after injury, and then bone traction was given for 4-6 weeks except 5 patients who received reduction in the other hospital. Primary healing of incision was obtained in all patients after surgery without complications of dislocation and lower limbs deep venous thrombosis. The mean follow-up time was 29.9 months (range, 25-36 months). During follow-up, there was no infection, breakage of internal fixation, or nonunion of femoral greater trochanter fracture. In 3 patients having necrosis of the femoral head, 2 had no obvious symptoms [staging as IIa and IIb respectively according to Association Research Circulation Osseous (ARCO) staging system], and 1 (stage IIIb) had nonunion of the femoral neck fracture, who underwent total hip arthroplasty (THA). In 4 patients having myositis ossificans (2 cases of grade I, 1 case of grade II, and 1 case of grade III based on Brooker grading), no treatment was given in 3 cases and the focus was removed during THA in 1 case. According to the Thompson-Epstein scale at last follow-up, the results were excellent in 9 cases, good in 3 cases, fair in 1 case, and poor in 2 cases, and the excellent and good rate was 80%. Surgical hip dislocation approach can not only protect the residual vessels of the

  4. Medial circumflex femoral artery flap for ischial pressure sore

    Palanivelu S

    2009-01-01

    Full Text Available A new axial pattern flap based on the terminal branches of the medial circumflex femoral artery is described for coverage of ischial pressure sore. Based on the terminal branches of the transverse branch of medial circumflex femoral artery, which exit through the gap between the quadratus femoris muscle above and the upper border of adductor magnus muscle below, this fascio cutaneous flap is much smaller than the posterior thigh flap but extremely useful to cover ischeal pressure sores. The skin redundancy below the gluteal fold allows a primary closure of the donor defect. It can also be used in combination with biceps femoris muscle flap.

  5. Case of slipped capital femoral epiphysis following radiation

    Terada, Hiroshi; Usui, Hiroshi; Nakamura, Yutaka; Chiba, Masahiro; Yamaji, Shushin; Oba, Yoshihiro

    1987-06-01

    A 12-year-old boy presented with pain of the right hip joint and claudication. At the age of 7 months, the patient had received prophylactic irradiation of 30 Gy to the pelvic area including lumbar vertebrae and bilateral hip joints following extirpation of the right undescended testicle for embryonal carcinoma. Roentgenograph showed slipped capial femoral epiphysis. A review of the literature suggests that bone growth and hormonal changes in the early stage of puberty are involved, in addition to radiation damaged epiphyseal cartilage, in the pathophysiologic mechanisms of radiation induced slipped capital femoral epiphysis. (Namekawa, K.).

  6. Can femoral dialysis catheter insertion cause a life threatening complication?

    Nurkay Katrancıoğlu

    2014-09-01

    Full Text Available Venous catheter (VC insertion may be necessary for the patients with renal failure facing vascular access problem. Femoral VCs are commonly used for their lower complication rates especially in emergency clinics. The incidence of bleeding associated with VC is reported 0.5-1.6%, however, life threatening hemorrhage and complications requiring surgical intervention are very rare. In this manuscript, we aimed to present a case with hemolytic uremic syndrome complicated with retroperitoneal hematoma after femoral VC insertion. J Clin Exp Invest 2014; 5 (3: 472-474

  7. Postoperative hemoglobin level in patients with femoral neck fracture

    Nagra, Navraj; van Popta, Dmitri; Whiteside, Sigrid; Holt, Edward

    2018-01-01

    Objective: The aim of this study was to analyze the changes of hemoglobin levels in patients undergoing fixation for femoral neck fracture.Methods: Peroperative hemoglobin levels of patients who underwent either dynamic hip screw (DHS) fixation (n=74; mean age: 80 years) or hip hemiarthroplasty (n=104; mean age: 84 years) for femoral neck fracture was monitored.Results: There was a statistically and clinically significant mean drop of 31.1 g/L between the preoperative (D0) and postoperative D...

  8. Identification of avascular necrosis in the dysplastic proximal femoral epiphysis

    Mandell, G.A.; Harcke, H.T.; MacKenzie, W.G.; Bassett, G.S.; Scott, C.I. Jr.; Wills, J.S.

    1989-01-01

    Bilateral radiographic irregularities and deformities of the proximal femoral epiphyses are features of both multiple epiphyseal dysplasia and bilateral idiopathic avascular necrosis. In the past these entities have been difficult to differentiate. This report documents radiographically the occurrence of avascular necrosis in 10 patients with multiple epiphyseal dysplasia by recognizing the superimposition of sclerosis and subchondral fissuring on pre-existing symmetrically irregular proximal femoral ossification centers. Scintigraphic (photopenia) or magnetic resonance (loss of signal) criteria of avascular necrosis confirm its added presence and help to establish an imaging scheme to identify avascular necrosis superimposed on multiple epiphyseal dysplasia. (orig.)

  9. Avascular necrosis associated with nailing of femoral neck fracture

    Stroemqvist, B.; Hansson, L.I.

    1983-01-01

    Two patients with femoral neck fractures, one displaced and one undisplaced, are presented. Preoperative intravital staining with tetracycline and Tc-MDP scintimetry both showed intact femoral head circulation while Tc-MDP-scintimetry 1 week after operation showed pronounced circulatory deficiency. SR 85 -scintimetry performed at the same time was inconclusive. Segmental collapse was observed radiographically, 8 and 12 months postoperatively. The major vascular injury resulting in avascularity most probably occured during the procedure of osteosynthesis, and Tc-MDP-scintimetry was found suitable for early postoperative recognition of avascular necrosis in both fractures. (author)

  10. Identification of avascular necrosis in the dysplastic proximal femoral epiphysis

    Mandell, G A; Harcke, H T [Alfred I. duPont Inst., Wilmington, DE (USA). Dept. of Medical Imaging; MacKenzie, W G; Bassett, G S [Alfred I. duPont Inst., Wilmington, DE (USA). Dept. of Orthopaedics; Scott, Jr, C I [Alfred I. duPont Inst., Wilmington, DE (USA). Dept. of Genetics; Wills, J S [Medical Center of Delaware, Newark, DE (USA). Dept. of Radiology

    1989-07-01

    Bilateral radiographic irregularities and deformities of the proximal femoral epiphyses are features of both multiple epiphyseal dysplasia and bilateral idiopathic avascular necrosis. In the past these entities have been difficult to differentiate. This report documents radiographically the occurrence of avascular necrosis in 10 patients with multiple epiphyseal dysplasia by recognizing the superimposition of sclerosis and subchondral fissuring on pre-existing symmetrically irregular proximal femoral ossification centers. Scintigraphic (photopenia) or magnetic resonance (loss of signal) criteria of avascular necrosis confirm its added presence and help to establish an imaging scheme to identify avascular necrosis superimposed on multiple epiphyseal dysplasia. (orig.).

  11. Avascular necrosis associated with nailing of femoral neck fracture

    Stroemqvist, B; Hansson, L I [Department of Orthopaedic Surgery, University Hospital in Lund, Sweden

    1983-01-01

    Two patients with femoral neck fractures, one displaced and one undisplaced, are presented. Preoperative intravital staining with tetracycline and Tc-MDP scintimetry both showed intact femoral head circulation while Tc-MDP-scintimetry 1 week after operation showed pronounced circulatory deficiency. Sr/sup 85/-scintimetry performed at the same time was inconclusive. Segmental collapse was observed radiographically, 8 and 12 months postoperatively. The major vascular injury resulting in avascularity most probably occured during the procedure of osteosynthesis, and Tc-MDP-scintimetry was found suitable for early postoperative recognition of avascular necrosis in both fractures.

  12. Principle plug design for deposition tunnels

    Haaramo, M.; Lehtonen, A.

    2009-06-01

    This report examines the plug structures to be built in the deposition tunnels of the repository. The deposition tunnels located below the depth of 400 metres have been used as input data. Each plug consists of a massive concrete structure. The planned maximum pressure acting on the plug is 7.5 MPa. It consists of 4.5 MPa of groundwater pressure and 3 MPa of swelling pressure of the backfill. Five different plug types have been examined. Two of them (butt and irregular plug) turned out to be difficult from the point of view of other works in the central and deposition tunnels. One type (straight plug) requires a lot of construction material. Wedge-shaped and dome plugs have been examined more carefully. The wedge shaped plug has advantageous properties in comparison with the dome plug, such as a three dimensional state of stress, the wedging effect which increases strength as pressure increases and larger tolerances for the excavation of the slot. Leakage water has a longer path through the wedge shaped plug than through the dome plug. Pressure load affects the wedge shaped plug, creating normal stresses, which are compressive along each coordinate axis. The long-term rise in temperature in the deposition tunnels can produce high extra stresses in all the plug alternatives. These stresses make it necessary to increase the strength of the concrete or the distance between the plug and the nearest deposition hole. The stability effects of different plug distances and deposition tunnel orientations have been examined. The plug does not significantly affect stresses in the surrounding bedrock or the stability of the bedrock. Stresses caused by excavation and temperature rise are decisive factors. A groundwater chloride content of 0-3% in the environment of the repository is used as input data. It affects the tightness of the concrete and the quality of the cement. Cement has to be sulphate resistant with a low pH value. Low pH results in the weakening of the corrosion

  13. The critical current of point symmetric Josephson tunnel junctions

    Monaco, Roberto

    2016-01-01

    Highlights: • We disclose some geometrical properties of the critical current field dependence that apply to a large class of Josephson junctions characterized by a point symmetric shape. • The developed theory is valid for any orientation of the applied magnetic field, therefore it allows the determine the consequences of field misalignment in the experimental setups. • We also address that the threshold curves of Josephson tunnel junctions with complex shapes can be expressed as a linear combination of the threshold curves of junctions with simpler point symmetric shapes. - Abstract: The physics of Josephson tunnel junctions drastically depends on their geometrical configurations. The shape of the junction determines the specific form of the magnetic-field dependence of its Josephson current. Here we address the magnetic diffraction patterns of specially shaped planar Josephson tunnel junctions in the presence of an in-plane magnetic field of arbitrary orientations. We focus on a wide ensemble of junctions whose shape is invariant under point reflection. We analyze the implications of this type of isometry and derive the threshold curves of junctions whose shape is the union or the relative complement of two point symmetric plane figures.

  14. [Ex vivo microCT analysis of possible microfractures of the femoral head during implantation of a cementless hip resurfacing femoral component].

    Lerch, M; Olender, G; von der Höh, N; Thorey, F; von Lewinski, G; Meyer-Lindenberg, A; Windhagen, H; Hurschler, C

    2009-01-01

    Microfractures of the femoral head during implantation of the femoral components are suspected to be a cause of fractures at the implant/neck junction which represent a common failure mode in hip resurfacing arthroplasty. Callus formation observed in femoral head retrievals suggests the occurrence of microfractures inside the femoral head, which might be inadvertently caused by the surgeon during implantation. The aim of this biomechanical study was to analyse whether or not the implantation of a cementless femoral component hip resurfacing system causes microfractures in the femoral head. After the preparation of 20 paired human cadaveric femoral heads, the cementless femoral component ESKA Typ BS (ESKA Implants GmbH & Co., Lübeck) was implanted on 9 specimens with an impaction device that generates 4.5 kN impaction force. On 9 specimens the femoral component was implanted by hand. One head was used as a fracture model, 1 specimen served as control without manipulation. The femoral component used for impaction was equipped with hinges to enable its removal without further interfering with the bone stock. Specimens were scanned with a microCT device before and after impaction and the microCT datasets before and after impaction were compared to identify possible microfractures. Twenty strikes per hand or with the impaction device provided sufficient implant seating. Neither the macroscopic examination nor the 2-dimensional microCT analysis revealed any fractures of the femoral heads after impaction. At least macroscopically and in the 2-dimensional microCT analysis, implantation of the cementless hip resurfacing femoral component ESKA Typ BS with 4.5 kN or by hand does not seem to cause fractures of the femoral head. Georg Thieme Verlag KG Stuttgart, New York.

  15. Early detection by sup(99m)Tc-Sn-pyrophosphate scintigraphy of femoral head necrosis following medial femoral neck fractures

    Greiff, J.; Lanng, S.; Hoeilund-Carlsen, P.F.; Karle, A.K.; Uhrenholdt, A.

    1980-01-01

    A selected series of 24 patients with displaced medial femoral neck fracture, treated with closed reduction and osteosynthesis with cancellous bone screws (ASIF), were investigated. During an observation period of 6 to 26 months, serial hip joint scintigraphies were performed and compared with serial X-ray examinations. At the first scintigraphic examination performed on average 5-6 weeks after the fracture, two separate investigators found a decreased amount of activity or no activity in the femoral head of 10 and 8 patients, respectively. At the second scintigraphic examination performed on average 11.1 weeks after the fracture both investigators found no activity or a decreased amount of activity in 8 patients. This figure declined to 7 during the following period, because one patient with decreased activity was recorded as having normal activity 15 months after the fracture. These 7 patients all developed radiological signs of femoral head collapse on average 16.3 months after the fracture (range 5-26 months), whereas their scintigrams displayed decreased or absent tracer uptake on average 1.2 months after the fracture (P<0.01). None of the patients with initially normal or increased uptake later showed decreased or absent uptake during the study and none developed radiological collapse. It may be concluded that absent or decreased uptake of sup(99m)Tc-Sn-pyrophosphate in the femoral head following medial femoral neck fracture indicates femoral head necrosis and a high risk of late segmental collapse, whereas normal or increased uptake implying preserved blood supply means that late segmental collapse will probably never develop. (author)

  16. Tunnelling without barriers

    Lee, K.

    1987-01-01

    The evolution in flat and curved space-time of quantum fields in theories with relative flat potential and its consequences are considered. It is shown that bubble nucleation, a quantum mechanical tunnelling process, may occur in flat space-time, having a bounce solution, even if V(phi) has no barrier. It is shown that bubble nucleation can also occur in curved space-time even though there is no bounce solution in the standard formalism for the bubble nucleation rate in curved space-time. Additionally, bubbles can nucleate during the slow rolling period on the potential in flat and curved space-time, in this case also there is no bounce solution. It is known in the new inflationary scenario that energy density perturbations caused by quantum fluctuations of the scalar field can satisfy the presently observed bounds on density perturbations. Bubble nucleation during the slow rolling period also gives rise to density perturbations. For a model potential density perturbations by bubbles are calculated at the horizon reentering. By applying the bound from the almost isotropic microwave black body radiation on these density perturbations, a constraint on the model potential is obtained. Finally, some further implications on the galaxy formation and applications in more realistic potential are discussed

  17. Sidewall GaAs tunnel junctions fabricated using molecular layer epitaxy

    Takeo Ohno and Yutaka Oyama

    2012-01-01

    Full Text Available In this article we review the fundamental properties and applications of sidewall GaAs tunnel junctions. Heavily impurity-doped GaAs epitaxial layers were prepared using molecular layer epitaxy (MLE, in which intermittent injections of precursors in ultrahigh vacuum were applied, and sidewall tunnel junctions were fabricated using a combination of device mesa wet etching of the GaAs MLE layer and low-temperature area-selective regrowth. The fabricated tunnel junctions on the GaAs sidewall with normal mesa orientation showed a record peak current density of 35 000 A cm-2. They can potentially be used as terahertz devices such as a tunnel injection transit time effect diode or an ideal static induction transistor.

  18. Evaluation in femoral neck fracture scintimetry: modes of region of interest selection and influence on results

    Holmberg, S.; Mesko, L.; Stroemqvist, B.; Thorngren, K.G.

    1985-04-01

    Different sized ROIs within the femoral head and different modes of calculation were used in (/sup 99m/Tc)MDP scintimetry after femoral neck fracture. In preoperative scintimetry, correction for increased trochanteric uptake gave the best discrimination, whereas in postoperative scintimetry the direct ratio fractured/intact femoral head was superior. The change in ROI size had little influence.

  19. Evaluation in femoral neck fracture scintimetry: modes of region of interest selection and influence on results

    Holmberg, S.; Mesko, L.; Stroemqvist, B.; Thorngren, K.G.

    1985-01-01

    Different sized ROIs within the femoral head and different modes of calculation were used in [/sup 99m/Tc]MDP scintimetry after femoral neck fracture. In preoperative scintimetry, correction for increased trochanteric uptake gave the best discrimination, whereas in postoperative scintimetry the direct ratio fractured/intact femoral head was superior. The change in ROI size had little influence

  20. The stability of the femoral component of a minimal invasive total hip replacement system.

    Willems, M.M.M.; Kooloos, J.G.M.; Gibbons, P.; Minderhoud, N.; Weernink, T.; Verdonschot, N.J.J.

    2006-01-01

    In this study, the initial stability of the femoral component of a minimal invasive total hip replacement was biomechanically evaluated during simulated normal walking and chair rising. A 20 mm diameter canal was created in the femoral necks of five fresh frozen human cadaver bones and the femoral

  1. 21 CFR 888.3360 - Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint femoral (hemi-hip) metallic cemented or... Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis is a device intended to be implanted...

  2. 21 CFR 888.3400 - Hip joint femoral (hemi-hip) metallic resurfacing prosthesis.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint femoral (hemi-hip) metallic resurfacing... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3400 Hip joint femoral (hemi-hip) metallic resurfacing prosthesis. (a) Identification. A hip joint femoral (hemi-hip...

  3. Factors that influence femoral neck length. Analysis of 1543 patients with advanced osteoarthritis of the hip

    Prins, Wybren; Kollen, Boudewijn J.; Ettema, Harmen B.; Verheyen, Cees C. P. M.

    2013-01-01

    Background and purpose: There is little known about the relationship between patient characteristic and the variance in geometrical properties of the femoral neck. The length of the femoral neck is relevant when considering a femoral neck preserving hip replacement. Based on surgical experience we

  4. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral (hemi-knee...

  5. Estimated carotid-femoral pulse wave velocity has similar predictive value as measured carotid-femoral pulse wave velocity

    Olsen, Michael; Greve, Sara; Blicher, Marie

    2016-01-01

    OBJECTIVE: Carotid-femoral pulse wave velocity (cfPWV) adds significantly to traditional cardiovascular (CV) risk prediction, but is not widely available. Therefore, it would be helpful if cfPWV could be replaced by an estimated carotid-femoral pulse wave velocity (ePWV) using age and mean blood...... pressure and previously published equations. The aim of this study was to investigate whether ePWV could predict CV events independently of traditional cardiovascular risk factors and/or cfPWV. DESIGN AND METHOD: cfPWV was measured and ePWV calculated in 2366 apparently healthy subjects from four age...

  6. Sexual Orientation (For Parents)

    ... Staying Safe Videos for Educators Search English Español Sexual Orientation KidsHealth / For Parents / Sexual Orientation What's in this ... orientation is part of that process. What Is Sexual Orientation? The term sexual orientation refers to the gender ( ...

  7. Scanning Tunneling Optical Resonance Microscopy

    Bailey, Sheila; Wilt, Dave; Raffaelle, Ryne; Gennett, Tom; Tin, Padetha; Lau, Janice; Castro, Stephanie; Jenkins, Philip; Scheiman, Dave

    2003-01-01

    Scanning tunneling optical resonance microscopy (STORM) is a method, now undergoing development, for measuring optoelectronic properties of materials and devices on the nanoscale by means of a combination of (1) traditional scanning tunneling microscopy (STM) with (2) tunable laser spectroscopy. In STORM, an STM tip probing a semiconductor is illuminated with modulated light at a wavelength in the visible-to-near-infrared range and the resulting photoenhancement of the tunneling current is measured as a function of the illuminating wavelength. The photoenhancement of tunneling current occurs when the laser photon energy is sufficient to excite charge carriers into the conduction band of the semiconductor. Figure 1 schematically depicts a proposed STORM apparatus. The light for illuminating the semiconductor specimen at the STM would be generated by a ring laser that would be tunable across the wavelength range of interest. The laser beam would be chopped by an achromatic liquid-crystal modulator. A polarization-maintaining optical fiber would couple the light to the tip/sample junction of a commercial STM. An STM can be operated in one of two modes: constant height or constant current. A STORM apparatus would be operated in the constant-current mode, in which the height of the tip relative to the specimen would be varied in order to keep the tunneling current constant. In this mode, a feedback control circuit adjusts the voltage applied to a piezoelectric actuator in the STM that adjusts the height of the STM tip to keep the tunneling current constant. The exponential relationship between the tunneling current and tip-to-sample distance makes it relatively easy to implement this mode of operation. The choice of method by which the photoenhanced portion of the tunneling current would be measured depends on choice of the frequency at which the input illumination would be modulated (chopped). If the frequency of modulation were low enough (typically tunneling current

  8. Thermopower in double planar tunnel junctions with ferromagnetic barriers and nonmagnetic electrodes

    Wilczyński, M., E-mail: wilczyns@if.pw.edu.pl

    2017-01-01

    The Seebeck effect is investigated in double planar tunnel junctions consisting of nonmagnetic electrodes and the central layer separated by ferromagnetic barriers. Calculations are performed in the linear response theory using the free-electron model. The thermopower is analyzed as a function of the thickness of the central layer, temperature of the junctions and the relative orientation of magnetic moments of the barriers. It has been found that the thermopower can be significantly enhanced in the junction with special central layer thickness due to electron tunneling by resonant states. The thickness of the central layer for which the thermopower is enhanced depends not only on the temperature of the junction but also on the orientation of magnetic moments in the barriers. - Highlights: • Thermopower in the double planar junctions with magnetic barriers is analyzed. • Thermopower can be enhanced due to the resonant tunneling. • Thermopower depends on the magnetic configuration of the junction.

  9. Numerical Simulation of Tunneling Current in an Anisotropic Metal-Oxide-Semiconductor Capacitor

    Khairurrijal khairurrijal

    2012-09-01

    Full Text Available In this paper, we have developed a model of the tunneling currents through a high-k dielectric stack in MOS capacitors with anisotropic masses. The transmittance was numerically calculated by employing a transfer matrix method and including longitudinal-transverse kinetic energy coupling which is represented by an electron phase velocity in the gate. The transmittance was then applied to calculate tunneling currents in TiN/HfSiOxN/SiO2/p-Si MOS capacitors. The calculated results show that as the gate electron velocity increases, the transmittance decreases and therefore the tunneling current reduces. The tunneling current becomes lower as the effective oxide thickness (EOT of HfSiOxN layer increases. When the incident electron passed through the barriers in the normal incident to the interface, the electron tunneling process becomes easier. It was also shown that the tunneling current was independent of the substrate orientation. Moreover, the model could be used in designing high speed MOS devices with low tunneling currents.

  10. Electronic noise of superconducting tunnel junction detectors

    Jochum, J.; Kraus, H.; Gutsche, M.; Kemmather, B.; Feilitzsch, F. v.; Moessbauer, R.L.

    1994-01-01

    The optimal signal to noise ratio for detectors based on superconducting tunnel junctions is calculated and compared for the cases of a detector consisting of one single tunnel junction, as well as of series and of parallel connections of such tunnel junctions. The influence of 1 / f noise and its dependence on the dynamical resistance of tunnel junctions is discussed quantitatively. A single tunnel junction yields the minimum equivalent noise charge. Such a tunnel junction exhibits the best signal to noise ratio if the signal charge is independent of detector size. In case, signal charge increases with detector size, a parallel or a series connection of tunnel junctions would provide the optimum signal to noise ratio. The equivalent noise charge and the respective signal to noise ratio are deduced as functions of tunnel junction parameters such as tunneling time, quasiparticle lifetime, etc. (orig.)

  11. Theory of superconducting tunneling without the tunneling Hamiltonian

    Arnold, G.B.

    1987-01-01

    When a tunneling barrier is nearly transparent, the standard tunneling (or transfer) Hamiltonian approximation fails. The author describes the theory which is necessary for calculating the tunneling current in these cases, and illustrate it by comparing theory and experiment on superconductor/insulator/superconductor (SIS) junctions have ultra-thin tunnel barriers. This theory accurately explains the subgap structure which appears in the dynamical resistance of such SIS junctions, including many observed details which no previous theory has reproduced. The expression for the current through an SIS junction with an ultrathin barrier is given by I(t) = Re{Sigma/sub n/ J/sub n/ (omega/sub o/)e/sup in omega/o/sup t/} where omega/sub o/ = 2eV/h is the Josephson frequency, V is the bias voltage, and the J/sub n/ are voltage dependent coefficients, one for each positive or negative integer, n, and n=0. The relative sign of the terms involving cos(n omega/sub o/t) and sin(n omega/sub o/t) agrees with experiment, in contrast to previous theories of Josephson tunneling

  12. Static properties of small Josephson tunnel junctions in an oblique magnetic field

    Monaco, Roberto; Aarøe, Morten; Mygind, Jesper

    2009-01-01

    We have carried out a detailed experimental investigation of the static properties of planar Josephson tunnel junctions in presence of a uniform external magnetic field applied in an arbitrary orientation with respect to the barrier plane. We considered annular junctions, as well as rectangular...

  13. A FUNCTIONAL EVALUATION STUDY OF DISTAL FEMORAL FRACTURES FIXED WITH DISTAL FEMORAL LOCKING PLATE

    Manikumar C. J

    2017-04-01

    Full Text Available BACKGROUND Fractures of the distal femur present considerable challenges in management. Older patients especially women sustain fractures due to osteoporosis. Supracondylar fractures of femur have a bimodal distribution. They account for 6% of all femur fractures and 31% if hip fractures were excluded. Nearly, 50% of distal femur intra-articular fractures are open fractures. Before 1970, most supracondylar fractures were treated nonoperatively; however, difficulties were often encountered including persistent angulatory deformity, knee joint incongruity, loss of knee motion and delayed mobilisation. The trend of open reduction and internal fixation has become evident in recent years with good results being obtained with AO blade plate, dynamic condylar screw, intramedullary supracondylar nail and locking compression plate. Elderly patients and osteoporosis pose difficulty in treating intra-articular fractures of the lower end of femur. Loss of stable fixation is of great concern in these cases. Hence, locking compression plate use has an advantage in these patients. MATERIALS AND METHODS In this study, 20 patients with closed fracture of distal femur were studied. All the cases were treated at the Department of Orthopaedics, Rangaraya Medical College/Government General Hospital, Kakinada, Andhra Pradesh, between November 2013 and November 2015. The method used for fracture fixation was open reduction and internal fixation with distal femoral locking plate. The duration of follow up ranged from 3 months to 24 months. All the fractures in this series were posttraumatic. The patients were functionally evaluated with Neer’s scoring system. 1 RESULTS Twenty distal femoral fractures were treated with distal femoral locking plates. 15 patients were males and 5 patients were females. The median age was 47 years ranging from 28-70 years. 16 of the fractures were caused by road traffic accidents and 2 were due to fall, 2 were due to assault. 12 patients

  14. Theoretical study of phosphorene tunneling field effect transistors

    Chang, Jiwon; Hobbs, Chris

    2015-01-01

    In this work, device performances of tunneling field effect transistors (TFETs) based on phosphorene are explored via self-consistent atomistic quantum transport simulations. Phosphorene is an ultra-thin two-dimensional (2-D) material with a direct band gap suitable for TFETs applications. Our simulation shows that phosphorene TFETs exhibit subthreshold slope below 60 mV/dec and a wide range of on-current depending on the transport direction due to highly anisotropic band structures of phosphorene. By benchmarking with monolayer MoTe 2 TFETs, we predict that phosphorene TFETs oriented in the small effective mass direction can yield much larger on-current at the same on-current/off-current ratio than monolayer MoTe 2 TFETs. It is also observed that a gate underlap structure is required for scaling down phosphorene TFETs in the small effective mass direction to suppress the source-to-drain direct tunneling leakage current

  15. Theoretical study of phosphorene tunneling field effect transistors

    Chang, Jiwon; Hobbs, Chris [SEMATECH, 257 Fuller Rd #2200, Albany, New York 12203 (United States)

    2015-02-23

    In this work, device performances of tunneling field effect transistors (TFETs) based on phosphorene are explored via self-consistent atomistic quantum transport simulations. Phosphorene is an ultra-thin two-dimensional (2-D) material with a direct band gap suitable for TFETs applications. Our simulation shows that phosphorene TFETs exhibit subthreshold slope below 60 mV/dec and a wide range of on-current depending on the transport direction due to highly anisotropic band structures of phosphorene. By benchmarking with monolayer MoTe{sub 2} TFETs, we predict that phosphorene TFETs oriented in the small effective mass direction can yield much larger on-current at the same on-current/off-current ratio than monolayer MoTe{sub 2} TFETs. It is also observed that a gate underlap structure is required for scaling down phosphorene TFETs in the small effective mass direction to suppress the source-to-drain direct tunneling leakage current.

  16. Improved multidimensional semiclassical tunneling theory.

    Wagner, Albert F

    2013-12-12

    We show that the analytic multidimensional semiclassical tunneling formula of Miller et al. [Miller, W. H.; Hernandez, R.; Handy, N. C.; Jayatilaka, D.; Willets, A. Chem. Phys. Lett. 1990, 172, 62] is qualitatively incorrect for deep tunneling at energies well below the top of the barrier. The origin of this deficiency is that the formula uses an effective barrier weakly related to the true energetics but correctly adjusted to reproduce the harmonic description and anharmonic corrections of the reaction path at the saddle point as determined by second order vibrational perturbation theory. We present an analytic improved semiclassical formula that correctly includes energetic information and allows a qualitatively correct representation of deep tunneling. This is done by constructing a three segment composite Eckart potential that is continuous everywhere in both value and derivative. This composite potential has an analytic barrier penetration integral from which the semiclassical action can be derived and then used to define the semiclassical tunneling probability. The middle segment of the composite potential by itself is superior to the original formula of Miller et al. because it incorporates the asymmetry of the reaction barrier produced by the known reaction exoergicity. Comparison of the semiclassical and exact quantum tunneling probability for the pure Eckart potential suggests a simple threshold multiplicative factor to the improved formula to account for quantum effects very near threshold not represented by semiclassical theory. The deep tunneling limitations of the original formula are echoed in semiclassical high-energy descriptions of bound vibrational states perpendicular to the reaction path at the saddle point. However, typically ab initio energetic information is not available to correct it. The Supporting Information contains a Fortran code, test input, and test output that implements the improved semiclassical tunneling formula.

  17. Surgical blood order equation in femoral fracture surgery

    Kajja, I.; Bimenya, G. S.; Eindhoven, G. B.; ten Duis, H. Jan; Sibinga, C. T. S.

    Aim: This study aimed at establishing the clinical utility of the surgical blood order equation (SBOE) in patients undergoing femoral fracture surgery. Background: A blood ordering schedule defines the perioperative blood use in elective surgery. It lists the number of units of blood required for

  18. Proximal focal femoral deficiency: evaluation by MR imaging

    Biko, David M.; Davidson, Richard; Pena, Andres; Jaramillo, Diego

    2012-01-01

    Proximal focal femoral deficiency (PFFD) is a rare congenital anomaly characterized by abnormal development of the proximal femur. The most common radiographic classification (Aitken) does not evaluate the cartilaginous and soft-tissue abnormalities. To demonstrate MR findings of PFFD focusing on features not seen with radiographs. Nine MR examinations of the hip and femurs of seven children with PFFD were retrospectively reviewed. Imaging was quantitatively and qualitatively assessed comparing the affected limb to the contralateral limb and age-matched controls. The children were classified via the Aitken classification. All children had at least mild acetabular dysplasia, and one type D patient had no acetabulum. MR demonstrated that 4/6 children had labral hypertrophy with a decreased distance from the greater trochanter to the acetabular rim, suggesting impingement (P < 0.05). The proximal femoral physis was abnormal in all cases. The connection between the femoral head and shaft if present was fibrous or fibrocartilaginous. MRI can help in evaluation of PFFD by defining the anatomy. MR demonstrates features of the acetabulum and cartilaginous femoral epiphysis and depicts ligamentous abnormalities of the knee. (orig.)

  19. Ender’s Nail fixation in paediatric femoral shaft fractures.

    Rajeev Dwivedi

    2013-12-01

    Flynn criteria 34 had excellent and 6 had satisfactory results. No poor results were seen. Conclusion: Ender’s nail fixation can be preferred method of treatment for femoral shaft fractures in age group 5 -15 years as the results are excellent and satisfactory. It is technically simple and can be done in a closed manner. It spares the vascularity and growth plate.

  20. ediatric femoral shaft fractures treated by flexible intramedullary nailing.

    Kapil Mani, K C; Dirgha Raj, R C; Parimal, Acharya

    2015-01-01

    Nowadays pediatric femoral fractures are more commonly managed with operative treatment rather than conservative treatment because of more rapid recovery and avoidance of prolonged immobilization. Children between the ages of 5-13 years are treated either by traction plus hip spica and flexible/elastic stable retrograde intramedullary nail, or external fixators in the case of open fractures. The aim of this study is to evaluate the outcome of pediatric femoral shaft fractures treated by stainless steel flexible intramedullary nail in children between 5 and 13 years of age. There were 32 cases of femoral shaft fractures which were all fixed with stainless steel flexible intramedullary nail under fluoroscopy. Long leg cast was applied at the time of fixation. Partial weight bearing was started 2 weeks after surgery. Patients were evaluated in follow-up study to observe the alignment of fracture, infection, delayed union, nonunion, limb length discrepancy, motion of knee joint, and time to unite the fracture. We were able to follow up 28 out of 32 patients. The patients were 8.14 years of age on average. The mean hospital stay after operation was 4 days and fracture union time was 9.57 weeks. There were 3 cases of varus angulation, 2 cases of anterior angulation, and 4 cases of limb lengthening. Patients aged between 5 and 13 years treated with flexible intramedullary nail for closed femoral shaft fracture have rapid union and recovery, short rehabilitation period, less immobilization and psychological impact, and cost-effective.

  1. MR imaging findings of the femoral marrow in myelodysplastic syndrome

    Tanaka, Osamu; Takagi, Shojiro; Matsuura, Katsuhiko; Ichikawa, Tamaki; Kobayashi, Yasuyuki; Nagai, Jun

    1995-01-01

    MR imaging of the femoral marrow was performed in 30 patients with myelodysplastic syndrome (MDS), 11 cases of which evolved to acute myeloid leukemia (AML). The MRI appearance was classified into five patterns: fatty marrow; faint signal; nodular pattern; heterogeneous infiltration; and diffuse infiltration. For each type of MDS, MRI patterns of the femoral marrow were evaluated and compared with those in normal subjects as well as in patients with aplastic anemia. Signal intensity alteration, a low signal on T1-weighted SE image and a high signal on STIR image, began in the proximal femoral marrow almost symmetrically in patients with MDS. The area of abnormal signal intensity tended to gradually extend towards the distal portion of the femur as the disease progressed. MRI patterns of the femoral marrow correlated with marrow cellularity, and diffuse marrow infiltration was noted in patients with a more advanced type of MDS or with severe anemia. There were limitations to making an accurate diagnosis of the MDS type on the basis of the MRI pattern. Progression of the MRI appearance in the course of MDS was thought to be a sign suggesting evolution to AML. It was difficult to differentiate hypoplastic MDS from aplastic anemia, although the nodular pattern was commonly seen in the latter disease. (author)

  2. MR imaging findings of the femoral marrow in myelodysplastic syndrome

    Tanaka, Osamu; Takagi, Shojiro; Matsuura, Katsuhiko; Ichikawa, Tamaki; Kobayashi, Yasuyuki; Nagai, Jun [Jichi Medical School, Minamikawachi, Tochigi (Japan)

    1995-10-01

    MR imaging of the femoral marrow was performed in 30 patients with myelodysplastic syndrome (MDS), 11 cases of which evolved to acute myeloid leukemia (AML). The MRI appearance was classified into five patterns: fatty marrow; faint signal; nodular pattern; heterogeneous infiltration; and diffuse infiltration. For each type of MDS, MRI patterns of the femoral marrow were evaluated and compared with those in normal subjects as well as in patients with aplastic anemia. Signal intensity alteration, a low signal on T1-weighted SE image and a high signal on STIR image, began in the proximal femoral marrow almost symmetrically in patients with MDS. The area of abnormal signal intensity tended to gradually extend towards the distal portion of the femur as the disease progressed. MRI patterns of the femoral marrow correlated with marrow cellularity, and diffuse marrow infiltration was noted in patients with a more advanced type of MDS or with severe anemia. There were limitations to making an accurate diagnosis of the MDS type on the basis of the MRI pattern. Progression of the MRI appearance in the course of MDS was thought to be a sign suggesting evolution to AML. It was difficult to differentiate hypoplastic MDS from aplastic anemia, although the nodular pattern was commonly seen in the latter disease. (author).

  3. Proximal focal femoral deficiency: evaluation by MR imaging

    Biko, David M. [National Naval Medical Center, Department of Radiology, Bethesda, MD (United States); Uniformed Services University of Health Sciences, Department of Radiology and Radiological Sciences, Bethesda, MD (United States); Davidson, Richard [The Children' s Hospital of Philadelphia, Department of Orthopedic Surgery, Philadelphia, PA (United States); Pena, Andres; Jaramillo, Diego [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States)

    2012-01-15

    Proximal focal femoral deficiency (PFFD) is a rare congenital anomaly characterized by abnormal development of the proximal femur. The most common radiographic classification (Aitken) does not evaluate the cartilaginous and soft-tissue abnormalities. To demonstrate MR findings of PFFD focusing on features not seen with radiographs. Nine MR examinations of the hip and femurs of seven children with PFFD were retrospectively reviewed. Imaging was quantitatively and qualitatively assessed comparing the affected limb to the contralateral limb and age-matched controls. The children were classified via the Aitken classification. All children had at least mild acetabular dysplasia, and one type D patient had no acetabulum. MR demonstrated that 4/6 children had labral hypertrophy with a decreased distance from the greater trochanter to the acetabular rim, suggesting impingement (P < 0.05). The proximal femoral physis was abnormal in all cases. The connection between the femoral head and shaft if present was fibrous or fibrocartilaginous. MRI can help in evaluation of PFFD by defining the anatomy. MR demonstrates features of the acetabulum and cartilaginous femoral epiphysis and depicts ligamentous abnormalities of the knee. (orig.)

  4. Isolated femoral hypoplasia: an intrauterine differential diagnosis to campomelia

    Koerber, Friederike; Benz-Bohm, Gabriele [University of Cologne, Department of Paediatric Radiology, Cologne (Germany); Schoenau, Eckard [University of Cologne, Department of Paediatrics, Cologne (Germany); Horwitz, A.Eldad [Klinikum Krefeld, Department of Paediatric Radiology, Krefeld (Germany)

    2005-06-01

    The isolated form of femoral bowing is an important differential diagnosis of campomelia. Therefore, knowledge of isolated anomalies is fundamental for prenatal diagnosis, especially for the differential diagnosis from severe syndromes. Four cases are presented to discuss the differential diagnosis of femoral bowing including a review of the literature. We report four newborn babies with unilateral bowing and shortening of the femur. Three had no further anomaly; one child had additional abnormalities due to coumarin embryopathy. The radiological findings were shortened femora with bowing and varus deformity and cortical thickening on the concave side. All other parts showed normal bone structure. The aetiology of femoral bowing is unknown. Early damage of the cartilaginous model followed by remodelling with thickening on the concave side of the bone similar to the healing of malaligned fractures is suspected. The isolated form of femoral bowing without any other anomalies has to be differentiated from complex and more often severe congenital syndromes such as campomelia. Postpartum radiological examination should be reduced to a single exposure of the affected limb and follow-up should be done by clinical examination. (orig.)

  5. Management of a femoral fracture complicated by clostridial myositis

    Thomson, M.J.; Eger, C.E.

    1997-01-01

    A clinical case of clostridial myositis secondary to a comminuted femoral fracture is described. This case is unusual because, despite the severe degree of obvious muscle necrosis and gas production, the dog had minimal signs of systemic toxicity. Union of the fracture was achieved but six months postoperatively muscular contracture had resulted in permanent stifle extension

  6. Incidental finding of hypertension and diminished femoral pulses ...

    2012-06-08

    Jun 8, 2012 ... Case Study: Incidental finding of hypertension and diminished femoral pulses. 168. Vol 55 No 2. S Afr Fam Pract 2013. Introduction. Coarctation of the aorta is ... Surgery of the aorta and its branches. Philadelphia: WB Saunders Company, 2000; p. 3-10. 2. Rao PS. Coarctation of the aorta. Curr Cardiol Rep.

  7. Treatment of femoral neck fracture by Moore Prosthesis in Cotonou ...

    Treatment of femoral neck fracture by Moore Prosthesis in Cotonou. AHM Akue, M Lawson, S Madougou, R Zannou, J Padonou. Abstract. Keywords: Benin; hip; Moore prosthesis; results. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  8. Early micromovement of the Articular Surface Replacement (ASR) femoral component

    Penny, J O; Ding, M; Varmarken, J E

    2012-01-01

    Radiostereometric analysis (RSA) can detect early micromovement in unstable implant designs which are likely subsequently to have a high failure rate. In 2010, the Articular Surface Replacement (ASR) was withdrawn because of a high failure rate. In 19 ASR femoral components, the mean micromovement...

  9. Blood flow and microdialysis in the human femoral head

    Bøgehøj, Morten; Emmeluth, Claus; Overgaard, Søren

    2007-01-01

    BACKGROUND: If it would be possible to detect lack of flow and/or the development of ischemia in bone, we might have a way of predicting whether a broken bone will heal. We established microdialysis (MD) and laser Doppler (LD) flow measurement in the human femoral head in order to be able to detect...

  10. Retained portion of latex glove during femoral nailing. Case report.

    Sadat-Ali, M; Marwah, S; al-Habdan, I

    1996-11-01

    A case of retained glove during Kuntscher intramedullary nailing is described. An abscess around the glove could have lead to osteomyelitis. One need to be cautious feeling the top end of the nail while femoral nailing to avoid such a complication.

  11. Radionuclide scintimetry for diagnosis of complications following femoral neck fracture

    Alberts, K.A.; Dahlborn, M.; Hindmarsh, J.; Soederborg, B.; Ringertz, H.

    1984-01-01

    A scintimetric study using Tc-99m MDP was made of 54 patients with delayed union, nonunion, or late segmental collapse of the femoral head, 4-92 months after femoral neck fracture. In radiographically verified collapse, the radionuclide uptake ratio between the femoral head on the fractured and on the intact side (HHR) was significantly higher than in fractures resulting in delayed union or nonunion. On the basis of scintimetric and radiographic findings, the patients with healing disturbances could be divided into three groups, characterized by the following features: (1) Satisfactory post-reduction position of the fracture without subsequent redisplacement and a high HHR, which as a rule turned out to be delayed union; (2) The same radiographic pattern but with a lower HHR, which in most cases resulted in nonunion; (3) Inadequate reduction or early redisplacement of the fracture with a high HHR, which resulted in nonunion. The fractional precision in discriminating between different types of disturbed fracture healing by means of skeletal scintimetry was 0.86 in this study. This non-invasive and technically simple method would therefore be a valuable complement to radiography in the assessment of healing, more than 4 months after fracture of the femoral neck. (author)

  12. Femoral fractures : indications an[d] biomechanics of external fixation

    A.H. Broekhuizen (Tom); B. van Linge

    1988-01-01

    textabstractInternal fixation can be carried out in various ways. For femoral shaft fractures, an (interlocking) nail is becoming increasingly popular, instead of open realignment of the fracture. External fixation, which has become a generally accepted method of treating fractures of the lower

  13. Application of monorail fixator for femoral gap nonunion.

    Agrawal, Hemendra-Kumar; Jaiman, Ashish; Khatkar, Vipin; Sharma, Vinod-Kumar

    2014-01-01

    Difficult femoral nonunion takes account of infective nonunion and aseptic gap nonunion. Limb length discrepancy and nonunion need to be tackled simultaneously. Conventionally Ilizarov ring fixator is in vogue but it has some limitations. To overcome these, monorail fixator is an effective alternative. Persistent good results can be obtained if we can get a perfect anatomical alignment and good regeneration.

  14. Scaling in Theropod Dinosaurs: Femoral Bone Strength and Locomotion II

    Lee, Scott

    2015-01-01

    In the second paper of this series, the effect of transverse femoral stresses due to locomotion in theropod dinosaurs of different sizes was examined for the case of an unchanging leg geometry. Students are invariably thrilled to learn about theropod dinosaurs, and this activity applies the concepts of torque and stress to the issue of theropod…

  15. fibular osteosynthesis of neglected femoral neck fracture in a young

    As soon as a diagnosis of non-displaced fracture of his right hip was made he discharged himself ... in dogs that cortical grafts provided structural support to the necrotic femoral head preventing its collapse ... possibility of future osteoarthritis of the index hip and the need for regular follow-up. In conclusion, the use of ...

  16. Femoral head injuries: Which treatment strategy can be recommended?

    Henle, Philipp; Kloen, Peter; Siebenrock, Klaus A.

    2007-01-01

    Despite different operative and non-operative treatment regimens, the outcome after femoral head fractures has changed little over the past decades. The initial trauma itself as well as secondary changes such as posttraumatic osteoarthritis, avascular necrosis or heterotopic ossification is often

  17. Bone scintigraphy in idiopathic aseptic femoral head necrosis (IAFHN)

    Dodig, D; Ugarkovic, B; Orlic, D

    1983-01-01

    Idiopathic aseptic femoral head necrosis (IAFHN) is a disease of unknown aetiology most commonly affecting adults, producing functional impairment of the hip joint and immobility. Characteristic macroscopic, microscopic and radiologic features include: (1) changes in joint cartilage, (2) subchondral necrotic area, (3) changes in fibrous tissue, and (4) osteosclerosis and vascular proliferation. The diagnosis is based on clinical and X-ray examinations. More recently scintigraphy has been used in diagnosing IAFHN. It is a very sensitive, but non-specific method. Nineteen patients aged 25-57 years were included in our study. Scintigrams were divided in four groups: (1) normal, (2) uniformly increased activity in the femoral head, (3) non-uniformly increased activity in the femoral head, and (4) a photon deficient area in the femoral head. A comparison of scintigraphy and radiological examination suggests that a photon deficient area corresponds with stage III of radiological classification, non-uniformly increased activity with stage II, and uniformly increased activity with stage I. These results indicate that scintigraphy can be used for staging of disease.

  18. Adductor Canal Block versus Femoral Nerve Block and Quadriceps Strength

    Jæger, Pia Therese; Nielsen, Zbigniew Jerzy Koscielniak; Henningsen, Lene Marianne

    2013-01-01

    : The authors hypothesized that the adductor canal block (ACB), a predominant sensory blockade, reduces quadriceps strength compared with placebo (primary endpoint, area under the curve, 0.5-6 h), but less than the femoral nerve block (FNB; secondary endpoint). Other secondary endpoints were...

  19. Technique and results of femoral bifurcation endarterectomy by eversion.

    Dufranc, Julie; Palcau, Laura; Heyndrickx, Maxime; Gouicem, Djelloul; Coffin, Olivier; Felisaz, Aurélien; Berger, Ludovic

    2015-03-01

    This study evaluated, in a contemporary prospective series, the safety and efficacy of femoral endarterectomy using the eversion technique and compared our results with results obtained in the literature for the standard endarterectomy with patch closure. Between 2010 and 2012, 121 patients (76% male; mean age, 68.7 years; diabetes, 28%; renal insufficiency, 20%) underwent 147 consecutive femoral bifurcation endarterectomies using the eversion technique, associating or not inflow or outflow concomitant revascularization. The indications were claudication in 89 procedures (60%) and critical limb ischemia in 58 (40%). Primary, primary assisted, and secondary patency of the femoral bifurcation, clinical improvement, limb salvage, and survival were assessed using Kaplan-Meier life-table analysis. Factors associated with those primary end-points were evaluated with univariate analysis. The technical success of eversion was of 93.2%. The 30-day mortality was 0%, and the complication rate was 8.2%; of which, half were local and benign. Median follow-up was 16 months (range, 1.6-31.2 months). Primary, primary assisted, and secondary patencies were, respectively, 93.2%, 97.2%, and 98.6% at 2 years. Primary, primary assisted, and secondary maintenance of clinical improvement were, respectively, 79.9%, 94.6%, and 98.6% at 2 years. The predictive factors for clinical degradation were clinical stage (Rutherford category 5 or 6, P = .024), platelet aggregation inhibitor treatment other than clopidogrel (P = .005), malnutrition (P = .025), and bad tibial runoff (P = .0016). A reintervention was necessary in 18.3% of limbs at 2 years: 2% involving femoral bifurcation, 6.1% inflow improvement, and 9.5% outflow improvement. The risk factors of reintervention were platelet aggregation inhibitor (other than clopidogrel, P = .049) and cancer (P = .011). Limb preservation at 2 years was 100% in the claudicant population. Limb salvage was 88.6% in the critical limb ischemia population

  20. Superconducting tunneling with the tunneling Hamiltonian. II. Subgap harmonic structure

    Arnold, G.B.

    1987-01-01

    The theory of superconducting tunneling without the tunneling Hamiltonian is extended to treat superconductor/insulator/superconductor junctions in which the transmission coefficient of the insulating barrier approaches unity. The solution for the current in such junctions is obtained by solving the problem of a particle hopping in a one-dimensional lattice of sites, with forward and reverse transfer integrals that depend on the site. The results are applied to the problem of subgap harmonic structure in superconducting tunneling. The time-dependent current at finite voltage through a junction exhibiting subgap structure is found to have terms that oscillate at all integer multiples of the Josephson frequency, n(2eV/h). The amplitudes of these new, and as yet unmeasured, ac current contributions as a function of voltage are predicted

  1. Study of the anatomical position of the femoral nerve by magnetic resonance imaging in patients with fractured neck of femur: relevance to femoral nerve block.

    Mehmood, Shehzad

    2012-01-31

    STUDY OBJECTIVE: To determine the anatomical location of the femoral nerve in patients who have sustained fracture of the neck of femur, and its relevance to femoral nerve block technique. DESIGN: Prospective, observational clinical study. SETTING: Orthopedic and Radiology departments of a regional hospital. SUBJECTS: 10 consecutive adult ASA physical status II and III patients (mean age, 78.5 yrs) and 4 adult healthy volunteers. INTERVENTIONS: A T1 magnetic resonance imaging scan was performed of both upper thighs in patients and healthy volunteers successfully. MEASUREMENTS: The distance (mm) between the midpoint of the femoral artery and the midpoint of the femoral nerve, and the distance of the femoral nerve from the skin was measured at the mid-inguinal ligament, the pubic tubercle, and at the mid-inguinal crease. Data are shown as means (SD). Differences between both sides were compared using paired Student\\'s t-tests. P < 0.05 was significant. MAIN RESULTS: In patients the mean distance (mm) between the midpoint of the femoral nerve from the midpoint of femoral artery at the mid-inguinal crease on the fractured and non-fractured sides was 10.7 and 11.0, respectively (P = 0.87). The mean distance (mm) between the midpoint of the femoral nerve from the midpoint of the femoral artery at the mid-inguinal ligament on the fractured and non-fractured sides was 9.64 and 12.5, respectively (P = 0.03). The mean distance (mm) between the midpoint of the femoral nerve from the midpoint of the femoral artery at the pubic tubercle on the fractured and non-fractured sides was 8.74 and 10.49, respectively (P = 0.18). CONCLUSIONS: Blockade of the femoral nerve may be easier to perform at the mid-inguinal crease in patients with fractured neck of femur.

  2. Typical Underwater Tunnels in the Mainland of China and Related Tunneling Technologies

    Kairong Hong

    2017-12-01

    Full Text Available In the past decades, many underwater tunnels have been constructed in the mainland of China, and great progress has been made in related tunneling technologies. This paper presents the history and state of the art of underwater tunnels in the mainland of China in terms of shield-bored tunnels, drill-and-blast tunnels, and immersed tunnels. Typical underwater tunnels of these types in the mainland of China are described, along with innovative technologies regarding comprehensive geological prediction, grouting-based consolidation, the design and construction of large cross-sectional tunnels with shallow cover in weak strata, cutting tool replacement under limited drainage and reduced pressure conditions, the detection and treatment of boulders, the construction of underwater tunnels in areas with high seismic intensity, and the treatment of serious sedimentation in a foundation channel of immersed tunnels. Some suggestions are made regarding the three potential great strait-crossing tunnels—the Qiongzhou Strait-Crossing Tunnel, Bohai Strait-Crossing Tunnel, and Taiwan Strait-Crossing Tunnel—and issues related to these great strait-crossing tunnels that need further study are proposed. Keywords: Underwater tunnel, Strait-crossing tunnel, Shield-bored tunnel, Immersed tunnel, Drill and blast

  3. Mortality Following Periprosthetic Proximal Femoral Fractures Versus Native Hip Fractures.

    Boylan, Matthew R; Riesgo, Aldo M; Paulino, Carl B; Slover, James D; Zuckerman, Joseph D; Egol, Kenneth A

    2018-04-04

    The number of periprosthetic proximal femoral fractures is expected to increase with the increasing prevalence of hip arthroplasties. While native hip fractures have a well-known association with mortality, there are currently limited data on this outcome among the subset of patients with periprosthetic proximal femoral fractures. Using the New York Statewide Planning and Research Cooperative System, we identified patients from 60 to 99 years old who were admitted to a hospital in the state with a periprosthetic proximal femoral fracture (n = 1,655) or a native hip (femoral neck or intertrochanteric) fracture (n = 97,231) between 2006 and 2014. Within the periprosthetic fracture cohort, the indication for the existing implant was not available in the data set. We used mixed-effects regression models to compare mortality at 1 and 6 months and 1 year for periprosthetic compared with native hip fractures. The risk of mortality for patients who sustained a periprosthetic proximal femoral fracture was no different from that for patients who sustained a native hip fracture at 1 month after injury (3.2% versus 4.6%; odds ratio [OR], 0.90; 95% confidence interval [CI], 0.68 to 1.19; p = 0.446), but was lower at 6 months (3.8% versus 6.5%; OR, 0.74; 95% CI, 0.57 to 0.95; p = 0.020) and 1 year (9.7% versus 15.9%; OR, 0.71; 95% CI, 0.60 to 0.85; p accounting for age and comorbidities. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

  4. Morphometric findings in avascular necrosis of the femoral head.

    Kamal, Diana; Trăistaru, Rodica; Alexandru, D O; Kamal, C K; Pirici, D; Pop, O T; Mălăescu, D Gh

    2012-01-01

    Avascular necrosis of the femoral head is an illness with a controversial etiology, the trigger event being the suppression of blood flow to the femoral head. The disease affects mostly young adults within their third and fifth decade, the majority of the patients being men. The main risk factors are trauma, chronic alcohol consumption, smoking, corticotherapy. The main goal of our study is to describe the morphometric changes found in the bone tissue of patients diagnosed with avascular necrosis of the femoral head, with different risk factors, by comparing the area of bone trabeculae inside the area of necrosis with that from the adjacent viable tissue. The morphometric study used biological material from 16 patients with ages between 29 and 57 years, who underwent surgery for avascular necrosis of the femoral head. They were admitted in the Orthopedics Department at the Emergency County Hospital in Craiova between 2010 and 2011 and were split into four groups. Group I presented trauma as the main risk factor, Group II had corticotherapy as the defining risk factor, Group III presented chronic alcohol consumption and Group IV was represented by the patients who smoked and exhibited chronic alcohol consumption. There was not a significant statistical difference between the areas of bone trabeculae of the four groups when we compared viable bone tissue to the necrotized one. Knowing the risk factors of the avascular necrosis of the femoral head is critical to the management of the disease, because diagnosing it in an early stage is a necessity for obtaining a good result for conservative treatment.

  5. Influence of semiconductor barrier tunneling on the current-voltage characteristics of tunnel metal-oxide-semiconductor diodes

    Nielsen, Otto M.

    1983-01-01

    of multistep tunneling recombination current and injected minority carrier diffusion current. This can explain the observed values of the diode quality factor n. The results also show that the voltage drop across the oxide Vox is increased with increased NA, with the result that the lowering of the minority...... carrier diode current Jmin is greater than in the usual theory. The conclusion drawn is that the increase in Vox and lowering of Jmin is due to multistep tunneling of majority carriers through the semiconductor barrier. Journal of Applied Physics is copyrighted by The American Institute of Physics.......Current–voltage characteristics have been examined for Al–SiO2–pSi diodes with an interfacial oxide thickness of delta[approximately-equal-to]20 Å. The diodes were fabricated on and oriented substrates with an impurity concentration in the range of NA=1014–1016 cm−3. The results show that for low...

  6. Current noise in tunnel junctions

    Frey, Moritz; Grabert, Hermann [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Strasse 3, 79104, Freiburg (Germany)

    2017-06-15

    We study current fluctuations in tunnel junctions driven by a voltage source. The voltage is applied to the tunneling element via an impedance providing an electromagnetic environment of the junction. We use circuit theory to relate the fluctuations of the current flowing in the leads of the junction with the voltage fluctuations generated by the environmental impedance and the fluctuations of the tunneling current. The spectrum of current fluctuations is found to consist of three parts: a term arising from the environmental Johnson-Nyquist noise, a term due to the shot noise of the tunneling current and a third term describing the cross-correlation between these two noise sources. Our phenomenological theory reproduces previous results based on the Hamiltonian model for the dynamical Coulomb blockade and provides a simple understanding of the current fluctuation spectrum in terms of circuit theory and properties of the average current. Specific results are given for a tunnel junction driven through a resonator. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Superconducting tunnel-junction refrigerator

    Melton, R.G.; Paterson, J.L.; Kaplan, S.B.

    1980-01-01

    The dc current through an S 1 -S 2 tunnel junction, with Δ 2 greater than Δ 1 , when biased with eV 1 +Δ 2 , will lower the energy in S 1 . This energy reduction will be shared by the phonons and electrons. This device is shown to be analogous to a thermoelectric refrigerator with an effective Peltier coefficient π* approx. Δ 1 /e. Tunneling calculations yield the cooling power P/sub c/, the electrical power P/sub e/ supplied by the bias supply, and the cooling efficiency eta=P/sub c//P/sub e/. The maximum cooling power is obtained for eV= +- (Δ 2 -Δ 1 ) and t 1 =T 1 /T/sub c/1 approx. 0.9. Estimates are made of the temperature difference T 2 -T 1 achievable in Al-Pb and Sn-Pb junctions with an Al 2 O 3 tunneling barrier. The performance of this device is shown to yield a maximum cooling efficiency eta approx. = Δ 1 /(Δ 2 -Δ 1 ) which can be compared with that available in an ideal Carnot refrigerator of eta=T 1 /(T 2 -T 1 ). The development of a useful tunnel-junction refrigerator requires a tunneling barrier with an effective thermal conductance per unit area several orders of magnitude less than that provided by the A1 2 O 3 barrier in the Al-Pb and Sn-Pb systems

  8. Radiographic anatomy of the proximal femur: femoral neck fracture vs. transtrochanteric fracture

    Ana Lecia Carneiro Leão de Araújo Lima

    Full Text Available ABSTRACT OBJECTIVE: To evaluate the correlation between radiographic parameters of the proximal femur with femoral neck fractures or transtrochanteric fractures. METHODS: Cervicodiaphyseal angle (CDA, femoral neck width (FNW, hip axis length (HAL, and acetabular tear drop distance (ATD were analyzed in 30 pelvis anteroposterior view X-rays of patients with femoral neck fractures (n = 15 and transtrochanteric fractures (n = 15. The analysis was performed by comparing the results of the X-rays with femoral neck fractures and with transtrochanteric fractures. RESULTS: No statistically significant differences between samples were observed. CONCLUSION: There was no correlation between radiographic parameters evaluated and specific occurrence of femoral neck fractures or transtrochanteric fractures.

  9. TunnelVision: LHC Tunnel Photogrammetry System for Structural Monitoring

    Fallas, William

    2014-01-01

    In this document an algorithm to detect deformations in the LHC Tunnel of CERN is presented. It is based on two images, one represents the ideal state of the tunnel and the other one the actual state. To find the differences between both, the algorithm is divided in three steps. First, an image enhancement is applied to make easier the detection. Second, two different approaches to reduce noise are applied to one or both images. And third, it is defined a group of characteristics about the type of deformation desired to detect. Finally, the conclusions show the effectiveness of the algorithm in the experimental results.

  10. A STUDY OF SURGICAL MANAGEMENT OF DISTAL FEMORAL FRACTURES BY DISTAL FEMORAL LOCKING COMPRESSION PLATE OSTEOSYNTHESIS

    Dema Rajaiah

    2016-08-01

    Full Text Available AIMS AND OBJECTIVES To study the fractures of distal end of femur and the mechanism of injury in distal end femur fractures, the advantages and disadvantages of open reduction and internal fixation of distal end femur fractures by distal femoral locking compression plate osteosynthesis and to analyse the outcome in terms of range of Knee motion, time to union, and limb shortening. RESULTS The mean age of patient is 44 years, 85% are males, road traffic accidents account for majority (80%, right side involved in 70%, Muller’s type C fracture is common, good range of movements is seen 90% of cases and union occurred in 95% in 5 months. The results were assessed using Neer’s score, seven (35% patients had excellent results, eight (40% patients had good results, four (20% patients had fair results and one (5% patient had poor result. CONCLUSION From our study, we conclude that DF-LCP is a safe and reliable implant and has shown excellent to satisfactory results in majority of intra-articular fractures (AO type C. Fixation with locking compression plate showed more effectiveness in severely osteoporotic bones, shorter operative stay, faster recovery, faster union rates and excellent functional outcome.

  11. Manifestation of spin selection rules on the quantum tunneling of magnetization in a single-molecule magnet.

    Henderson, J J; Koo, C; Feng, P L; del Barco, E; Hill, S; Tupitsyn, I S; Stamp, P C E; Hendrickson, D N

    2009-07-03

    We present low temperature magnetometry measurements on a new Mn3 single-molecule magnet in which the quantum tunneling of magnetization (QTM) displays clear evidence for quantum mechanical selection rules. A QTM resonance appearing only at high temperatures demonstrates tunneling between excited states with spin projections differing by a multiple of three. This is dictated by the C3 molecular symmetry, which forbids pure tunneling from the lowest metastable state. Transverse field resonances are understood by correctly orienting the Jahn-Teller axes of the individual manganese ions and including transverse dipolar fields. These factors are likely to be important for QTM in all single-molecule magnets.

  12. In Situ Observation of Rock Spalling in the Deep Tunnels of the China Jinping Underground Laboratory (2400 m Depth)

    Feng, Xia-Ting; Xu, Hong; Qiu, Shi-Li; Li, Shao-Jun; Yang, Cheng-Xiang; Guo, Hao-Sen; Cheng, Yuan; Gao, Yao-Hui

    2018-04-01

    To study rock spalling in deep tunnels at China Jinping Underground Laboratory Phase II (CJPL-II), photogrammetry method and digital borehole camera were used to quantify key features of rock spalling including orientation, thickness of slabs and the depth of spalling. The failure mechanism was analysed through scanning electron microscope and numerical simulation based on FLAC3D. Observation results clearly showed the process of rock spalling failure: a typical spalling pattern around D-shaped tunnels after top-heading and bottom bench were discovered. The orientation and thickness of the slabs were obtained. The slabs were parallel to the excavated surfaces of the tunnel and were related to the shape of the tunnel surface and orientation of the principal stress. The slabs were alternately thick and thin, and they gradually increased in thickness from the sidewall inwards. The form and mechanism of spalling at different locations in the tunnels, as influenced by stress state and excavation, were analysed. The result of this study was helpful to those rethinking the engineering design, including the excavation and support of tunnels, or caverns, at high risk of spalling.

  13. [Midterm follow-up results on Asian femoral intramedullary nail for the treatment of segmental and comminuted femoral fractures].

    Li, Lang; Gao, Feng; Huang, Qi; Li, Qiang; Xie, Lin; Zhang, Bin

    2016-06-01

    To investigate midterm follow-up results on Asian femoral intramedullary nail in treating segmental and comminuted femoral fractures. Between June 2011 and October 2012,16 patients with segmental and comminuted femoral fractures were treated with minimally invasive reset and Asian femoral intramedullary nail under extension table. Among them, there were 10 males and 6 females aged from 21 to 49 years old with an average of 34.5 years old; the time from injury to operation ranged from 3 to 24 d with an average of 9.1 d. There were 6 cases were type C1,2 cases were type C2 and 8 cases were type C3 according to AO classification. X-ray of femoral segment at 3,6 and 12 months after operation were applied for evaluating fracture healing. Harris score of hip joint and HSS score of knee joint were used to evaluate postoperative function. All patients were followed up from 24 to 36 months with an average of 28.4 months. Operative time was from 88 to 112 min with an average of 90.7 min; blood loss ranged from 150 to 200 ml with an average of 188.75 ml; the time of fracture healing was from 5 to 9 months with an average of 5.4 months. All incision were healed at stage I. No loosening, breakage of internal fixation and displacement of fracture were occurred. There were no significant differences in Harris score of hip joint at 3, 6 and 12 months after operation (F = 0.07, P = 0.893 > 0.05), 10 cases obtained excellent results, 5 good and 1 moderate. There was no obvious meaning in HSS score of knee joint (F = 0.08,P = 0.876 > 0.05), 9 cases obtained excellent results, 6 good and 1 poor. Asian femoral intramedullary nail could treat segmental and comminuted femoral fractures by using variety of less invasive ways,which has advantages of less trauma, quick recovery of function and satisfied midterm following-up results. But long term following-up effects remains to be seen.

  14. Is Assessment of Femoral Head Perfusion During Modified Dunn for Unstable Slipped Capital Femoral Epiphysis an Accurate Indicator of Osteonecrosis?

    Novais, Eduardo N; Sink, Ernest L; Kestel, Lauryn A; Carry, Patrick M; Abdo, João C M; Heare, Travis C

    2016-08-01

    The modified Dunn procedure, which is an open subcapital realignment through a surgical dislocation approach, has gained popularity for the treatment of unstable slipped capital femoral epiphysis (SCFE). Intraoperative monitoring of the femoral head perfusion has been recommended as a method of predicting osteonecrosis; however, the accuracy of this assessment has not been well documented. We asked (1) whether intraoperative assessment of femoral head perfusion would help identify hips at risk of developing osteonecrosis; (2) whether one of the four methods of assessment of femoral head perfusion is more accurate (highest area under the curve) at identifying hips at risk of osteonecrosis; and (3) whether specific clinical features would be associated with osteonecrosis occurrence after a modified Dunn procedure for unstable SCFE. Between 2007 and 2014, we performed 29 modified Dunn procedures for unstable SCFE (16 boys, 11 girls; median age, 13 years; range, 8-17 years); two were lost to followup before 1 year. During this period, six patients with unstable SCFE were treated by other procedures. All patients undergoing modified Dunn underwent assessment of epiphyseal perfusion by the presence of active bleeding and/or by intracranial pressure (ICP) monitoring. In the initial five patients perfusion was recorded once, either before dissection of the retinacular flap or after fixation by one of the two methods. In the remaining 22 patients (81%), perfusion was systematically assessed before dissection of the retinacular flap and after fixation by both methods. Minimum followup was 1 year (median, 2.5 years; range, 1-8 years) because osteonecrosis typically develops within the first year after surgery. Patients were assessed for osteonecrosis by the presence of femoral head collapse at radiographs obtained every 3 months during the first year after surgery. Seven (26%) of the 27 patients developed osteonecrosis. Measures of diagnostic accuracy including sensitivity

  15. Hybrid inflation exit through tunneling

    Garbrecht, Bjoern; Konstandin, Thomas

    2007-01-01

    For hybrid inflationary potentials, we derive the tunneling rate from field configurations along the flat direction towards the waterfall regime. This process competes with the classically rolling evolution of the scalar fields and needs to be strongly subdominant for phenomenologically viable models. Tunneling may exclude models with a mass scale below 10 12 GeV, but can be suppressed by small values of the coupling constants. We find that tunneling is negligible for those models, which do not require fine tuning in order to cancel radiative corrections, in particular for GUT-scale SUSY inflation. In contrast, electroweak scale hybrid inflation is not viable, unless the inflaton-waterfall field coupling is smaller than approximately 10 -11

  16. Transtrochanteric rotational osteotomy for avascular necrosis of the femoral head after unstable slipped capital femoral epiphysis: 10-year clinical results.

    Nakashima, Yasuharu; Yamamoto, Takuaki; Fukushi, Jun-Ichi; Motomura, Goro; Hamai, Satoshi; Kohno, Yusuke; Iwamoto, Yukihide

    2016-11-01

    Avascular necrosis of the femoral head (AVN) is the most serious complication after unstable slipped capital femoral epiphysis (SCFE), and is often unsalvageable. We report a minimum 10 years of clinical results for transtrochanteric rotational osteotomy of the femoral head (TRO) for AVN. This study included 7 patients (7 hips) with a mean age at surgery of 13.3 years, and the follow-up period was 15.8 years. All patients had prior treatment via closed reduction and pinning of the unstable SCFE, and showed severely collapsed femoral heads. The direction of rotation was anterior in 3 hips and posterior in 4. The Merle d'Aubigné-Postel score (MDPS) was used for clinical assessment, and joint degeneration was assessed with the Kellgren and Lawrence classification (KL-grade). The spherical intact area of the femoral head was moved to the weight-bearing portion, and subluxation was corrected via rotation combined with intentional varus positioning. The mean MDPS improved from 10.3 points to 15.6 points at 5 years, and it was maintained at 15.0 points by 10 years; 3 hips were excellent, 1 was good, 2 were fair, and 1 showed poor outcomes. No patient experienced re-collapse after TRO or required conversion to hip replacement or arthrodesis. After 10 years, degenerative changes became evident over time, and 2 hips progressed to KL-4 with a decreased MDPS. Although some joint degeneration is inevitable in the long-term, TRO is an effective salvage procedure for treating AVN after unstable SCFE. Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

  17. Quantum mechanical tunneling in chemical physics

    Nakamura, Hiroki

    2016-01-01

    Quantum mechanical tunneling plays important roles in a wide range of natural sciences, from nuclear and solid-state physics to proton transfer and chemical reactions in chemistry and biology. Responding to the need for further understanding of multidimensional tunneling, the authors have recently developed practical methods that can be applied to multidimensional systems. Quantum Mechanical Tunneling in Chemical Physics presents basic theories, as well as original ones developed by the authors. It also provides methodologies and numerical applications to real molecular systems. The book offers information so readers can understand the basic concepts and dynamics of multidimensional tunneling phenomena and use the described methods for various molecular spectroscopy and chemical dynamics problems. The text focuses on three tunneling phenomena: (1) energy splitting, or tunneling splitting, in symmetric double well potential, (2) decay of metastable state through tunneling, and (3) tunneling effects in chemical...

  18. Tunnel Boring Machine Performance Study. Final Report

    1984-06-01

    Full face tunnel boring machine "TBM" performance during the excavation of 6 tunnels in sedimentary rock is considered in terms of utilization, penetration rates and cutter wear. The construction records are analyzed and the results are used to inves...

  19. Femoral head allograft disinfection system using moderate heat

    Knaepler, H.; Von Garrel, T.

    1999-01-01

    The employment of a reliable thermal viral inactivation process, which minimally manipulates tissues, for surgically retrieved femoral head allografts addresses the increased concerns with virus transmissibility while minimizing the loss of biological properties. The newest European and German surgical bone banking guidelines have incorporated the use of independently validated then-nal viral inactivation methods in place of repeat serological testing of donor. Our investigations have shown that heat treatment at 80 degree C for a minimum of 10 minutes provides safe, good quality cancellous bone allografts and increases the cost-effectiveness and simplicity of managing a hospital frozen femoral head bone bank. Human femoral head centers were contaminated with different vegetative bacterial and viral suspensions. A core temperature of 80 degree C for 10 minutes was sufficient to fully inactivate 3 x 106 ml Staphylococcus aureus and Streptococcus faecalis, and >5 loglo steps of cytomeglia (herpes group), polio (enterovirus), and yellow fever (arbovirus) viruses. A one hour treatment in a water bath set at 80 degree sufficient to fully inactivate E. coli, proteus vulgaris, and Pseudomonas aerog. vegetative suspensions; 20 minutes was sufficient to fully inactivate the D antigen (rhesus factor) but had no effect on A or B antigens. Several biomechanical and biological properties of bone following a one hour treatment in a water bath set at 80 degree C were investigated. Employing compression and tension tests, 80 degree C treated human and porcine cancellous bone blocks showed reductions in properties ranging from 8-19% compared to untreated control groups. Osteointegration at 3 months following treatment of explanted and then reimplanted autograft rat diaphyseal segment was 15% less than untreated controls. Subsequently, a thermal disinfection system for femoral heads from living donors (Lobator Marburg Bone Bank System, Telos GmbH, Hungen, Germany) was developed. A

  20. London forces in highly oriented pyrolytic graphite

    L.V. Poperenko

    2017-07-01

    Full Text Available Surface of highly oriented pyrolytic graphite with terrace steps was studied using scanning tunneling microscopy with high spatial resolution. Spots with positive and negative charges were found in the vicinity of the steps. Values of the charges depended both on the microscope needle scan velocity and on its motion direction. The observed effect was theoretically explained with account of London forces that arise between the needle tip and the graphite surface. In this scheme, a terrace step works as a nanoscale diode for surface electric currents.

  1. Transit time for resonant tunneling

    Garcia Calderon, G.; Rubio, A.

    1990-09-01

    This work considers properties of the partial widths in one dimensional elastic resonant tunneling in order to propose a transit-time τ tr = (h/2π)/Γ n T res ) where Γ n is the elastic width and T res the transmission coefficient at resonance energy. This time is interpreted as an average over the resonance energy width. It is shown that the tunneling current density integrated across a sharp resonance is inversely proportional to τ tr . This transit time may be much larger than the values predicted by other definitions. (author). 20 refs

  2. Spin tunnelling in mesoscopic systems

    Garg, Anupam

    2001-02-01

    We study spin tunnelling in molecular magnets as an instance of a mesoscopic phenomenon, with special emphasis on the molecule Fe8. We show that the tunnel splitting between various pairs of Zeeman levels in this molecule oscillates as a function of applied magnetic field, vanishing completely at special points in the space of magnetic fields, known as diabolical points. This phenomena is explained in terms of two approaches, one based on spin-coherent-state path integrals, and the other on a generalization of the phase integral (or WKB) method to difference equations. Explicit formulas for the diabolical points are obtained for a model Hamiltonian.

  3. Tunneling field effect transistor technology

    Chan, Mansun

    2016-01-01

    This book provides a single-source reference to the state-of-the art in tunneling field effect transistors (TFETs). Readers will learn the TFETs physics from advanced atomistic simulations, the TFETs fabrication process and the important roles that TFETs will play in enabling integrated circuit designs for power efficiency. · Provides comprehensive reference to tunneling field effect transistors (TFETs); · Covers all aspects of TFETs, from device process to modeling and applications; · Enables design of power-efficient integrated circuits, with low power consumption TFETs.

  4. Inelastic scattering in resonant tunneling

    Wingreen, Ned S.; Jacobsen, Karsten Wedel; Wilkins, John W.

    1989-01-01

    The exact resonant-tunneling transmission probability for an electron interacting with phonons is presented in the limit that the elastic coupling to the leads is independent of energy. The phonons produce transmission sidebands but do not affect the integrated transmission probability or the esc......The exact resonant-tunneling transmission probability for an electron interacting with phonons is presented in the limit that the elastic coupling to the leads is independent of energy. The phonons produce transmission sidebands but do not affect the integrated transmission probability...

  5. Molecular series-tunneling junctions.

    Liao, Kung-Ching; Hsu, Liang-Yan; Bowers, Carleen M; Rabitz, Herschel; Whitesides, George M

    2015-05-13

    Charge transport through junctions consisting of insulating molecular units is a quantum phenomenon that cannot be described adequately by classical circuit laws. This paper explores tunneling current densities in self-assembled monolayer (SAM)-based junctions with the structure Ag(TS)/O2C-R1-R2-H//Ga2O3/EGaIn, where Ag(TS) is template-stripped silver and EGaIn is the eutectic alloy of gallium and indium; R1 and R2 refer to two classes of insulating molecular units-(CH2)n and (C6H4)m-that are connected in series and have different tunneling decay constants in the Simmons equation. These junctions can be analyzed as a form of series-tunneling junctions based on the observation that permuting the order of R1 and R2 in the junction does not alter the overall rate of charge transport. By using the Ag/O2C interface, this system decouples the highest occupied molecular orbital (HOMO, which is localized on the carboxylate group) from strong interactions with the R1 and R2 units. The differences in rates of tunneling are thus determined by the electronic structure of the groups R1 and R2; these differences are not influenced by the order of R1 and R2 in the SAM. In an electrical potential model that rationalizes this observation, R1 and R2 contribute independently to the height of the barrier. This model explicitly assumes that contributions to rates of tunneling from the Ag(TS)/O2C and H//Ga2O3 interfaces are constant across the series examined. The current density of these series-tunneling junctions can be described by J(V) = J0(V) exp(-β1d1 - β2d2), where J(V) is the current density (A/cm(2)) at applied voltage V and βi and di are the parameters describing the attenuation of the tunneling current through a rectangular tunneling barrier, with width d and a height related to the attenuation factor β.

  6. Watertightness of concrete tunnel structures

    Glerum, A.

    1982-01-01

    The Netherlands are situated in the delta. of the rivers Rhine, Meuse and Scheldt. Therefore the ground mainly consists.of sediments, such as sand, clay and silt. In certain regions peat layers of varying thickness are found. The high permeability of some of these materials and the fact that the groundwater table is generally only 1 m below ground level, make an adequate watertightness one of the main features of tunnel engineering in the Netherlands. Tunnels in Holland are both of the immers...

  7. Enhanced tunneling through nonstationary barriers

    Palomares-Baez, J. P.; Rodriguez-Lopez, J. L.; Ivlev, B.

    2007-01-01

    Quantum tunneling through a nonstationary barrier is studied analytically and by a direct numerical solution of Schroedinger equation. Both methods are in agreement and say that the main features of the phenomenon can be described in terms of classical trajectories which are solutions of Newton's equation in complex time. The probability of tunneling is governed by analytical properties of a time-dependent perturbation and the classical trajectory in the plane of complex time. Some preliminary numerical calculations of Euclidean resonance (an easy penetration through a classical nonstationary barrier due to an underbarrier interference) are presented

  8. Drill and blast tunnelling; Konvensjonell drift av tunneler

    Roenn, Paal-Egil

    1997-12-31

    This thesis treats drill and blast tunnelling. The rapid technological advance necessitates revised and updated design criteria, quality requirements and quality control. In situ blast experiments were carried out in order to test new methods and improve the basis for calculation and design. The main topics of the experiments were (1) longer rounds and increased drillhole diameter, (2) emulsion slurry as explosives in tunnelling, and (3) electronic detonators in contour blasting. The experiments show that it is technically feasible to blast rounds of up to 8.6 m length. Using current technology, the economical optimum round length is substantially shorter. Dust, low visibility, noise and toxic fumes are occupational environmental strains for the tunnel workers. Several of the environmental factors are strongly influenced by the type of explosives used. For example, emulsion slurry resulted in 4 to 5 times better visibility than Anolit and the concentration of respirable dust and total dust was reduced by 30-50 %. Electronic detonators were tested and found to give a higher percentage of remaining drillholes in the contour than Nonel detonators. The thesis includes a chapter on economic design of hydropower tunnels. 42 refs., 83 figs., 45 tabs.

  9. Spin-dependent tunnelling in magnetic tunnel junctions

    Tsymbal, Evgeny Y; Mryasov, Oleg N; LeClair, Patrick R

    2003-01-01

    The phenomenon of electron tunnelling has been known since the advent of quantum mechanics, but continues to enrich our understanding of many fields of physics, as well as creating sub-fields on its own. Spin-dependent tunnelling (SDT) in magnetic tunnel junctions (MTJs) has recently aroused enormous interest and has developed in a vigorous field of research. The large tunnelling magnetoresistance (TMR) observed in MTJs garnered much attention due to possible applications in non-volatile random-access memories and next-generation magnetic field sensors. This led to a number of fundamental questions regarding the phenomenon of SDT. In this review article we present an overview of this field of research. We discuss various factors that control the spin polarization and magnetoresistance in MTJs. Starting from early experiments on SDT and their interpretation, we consider thereafter recent experiments and models which highlight the role of the electronic structure of the ferromagnets, the insulating layer, and the ferromagnet/insulator interfaces. We also discuss the role of disorder in the barrier and in the ferromagnetic electrodes and their influence on TMR. (topical review)

  10. Differences in Femoral Geometry and Structure Due to Immobilization

    Kiratli, Beatrice Jenny; Yamada, M.; Smith, A.; Marcus, R. M.; Arnaud, S.; vanderMeulen, M. C. H.; Hargens, Alan R. (Technical Monitor)

    1996-01-01

    Reduction in bone mass of the lower extremity is well documented in individuals with paralysis resulting from spinal cord injury (SCI). The consequent osteopenia leads to elevated fracture risk with fractures occurring more commonly in the femoral shaft and supracondylar regions than the hip. A model has recently been described to estimate geometry and structure of the femoral midshaft from whole body scans by dual X-ray absorptiometry (DXA). Increases in femoral geometric and structural properties during growth were primarily related to mechanical loading as reflected by body mass. In this study, we investigate the relationship between body mass and femoral geometry and structure in adults with normal habitual mechanical loading patterns and those with severely reduced loading. The subjects were 78 ambulatory men (aged 20-72 yrs) and 113 men with complete paralysis from SCI of more than 4 years duration (aged 21 73 yrs). Subregional analysis was performed on DXA whole body scans to obtain bone mineral content (BMC, g), cortical thickness (cm), crosssectional moment of inertia (CSMI, cm4), and section modulus (cm3) of the femoral midshaft. All measured bone variables were significantly lower in SCI compared with ambulatory subjects: -29% (BMC), -33% (cortical thickness), -23% (CSMI), and -22% (section modulus) while body mass was not significantly different. However, the associations between body mass and bone properties were notably different; r2 values were higher for ambulatory than SCI subjects in regressions of body mass on BMC (0.48 vs 0.20), CSMI (0.59 vs 0.32), and section modulus (0.59 vs 0.31). No association was seen between body mass and cortical thickness for either group. The greatest difference between groups is in the femoral cortex, consistent with reduced bone mass via endosteal expansion. The relatively lesser difference in geometric and structural properties implies that there is less effect on mechanical integrity than would be expected from

  11. REcanalisation and Balloon-Oriented Puncture for Re-Insertion of Dialysis Catheter in Nonpatent Central Veins (REBORN)

    Too, Chow Wei; Sayani, Raza; Lim, Elvin Yuan Ting; Leong, Sum; Gogna, Apoorva; Teo, Terence K.

    2016-01-01

    PurposeTo describe a technique involving REcanalisation and Balloon-Oriented puncture for Re-insertion of dialysis catheter in Nonpatent central veins (REBORN) and to report long-term results.Materials and MethodsThis is a retrospective study of ten subjects in whom dialysis catheters were inserted using the REBORN technique from March 2012 to October 2014 and followed up till April 2016. Data on the duration of catheter usage, complications and reasons for removal were obtained. Seven patients had partially occluded lower internal jugular veins (IJV) recanalised in an antegrade fashion via a more cranial puncture. The balloon was then inflated at usual puncture site with an 18G needle. The collapsed balloon was cannulated with a guide wire, and both balloon and guide wire were advanced together into the superior vena cava. This was followed by tunnelled catheter placement using standard techniques. Two patients had catheters placed in the subclavian vein using a similar antegrade technique, and one patient had catheter placed via the left IJV following retrograde recanalisation from a right femoral puncture.ResultsMean duration of catheter use was 278 days (range 32–503). Three catheters were removed due to matured arteriovenous accesses. Four patients had successful catheter change over the same subcutaneous track due to catheter malfunction. One catheter was removed after 7 months because of sepsis. No complications were reported.ConclusionThe REBORN technique allows for the preservation of central veins for future haemodialysis access, which can be challenging in patients requiring long-term dialysis.

  12. REcanalisation and Balloon-Oriented Puncture for Re-Insertion of Dialysis Catheter in Nonpatent Central Veins (REBORN)

    Too, Chow Wei, E-mail: toochowwei@gmail.com [Singapore General Hospital (Singapore); Sayani, Raza [Aga Khan University Hospital (Pakistan); Lim, Elvin Yuan Ting; Leong, Sum; Gogna, Apoorva [Singapore General Hospital (Singapore); Teo, Terence K. [Mount Elizabeth Novena Hospital (Singapore)

    2016-08-15

    PurposeTo describe a technique involving REcanalisation and Balloon-Oriented puncture for Re-insertion of dialysis catheter in Nonpatent central veins (REBORN) and to report long-term results.Materials and MethodsThis is a retrospective study of ten subjects in whom dialysis catheters were inserted using the REBORN technique from March 2012 to October 2014 and followed up till April 2016. Data on the duration of catheter usage, complications and reasons for removal were obtained. Seven patients had partially occluded lower internal jugular veins (IJV) recanalised in an antegrade fashion via a more cranial puncture. The balloon was then inflated at usual puncture site with an 18G needle. The collapsed balloon was cannulated with a guide wire, and both balloon and guide wire were advanced together into the superior vena cava. This was followed by tunnelled catheter placement using standard techniques. Two patients had catheters placed in the subclavian vein using a similar antegrade technique, and one patient had catheter placed via the left IJV following retrograde recanalisation from a right femoral puncture.ResultsMean duration of catheter use was 278 days (range 32–503). Three catheters were removed due to matured arteriovenous accesses. Four patients had successful catheter change over the same subcutaneous track due to catheter malfunction. One catheter was removed after 7 months because of sepsis. No complications were reported.ConclusionThe REBORN technique allows for the preservation of central veins for future haemodialysis access, which can be challenging in patients requiring long-term dialysis.

  13. Correlation between baseline femoral neck marrow status and the development of femoral head osteonecrosis in corticosteroid-treated patients: A longitudinal study by MR imaging

    Vande Berg, Bruno C.; Gilon, Raphael; Malghem, Jacques; Lecouvet, Frederic; Depresseux, Genevieve; Houssiau, Frederic A.

    2006-01-01

    Objective: To test the hypothesis that the development of corticosteroid (CS)-associated femoral head osteonecrosis (ON) is influenced by baseline femoral neck marrow status. Patients and methods: The population consisted of 20 untreated patients with a newly diagnosed rheumatic disease in whom a standardized CS regimen was planned. Before CS treatment, baseline femoral neck marrow status was determined by magnetic resonance (MR) imaging on T1-weighted images (proportion of surface area of femoral neck and intertrochanteric area occupied by fatty marrow; index of marrow conversion [IMC]) and on a quantitative MR sequence (bulk T1 values of femoral head and neck). The presence of ON was assessed by coronal T1-weighted MR images of the hips at 6 and 12 months. Results: None of the patients suffered from ON at baseline. Four patients (20%) developed bilateral femoral head ON at 6 months. The mean percentage of fat marrow in the femoral neck before treatment was significantly higher in ON-positive than in ON-negative patients (p = 0.0025). The mean baseline femoral neck IMC value, which parallels the degree of red to yellow marrow conversion, was higher in ON-positive than in ON-negative patients (p = 0.089). The mean baseline bulk T1 value of the femoral neck (but not of the femoral head), which inversely correlates with the amount of fat marrow, was significantly shorter in ON-positive than in ON-negative patients (p = 0.0298). Conclusion: The development of CS-associated femoral head ON is correlated with a high fat content in the proximal femur before CS therapy

  14. Characterization of magnetic tunnel junction test pads

    Østerberg, Frederik Westergaard; Kjær, Daniel; Nielsen, Peter Folmer

    2015-01-01

    We show experimentally as well as theoretically that patterned magnetic tunnel junctions can be characterized using the current-in-plane tunneling (CIPT) method, and the key parameters, the resistance-area product (RA) and the tunnel magnetoresistance (TMR), can be determined. The CIPT method...

  15. Tunnel Face Stability & New CPT Applications

    Broere, W.

    2001-01-01

    Nearly all tunnels bored in soft soils have encountered problems with the stability of the tunnel face. In several cases these problems led to an extended stand-still of the boring process. A better understanding of the face stability, and of the soil conditions around the tunnel boring machine, can

  16. Entrepreneurial orientation, market orientation, and competitive environment

    Sørensen, Hans Eibe; Cadogan, John W.

    This study sheds light on the role that the competitive environment plays in determining how elements of market orientation and elements of entrepreneurial orientation interact to influence business success. We develop a model in which we postulate that market orientation, entrepreneurial...... orientation, and competitive environment shape business performance via a three-way interaction. We test the model using primary data from the CEOs of 270 CEO of manufacturing firms, together with secondary data on these firms' profit performance. An assessment of the results indicates that customer...... orientation moderates the positive relationships between the competitiveness element of entrepreneurial orientation and market share and return on assets (ROA): the positive relationships between competitiveness and market share and competitiveness and ROA become stronger the greater the firms' customer...

  17. Tunneling into quantum wires: regularization of the tunneling Hamiltonian and consistency between free and bosonized fermions

    Filippone, Michele; Brouwer, Piet

    2016-01-01

    Tunneling between a point contact and a one-dimensional wire is usually described with the help of a tunneling Hamiltonian that contains a delta function in position space. Whereas the leading order contribution to the tunneling current is independent of the way this delta function is regularized, higher-order corrections with respect to the tunneling amplitude are known to depend on the regularization. Instead of regularizing the delta function in the tunneling Hamiltonian, one may also obta...

  18. Macroscopic quantum tunneling in Josephson tunnel junctions and Coulomb blockade in single small tunnel junctions

    Cleland, A.N.

    1991-04-01

    Experiments investigating the process of macroscopic quantum tunneling in a moderately-damped, resistively shunted, Josephson junction are described, followed by a discussion of experiments performed on very small capacitance normal-metal tunnel junctions. The experiments on the resistively-shunted Josephson junction were designed to investigate a quantum process, that of the tunneling of the Josephson phase variable under a potential barrier, in a system in which dissipation plays a major role in the dynamics of motion. All the parameters of the junction were measured using the classical phenomena of thermal activation and resonant activation. Theoretical predictions are compared with the experimental results, showing good agreement with no adjustable parameters; the tunneling rate in the moderately damped (Q ∼ 1) junction is seen to be reduced by a factor of 300 from that predicted for an undamped junction. The phase is seen to be a good quantum-mechanical variable. The experiments on small capacitance tunnel junctions extend the measurements on the larger-area Josephson junctions from the region in which the phase variable has a fairly well-defined value, i.e. its wavefunction has a narrow width, to the region where its value is almost completely unknown. The charge on the junction becomes well-defined and is predicted to quantize the current through the junction, giving rise to the Coulomb blockade at low bias. I present the first clear observation of the Coulomb blockade in single junctions. The electrical environment of the tunnel junction, however, strongly affects the behavior of the junction: higher resistance leads are observed to greatly sharpen the Coulomb blockade over that seen with lower resistance leads. I present theoretical descriptions of how the environment influences the junctions; comparisons with the experimental results are in reasonable agreement

  19. A Case of Femoral Fracture in Klippel Trenaunay Syndrome

    Sam Nahas

    2014-01-01

    Full Text Available We present a case of Klippel Trenaunay syndrome (KTS who presented with severe bilateral knee osteoarthritis (OA. Preoperative planning was commenced for a total knee replacement (TKR. Whilst on the waiting list the patient suffered a fall and sustained a complete femoral diaphysis fracture. Conservative management in the form of skin traction was initially chosen as significant extra- and intramedullary vascular malformations posed an increased risk of perioperative bleeding. This failed to progress to union, and so open reduction and internal fixation was performed. This subsequently resulted in on-going delayed union, which was subsequently managed with low intensity pulsed ultrasound (LIPUS, otherwise known as Exogen (Bioventus. exogen. Secondary exogen, 2012. There are only two previous documented cases of femoral fracture in KTS. This is the first report of a patient with this rare syndrome receiving this treatment. We discuss the management of fracture in this challenging group of patients.

  20. Bilateral simultaneous femoral neck and shafts fractures - a case report.

    Sadeghifar, Amirreza; Saied, Alireza

    2014-10-01

    Simultaneous fractures of the femoral neck and shaft are not common injuries, though they cannot be considered rare. Herein, we report our experience with a patient with bilateral occurance of this injury. Up to the best of our knowkedge this is the first case reported in literature in which correct diagnosis was made initially. Both femurs were fixed using broad 4.5 mm dynamic compression plate and both necks were fixed using 6.5 mm cannulated screws. Femur fixation on one side was converted to retrograde nailing because of plate failure. Both neck fractures healed uneventfully. In spite of rarity of concomitant fractures of femoral neck and shaft, this injury must be approached carefully demanding especial attention and careful device selection.

  1. Confronting hip resurfacing and big femoral head replacement gait analysis

    Panagiotis K. Karampinas

    2014-03-01

    Full Text Available Improved hip kinematics and bone preservation have been reported after resurfacing total hip replacement (THRS. On the other hand, hip kinematics with standard total hip replacement (THR is optimized with large diameter femoral heads (BFH-THR. The purpose of this study is to evaluate the functional outcomes of THRS and BFH-THR and correlate these results to bone preservation or the large femoral heads. Thirty-one patients were included in the study. Gait speed, postural balance, proprioception and overall performance. Our results demonstrated a non-statistically significant improvement in gait, postural balance and proprioception in the THRS confronting to BFH-THR group. THRS provide identical outcomes to traditional BFH-THR. The THRS choice as bone preserving procedure in younger patients is still to be evaluated.

  2. Proximal Femoral Geometry and the Risk of Fractures: Literature Review

    N.V. Grygorieva

    2016-02-01

    Full Text Available This article presents the literature review of the impact of the upper third of the femur geometry (hip axis length, femoral neck angle, inter-trochanteric length, horizontal offset, thickness of the cortical bone, etc. on the risk of fractures. The article demonstrates the capabilities of techniques for measurement of hip geometry, namely conventional X-ray of pelvic bones, dual-energy X-ray absorptiometry, computed tomography. Possible correlation is shown between some genetic markers and features of the geometry of the upper third of the femur. Also, there are presented the results of own researches of age and sex characteristics of proximal hip geometry parameters in patients without fractures, as well as in patients of older age groups with internal and extraarticular femoral fractures.

  3. Quality of life in old patients with proximal femoral fractures

    T A Raskina

    2012-01-01

    Full Text Available Objective: to study quality of life in Kemerovo old patients with proximal femoral fractures. Patients and methods. Quality of life in osteoporotic fractures was analyzed in 219 patients (173 women and 46 men who had sustained the injury in January 2004 to December 2008. Results. In the patients with hip fractures, the lowest (41.94+31.16 scores values were recorded by the physical functioning scale reflecting the degree to which their health limited the performance of physical exercises (self-service, walking, going upstairs, weight carriage, etc.. The role functioning and life activity scales showed the highest values (50.96+19.04 and 51.44+26.51 scores, respectively. The mean value of the physical component scale was 46.42+28.26 scores. That of the psychological component scale was 49.56+19.55 scores. Conclusion. The patients with proximal femoral fractures were found to have lower scores on all SF-36 dimensions.

  4. Periprosthetic femoral fracture within two years after total hip replacement:

    Thien, T. M.; Chatziagorou, G.; Garellick, G.

    2014-01-01

    BACKGROUND: We used the Nordic Arthroplasty Register Association database to evaluate whether age, sex, preoperative diagnosis, fixation, and implant design influence the risk of revision arthroplasty due to periprosthetic fracture within two years from operation of a primary total hip replacement....... METHODS: Included in the study were 325,730 cemented femoral stems and 111,899 uncemented femoral stems inserted from 1995 to 2009. Seven frequently used stems (two cemented stems [Exeter and Lubinus SP II] and five uncemented stems [Bi-Metric, Corail, CLS Spotorno, ABG I, and ABG II]) were specifically...... studied. RESULTS: The incidence of revision at two years was low: 0.47% for uncemented stems and 0.07% for cemented stems. Uncemented stems were much more likely to have this complication (relative risk, 8.72 [95% confidence interval, 7.37 to 10.32]; p

  5. Development of Phantom Limb Pain after Femoral Nerve Block

    Sadiah Siddiqui

    2014-01-01

    Full Text Available Historically, phantom limb pain (PLP develops in 50–80% of amputees and may arise within days following an amputation for reasons presently not well understood. Our case involves a 29-year-old male with previous surgical amputation who develops PLP after the performance of a femoral nerve block. Although there have been documented cases of reactivation of PLP in amputees after neuraxial technique, there have been no reported events associated with femoral nerve blockade. We base our discussion on the theory that symptoms of phantom limb pain are of neuropathic origin and attempt to elaborate the link between regional anesthesia and PLP. Further investigation and understanding of PLP itself will hopefully uncover a relationship between peripheral nerve blocks targeting an affected limb and the subsequent development of this phenomenon, allowing physicians to take appropriate steps in prevention and treatment.

  6. MR imaging of avascular necrosis of the femoral head

    Choi, Eun Wan; Cho, Won Soo; Hong, Hyun Sook; Lee, Hae Kyung; Choi, Deuk Lin; Kim, Ki Jung [Soonchunhyang University Hospital, Seoul (Korea, Republic of)

    1993-09-15

    We evaluated the magnetic resonance imaging (MRI) findings of femoral heads in 20 normal and 45 abnormal patients. The bone marrow in the healthy adults consisted of a combination of hematopoietic and fatty marrow, which showed age-related dirtribation, that is the component of fatty marrow was increased and the marrow vascularity was decreased with age. Avascular necrosis (AVN) showed a decreased bone marrow signal within an normal appearing femoral head on T1 and T2 -weighted images. In addition, we could see inhomogeneous low signal intensive (31 cases), a ring of low intensive with central normal signal intensity (25 cases), focal low signal intensity (12 case), or a band of low signal intensity (4 cases). MRI findings were abnormal in 10 cases with normal radiographic findings as well as in all the cases with abnormal ones. In conclusion, MRI should be the choice of the imaging modality for the evaluation of early bone marrow changes of AVN.

  7. MR imaging of avascular necrosis of the femoral head

    Choi, Eun Wan; Cho, Won Soo; Hong, Hyun Sook; Lee, Hae Kyung; Choi, Deuk Lin; Kim, Ki Jung

    1993-01-01

    We evaluated the magnetic resonance imaging (MRI) findings of femoral heads in 20 normal and 45 abnormal patients. The bone marrow in the healthy adults consisted of a combination of hematopoietic and fatty marrow, which showed age-related dirtribation, that is the component of fatty marrow was increased and the marrow vascularity was decreased with age. Avascular necrosis (AVN) showed a decreased bone marrow signal within an normal appearing femoral head on T1 and T2 -weighted images. In addition, we could see inhomogeneous low signal intensive (31 cases), a ring of low intensive with central normal signal intensity (25 cases), focal low signal intensity (12 case), or a band of low signal intensity (4 cases). MRI findings were abnormal in 10 cases with normal radiographic findings as well as in all the cases with abnormal ones. In conclusion, MRI should be the choice of the imaging modality for the evaluation of early bone marrow changes of AVN

  8. [The comparative characteristics of sawcuts across the femoral bone].

    Sarkisian, B A; Azarov, P A

    2014-01-01

    The objective of the present work was to study the differences between the morphological features of the wounds in the long tubular bones inflicted by joinery hand saws designed for longitudinal and transverse, sawing. The experimental injuries to the femoral bones were inflicted by the recurring and reciprocating saw movements. The hand saws had 5 mm high "sharp" and "blunt"-tipped teeth. A total of 40 experiments were carried out. It was shown that the sawcuts across the femoral bones and their edges have different size, shape, and morphological characteristics (defects, ledges, projections, bright spots) depending on the type of the saw, the sharpness of its teeth, and the mode of sawing. The results of the study may be used to improve diagnostics of injuries to the long tubular bones inflicted by different types of joinery saws.

  9. Earth Pressure on Tunnel Crown

    Andersen, Lars

    Two different analyses have been carried out in order to find the vertical earth pressure, or overburden pressure, at the crown of a tunnel going through a dike. Firstly, a hand calculation is performed using a simple dispersion of the stresses over depth. Secondly, the finite‐element program...

  10. Introduction to scanning tunneling microscopy

    Chen, C Julian

    2008-01-01

    The scanning tunneling and the atomic force microscope, both capable of imaging individual atoms, were crowned with the Physics Nobel Prize in 1986, and are the cornerstones of nanotechnology today. This is a thoroughly updated version of this 'bible' in the field.

  11. Installation in the SPS tunnel

    1974-01-01

    The SPS tunnel is 6910 m in circumference and has a cross section of 4 m inner diameter. It is situated at an elevation of 400 m above sea level at a depth below the surface varying between 23 and 65 m. Its walls are lined with a concrete shell of about 30 cm thickness. See also 7410043X

  12. Principles of electron tunneling spectroscopy

    Wolf, E L

    2012-01-01

    Electron tunnelling spectroscopy as a research tool has strongly advanced understanding of superconductivity. This book explains the physics and instrumentation behind the advances illustrated in beautiful images of atoms, rings of atoms and exotic states in high temperature superconductors, and summarizes the state of knowledge that has resulted.

  13. Time tunnels meet warped passages

    Kushner, David

    2006-01-01

    "Just in time for its 40th anniversary, the classic sci-fi television show "The time tunnel" is out on DVD. The conceit is something every engineer can relate to: a pulled plug. Scientists in an underground lab are working on a secret government experiment in time travel. (1 page)

  14. Zero energy Tunnel-concept

    Dzhusupova, R.

    2012-01-01

    Creating a zero energy environment is a hot topic. The developments in this field are based on the concept of the "Trias Energetica": reducing energy consumption, using renewable energy sources, and efficiently using fossil fuels. A zero energy concept can also be applied to road tunnels to improve

  15. Travelling inside the SPS tunnel

    1974-01-01

    The golf cart proved to be a very useful form of transport around the 7 km circumference of the machine. It could carry four passengers and pull light equipment in its trailer. Here Peter Zettwoch is the driver along a mock-up tunnel for installation tests. (see photo 7401011X and Photo Archive 7401018)

  16. A Seamless Ubiquitous Telehealthcare Tunnel

    Sao-Jie Chen

    2013-08-01

    Full Text Available Mobile handheld devices are rapidly using to implement healthcare services around the World. Fundamentally, these services utilize telemedicine technologies. A disconnection of a mobile telemedicine system usually results in an interruption, which is embarrassing, and reconnection is necessary during the communication session. In this study, the Stream Control Transmission Protocol (SCTP is adopted to build a stable session tunnel to guarantee seamless switching among heterogeneous wireless communication standards, such as Wi-Fi and 3G. This arrangement means that the telemedicine devices will not be limited by a fixed wireless connection and can switch to a better wireless channel if necessary. The tunnel can transmit plain text, binary data, and video streams. According to the evaluation of the proposed software-based SCTP-Tunnel middleware shown, the performance is lower than anticipated and is slightly slower than a fixed connection. However, the transmission throughput is still acceptable for healthcare professionals in a healthcare enterprise or home care site. It is necessary to build more heterogeneous wireless protocols into the proposed tunnel-switching scheme to support all possible communication protocols. In addition, SCTP is another good choice for promoting communication in telemedicine and healthcare fields.

  17. Tunnel Vision in Environmental Management.

    Miller, Alan

    1982-01-01

    Discusses problem-solving styles in environmental management and the specific deficiencies in these styles that might be grouped under the label "tunnel vision," a form of selective attention contributing to inadequate problem-formulation, partial solutions to complex problems, and generation of additional problems. Includes educational…

  18. Management of Carpal Tunnel Syndrome.

    Mooar, Pekka A; Doherty, William J; Murray, Jayson N; Pezold, Ryan; Sevarino, Kaitlyn S

    2018-03-15

    The American Academy of Orthopaedic Surgeons (AAOS) has developed Appropriate Use Criteria (AUC) for Management of Carpal Tunnel Syndrome. Evidence-based information, in conjunction with the clinical expertise of physicians, was used to develop the criteria to improve patient care and obtain best outcomes while considering the subtleties and distinctions necessary in making clinical decisions. To provide the evidence foundation for this AUC, the AAOS Evidence-Based Medicine Unit provided the writing panel and voting panel with the 2016 AAOS Clinical Practice Guideline titled Management of Carpal Tunnel Syndrome Evidence-Based Clinical Practice Guideline. The Management of Carpal Tunnel Syndrome AUC clinical patient scenarios were derived from indications typical of patients with suspected carpal tunnel syndrome in clinical practice, as well as from current evidence-based clinical practice guidelines and supporting literature to identify the appropriateness of treatments. The 135 patient scenarios and 6 treatments were developed by the writing panel, a group of clinicians who are specialists in this AUC topic. Next, a separate, multidisciplinary, voting panel (made up of specialists and nonspecialists) rated the appropriateness of treatment of each patient scenario using a 9-point scale to designate a treatment as Appropriate (median rating, 7 to 9), May Be Appropriate (median rating, 4 to 6), or Rarely Appropriate (median rating, 1 to 3).

  19. Kinetic examination of femoral bone modeling in broilers.

    Prisby, R; Menezes, T; Campbell, J; Benson, T; Samraj, E; Pevzner, I; Wideman, R F

    2014-05-01

    Lameness in broilers can be associated with progressive degeneration of the femoral head leading to femoral head necrosis and osteomyelitis. Femora from clinically healthy broilers were dissected at 7 (n = 35, 2), 14 (n = 32), 21 (n = 33), 28 (n = 34), and 42 (n = 28) d of age, and were processed for bone histomorphometry to examine bone microarchitecture and bone static and dynamic properties in the secondary spongiosa (IISP) of the proximal femoral metaphysis. Body mass increased rapidly with age, whereas the bone volume to tissue volume ratio remained relatively consistent. The bone volume to tissue volume ratio values generally reflected corresponding values for both mean trabecular thickness and mean trabecular number. Bone metabolism was highest on d 7 when significant osteoblast activity was reflected by increased osteoid surface to bone surface and mineralizing surface per bone surface ratios. However, significant declines in osteoblast activity and bone formative processes occurred during the second week of development, such that newly formed but unmineralized bone tissue (osteoid) and the percentages of mineralizing surfaces both were diminished. Osteoclast activity was elevated to the extent that measurement was impossible. Intense osteoclast activity presumably reflects marked bone resorption throughout the experiment. The overall mature trabecular bone volume remained relatively low, which may arise from extensive persistence of chondrocyte columns in the metaphysis, large areas in the metaphysis composed of immature bone, destruction of bone tissue in the primary spongiosa, and potentially reduced bone blood vessel penetration that normally would be necessary for robust development. Delayed bone development in the IISP was attributable to an uncoupling of osteoblast and osteoclast activity, whereby bone resorption (osteoclast activity) outpaced bone formation (osteoblast activity). Insufficient maturation and mineralization of the IISP may contribute

  20. Augmentation of proximal femoral nail in unstable trochanteric fractures

    Gadegone Wasudeo M.

    2017-01-01

    Full Text Available Introduction: Biomechanically proximal femoral nail (PFN is a better choice of implant, still it is associated with screw breakage, cut out of screw through femoral head, Z effect, reverse Z effect, and lateral migration of screws. The purpose of this study is to evaluate the results of augmented PFN in terms of prevention of postoperative complications and failure rates in unstable trochanteric fractures. Material and methods: We carried out a prospective study of 82 cases with unstable trochanteric femoral fractures from April 2010 to December 2015. Forty-two females and 40 males in the age group between 58 and 81 years were included in this study. There were 45 cases of AO 31 A2 (2.2, 2.3 and 37 cases of AO 31 A3 (3.1, 3.2, 3.3. Fractures were fixed by PFN with augmentation by an additional screw from trochanter to inferior quadrant of femoral head or cerclage wire to strengthen the lateral trochanteric wall. Results: The bone healing is observed in all the cases in the mean period of 14.2 weeks. Nine patients developed complications, including lateral migration of neck screws (n = 5, Z effect (n = 1, infection (n = 2, and breakage of distal interlocking bolt in one case. Removal of screws was required in five cases. Patients were followed up for a mean of 8.4 months. At the end of follow-up the Salvati and Wilson hip function was 32 (out of 40 in 88% of patients. Conclusion: The stabilization of lateral trochanteric wall with additional screw or cerclage wire increases the stability of construct.

  1. A low morbidity surgical approach to the sheep femoral trochlea

    Orth Patrick

    2013-01-01

    Full Text Available Abstract Background The ovine stifle joint is an important location for investigations on the repair of articular cartilage defects in preclinical large animals. The classical medial parapatellar approach to the femoral trochlea is hazardous because of the high risk of postoperative patellar luxation. Here, we describe a low morbidity surgical exposure of the ovine trochlea without the necessity for intraoperative patellar luxation. Methods Bilateral surgical exposure of the femoral trochlea of the sheep stifle joint was performed using the classical medial parapatellar approach with intraoperative lateral patellar luxation and transection of the medial patellar retinaculum in 28 ovine stifle joints. A low morbidity approach was performed bilaterally in 116 joints through a mini-arthrotomy without the need to transect the medial patellar retinaculum or the oblique medial vastus muscle nor surgical patellar luxation. Postoperatively, all 72 animals were monitored to exclude patellar luxations and deep wound infections. Results The novel approach could be performed easily in all joints and safely exposed the distal two-thirds of the medial and lateral trochlear facet. No postoperative patellar luxations were observed compared to a postoperative patellar luxation rate of 25% experienced with the classical medial parapatellar approach and a re-luxation rate of 80% following revision surgery. No signs of lameness, wound infections, or empyema were observed for both approaches. Conclusions The mini-arthrotomy presented here yields good exposure of the distal ovine femoral trochlea with a lower postoperative morbidity than the classical medial parapatellar approach. It is therefore suitable to create articular cartilage defects on the femoral trochlea without the risk of postoperative patellar luxation.

  2. Femoral sizing in total knee arthroplasty is rotation dependant.

    Koninckx, Angelique; Deltour, Arnaud; Thienpont, Emmanuel

    2014-12-01

    The mismatch between the medio-lateral (ML) and the antero-posterior (AP) size of femoral components in total knee arthroplasty (TKA) has been linked to gender, ethnicity, morphotype and height differences in patients. The hypothesis of this study was that the AP size measurement of a femoral component increases with more external rotation in posterior referencing TKA. During a 2-year period, 201 patients were included in this prospective study. The AP distance of the distal femur was measured with an AP sizer of the Vanguard (Biomet, Warsaw, US) knee system. This AP sizer allows to dial in external rotation by 1° increments and to determine the femoral size with an anterior boom. AP size was noted at 0°, 3° and 5° of external rotation and then compared for ML matching. Antero-posterior and corresponding ML sizes match perfectly for the Vanguard at 0° of external rotation and a central boom position on the anterior femoral surface. Then, the anterior boom was positioned on the antero-lateral cortex and the AP size increased a mean (SD) 1 (0.5) mm. With 3° of external rotation, the AP size increased a mean (SD) 2.3 (0.4) mm and for 5° a mean (SD) 3.8 (0.3) mm (P external rotation that is dialled in during surgery. Since these parameters vary case per case, the availability of narrow components offers more surgical options to the surgeon and its importance extends beyond the gender aspect allowing different amounts of external rotation to be used without ML overhang. II.

  3. Does Tranexamic Acid Reduce Bleeding during Femoral Fracture Operation?

    Mohammad Haghighi

    2017-03-01

    Full Text Available Background:Proximal Femoral shaft fractures are commonly associated with marked blood loss which can lead topostoperative acute anemia and some other complications.Tranexamic acid (TA is an antifibrinolytic medication that reduces intra-and postoperative blood loss and transfusionrequirements during some elective surgeries (1-3.The aim of this study is to evaluate the effect of intravenous Tranexamic acid (TA on intraoperative blood loss and asubsequent need for transfusion in patients who were undergoing surgery for femoral shaft fractures in trauma setting.Methods:Thirty-eight ASA grade I-II patients undergoing proximal femoral shaft fracture surgery with intra medullarynailing were included in this double blind randomized controlled clinical trial. They were allocated into two groups. GroupI, the intervention group with eighteen patients received 15 mg/kg (TA via intravenous infusion before surgical incision.Patients in the placebo group received an identical volume of normal saline.Hemoglobin level was measured four hours before and after the surgeries. Postoperative blood loss and hemoglobinchange as well as transfusion rates and volumes were compared between the two groups.Results:Mean Percentage fall in hemoglobin after surgery were 1.75±0.84 and 2.04±1.9 in the study and placebo groups,respectively (P=0.570. Hemoglobin loss was higher in the placebo group. Transfusion rates was lower in TA group(5.6% compared to the placebo group (30% (P=0.06. No significant difference in The Allowable Blood Loss during thesurgery was found between the two groups (P=0.894.Conclusion:Preoperative treatment with TA reduces postoperative blood loss and the need for blood transfusion duringtraumatic femoral fracture operation.

  4. The successful use of peripheral nerve blocks for femoral amputation

    Bech, Birgitte Louise; Melchiors, J; Børglum, J

    2009-01-01

    We present a case report of four patients with severe cardiac insufficiency where peripheral nerve blocks guided by either nerve stimulation or ultrasonography were the sole anaesthetic for above-knee amputation. The patients were breathing spontaneously and remained haemodynamically stable during...... surgery. Thus, use of peripheral nerve blocks for femoral amputation in high-risk patients seems to be the technique of choice that can lower perioperative risk....

  5. Optimization of Ecg Gating in Quantitative Femoral Angiography

    Nilsson, S.; Berglund, I.; Erikson, U.; Johansson, J.; Walldius, G.

    2003-01-01

    Purpose: To determine which phase of the heart cycle would yield the highest reproducibility in measuring atherosclerosis-related variables such as arterial lumen volume and edge roughness. Material and Methods: 35 patients with hypercholesterolemia underwent select ive femoral angiography, repeated four times at 10-min intervals. The angiographies were performed with Ecg-gated exposures. In angiographies 1 and 2 the delay from R-wave maximum to each exposure was 0.1 s, in angiographies 3 and 4 the delay was 0.1, 0.3, 0.5 or 0.7 s or the exposures were performed 1/s without Ecg gating. Arterial lumen volume and edge roughness were measured in a 20-cm segment of the superficial femoral artery using a computer-based densitometric method. Measurement reproducibility was determined by comparing angiographies 1-2 and angiographies 3-4. Results: When measuring arterial lumen volume and edge roughness of a 20-cm segment of the femoral artery, reproducibility was not dependent on Ecg gating. In measuring single arterial diameters and cross-sectional areas, the reproducibility was better when exposures were made 0.1 s after the R-wave maximum than when using other settings of the Ecg gating device or without Ecg gating. Conclusion: The influence of pulsatile flow upon quantitative measurement in femoral angiograms seems to be the smallest possible in early systole, as can be demonstrated when measuring single diameters and cross-sectional areas. In variables based on integration over longer segments, measurement reproducibility seems to be independent of phase

  6. Optimization of Ecg Gating in Quantitative Femoral Angiography

    Nilsson, S.; Berglund, I.; Erikson, U. [Univ. Hospital, Uppsala (Sweden). Dept. of Oncology, Radiology and Clinical Immunology; Johansson, J.; Walldius, G. [Karolinska Hospital, Stockholm (Sweden). King Gustav V Research Inst.

    2003-09-01

    Purpose: To determine which phase of the heart cycle would yield the highest reproducibility in measuring atherosclerosis-related variables such as arterial lumen volume and edge roughness. Material and Methods: 35 patients with hypercholesterolemia underwent select ive femoral angiography, repeated four times at 10-min intervals. The angiographies were performed with Ecg-gated exposures. In angiographies 1 and 2 the delay from R-wave maximum to each exposure was 0.1 s, in angiographies 3 and 4 the delay was 0.1, 0.3, 0.5 or 0.7 s or the exposures were performed 1/s without Ecg gating. Arterial lumen volume and edge roughness were measured in a 20-cm segment of the superficial femoral artery using a computer-based densitometric method. Measurement reproducibility was determined by comparing angiographies 1-2 and angiographies 3-4. Results: When measuring arterial lumen volume and edge roughness of a 20-cm segment of the femoral artery, reproducibility was not dependent on Ecg gating. In measuring single arterial diameters and cross-sectional areas, the reproducibility was better when exposures were made 0.1 s after the R-wave maximum than when using other settings of the Ecg gating device or without Ecg gating. Conclusion: The influence of pulsatile flow upon quantitative measurement in femoral angiograms seems to be the smallest possible in early systole, as can be demonstrated when measuring single diameters and cross-sectional areas. In variables based on integration over longer segments, measurement reproducibility seems to be independent of phase.

  7. Corticosteroid Reduces Blood Flow to Femoral Heads in Rabbits.

    Hou, S.M.; Liu, T.K.; Kao, M.C.

    1994-12-01

    Avascular necrosis of the femoral head is one of the common problems in orthopedic practice in Taiwan. The subchondral bone loses its blood supply which weakens its biomechanical support. Steroid overuse is one of many possible etiologies in reducing blood flow to the femoral head. Laser Doppler velocimeter is a precise monitor of regional blood flow of bone which is expressed in perfusion units (PU). In the control group the rabbits were injected with normal saline and there were no statistical differences between blood flow to the right hip (39.26 +/- 5.64 PU) and left hip (38.58 +/- 4.35 PU). In group B a weekly injection of methylprednisolone into rabbits for 6 weeks demonstrated the reduction of blood flow of femoral head (24.74 +/- 3.13 PU) by the laser Doppler velocimeter. The flow decreased further (15.93 +/- 2.33 PU) by 12 weeks of steroid treatment. In group C after a weekly injection of steroid for 6 weeks the flow became 31.63 +/- 4.79 PU. The steroid was then discontinued for 3 weeks and the flow was 34.6 +/- 1.34 PU. In group D the blood flow was 25.89 +/- 4.01 PU after 6 weeks of steroid treatment and we stopped the steroid for 6 weeks, the blood flow became 29.86 +/- 2.59 PU. The merit of our experiment established a model of study in avascular necrosis of the femoral head in rabbits. Copyright 1994 S. Karger AG, Basel

  8. Patellofemoral dysbalance and genua valga: outcome after femoral varisation osteotomies.

    Dickschas, Jörg; Ferner, Felix; Lutter, Christoph; Gelse, Kolja; Harrer, Jörg; Strecker, Wolf

    2018-01-01

    Patellofemoral dysbalance may be caused by trochlear dysplasia, an elevated TTTG distance, femoral or tibial torsional deformities, patella alta, or a genu valgum. The surgical procedure for the treatment of a genu valgum is varisation osteotomy, usually in the femoral aspect. Several authors believe that a genu valgum is one cause of patellofemoral dysbalance, but studies about the outcome of the treatment with a varisation osteotomy are rare. Nineteen knees in 18 patients, aged on average 28 (16-52) years were investigated in a retrospective study. The patients had symptoms of patellofemoral instability or anterior knee pain due to a genu valgum, without symptoms of a lateral femorotibial compartment. All patients underwent a femoral varisation osteotomy. The diagnostic investigation prior to surgery included full-leg radiographs and torsional angle CT scans. The pre-surgery and follow-up investigation included the visual analog scale (VAS), the Kujala score, the Japanese Knee Society score, the Lysholm score. The mean duration of follow-up was 44(10-132) months. The mean preoperative mechanical valgus was 5.6° (range 4-10°). Twelve patients mentioned patellar instability as the main symptom while 14 mentioned anterior knee pain. No redislocation occurred in the follow-up period. Anterior knee pain on the VAS (p value patellofemoral dysbalance, treatment of this condition is femoral varisation osteotomy. In this study, patellofemoral stability was achieved and anterior knee pain was significantly reduced. Significant improvements in clinical scores proved the success of the treatment. IV, case series.

  9. Application of monorail fixator for femoral gap nonunion

    Agrawal Hemendra Kumar

    2014-07-01

    Full Text Available 【Abstract】Difficult femoral nonunion takes account of infective nonunion and aseptic gap nonunion. Limb length discrepancy and nonunion need to be tackled simultaneously. Conventionally Ilizarov ring fixator is in vogue but it has some limitations. To overcome these, monorail fixator is an effective alternative. Persistent good results can be obtained if we can get a perfect anatomical alignment and good regeneration. Key words: Femur; Ilizarov technique; External fixators

  10. Pravastatin Protects Against Avascular Necrosis of Femoral Head via Autophagy.

    Liao, Yun; Zhang, Ping; Yuan, Bo; Li, Ling; Bao, Shisan

    2018-01-01

    Autophagy serves as a stress response and may contribute to the pathogenesis of avascular necrosis of the femoral head induced by steroids. Statins promote angiogenesis and ameliorate endothelial functions through apoptosis inhibition and necrosis of endothelial progenitor cells, however the process used by statins to modulate autophagy in avascular necrosis of the femoral head remains unclear. This manuscript determines whether pravastatin protects against dexamethasone-induced avascular necrosis of the femoral head by activating endothelial progenitor cell autophagy. Pravastatin was observed to enhance the autophagy activity in endothelial progenitor cells, specifically by upregulating LC3-II/Beclin-1 (autophagy related proteins), and autophagosome formation in vivo and in vitro . An autophagy inhibitor, 3-MA, reduced pravastatin protection in endothelial progenitor cells exposed to dexamethasone by attenuating pravastatin-induced autophagy. Adenosine monophosphate-activated protein kinase (AMPK) is a key autophagy regulator by sensing cellular energy changes, and indirectly suppressing activation of the mammalian target of rapamycin (mTOR). We found that phosphorylation of AMPK was upregulated however phosphorylation of mTOR was downregulated in pravastatin-treated endothelial progenitor cells, which was attenuated by AMPK inhibitor compound C. Furthermore, liver kinase B1 (a phosphorylase of AMPK) knockdown eliminated pravastatin regulated autophagy protein LC3-II in endothelial progenitor cells in vitro . We therefore demonstrated pravastatin rescued endothelial progenitor cells from dexamethasone-induced autophagy dysfunction through the AMPK-mTOR signaling pathway in a liver kinase B1-dependent manner. Our results provide useful information for the development of novel therapeutics for management of glucocorticoids-induced avascular necrosis of the femoral head.

  11. Selective angiography of the avascular necrosis of the femoral head

    Choi, Joong Chan; Park, Cheong Hee; Rho, Tae Jin; Yune, Seung Ho; Rhee, Byung Chull [Chung Nam National University College of Medicine, Deajeon (Korea, Republic of)

    1988-10-15

    The diagnosis of the avascular of the femoral head (AVN) has advanced. RI scan, intraosseous pressure monitoring, intramedullary venography, CT, MRI, and selective femoral angiography are used in diagnosis. Among these methods, selective or superselective angiography is necessary to study the change of the vessels of the hip, because the vascular insufficiency could be a major etiology of AVN. Selective femoral angiography was performed for 23 hips of 22 patients who were suspected as AVN by simple rediographs and RI scans in order to estimate the change of vascularity of the femoral head. The results were as follow. 1. The alteration of vasculature appeared in 21 cases among all 23 cases (91%), which included 100% in the traumatic group (4/4 cases) and 90% in nontraumatic group (17/19 cases). 2. The affected vessles in nontraumatic group were the proximal portion of the posterior branch of the medical circumflex artery in 2 cases, the modportion of posterior branch in 2 cases, the distal portion of the posterior branch in 11 cases, and superior capsular branch in 2 cases. 3. The affected vessels in traumatic group were proximal portion in 1 cases, midportion in 1 case, and superior capsular artrey in 2 cases. 4. The obstruction of inferior casular artery was noted in 6 cases of nontraumatic group. 5. The retrograde filling of the posterior branch of medial circumflex artery were noted in 1 case from superior gluteal artery, in 1 case from inferior gluteal artery, in 1 case form superior and inferior gluteal artery and retrograde filling of inferior gluteal artery from medial circumflex artery was in 6 cases.

  12. Selective angiography of the avascular necrosis of the femoral head

    Choi, Joong Chan; Park, Cheong Hee; Rho, Tae Jin; Yune, Seung Ho; Rhee, Byung Chull

    1988-01-01

    The diagnosis of the avascular of the femoral head (AVN) has advanced. RI scan, intraosseous pressure monitoring, intramedullary venography, CT, MRI, and selective femoral angiography are used in diagnosis. Among these methods, selective or superselective angiography is necessary to study the change of the vessels of the hip, because the vascular insufficiency could be a major etiology of AVN. Selective femoral angiography was performed for 23 hips of 22 patients who were suspected as AVN by simple rediographs and RI scans in order to estimate the change of vascularity of the femoral head. The results were as follow. 1. The alteration of vasculature appeared in 21 cases among all 23 cases (91%), which included 100% in the traumatic group (4/4 cases) and 90% in nontraumatic group (17/19 cases). 2. The affected vessles in nontraumatic group were the proximal portion of the posterior branch of the medical circumflex artery in 2 cases, the modportion of posterior branch in 2 cases, the distal portion of the posterior branch in 11 cases, and superior capsular branch in 2 cases. 3. The affected vessels in traumatic group were proximal portion in 1 cases, midportion in 1 case, and superior capsular artrey in 2 cases. 4. The obstruction of inferior casular artery was noted in 6 cases of nontraumatic group. 5. The retrograde filling of the posterior branch of medial circumflex artery were noted in 1 case from superior gluteal artery, in 1 case from inferior gluteal artery, in 1 case form superior and inferior gluteal artery and retrograde filling of inferior gluteal artery from medial circumflex artery was in 6 cases.

  13. Titanium elastic nailing in pediatric femoral diaphyseal fractures

    Singh Roop

    2006-01-01

    Full Text Available Background: The need for operative fixation of pediatric femoral fractures is increasingly being recognised in the present decade. The conventional traction and casting method for management of pediatric femoral fractures is giving way for the operative stabilisation of the fracture. Methods : Thirty five pediatric patients in age group 6-14 years with diaphyseal femoral fractures were stabilised with two titanium nails. Patients were followed up clinically and radiologically for two years. The final results were evaluated using the criteria of Flynn et al. Technical problems and complications associated with the procedure were also analysed. Results : Overall results observed were excellent in 25, satisfactory in 8 and poor in 2 patients. Hospital time averaged 12.30 days in the series. All the fractures healed with an average time to union of 9.6 (6-14.4 weeks. Return to school was early with an average of 7.8 weeks. The soft tissue discomfort near the knee produced by the nails ends was the most common problem encountered. Shortening was observed in three cases and restriction of knee flexion in 5 patients. There was no delayed union, infection or refractures. Per operative technical problems included failure of closed reduction in 2 cases and cork screwing of nails in one case. Conclusion : We believe that with proper operative technique and aftercare TENs may prove to be an ideal implant for pediatric femoral fracture fixation. The most of the complication associated with the procedure are infact features of inexact technique and can be eliminated by strictly adhering to the basic principles and technical aspects.

  14. Three-Dimensional Analysis of the Characteristics of the Femoral Canal Isthmus: An Anatomical Study

    Xiu-yun Su

    2015-01-01

    Full Text Available Purpose. To establish a new approach for measuring and locating the femoral intramedullary canal isthmus in 3-dimensional (3D space. Methods. Based on the computed tomography data from 204 Chinese patients, 3D models of the whole femur and the corresponding femoral isthmus tube were reconstructed using Mimics software (Materialise, Haasrode, Belgium. The anatomical parameters of the femur and the isthmus, including the femur length and radius, and the isthmus diameter and height, were measured accordingly. Results. The mean ratio of the isthmus height versus the femoral height was 55 ± 4.8%. The mean diameter of the isthmus was 10.49 ± 1.52 mm. The femoral length, the isthmus diameter, and the isthmus tube length were significantly larger in the male group. Significant correlations were observed between the femoral length and the isthmus diameter (r=0.24, p<0.01 and between the femoral length and the isthmus height (r=0.6, p<0.01. Stepwise linear regression analyses demonstrated that the femoral length and radius were the most important factors influencing the location and dimension of the femoral canal isthmus. Conclusion. The current study developed a new approach for measuring the femoral canal and for optimization of customer-specific femoral implants.

  15. COMPARATIVE STUDY OF ARTHROSCOPIC SINGLE BUNDLE ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION AND NON-ANATOMICAL DOUBLE BUNDLE WITH SINGLE TIBIAL TUNNEL ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION WITH SEMITENDINOSUS ± GRACILIS AUTOGRAFTS USING LAXOMETRY

    Sivananda

    2016-01-01

    Full Text Available BACKGROUND The knee joint is the most commonly injured of all joints and the ACL is the most commonly injured ligament. Arthroscopic reconstruction of ACL has become gold standard in treating these injuries. AIM 1. To compare the short-term results of ACL reconstruction using single bundle (one Tibial + one Femoral tunnel and non-anatomical double-bundle (one Tibial + two Femoral tunnels techniques using Hamstrings (Semitendinosus ± Gracilis graft. 2. To evaluate ACL graft reconstruction stability measured by laxometry and to find out an association with clinical findings. MATERIAL & METHODS We performed a prospective study between 2014-2015 of 20 case of ACL injuries & compared single bundle reconstruction with Non – anatomical double Bundle reconstruction with semitendinosus ± Gracilis, Autograft using laxometry. CONCLUSION Arthroscopic Non-anatomical double ACL Reconstruction is Bio-mechanically stable reconstruction resembling anatomy of the ACL.

  16. Tunneling time, what is its meaning?

    McDonald, C R; Orlando, G; Vampa, G; Brabec, T

    2015-01-01

    The tunnel time ionization dynamics for bound systems in laser fields are investigated. Numerical analysis for a step function switch-on of the field allows for the tunnel time to be defined as the time it takes the ground state to develop the under-barrier wavefunction components necessary to achieve the static field ionization rate. A relation between the tunnel time and the Keldysh time is established. The definition of the tunnel time is extended to time varying fields and experimental possibilities for measuring the tunnel time are discussed

  17. Dirac particle tunneling from black rings

    Jiang Qingquan

    2008-01-01

    Recent research shows that Hawking radiation can be treated as a quantum tunneling process, and Hawking temperatures of Dirac particles across the horizon of a black hole can be correctly recovered via the fermion tunneling method. In this paper, motivated by the fermion tunneling method, we attempt to apply the analysis to derive Hawking radiation of Dirac particles via tunneling from black ring solutions of 5-dimensional Einstein-Maxwell-dilaton gravity theory. Finally, it is interesting to find that, as in the black hole case, fermion tunneling can also result in correct Hawking temperatures for the rotating neutral, dipole, and charged black rings.

  18. Experimental Evidence for Quantum Tunneling Time

    Camus, Nicolas; Yakaboylu, Enderalp; Fechner, Lutz; Klaiber, Michael; Laux, Martin; Mi, Yonghao; Hatsagortsyan, Karen Z.; Pfeifer, Thomas; Keitel, Christoph H.; Moshammer, Robert

    2017-07-01

    The first hundred attoseconds of the electron dynamics during strong field tunneling ionization are investigated. We quantify theoretically how the electron's classical trajectories in the continuum emerge from the tunneling process and test the results with those achieved in parallel from attoclock measurements. An especially high sensitivity on the tunneling barrier is accomplished here by comparing the momentum distributions of two atomic species of slightly deviating atomic potentials (argon and krypton) being ionized under absolutely identical conditions with near-infrared laser pulses (1300 nm). The agreement between experiment and theory provides clear evidence for a nonzero tunneling time delay and a nonvanishing longitudinal momentum of the electron at the "tunnel exit."

  19. Evaluation of the Superior Gluteal Nerve During Proximal Femoral Nailing

    Mehmet Sonmez

    2017-05-01

    Full Text Available Aim: The superior gluteal nerve may be compromised during hip surgery. We retrospectively evaluated the patients who underwent proximal femoral nailing for unstable trochanteric fractures in order to investigate the presence of superior gluteal nerve injury and its clinical findings. Material and Method: Twenty five patients (14 women, 11 men were included in the study who had femoral nailing between January 2004 and March 2010 at Hamidiye Sisli Etfal Training and Research Hospital Department of Orthopaedics. Two different types of nails which have similar designs and surgical techniques were used for fracture fixation. Patients who had a history of cerebrovascular disease, electromyography findings of polyneuropathy, or degenerative vertebral disease were excluded from the study. Patients were evaluated clinically and radiologically. Findings related to acute denervation in the gluteus medius muscle and motor unit action potential changes were accepted as signs of superior gluteal nerve injury. Results: Eight patients were using support during walking and three of these patients had positive Trendelenburg sign, but only one patient had acute denervation signs of the superior gluteal nerve. Discussion: Based on the present study the incidence of iatrogenic nerve injury is a rare complication of proximal femoral nailing. Elderly patients, regardless of whether they have nerve injury, may limp and need to use a walking support.

  20. Radiographic features of teriparatide-induced healing of femoral fractures

    Youngwoo Kim

    2015-12-01

    Full Text Available Teriparatide is a drug that is used to increase bone remodeling, formation, and density for the treatment of osteoporosis. We present three cases of patients with a femoral insufficiency fracture. The patients were administered teripatatide in an attempt to treat severe osteoporosis and to enhance fracture healing. We found several radiographic features around the femoral fractures during the healing period. 1 Callus formation was found at a very early stage in the treatment. Teriparatide substantially increased the unusually abundant callus formation around the fracture site at 2 weeks. Moreover, this callus formation continued for 8 weeks and led to healing of the fracture. 2 Abundant callus formation was found circumferentially around the cortex with a ‘cloud-like’ appearance. 3 Remodeling of the teriparatide-induced callus formation was found to be part of the normal fracture healing process. After 1 year, normal remodeling was observed on plain radiographs. These findings indicate that teriparatide can be used as an adjuvant therapy in the management of femoral insufficiency fractures.