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Sample records for femoral tunnel orientation

  1. Anterior Cruciate Ligament Graft Isometry Is Affected by the Orientation of the Femoral Tunnel.

    PubMed

    Ebersole, Gregg M; Eckerle, Paul; Farrow, Lutul D; Cutuk, Adnan; Bledsoe, Gary; Kaar, Scott

    2016-04-01

    Purpose The purpose of this study was to compare anterior cruciate ligament (ACL) graft length and tension throughout knee range of motion with transtibial, anteromedial (AM) portal, and all-epiphyseal drilling techniques with suspensory and apical femoral fixation. Methods The three different femoral tunnel drilling techniques using the same intra-articular starting point within the center of the femoral footprint were performed on fresh-frozen cadaveric specimens. All groups underwent standard tibial drilling in the center of the ACL tibial footprint. FiberWire (Arthrex Inc., Naples, FL) was used to simulate anatomic single bundle reconstructions. Changes in graft length and tension were measured at knee flexion angles of 0, 30, 60, 90, 120, and 135 degrees. Results Graft length and tension decreased from 0 through 60 degrees and subsequently increased from 90 to 135 degrees for all groups. The transtibial, AM portal suspensory, and apical fixation groups were similar. However, the all-epiphyseal tunnel with suspensory fixation had a significantly increased change in length (90, 120, and 135 degrees) and tension (120 and 135 degrees). Conclusion Transtibial and AM portal suspensory fixation and apical fixation demonstrate similar changes in length and tension throughout knee range of motion. The all-epiphyseal tunnel with suspensory fixation was associated with greater length and tension changes at higher degrees of knee flexion. All techniques demonstrated decreased graft length and tension with knee flexion to 60 degrees after which they increased with further knee flexion. Clinical Relevance ACL graft length and tension change throughout knee range of motion and also depend on femoral tunnel orientation and fixation type. The use of an all-epiphyseal tunnel with suspensory fixation should be studied further for evidence of graft elongation. PMID:26190786

  2. Determinants of Femoral Tunnel Length in Anterior Cruciate Ligament Reconstruction: CT Analysis of the Influence of Tunnel Orientation on the Length

    PubMed Central

    Raman, Easwar Thirunellai; Rajan, David Vaithyalingam; Krishnamoorthy, Ajith; Sahanand, Santhosh

    2013-01-01

    Purpose The purpose of the study was to identify the femoral tunnel orientation that consistently results in a tunnel length of more than 35 mm in anterior cruciate ligament reconstruction. Materials and Methods Computed tomography (CT) scans were obtained from 30 patients who did not have any pathology in the distal femur. Virtual tunnels were marked on 3D (3-dimensional) reconstructed CT images after determining the orientation defined by sagittal inclination and axial angle. The length of a femoral tunnel in 64 different combinations of orientations (between 30° and 65° in 5° increments in two planes) was measured on 3D reconstructed images in both knees in 30 patients. Reliability of measurement was assessed with correlation coefficient for intra-observer and inter-observer measurements. A one-way analysis of variance (ANOVA) was used for statistical analysis. Results The mean femoral tunnel length varied significantly with each 10° change in orientation in both planes (p<0.05, ANOVA). A femoral tunnel of more than 35 mm in length could be obtained only with a sagittal inclination of more than 50° and axial angle of 30°-45°. When the axial angle was kept constant, the tunnel length increased with the increase in sagittal inclination. Higher sagittal inclinations consistently resulted in longer tunnels (r>0.9) and reduced the incidence of posterior cortical breakage. Conclusions A tunnel orientation with an axial angle between 30°-45° and a sagittal inclination of more than 50° can result in a tunnel length of more than 35 mm. PMID:24368999

  3. Femoral tunnel malposition in ACL revision reconstruction.

    PubMed

    Morgan, Joseph A; Dahm, Diane; Levy, Bruce; Stuart, Michael J

    2012-11-01

    The Multicenter Anterior Cruciate Ligament (ACL) Revision Study (MARS) group was formed to study a large cohort of revision ACL reconstruction patients. The purpose of this subset analysis study of the MARS database is to describe specific details of femoral tunnel malposition and subsequent management strategies that surgeons chose in the revision setting. The design of this study is a case series. The multicenter MARS database is compiled from a questionnaire regarding 460 ACL reconstruction revision cases returned by 87 surgeons. This subset analysis described technical aspects and operative findings in specifically those cases in which femoral tunnel malposition was cited as the cause of primary ACL reconstruction failure. Of the 460 revisions included for study, 276 (60%) cases cited a specific "technical cause of failure." Femoral tunnel malposition was cited in 219 (47.6%) of 460 cases. Femoral tunnel malposition was cited as the only cause of failure in 117 cases (25.4%). Surgeons judged the femoral tunnel too vertical in 42 cases (35.9%), too anterior in 35 cases (29.9%), and too vertical and anterior in 31 cases (26.5%). Revision reconstruction involved the drilling of an entirely new femoral tunnel in 91 cases (82.1%). For primary reconstruction, autograft tissue was used in 82 cases (70.1%). For revision reconstruction, autograft tissue was used in 61 cases (52.1%) and allograft tissue in 56 cases (47.9%). Femoral tunnel malposition in primary ACL reconstruction was the most commonly cited reason for graft failure in this cohort. Graft selection is widely variable among surgeons. PMID:23150344

  4. Femoral Tunnel Malposition in ACL Revision Reconstruction

    PubMed Central

    Morgan, Joseph A.; Dahm, Diane; Levy, Bruce; Stuart, Michael J.

    2013-01-01

    The Multicenter Anterior Cruciate Ligament (ACL) Revision Study (MARS) group was formed to study a large cohort of revision ACL reconstruction patients. The purpose of this subset analysis study of the MARS database is to describe specific details of femoral tunnel malposition and subsequent management strategies that surgeons chose in the revision setting. The design of this study is a case series. The multicenter MARS database is compiled from a questionnaire regarding 460 ACL reconstruction revision cases returned by 87 surgeons. This subset analysis described technical aspects and operative findings in specifically those cases in which femoral tunnel malposition was cited as the cause of primary ACL reconstruction failure. Of the 460 revisions included for study, 276 (60%) cases cited a specific “technical cause of failure.” Femoral tunnel malposition was cited in 219 (47.6%) of 460 cases. Femoral tunnel malposition was cited as the only cause of failure in 117 cases (25.4%). Surgeons judged the femoral tunnel too vertical in 42 cases (35.9%), too anterior in 35 cases (29.9%), and too vertical and anterior in 31 cases (26.5%). Revision reconstruction involved the drilling of an entirely new femoral tunnel in 91 cases (82.1%). For primary reconstruction, autograft tissue was used in 82 cases (70.1%). For revision reconstruction, autograft tissue was used in 61 cases (52.1%) and allograft tissue in 56 cases (47.9%). Femoral tunnel malposition in primary ACL reconstruction was the most commonly cited reason for graft failure in this cohort. Graft selection is widely variable among surgeons. PMID:23150344

  5. Editorial Commentary: Anatomic Femoral Tunnel Drilling: Does It Really Matter?

    PubMed

    Hohmann, Erik

    2016-01-01

    An anatomic anteromedial portal and outside-in technique for creating the anterior cruciate ligament femoral tunnel may improve rotational stability but shows no published differences in clinical outcomes. PMID:26743417

  6. The Correlation of Tunnel Position, Orientation and Tunnel Enlargement in Outside-in Single-Bundle Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Ko, Young Won; Rhee, Seung Jun; Kim, In Woo

    2015-01-01

    Purpose Tunnel widening after anterior cruciate ligament (ACL) reconstruction is a frequently described phenomenon. The possible etiology is multi-factorial with some mechanical and biological factors. Among those, we intended to determine the relation between the location and orientation of the femoral tunnel and the femoral tunnel enlargement after outside-in single-bundle ACL reconstruction. Materials and Methods A retrospective study including 42 patients who received single-bundle ACL reconstruction with the outside-in technique was conducted. Femoral and tibial tunnel locations were evaluated with the quadrant method and bird's-eye view using volume-rendering computed tomography. The angle and diameter of bone tunnel and the degree of tunnel enlargement were evaluated using standard radiographs. Results The degree of femoral tunnel enlargements were 42% and 36% on the anteroposterior (AP) and lateral radiographs, respectively, and the degree of tibial tunnel enlargements were 22% and 23%, respectively. Shallower location of the femoral tunnel was significantly correlated with greater femoral tunnel enlargement on the AP radiograph (r=0.998, p=0.004) and the lateral radiograph (r=0.72, p=0.005) as was the higher location of the femoral tunnel on the AP radiograph (r=-0.47, p=0.01) and the lateral radiograph (r=-0.36, p=0.009) at 12 months after surgery. Conclusions This study revealed that more anterior and higher location and more horizontal orientation of the femoral tunnel in coronal plane could result in widening of the femoral tunnel in outside-in single-bundle ACL reconstruction. PMID:26672479

  7. Direct Visualization of Existing Footprint and Outside-In Drilling of the Femoral Tunnel in Anterior Cruciate Ligament Reconstruction in the Knee

    PubMed Central

    Sutter, E. Grant; Anderson, John A.; Garrett, William E.

    2015-01-01

    Improper femoral tunnel placement in anterior cruciate ligament (ACL) reconstruction is a significant problem and may be a cause of ACL graft failure and abnormal kinematics, which may lead to late degenerative changes after reconstruction. Recently, there has been concern that the transtibial approach may contribute to nonanatomic placement of the femoral tunnel, resulting in abnormal knee kinematics. Tibial-independent techniques can provide more anatomic placement of the ACL graft, but these can be technically demanding. This technical note describes the senior author's technique to directly identify the femoral ACL remnant and use the center of the femoral ACL footprint and retrograde drilling to create an anatomic femoral socket for single-bundle reconstruction. This technique provides femoral tunnel placement based on identification of a patient-specific ACL footprint instead of averaged anatomic measurements from large groups. This technique has been shown to produce anatomic ACL graft position and orientation and restore more normal knee kinematics. PMID:26052485

  8. THA Retrievals: The Need to Mark the Anatomic Orientation of the Femoral Head.

    PubMed

    Heiner, Anneliese D; Kruger, Karen M; Tikekar, Nishant M; Callaghan, John J; Lannutti, John J; Brown, Thomas D

    2015-06-01

    The hypothesis of this study was that the rotational orientation of femoral head damage would greatly affect the volumetric wear rate of the opposing polyethylene (PE) liner. Damage on twenty retrieved cobalt-chromium femoral heads was simulated in a validated damage-feature-based finite element model. For each individual retrieval, the anatomic orientation of the femoral head about the femoral neck axis was systematically varied, in 30° increments. The PE wear rate differential between the maximum- versus minimum-wear orientations was often sizable, as high as 7-fold. Knowing the correct femoral head anatomic orientation is therefore important when analyzing the effects of femoral head damage on PE liner wear. Surgeons retrieving modular femoral heads should routinely mark the anatomic orientation of those components. PMID:25682206

  9. How much hamstring graft needs to be in the femoral tunnel? A MOON cohort study

    PubMed Central

    Mariscalco, Michael W.; Magnussen, Robert A.; Mitchell, Joshua; Pedroza, Angela D.; Jones, Morgan H.; Andrish, Jack T.; Parker, Richard D.; Kaeding, Christopher C.; Flanigan, David C.

    2014-01-01

    Background Recent evidence that smaller hamstring graft diameter is associated with increased failure risk following anterior cruciate ligament (ACL) reconstruction has increased the popularity of graft configurations that increase graft diameter at the expense of graft length. A key question is how much graft needs to be in contact with the femoral tunnel to ensure that healing occurs. We hypothesize that no difference in two-year patient-reported outcomes or failure risk exists based on the amount of graft in the femoral tunnel. Methods Through the use of prospectively collected cohort data augmented with retrospective chart review, 120 of 181 consecutive patients (66.3 %) undergoing primary ACL reconstruction with hamstring autograft were evaluated. Patient and surgical factors along with pre-operative and two-year postoperative knee injury and osteoarthritis outcome score (KOOS) and International Knee Documentation Committee (IKDC) scores and whether each patient underwent revision ACL reconstruction during the two-year follow-up period were recorded. Results No differences in two-year patient-reported outcome scores were noted between patients with graft length in the femoral tunnel less than 25 mm and those with graft length in the femoral tunnel of at least 25 mm. Controlling for age, sex, BMI, and femoral tunnel technique, no correlation was noted between KOOS or IKDC scores and either the length of graft in the femoral tunnel or the contact area between the graft and the tunnel. Conclusions Variation of the length of hamstring autograft in the femoral tunnel between 14 and 35 mm does not predict KOOS or IKDC scores at 2 years postoperative. PMID:25984246

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

    SciTech Connect

    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.

    2012-12-15

    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.

  11. A three-dimensional axis for the study of femoral neck orientation

    PubMed Central

    Bonneau, Noémie; Libourel, Paul-Antoine; Simonis, Caroline; Puymerail, Laurent; Baylac, Michel; Tardieu, Christine; Gagey, Olivier

    2012-01-01

    A common problem in the quantification of the orientation of the femoral neck is the difficulty to determine its true axis; however, this axis is typically estimated visually only. Moreover, the orientation of the femoral neck is commonly analysed using angles that are dependent on anatomical planes of reference and only quantify the orientation in two dimensions. The purpose of this study is to establish a method to determine the three-dimensional orientation of the femoral neck using a three-dimensional model. An accurate determination of the femoral neck axis requires a reconsideration of the complex architecture of the proximal femur. The morphology of the femoral neck results from both the medial and arcuate trabecular systems, and the asymmetry of the cortical bone. Given these considerations, two alternative models, in addition to the cylindrical one frequently assumed, were tested. The surface geometry of the femoral neck was subsequently used to fit one cylinder, two cylinders and successive cross-sectional ellipses. The model based on successive ellipses provided a significantly smaller average deviation than the two other models (P < 0.001) and reduced the observer-induced measurement error. Comparisons with traditional measurements and analyses on a sample of 91 femora were also performed to assess the validity of the model based on successive ellipses. This study provides a semi-automatic and accurate method for the determination of the functional three-dimensional femoral neck orientation avoiding the use of a reference plane. This innovative method has important implications for future studies that aim to document and understand the change in the orientation of the femoral neck associated with the acquisition of a bipedal gait in humans. Moreover, the precise determination of the three-dimensional orientation has implications in current research involved in developing clinical applications in diagnosis, hip surgery and rehabilitation. PMID:22967192

  12. Effect of Femoral Tunnel Placement for Reconstruction of the Anterior Cruciate Ligament on Tibial Rotation

    PubMed Central

    Ristanis, Stavros; Stergiou, Nicholas; Siarava, Eleftheria; Ntoulia, Aikaterini; Mitsionis, Grigorios; Georgoulis, Anastasios D.

    2009-01-01

    Background: Rotational knee movement after reconstruction of the anterior cruciate ligament has been difficult to quantify. The purpose of this study was to identify in vivo whether a more horizontal placement of the femoral tunnel (in the ten o'clock position rather than in the eleven o'clock position) can restore rotational kinematics, during highly demanding dynamic activities, in a knee in which a bone-patellar tendon-bone graft had been used to reconstruct the anterior cruciate ligament. Methods: We evaluated ten patients in whom a bone-patellar tendon-bone graft had been used to reconstruct the anterior cruciate ligament with the femoral tunnel in the eleven o'clock position, ten patients who had had the same procedure with the femoral tunnel in the ten o'clock position, and ten healthy controls. Kinematic data were collected while the subjects (1) descended from a stairway, made foot contact, and then pivoted 90° on the landing lower limb and (2) jumped from a platform, landed with both feet on the ground, and pivoted 90° on the right or left lower limb. The dependent variable that we examined was tibial rotation during pivoting. Results: The results demonstrated that reconstruction of the anterior cruciate ligament with the femoral tunnel in either the ten or the eleven o'clock position successfully restored anterior tibial translation. However, both techniques resulted in tibial rotation values, during the dynamic activities evaluated, that were significantly larger than those in the intact contralateral lower limbs and those in the healthy controls. Tibial rotation did not differ significantly between the two reconstruction groups or between the healthy controls and the intact contralateral lower limbs. However, we noticed that positioning the tunnel at ten o'clock resulted in slightly decreased rotation values that may have clinical relevance but not statistical significance. Conclusions: Regardless of which of the two tested positions was utilized to

  13. RISKS AND CONSEQUENCES OF USING THE TRANSPORTAL TECHNIQUE IN RECONSTRUCTING THE ANTERIOR CRUCIATE LIGAMENT: RELATIONSHIPS BETWEEN THE FEMORAL TUNNEL, LATERAL SUPERIOR GENICULAR ARTERY AND LATERAL EPICONDYLE OF THE FEMORAL CONDYLE

    PubMed Central

    Astur, Diego Costa; Aleluia, Vinicius; Santos, Ciro Veronese; Arliani, Gustavo Gonçalves; Badra, Ricardo; Oliveira, Saulo Gomes; Kaleka, Camila Cohen; Cohen, Moisés

    2015-01-01

    Objective: Define a security zone to avoid possibles vascular and ligamentar complications during anterior cruciate ligament reconstruction. Methods: Arthroscopic reconstruction using the transtibial and transportal technique in cadaver knees was performed followed by dissection and measurement of the distance between the femoral tunnel and the proximal attachment of the lateral collateral ligament and the femoral tunnel and the lateral superior genicular artery. Results: The measure of the analysed distances show us an aproximation between the major branch of the lateral superior genicular artery and the femoral insertion of the colateral lateral ligament and the femoral tunnel during the transportal technique. Conclusion: We realize that the use of technical ship it to arthroscopic ACL reconstruction has a higher probability of injury to the lateral geniculate artery and insertion of the lateral collateral ligament, promoting post-surgical complications such as instability of the knee, osteonecrosis of the femoral condyle and ligamentização graft. PMID:27047873

  14. Orientation and depth estimation for femoral components using image sensor, magnetometer and inertial sensors in THR surgeries.

    PubMed

    Jiyang Gao; Shaojie Su; Hong Chen; Zhihua Wang

    2015-08-01

    Malposition of the acetabular and femoral component has long been recognized as an important cause of dislocation after total hip replacement (THR) surgeries. In order to help surgeons improve the positioning accuracy of the components, a visual-aided system for THR surgeries that could estimate orientation and depth of femoral component is proposed. The sensors are fixed inside the femoral prosthesis trial and checkerboard patterns are printed on the internal surface of the acetabular prosthesis trial. An extended Kalman filter is designed to fuse the data from inertial sensors and the magnetometer orientation estimation. A novel image processing algorithm for depth estimation is developed. The algorithms have been evaluated under the simulation with rotation quaternion and translation vector and the experimental results shows that the root mean square error (RMSE) of the orientation estimation is less then 0.05 degree and the RMSE for depth estimation is 1mm. Finally, the femoral head is displayed in 3D graphics in real time to help surgeons with the component positioning. PMID:26736858

  15. Radiological analysis on femoral tunnel positioning between isometric and anatomical reconstructions of the anterior cruciate ligament☆☆☆

    PubMed Central

    Vieira, Rodrigo Barreiros; de Pinho Tavares, Leonardo Augusto; Pace Lasmar, Rodrigo Campos; da Cunha, Fernando Amaral; de Melo Lisboa, Lucas Araujo

    2014-01-01

    Objective the aim of this study was to radiologically evaluate the femoral tunnel position in anterior cruciate ligament (ACL) reconstructions using the isometric and anatomical techniques. Methods a prospective analytical study was conducted on patients undergoing ACL reconstruction by means of the isometric and anatomical techniques, using grafts from the knee flexor tendons or patellar tendon. Twenty-eight patients were recruited during the immediate postoperative period, at the knee surgery outpatient clinic of FCMMG-HUSJ. Radiographs of the operated knee were produced in anteroposterior (AP) view with the patient standing on both feet and in lateral view with 30° of flexion. The lines were traced out and the distances and angles were measured on the lateral radiograph to evaluate the sagittal plane. The distance from the center of the screw to the posterior cortical bone of the lateral condyle was measured and divided by the Blumensaat line. In relation to the height of the screw, the distance from the center of the screw to the joint surface of the lateral condyle of the knee was measured. On the AP radiograph, evaluating the coronal plane, the angle between the anatomical axis of the femur and a line traced at the center of the screw was measured. Results with regard to the p measurement (posteriorization of the interference screw), the tests showed that the p-value (0.4213) was greater than the significance level used (0.05); the null hypothesis was not rejected and it could be stated that there was no statistically significant difference between the anatomical and isometric techniques. With regard to the H measurement (height of the screw in relation to the lower cortical bone of the knee), the p-value observed (0.0006) was less than the significance level used (0.05); the null hypothesis was rejected and it could be stated that there was a statistically significant difference between the anatomical and isometric techniques. It can be concluded that the

  16. Time to get rid of the clock: intraobserver and interobserver reliability in determination of the o'clock position of the femoral tunnel in ACL reconstruction.

    PubMed

    Wittstein, Jocelyn Ross; Garrett, William E

    2014-02-01

    This study evaluates intraobserver and interobserver agreement in reporting the o'clock position of the femoral tunnel during anterior cruciate ligament (ACL) reconstruction. Four PGY2 residents, four PGY5 residents, and four sports medicine orthopedic surgeons reported the o'clock position of the femoral ACL tunnel in 10 arthroscopic pictures on two occasions 3 months apart. Intraobserver agreement was determined using the intraobserver correlation coefficient (r > 0.576 for 0.05 significance level). Interobserver agreement between members of each group and between reviewer groups was evaluated with the intraclass correlation coefficient (ICC > 0.75 considered good agreement). Poor interobserver agreement was demonstrated between the attending and PGY2 groups (ICC = 0.1685), between the attending and PGY5 groups (ICC = 0.2982), and between the PGY5 and PGY2 groups (ICC = 0.267). Attending surgeons, PGY5s, and PGY2s demonstrated poor interobserver agreement amongst themselves (ICC = 0.2244, 0.471, and 0.0859, respectively). PGY2s and PGY5s demonstrated good intraobserver agreement, but attending surgeons demonstrated poor intraobserver agreement. Attending orthopedic surgeons and residents of different levels of training interpret the o'clock position of the femoral tunnel differently. Greater years of experience does not improve intraobserver or interobserver agreement on the o'clock position. The clock face terminology for femoral tunnel placement may not be a reliable descriptor for scientific investigations or clinical instruction. PMID:24227399

  17. The effects of necrotic lesion size and orientation of the femoral component on stress alterations in the proximal femur in hip resurfacing - a finite element simulation

    PubMed Central

    2014-01-01

    Background Due to the advantages of its bone-conserving nature, hip resurface arthroplasty (HRA) has recently gained the interest of orthopedic surgeons for the treatment of young and active patients who have osteonerosis of the femoral head. However, in long-term follow-up studies after HRA, narrowing of the femoral neck has often been found, which may lead to fracture. This phenomenon has been attributed to the stress alteration (stress shielding). Studies addressing the effects of necrotic size and the orientation of the implant on stress alterations are lacking. Methods Computed tomography images of a standard composite femur were used to create a three-dimensional finite-element (FE) intact femur model. Based on the intact model, FE models simulating four different levels of necrotic regions (0°, 60°, 100°, 115°) and three different implant insertion angles (varus 10°, neutral, valgus 10°) were created. The von Mises stress distributions and the displacement of the stem tip of each model were analyzed and compared for loading conditions that simulated a single-legged stance. Results Stress shielding occurred at the femoral neck after HRA. More severe stress shielding and an increased displacement of the stem tip were found for femoral heads that had a wider necrotic lesion. From a biomechanics perspective, the results were consistent with clinical evidence of femoral neck narrowing after HRA. In addition, a varus orientation of the implant resulted in a larger displacement of the stem tip, which could lead to an increased risk of implant loosening. Conclusions A femoral head with a wide necrotic lesion combined with a varus orientation of the prosthesis increases the risk of femoral neck narrowing and implant loosening following HRA. PMID:25095740

  18. Evaluating the distance between the femoral tunnel centers in anatomic double-bundle anterior cruciate ligament reconstruction using a computer simulation

    PubMed Central

    Tashiro, Yasutaka; Okazaki, Ken; Iwamoto, Yukihide

    2015-01-01

    Purpose We aimed to clarify the distance between the anteromedial (AM) bundle and posterolateral (PL) bundle tunnel-aperture centers by simulating the anatomical femoral tunnel placement during double-bundle anterior cruciate ligament reconstruction using 3-D computer-aided design models of the knee, in order to discuss the risk of tunnel overlap. Relationships between the AM to PL center distance, body height, and sex difference were also analyzed. Patients and methods The positions of the AM and PL tunnel centers were defined based on previous studies using the quadrant method, and were superimposed anatomically onto the 3-D computer-aided design knee models from 68 intact femurs. The distance between the tunnel centers was measured using the 3-D DICOM software package. The correlation between the AM–PL distance and the subject’s body height was assessed, and a cutoff height value for a higher risk of overlap of the AM and PL tunnel apertures was identified. Results The distance between the AM and PL centers was 10.2±0.6 mm in males and 9.4±0.5 mm in females (P<0.01). The AM–PL center distance demonstrated good correlation with body height in both males (r=0.66, P<0.01) and females (r=0.63, P<0.01). When 9 mm was defined as the critical distance between the tunnel centers to preserve a 2 mm bony bridge between the two tunnels, the cutoff value was calculated to be a height of 160 cm in males and 155 cm in females. Conclusion When AM and PL tunnels were placed anatomically in simulated double-bundle anterior cruciate ligament reconstruction, the distance between the two tunnel centers showed a strong positive correlation with body height. In cases with relatively short stature, the AM and PL tunnel apertures are considered to be at a higher risk of overlap when surgeons choose the double-bundle technique. PMID:26170727

  19. Induced Superconductivity and Engineered Josephson Tunneling Devices in Epitaxial (111)-Oriented Gold/Vanadium Heterostructures

    NASA Astrophysics Data System (ADS)

    Wei, Peng; Katmis, Ferhat; Chang, Cui-Zu; Moodera, Jagadeesh S.

    2016-04-01

    We report a unique experimental approach to create topological superconductors by inducing superconductivity into epitaxial metallic thin film with strong spin-orbit coupling. Utilizing molecular beam epitaxy technique under ultra-high vacuum condition, we are able to achieve (111) oriented single phase of gold (Au) thin film grown on a well-oriented vanadium (V) s-wave superconductor film with clean interface. We obtained atomically smooth Au thin films with thicknesses even down to below a nanometer showing near-ideal surface quality. The as-grown V/Au bilayer heterostructure exhibits superconducting transition at around 4 K. Clear Josephson tunneling and Andreev reflection are observed in S-I-S tunnel junctions fabricated from the epitaxial bi-layers. The barrier thickness dependent tunneling and the associated subharmonic gap structures (SGS) confirmed the induced superconductivity in Au (111), paving the way for engineering thin film heterostructure based p-wave superconductors and nano devices for Majorana fermion.

  20. Resonant spin tunneling in randomly oriented nanospheres of Mn12 acetate

    NASA Astrophysics Data System (ADS)

    Lendínez, S.; Zarzuela, R.; Tejada, J.; Terban, M. W.; Billinge, S. J. L.; Espin, J.; Imaz, I.; Maspoch, D.; Chudnovsky, E. M.

    2015-01-01

    We report measurements and theoretical analysis of resonant spin tunneling in randomly oriented nanospheres of a molecular magnet. Amorphous nanospheres of Mn12 acetate have been fabricated and characterized by chemical, infrared, TEM, x-ray, and magnetic methods. Magnetic measurements have revealed sharp tunneling peaks in the field derivative of the magnetization that occur at the typical resonant field values for the Mn12 acetate crystal in the field parallel to the easy axis. Theoretical analysis is provided that explains these observations. We argue that resonant spin tunneling in a molecular magnet can be established in a powder sample, without the need for a single crystal and without aligning the easy magnetization axes of the molecules. This is confirmed by reanalyzing the old data on a powdered sample of nonoriented micron-size crystals of Mn12 acetate. Our findings can greatly simplify the selection of candidates for quantum spin tunneling among newly synthesized molecular magnets.

  1. Atomistic Insights Into the Oriented Attachment of Tunnel-Based Oxide Nanostructures

    SciTech Connect

    Yuan, Yifei; Wood, Stephen M; He, Kun; Yao, Wentao; Tompsett, David; Lu, Jun; Nie, Anmin; Islam, M. Saiful; Shahbazian-Yassar, Reza

    2016-01-01

    Controlled synthesis of nanomaterials is one of the grand challenges facing materials scientists. In particular, how tunnel-based nanomaterials aggregate during synthesis while maintaining their well-aligned tunneled structure is not fully understood. Here, we describe the atomistic mechanism of oriented attachment (OA) during solution synthesis of tunneled α-MnO2 nanowires based on a combination of in situ liquid cell transmission electron microscopy (TEM), aberration-corrected scanning TEM with subangstrom spatial resolution, and first-principles calculations. It is found that primary tunnels (1 × 1 and 2 × 2) attach along their common {110} lateral surfaces to form interfaces corresponding to 2 × 3 tunnels that facilitate their short-range ordering. The OA growth of α-MnO2 nanowires is driven by the stability gained from elimination of {110} surfaces and saturation of Mn atoms at {110}-edges. During this process, extra [MnOx] radicals in solution link the two adjacent {110} surfaces and bond with the unsaturated Mn atoms from both surface edges to produce stable nanowire interfaces. Our results provide insights into the controlled synthesis and design of nanomaterials in which tunneled structures can be tailored for use in catalysis, ion exchange, and energy storage applications.

  2. Resonant spin tunneling in randomly oriented nanospheres of Mn12 acetate

    DOE PAGESBeta

    Lendínez, S.; Zarzuela, R.; Tejada, J.; Terban, M. W.; Billinge, S. J. L.; Espin, J.; Imaz, I.; Maspoch, D.; Chudnovsky, E. M.

    2015-01-06

    We report measurements and theoretical analysis of resonant spin tunneling in randomly oriented nanospheres of a molecular magnet. Amorphous nanospheres of Mn₁₂ acetate have been fabricated and characterized by chemical, infrared, TEM, X-ray, and magnetic methods. Magnetic measurements have revealed sharp tunneling peaks in the field derivative of the magnetization that occur at the typical resonant field values for the Mn₁₂ acetate crystal in the field parallel to the easy axis.Theoretical analysis is provided that explains these observations. We argue that resonant spin tunneling in a molecular magnet can be established in a powder sample, without the need for amore » single crystal and without aligning the easy magnetization axes of the molecules. This is confirmed by re-analyzing the old data on a powdered sample of non-oriented micron-size crystals of Mn₁₂ acetate. In conclusion, our findings can greatly simplify the selection of candidates for quantum spin tunneling among newly synthesized molecular magnets.« less

  3. Imaging of stacking faults in highly oriented pyrolytic graphite using scanning tunneling microscopy

    SciTech Connect

    Snyder, S.R.; Foecke, T.; White, H.S.; Gerberich, W.W. )

    1992-02-01

    Scanning tunneling microscopy images of the (0001) plane of highly oriented pyrolytic graphite show defect regions consisting of an extensive network of partial dislocations that form extended and contracted nodes. The partial dislocations in hexagonal graphite enclose triangular regions ({similar to}1000 nm on a side) of faulted material comprised of rhombohedral graphite. Electronic and elastic interactions of the tip with the HOPG surface are proposed to explain the observed image contrast between hexagonal and rhombohedral graphite.

  4. Induced Superconductivity and Engineered Josephson Tunneling Devices in Epitaxial (111)-Oriented Gold/Vanadium Heterostructures.

    PubMed

    Wei, Peng; Katmis, Ferhat; Chang, Cui-Zu; Moodera, Jagadeesh S

    2016-04-13

    We report a unique experimental approach to create topological superconductors by inducing superconductivity into epitaxial metallic thin film with strong spin-orbit coupling. Utilizing molecular beam epitaxy technique under ultrahigh vacuum conditions, we are able to achieve (111) oriented single phase of gold (Au) thin film grown on a well-oriented vanadium (V) s-wave superconductor film with clean interface. We obtained atomically smooth Au thin films with thicknesses even down to below a nanometer showing near-ideal surface quality. The as-grown V/Au bilayer heterostructure exhibits superconducting transition at around 3.9 K. Clear Josephson tunneling and Andreev reflection are observed in S-I-S tunnel junctions fabricated from the epitaxial bilayers. The barrier thickness dependent tunneling and the associated subharmonic gap structures (SGS) confirmed the induced superconductivity in Au (111), paving the way for engineering thin film heterostructures based on p-wave superconductivity and nano devices exploiting Majorana Fermions for quantum computing. PMID:26943807

  5. Fabrication of [001]-oriented tungsten tips for high resolution scanning tunneling microscopy

    PubMed Central

    Chaika, A. N.; Orlova, N. N.; Semenov, V. N.; Postnova, E. Yu.; Krasnikov, S. A.; Lazarev, M. G.; Chekmazov, S. V.; Aristov, V. Yu.; Glebovsky, V. G.; Bozhko, S. I.; Shvets, I. V.

    2014-01-01

    The structure of the [001]-oriented single crystalline tungsten probes sharpened in ultra-high vacuum using electron beam heating and ion sputtering has been studied using scanning and transmission electron microscopy. The electron microscopy data prove reproducible fabrication of the single-apex tips with nanoscale pyramids grained by the {011} planes at the apexes. These sharp, [001]-oriented tungsten tips have been successfully utilized in high resolution scanning tunneling microscopy imaging of HOPG(0001), SiC(001) and graphene/SiC(001) surfaces. The electron microscopy characterization performed before and after the high resolution STM experiments provides direct correlation between the tip structure and picoscale spatial resolution achieved in the experiments. PMID:24434734

  6. Mechanism of Orientation-Dependent Asymmetric Charge Transport in Tunneling Junctions Comprising Photosystem I.

    PubMed

    Castañeda Ocampo, Olga E; Gordiichuk, Pavlo; Catarci, Stefano; Gautier, Daniel A; Herrmann, Andreas; Chiechi, Ryan C

    2015-07-01

    Recently, photoactive proteins have gained a lot of attention due to their incorporation into bioinspired (photo)electrochemical and solar cells. This paper describes the measurement of the asymmetry of current transport of self-assembled monolayers (SAMs) of the entire photosystem I (PSI) protein complex (not the isolated reaction center, RCI), on two different "director SAMs" supported by ultraflat Au substrates. The director SAMs induce the preferential orientation of PSI, which manifest as asymmetry in tunneling charge-transport. We measured the oriented SAMs of PSI using eutectic Ga-In (EGaIn), a large-area technique, and conducting probe atomic force microscopy (CP-AFM), a single-complex technique, and determined that the transport properties are comparable. By varying the temperatures at which the measurements were performed, we found that there is no measurable dependence of the current on temperature from ±0.1 to ±1.0 V bias, and thus, we suggest tunneling as the mechanism for transport; there are no thermally activated (e.g., hopping) processes. Therefore, it is likely that relaxation in the electron transport chain is not responsible for the asymmetry in the conductance of SAMs of PSI complexes in these junctions, which we ascribe instead to the presence of a large, net dipole moment present in PSI. PMID:26057523

  7. Mechanism of Orientation-Dependent Asymmetric Charge Transport in Tunneling Junctions Comprising Photosystem I

    PubMed Central

    2016-01-01

    Recently, photoactive proteins have gained a lot of attention due to their incorporation into bioinspired (photo)electrochemical and solar cells. This paper describes the measurement of the asymmetry of current transport of self-assembled monolayers (SAMs) of the entire photosystem I (PSI) protein complex (not the isolated reaction center, RCI), on two different “director SAMs” supported by ultraflat Au substrates. The director SAMs induce the preferential orientation of PSI, which manifest as asymmetry in tunneling charge-transport. We measured the oriented SAMs of PSI using eutectic Ga–In (EGaIn), a large-area technique, and conducting probe atomic force microscopy (CP-AFM), a single-complex technique, and determined that the transport properties are comparable. By varying the temperatures at which the measurements were performed, we found that there is no measurable dependence of the current on temperature from ±0.1 to ±1.0 V bias, and thus, we suggest tunneling as the mechanism for transport; there are no thermally activated (e.g., hopping) processes. Therefore, it is likely that relaxation in the electron transport chain is not responsible for the asymmetry in the conductance of SAMs of PSI complexes in these junctions, which we ascribe instead to the presence of a large, net dipole moment present in PSI. PMID:26057523

  8. Direct observation of oriented molecular adsorption at step edges: a cryogenic scanning tunneling microscopy study

    NASA Astrophysics Data System (ADS)

    Frank, E. R.; Chen, X. X.; Hamers, R. J.

    1995-07-01

    A cryogenic scanning tunneling microscope has been used to investigate the adsorption of thiophene, 2,5-dimethylthiophene, and 2,2'-bithiophene on the Ag(111) surface at 120 K. STM images reveal that all three molecules preferentially bond at step edges. Images of 2,2'-bithiophene and 2,5-dimethylthiophene at the step edge show them to be elongated, while thiophene molecules appear nearly circular. The observed elongation for 2,2'-bithiophene and 2,5-dimethylthiophene is attributed to geometric contrast reflecting the intrinsic shape of these molecules. All molecules of a given chemical identity appear to be oriented in the same direction with respect to the step edge, demonstrating that the interactions between the molecules and the step edge are sufficiently strong and sufficiently local to hold the molecules in specific rotational configurations at the step edge.

  9. Quantum tunnelling of the magnetization in a monolayer of oriented single-molecule magnets.

    PubMed

    Mannini, M; Pineider, F; Danieli, C; Totti, F; Sorace, L; Sainctavit, Ph; Arrio, M-A; Otero, E; Joly, L; Cezar, J C; Cornia, A; Sessoli, R

    2010-11-18

    A fundamental step towards atomic- or molecular-scale spintronic devices has recently been made by demonstrating that the spin of an individual atom deposited on a surface, or of a small paramagnetic molecule embedded in a nanojunction, can be externally controlled. An appealing next step is the extension of such a capability to the field of information storage, by taking advantage of the magnetic bistability and rich quantum behaviour of single-molecule magnets (SMMs). Recently, a proof of concept that the magnetic memory effect is retained when SMMs are chemically anchored to a metallic surface was provided. However, control of the nanoscale organization of these complex systems is required for SMMs to be integrated into molecular spintronic devices. Here we show that a preferential orientation of Fe(4) complexes on a gold surface can be achieved by chemical tailoring. As a result, the most striking quantum feature of SMMs-their stepped hysteresis loop, which results from resonant quantum tunnelling of the magnetization-can be clearly detected using synchrotron-based spectroscopic techniques. With the aid of multiple theoretical approaches, we relate the angular dependence of the quantum tunnelling resonances to the adsorption geometry, and demonstrate that molecules predominantly lie with their easy axes close to the surface normal. Our findings prove that the quantum spin dynamics can be observed in SMMs chemically grafted to surfaces, and offer a tool to reveal the organization of matter at the nanoscale. PMID:20981008

  10. [The "tunnel task": a method for examination of cognitive processes in spatial orientation performance].

    PubMed

    Schönebeck, B; Thanhäuser, J; Debus, G

    2001-01-01

    We report on the theoretical development and empirical testing of a new spatial cognition task, during which participants complete a tour through a virtual tunnel. Upon arrival they are asked to specify a "homing" vector by pointing an arrow towards the starting point of their virtual journey. Systematic experimental variations include number, length and sharpness of turns. Solving the task requires the development of a spatial representation, as alternative strategic cues (e.g., visual landmarks) are not available. Performance measures discriminate between general training effects and specific task variables. As an example, "side errors" indicate a loss of orientation and "position hits" reflect the accuracy of the spatial representation. Participants use either an egocentric or allocentric frame of reference. The task does not imply the use of egocentric vs. allocentric spatial co-ordinates, yet it allows for a reliable a-priori identification of individually preferred strategies. Our data indicate that the spatial representations formed by both groups are functionally equivalent. However, the groups differ with respect to specific patterns of orientation errors. PMID:11688148

  11. Arthroscopically confirmed femoral button deployment.

    PubMed

    Sonnery-Cottet, Bertrand; Rezende, Fernando C; Martins Neto, Ayrton; Fayard, Jean M; Thaunat, Mathieu; Kader, Deiary F

    2014-06-01

    The anterior cruciate ligament TightRope RT (Arthrex, Naples, FL) is a graft suspension device for cruciate ligament reconstruction. It is an adjustable-length graft loop cortical fixation device designed to eliminate the requirement for loop length calculation and to facilitate complete graft fill of short femoral sockets that are common with anatomic anterior cruciate ligament placement. The adjustable loop length means "one size fits all," thus removing the need for multiple implant sizes and allowing graft tensioning even after fixation. However, the device has been associated with the same complications that have been described with EndoButton (Smith & Nephew Endoscopy, Andover, MA) fixation. The button of the TightRope RT may remain in the femoral tunnel rather than flipping outside of the tunnel to rest on the lateral femoral cortex, or it may become jammed inside the femoral canal. Conversely, the button may be pulled too far off the femoral cortex into the overlying soft tissue and flip in the substance of the vastus lateralis. We describe a new and simple arthroscopic technique to directly visualize the deployment and seating of the TightRope button on the lateral cortex of the femur to avoid all the aforementioned complications. PMID:25126492

  12. POSTERIOR CRUCIATE LIGAMENT RECONSTRUCTION WITH AUTOGRAFT OF THE DOUBLE SEMITENDINOSUS MUSCLES AND MIDDLE THIRD OF THE QUADRICEPS TENDON WITH DOUBLE FEMORAL AND SINGLE TIBIAL TUNNELS: CLINICAL RESULTS IN TWO YEARS FOLLOW UP

    PubMed Central

    Cury, Ricardo de Paula Leite; Severino, Nilson Roberto; Camargo, Osmar Pedro Arbix; Aihara, Tatsuo; de Oliveira, Victor Marques; Avakian, Roger

    2015-01-01

    Objective: To evaluate the surgical aspects that may offer good anatomic and functional results in posterior cruciate ligament (PCL) reconstruction using an autologous graft of the quadriceps tendon and double semitendinosus through a double femoral tunnel. Methods: Fourteen patients with isolated PCL lesions, instability and pain were operated on by arthroscopy and evaluated according to the International Knee Documentation Committee (IKDC) and Lysholm scales. Posterior knee laxity was examined with a KT1000 arthrometer. Results: The mean postoperative posterior side-to-side difference was between 0-2 mm in 57.1% of patients and between 3 and 5 mm in 35.7% of cases. The average Lysholm score was 93 points in the final follow-up. In the IKDC evaluation, 3 patients were graded A, 10 were graded B, and 1 patient was graded C. Conclusions: Double bundle arthroscopic PCL reconstruction based on the anatomical positioning of the tunnels, with double semitendinosus tendon and single quadriceps, provides a clinically evident reduction in symptoms and restores satisfactory stability, although no statistically significant difference was found due to the small sample. PMID:27027083

  13. Lateral femoral cutaneous neuralgia: an anatomical insight.

    PubMed

    Dias Filho, L C; Valença, M M; Guimarães Filho, F A V; Medeiros, R C; Silva, R A M; Morais, M G V; Valente, F P; França, S M L

    2003-07-01

    A detailed anatomic study was carried out on the lateral femoral cutaneous nerve to better understand the etiology and treatment of lateral femoral cutaneous neuralgia. As it passed from the pelvis into the thigh, the lateral femoral cutaneous nerve ran through an "aponeuroticofascial tunnel," beginning at the iliopubic tract and ending at the inguinal ligament; as it passed through the tunnel, an enlargement in its side-to-side diameter was observed, suggesting that the fascial structures proximal to the inguinal ligament may be implicated in the genesis of lateral femoral cutaneous neuralgia. The finding of pseudoneuromas at this location, distant from the inguinal ligament, supports this hypothesis. The anterior superior iliac spine is located approximately 0.7 cm from the lateral femoral cutaneous nerve and serves as the bony landmark for nerve localization. Within the first 3 cm of leaving the pelvis, the lateral femoral cutaneous nerve was observed deep to the fascia lata; therefore, surgical dissection within the subcutaneous fascia may be conducted with relative impunity near the anterior superior iliac spine just inferior to the inguinal ligament. In 36% of cases there was no posterior branch of the nerve, which is correlated to lateral femoral cutaneous neuralgia symptoms often being limited to the anterior branch region. An accessory nerve was found in 30% of cases. PMID:12794914

  14. Femoral nerve damage (image)

    MedlinePlus

    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. Femoral nerve dysfunction

    MedlinePlus

    Neuropathy - femoral nerve; Femoral neuropathy ... Craig EJ, Clinchot DM. Femoral neuropathy. In: Frontera WR, Silver JK, Rizzo TD Jr, eds. Essentials of Physical Medicine and Rehabilitation: Musculoskeletal Disorders, Pain, and Rehabilitation . 3rd ...

  16. Electron-bombarded ⟨110⟩-oriented tungsten tips for stable tunneling electron emission.

    PubMed

    Yamada, T K; Abe, T; Nazriq, N M K; Irisawa, T

    2016-03-01

    A clean tungsten (W) tip apex with a robust atomic plane is required for producing a stable tunneling electron emission under strong electric fields. Because a tip apex fabricated from a wire by aqueous chemical etching is covered by impurity layers, heating treatment in ultra-high vacuum is experimentally known to be necessary. However, strong heating frequently melts the tip apex and causes unstable electron emissions. We investigated quantitatively the tip apex and found a useful method to prepare a tip with stable tunneling electron emissions by controlling electron-bombardment heating power. Careful characterizations of the tip structures were performed with combinations of using field emission I-V curves, scanning electron microscopy, X-ray diffraction (transmitted Debye-Scherrer and Laue) with micro-parabola capillary, field ion microscopy, and field emission microscopy. Tips were chemically etched from (1) polycrystalline W wires (grain size ∼1000 nm) and (2) long-time heated W wires (grain size larger than 1 mm). Heating by 10-40 W (10 s) was found to be good enough to remove oxide layers and produced stable electron emission; however, around 60 W (10 s) heating was threshold power to increase the tip radius, typically +10 ± 5 nm (onset of melting). Further, the grain size of ∼1000 nm was necessary to obtain a conical shape tip apex. PMID:27036780

  17. Electron-bombarded <110>-oriented tungsten tips for stable tunneling electron emission

    NASA Astrophysics Data System (ADS)

    Yamada, T. K.; Abe, T.; Nazriq, N. M. K.; Irisawa, T.

    2016-03-01

    A clean tungsten (W) tip apex with a robust atomic plane is required for producing a stable tunneling electron emission under strong electric fields. Because a tip apex fabricated from a wire by aqueous chemical etching is covered by impurity layers, heating treatment in ultra-high vacuum is experimentally known to be necessary. However, strong heating frequently melts the tip apex and causes unstable electron emissions. We investigated quantitatively the tip apex and found a useful method to prepare a tip with stable tunneling electron emissions by controlling electron-bombardment heating power. Careful characterizations of the tip structures were performed with combinations of using field emission I-V curves, scanning electron microscopy, X-ray diffraction (transmitted Debye-Scherrer and Laue) with micro-parabola capillary, field ion microscopy, and field emission microscopy. Tips were chemically etched from (1) polycrystalline W wires (grain size ˜1000 nm) and (2) long-time heated W wires (grain size larger than 1 mm). Heating by 10-40 W (10 s) was found to be good enough to remove oxide layers and produced stable electron emission; however, around 60 W (10 s) heating was threshold power to increase the tip radius, typically +10 ± 5 nm (onset of melting). Further, the grain size of ˜1000 nm was necessary to obtain a conical shape tip apex.

  18. Band to band tunneling in III-V semiconductors: Implications of complex band structure, strain, orientation, and off-zone center contribution

    SciTech Connect

    Majumdar, Kausik

    2014-05-07

    In this paper, we use a tight binding Hamiltonian with spin orbit coupling to study the real and complex band structures of relaxed and strained GaAs. A simple d orbital on-site energy shift coupled with appropriate scaling of the off-diagonal terms is found to correctly reproduce the band-edge shifts with strain. Four different 〈100〉 strain combinations, namely, uniaxial compressive, uniaxial tensile, biaxial compressive, and biaxial tensile strain are studied, revealing rich valence band structure and strong relative orientation dependent tunneling. It is found that complex bands are unable to provide unambiguous tunneling paths away from the Brillouin zone center. Tunneling current density distribution over the Brillouin zone is computed using non-equilibrium Green's function approach elucidating a physical picture of band to band tunneling.

  19. Semiclassical complex-time method for tunneling ionization: Molecular suppression and orientational dependence

    SciTech Connect

    Gallup, Gordon A.; Fabrikant, Ilya I.

    2010-03-15

    We apply a previously developed semiclassical complex time method to the calculation of tunneling ionization of several diatomic molecules and CO{sub 2}. We investigate the presence or absence of the molecular suppression effect by calculating ionization rates of N{sub 2} versus Ar, O{sub 2} versus Xe, F{sub 2} versus Ar, and CO versus Kr. Comparisons with other theories, including the molecular-orbital-Ammosov-Delone-Krainov (MO-ADK) model and the strong-field approximation, are given. We also analyze the dependence of the ionization rate on the angle {theta}{sub F} between the molecular axis and the field direction. The theoretical results agree quite well with experiment for N{sub 2} and O{sub 2} but give too low a value of the peak angle {theta}{sub F} for CO{sub 2}. Our calculations give small values of the ionization rates for O{sub 2} and CO{sub 2} at {theta}{sub F}=0 and 90 deg., in agreement with experiment. Other calculations, including the MO-ADK model and methods involving a numerical integration of the time-dependent Schroedinger equation, exhibit substantially weaker suppression at these angles.

  20. Resonant spin tunneling in randomly oriented nanospheres of Mn12 acetate

    SciTech Connect

    Lendínez, S.; Zarzuela, R.; Tejada, J.; Terban, M. W.; Billinge, S. J. L.; Espin, J.; Imaz, I.; Maspoch, D.; Chudnovsky, E. M.

    2015-01-06

    We report measurements and theoretical analysis of resonant spin tunneling in randomly oriented nanospheres of a molecular magnet. Amorphous nanospheres of Mn₁₂ acetate have been fabricated and characterized by chemical, infrared, TEM, X-ray, and magnetic methods. Magnetic measurements have revealed sharp tunneling peaks in the field derivative of the magnetization that occur at the typical resonant field values for the Mn₁₂ acetate crystal in the field parallel to the easy axis.Theoretical analysis is provided that explains these observations. We argue that resonant spin tunneling in a molecular magnet can be established in a powder sample, without the need for a single crystal and without aligning the easy magnetization axes of the molecules. This is confirmed by re-analyzing the old data on a powdered sample of non-oriented micron-size crystals of Mn₁₂ acetate. In conclusion, our findings can greatly simplify the selection of candidates for quantum spin tunneling among newly synthesized molecular magnets.

  1. Reconstruction of medial patello-femoral ligament: Comparison of two surgical techniques.

    PubMed

    Criscenti, G; De Maria, C; Sebastiani, E; Tei, M; Placella, G; Speziali, A; Vozzi, G; Cerulli, G

    2016-06-01

    The medial patello-femoral ligament is considered the most important passive patellar stabilizer and its proper functionality is essential for the patello-femoral joint stability. In this work, 18 human knees were randomly divided into two groups and reconstructed through two different surgical techniques: the "Through tunnel tendon" and the "Double converging tunnel" reconstructions. Subsequently, the samples were mechanically tested to evaluate the structural properties of reconstructed femur-MPFL-Patella complex (rFMPC). Particular attention was given to maintain the anatomical orientation between the patella and the graft. Both procedures showed lower stiffness and higher ultimate strain and absorbed energy compared to the native MPFL, but the advantages of the double converging tunnel technique are related to the restoration of the native MPFL sail-shape, to a better stress distribution on the patella, to the use of a single interference screw as fixation device and to the simplicity, rapidity and cost-effectivity of the surgical procedure. The evaluation of the structural properties of rMPFL is fundamental to evaluate the adequacy of the different techniques to restore the physiological structural properties of the native MPFL. PMID:26894660

  2. Slipped capital femoral epiphysis

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/000972.htm Slipped capital femoral epiphysis To use the sharing features on this page, please enable JavaScript. A slipped capital femoral epiphysis is a separation of the ball ...

  3. Magnetic properties of epitaxial Fe{sub 3}O{sub 4} films with various crystal orientations and tunnel magnetoresistance effect at room temperature

    SciTech Connect

    Nagahama, Taro Matsuda, Yuya; Tate, Kazuya; Kawai, Tomohiro; Takahashi, Nozomi; Hiratani, Shungo; Watanabe, Yusuke; Yanase, Takashi; Shimada, Toshihiro

    2014-09-08

    Fe{sub 3}O{sub 4} is a ferrimagnetic spinel ferrite that exhibits electric conductivity at room temperature (RT). Although the material has been predicted to be a half metal according to ab-initio calculations, magnetic tunnel junctions (MTJs) with Fe{sub 3}O{sub 4} electrodes have demonstrated a small tunnel magnetoresistance (TMR) effect. Not even the sign of the tunnel magnetoresistance ratio has been experimentally established. Here, we report on the magnetic properties of epitaxial Fe{sub 3}O{sub 4} films with various crystal orientations. The films exhibited apparent crystal orientation dependence on hysteresis curves. In particular, Fe{sub 3}O{sub 4}(110) films exhibited in-plane uniaxial magnetic anisotropy. With respect to the squareness of hysteresis, Fe{sub 3}O{sub 4} (111) demonstrated the largest squareness. Furthermore, we fabricated MTJs with Fe{sub 3}O{sub 4}(110) electrodes and obtained a TMR effect of −12% at RT. The negative TMR ratio corresponded to the negative spin polarization of Fe{sub 3}O{sub 4} predicted from band calculations.

  4. Slipped capital femoral epiphysis

    MedlinePlus

    A slipped capital femoral epiphysis is a separation of the ball of the hip joint from the thigh bone (femur) at ... A slipped capital femoral epiphysis may affect both hips. An epiphysis is an area at the end of a long bone . ...

  5. RigidFix femoral fixation: a test for detecting inaccurate cross pin positioning.

    PubMed

    Papastergiou, Stergios G; Koukoulias, Nikolaos E; Dimitriadis, Theofilos; Pappis, Georgios; Parisis, Constantinos A

    2007-11-01

    The RigidFix Cross Pin System (DePuy Mitek, Raynham, MA) is a popular technique for femoral fixation of graft in ACL reconstruction. In some cases, though, cross pins miss the femoral tunnel resulting in inadequate proximal graft fixation. We present a simple test to detect the incorrect placement of cross pins. The pinholes are drilled through the guide frame, leaving 2 sleeves for cross pins insertion. The manufacturer's recommendations, at this stage, are to reinsert the femoral tunnel guidewire, remove the guide frame, and insert the graft without verifying accurate pinhole positioning. We reinsert the femoral tunnel guidewire without removing the guide frame, and a second guidewire is introduced through each of the sleeves in turn. In case of appropriate pinhole placement, the 2 guidewires will meet in the cannulated rod of the guide frame and the surgeon will have the metal-to-metal feeling. If the pinhole misses the femoral tunnel, the 2 guidewires will not meet and the surgeon will not have the metal-to-metal feeling. In our practice, 9 cases of inaccurate pinhole placement were detected with this test and verified by direct vision of the femoral tunnel with the arthroscope. We find this test simple, reliable, and not time consuming. PMID:17986419

  6. Prevascular femoral hernia and its relation with inferior epigastric vessels: a rare presentation of the femoral hernia sac.

    PubMed

    Boshnaq, Mohamed; Phan, Yih Chyn; Akhtar, Mansoor; Hamade, Ayman

    2016-01-01

    A 61-year-old man presented to the emergency department, with a 2-week history of a painful lump on his right groin. A diagnosis of an irreducible right femoral hernia was made. As such, an urgent operation was carried out on the same day, and the patient was found to have a rare prevascular femoral hernia in which the sac was lying over the femoral vessels and split by the inferior epigastric vessels into 2 components resembling 2 trouser limbs. The hernia sac presented in a different and challenging way that necessitated meticulous dissection and full orientation of the anatomy of the femoral triangle. Complete dissection and control of the inferior epigastric vessels, and complete reduction of the sac followed by repair with a prosthetic mesh plug were performed successfully. The patient was discharged home the next day. PMID:27090547

  7. A preliminary scanning tunnelling microscopy study of the surface-organised structures of gramicidin S hydrochloride on highly oriented pyrolytic graphite.

    PubMed

    Brown, N M; You, H X

    1991-12-01

    For an initial study of potentially surface-structural self-organising systems of biological significance by scanning tunnelling microscopy (STM), gramicidin S, a pseudocentrosymmetric cyclodecapeptide with antibiotic properties, was chosen as prototype, recognising its structure as having both intramolecular and intermolecular hydrogen-bond forming propensity. The surface-organised structures, based on gramicidin S hydrochloride deposited on a highly oriented pyrolytic graphite (HOPG) substrate, have been observed by STM in air under ambient conditions. These are characterised in the main by rectangular or rectangle-like structural elements identified with the individual gramicidin S hydrochloride molecules. Two kinds of arrangements of gramicidin S hydrochloride in a two-dimensional array are found, i.e., as a centred rectangular lattice and a primitive rectangular lattice. The STM topographical arrays and the molecular dimensions obtained are in good quantitative agreement with the corresponding X-ray crystallographic data. The differences between the STM results, the theoretical models, and the X-ray crystallographic data are attributed to the intermolecular interactions present in the three-dimensional gramicidin S crystal but absent in the lower dimensional arrays and to the environments in which a gramicidin S hydrochloride molecule finds itself during deposition and drying on the HOPG substrate. PMID:1725492

  8. Self-assembly of [Et,Et]-bacteriochlorophyll cF on highly oriented pyrolytic graphite revealed by scanning tunneling microscopy.

    PubMed

    Möltgen, H; Kleinermanns, K; Jesorka, A; Schaffner, K; Holzwarth, A R

    2002-06-01

    The chlorosomal light-harvesting antennae of green phototrophic bacteria consist of large supramolecular aggregates of bacteriochlorophyll c (BChl c). The supramolecular structure of (3(1)-R/S)-BChl c on highly oriented pyrolytic graphite (HOPG) and molybdenum disulfide (MoS2) has been investigated by scanning tunneling microscopy (STM). On MoS2, we observed single BChl c molecules, dimers or tetramers, depending on the polarity of the solvent. On HOPG, we observed extensive self-assembly of the dimers and tetramers. We propose C=O...H-O...Mg bonding networks for the observed dimer chains, in agreement with former ultraviolet-visible and infrared spectroscopic work. The BChl c moieties in the tetramers are probably linked by four C=O...H-O hydrogen bonds to form a circle and further stabilized by Mg...O-H bondings to underlying BChl c layers. The tetramers form highly ordered, distinct chains and extended two-dimensional networks. We investigated semisynthetic chlorins for comparison by STM but observed that only BChl c self-assembles to well-structured large aggregates on HOPG. The results on the synthetic chlorins support our structure proposition. PMID:12081324

  9. Electric field control of spin re-orientation in perpendicular magnetic tunnel junctions—CoFeB and MgO thickness dependence

    SciTech Connect

    Meng, Hao; Naik, Vinayak Bharat; Liu, Ruisheng; Han, Guchang

    2014-07-28

    We report an investigation of electric-field (EF) control of spin re-orientation as functions of the thicknesses of CoFeB free layer (FL) and MgO layer in synthetic-antiferromagnetic pinned magnetic tunnel junctions with perpendicular magnetic anisotropy. It is found that the EF modulates the coercivity (Hc) of the FL almost linearly for all FL thicknesses, while the EF efficiency, i.e., the slope of the linearity, increases as the FL thickness increases. This linear variation in Hc is also observed for larger MgO thicknesses (≥1.5 nm), while the EF efficiency increases only slightly from 370 to 410 Oe nm/V when MgO thickness increases from 1.5 to 1.76 nm. We have further observed the absence of quasi-DC unipolar switching. We discuss its origin and highlight the underlying challenges to implement the EF controlled switching in a practical magnetic memory.

  10. [Trochanteric femoral fractures].

    PubMed

    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 (p<0.001) and represented 30% of the group. The fractures were 2.3-times more frequent in women than in men. In the category under 60 years, men significantly outnumbered women (p<0.001). The patients with pertrochanteric fractures were, on the average, eight years older than the patients with intertrochanteric fractures, which is a significant difference (p<0.001). The mortality rate within a year of injury was about 30%. Trochanteric 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 (p<0.001). A total of 1 394 fractures were treated with a proximal

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

    PubMed

    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. PMID:24951951

  12. Tunnel closure calculations

    SciTech Connect

    Moran, B.; Attia, A.

    1995-07-01

    When a deeply penetrating munition explodes above the roof of a tunnel, the amount of rubble that falls inside the tunnel is primarily a function of three parameters: first the cube-root scaled distance from the center of the explosive to the roof of the tunnel. Second the material properties of the rock around the tunnel, and in particular the shear strength of that rock, its RQD (Rock Quality Designator), and the extent and orientation of joints. And third the ratio of the tunnel diameter to the standoff distance (distance between the center of explosive and the tunnel roof). The authors have used CALE, a well-established 2-D hydrodynamic computer code, to calculate the amount of rubble that falls inside a tunnel as a function of standoff distance for two different tunnel diameters. In particular they calculated three of the tunnel collapse experiments conducted in an iron ore mine near Kirkeness, Norway in the summer of 1994. The failure model that they used in their calculations combines an equivalent plastic strain criterion with a maximum tensile strength criterion and can be calibrated for different rocks using cratering data as well as laboratory experiments. These calculations are intended to test and improve the understanding of both the Norway Experiments and the ACE (Array of conventional Explosive) phenomenology.

  13. Accuracy of femoral templating in reproducing anatomical femoral offset in total hip replacement.

    PubMed

    Davies, H; Foote, J; Spencer, R F

    2007-01-01

    Restoration of hip biomechanics is a crucial component of successful total hip replacement. Preoperative templating is recommended to ensure that the size and orientation of implants is optimised. We studied how closely natural femoral offset could be reproduced using the manufacturers' templates for 10 femoral stems in common use in the UK. A series of 23 consecutive preoperative radiographs from patients who had undergone unilateral total hip replacement for unilateral osteoarthritis of the hip was employed. The change in offset between the templated position of the best-fitting template and the anatomical centre of the hip was measured. The templates were then ranked according to their ability to reproduce the normal anatomical offset. The most accurate was the CPS-Plus (Root Mean Square Error 2.0 mm) followed in rank order by: C stem (2.16), CPT (2.40), Exeter (3.23), Stanmore (3.28), Charnley (3.65), Corail (3.72), ABG II (4.30), Furlong HAC (5.08) and Furlong modular (7.14). A similar pattern of results was achieved when the standard error of variability of offset was analysed. We observed a wide variation in the ability of the femoral prosthesis templates to reproduce normal femoral offset. This variation was independent of the seniority of the observer. The templates of modern polished tapered stems with high modularity were best able to reproduce femoral offset. The current move towards digitisation of X-rays may offer manufacturers an opportunity to improve template designs in certain instances, and to develop appropriate computer software. PMID:19197861

  14. Current concepts in management of slipped capital femoral epiphysis.

    PubMed

    Bittersohl, Bernd; Hosalkar, Harish S; Zilkens, Christoph; Krauspe, Rüdiger

    2015-01-01

    Slipped capital femoral epiphysis (SCFE) is a common hip condition that can be disabling. In this review, we provide an orientation on current trends in the clinical management of SCFE including conventional procedures and specialised surgical developments. Different methods of fixation of the epiphysis, risks of complications, and the rationale of addressing deformity, primarily or secondarily, are presented. Although improved understanding of the anatomy, vascularity and implications of residual deformity have changed management strategies, the best modality of treatment that would restore complete vascularity to the femoral head and prevent any residual deformity, impingement and early osteoarthritis remains elusive. PMID:25362879

  15. An audit of tunnel position in anterior cruciate ligament reconstruction.

    PubMed

    Topliss, C; Webb, J

    2001-03-01

    We audited 114 primary anterior cruciate ligament (ACL) reconstructions. Notes were reviewed and tunnel positions assessed on lateral and AP radiographs. A literature review established optimal tunnel position. Sixteen surgeons performed 57 arthroscopic and 57 open reconstructions, using 24 hamstring and 90 bone-tendon-bone autografts. Eighty-five sets of radiographs were available for review. Sixty-five percent of femoral tunnels and 59% of the tibial tunnels were malpositioned in the sagittal plane. Guidelines for best practice are required for key procedures in each speciality. Tunnel position in ACL reconstruction can be easily measured and should be correct in at least 90% of cases. PMID:11248570

  16. [Pathogenesis of atypical femoral fracture].

    PubMed

    Iwata, Ken; Mashiba, Tasuku

    2016-01-01

    We demonstrated microdamage accumulation in the fracture sites in the patients of subtrochanteric atypical femoral fracture with long term bisphosphonate therapy and of incomplete shaft fracture of lateral femoral bowing without bisphosphonate therapy. Based on these findings, pathogenesis of atypical femoral fracture is revealed stress fracture caused by accumulation of microdamages between distal to the lesser trochanter and proximal to the supracondylar flare in the femur in association with severely suppressed bone turnover and/or abnormal lower limb alignment, that causes stress concentration on the lateral side cortex of the femur. PMID:26728533

  17. Femoral approach to lead extraction.

    PubMed

    Mulpuru, Siva K; Hayes, David L; Osborn, Michael J; Asirvatham, Samuel J

    2015-03-01

    Laser and radiofrequency energy-assisted lead extraction has greatly facilitated this complex procedure. Although success rates are high, in some instances alternate methods of extraction are required. In this review, we discuss techniques for femoral extraction of implanted leads and retained fragments. The major tools available, including commonly used snares and delivery tools, are discussed. We briefly describe combined internal jugular and femoral venous extraction approaches, as well as complimentary utilization of more than one technique via the femoral vein. Animated and procedural sequences are included to help the reader visualize the key components of these techniques. PMID:25311643

  18. Quantifying lateral femoral condyle ellipticalness in chimpanzees, gorillas, and humans.

    PubMed

    Sylvester, Adam D; Pfisterer, Theresa

    2012-11-01

    Articular surfaces of limb bones provide information for understanding animal locomotion because their size and shape are a reflection of habitual postures and movements. Here we present a novel method for quantifying the ellipticalness (i.e., departure from perfectly circular) of the lateral femoral condyle (LFC), applying this technique to hominid femora. Three-dimensional surface models were created for 49 Homo sapiens, 34 Pan troglodytes and 25 Gorilla gorilla femora. Software was developed that fit separate cylinders to each of the femoral condyles. These cylinders were constrained to have a single axis, but could have different radii. The cylinder fit to the LFC was allowed to assume an elliptical cross-section, while the cylinder fit to the medial condyle was constrained to remain circular. The shape of the elliptical cylinder (ratio of the major and minor axes of the ellipse) was recorded, and the orientation of the elliptical cylinder quantified as angles between the major axis of the ellipse and the anatomical and mechanical axes of the femur. Species were compared using analysis of variance and post hoc multiple comparisons tests. Confirming qualitative descriptions, human LFCs are more elliptical than those of chimpanzees and gorillas. Human femora exhibit a narrow range for the angle between the major axis of the elliptical cylinder and femoral axes. Conversely, the chimpanzee sample is bimodal for these angles, exhibiting two ellipse orientations, while Gorilla shows no preferred angle. Our results suggest that like modern human femora, chimpanzee femoral condyles have preferentially used regions. PMID:23042636

  19. Inelastic electron tunneling spectroscopy

    NASA Technical Reports Server (NTRS)

    Khanna, S. K.; Lambe, J.

    1983-01-01

    Inelastic electron tunneling spectroscopy is a useful technique for the study of vibrational modes of molecules adsorbed on the surface of oxide layers in a metal-insulator-metal tunnel junction. The technique involves studying the effects of adsorbed molecules on the tunneling spectrum of such junctions. The data give useful information about the structure, bonding, and orientation of adsorbed molecules. One of the major advantages of inelastic electron tunneling spectroscopy is its sensitivity. It is capable of detecting on the order of 10 to the 10th molecules (a fraction of a monolayer) on a 1 sq mm junction. It has been successfully used in studies of catalysis, biology, trace impurity detection, and electronic excitations. Because of its high sensitivity, this technique shows great promise in the area of solid-state electronic chemical sensing.

  20. Bone scintigraphy in slipped capital femoral epiphysis

    SciTech Connect

    Gelfand, M.J.; Strife, J.L.; Graham, E.J.; Crawford, A.H.

    1983-12-01

    Tc-/sub 99m/ diphosphonate bone scans were performed on 11 children with slipped capital femoral epiphysis. On pinhole hip images, seven hips in seven patients had increased radionuclide uptake in the physis and adjacent proximal femoral metaphysis where the slip had occurred. Three hips in three patients had decreased radionuclide uptake in the femoral head on the side of the slipped epiphysis, indicating compromise of the femoral head blood supply. Three or more months following internal fixation, three children had scintigraphy that showed loss of the usual focal uptake in the physis and adjacent proximal femoral metaphysis. Bone scintigraphy in pediatric patients with slipped capital femoral epiphysis is valuable in defining the metabolic status of the femoral head. Absence of radiopharmaceutical uptake in the affected femoral head indicates that the femoral head is at risk for development of radiographic changes associated with aseptic necrosis.

  1. Arthroscopic repair of "peel-off" lesion of the posterior cruciate ligament at the femoral condyle.

    PubMed

    Rosso, Federica; Bisicchia, Salvatore; Amendola, Annunziato

    2014-02-01

    Posterior cruciate ligament (PCL) injuries are uncommon, and most occur in association with other lesions. The treatment of PCL injuries remains controversial; in addition, PCL injuries have been documented to have a propensity to heal. In the literature several different patterns of PCL injury have been described including midsubstance tears/injuries, tibial bony avulsions, femoral bony avulsions, and femoral "peel-off" injuries. A peel-off injury is a complete or incomplete soft-tissue disruption of the PCL at its femoral attachment site without associated bony avulsion. In recent years arthroscopic repair of femoral avulsion and peel-off lesions of the PCL has been reported. In most of these articles, a transosseous repair with sutures passed through 2 bone tunnels into the medial femoral condyle has been described. We present a case of a femoral PCL avulsion in a 20-year-old collegiate football player with an associated medial collateral ligament injury, and we report about a novel technique for PCL repair using 2 No. 2 FiberWire sutures and two 2.9-mm PushLock anchors (Arthrex) to secure tensioning the ligament at its footprint. PMID:24749037

  2. The suitability of the femoral vein for permanent vascular access.

    PubMed

    Pecorari, M

    2004-01-01

    In our dialysis unit, we commonly position permanent catheters (the Tesio twin catheter) in femoral veins with 'high' exit sites, in the abdominal area. We prefer this method because of its intrinsic safety in patients immediately requiring hemodialysis (HD), because there is no need for ultrasound guidance and a low incidence of complications during and after positioning. In addition, we consider that this method is suitable for older patients without good native vessels for an arteriovenous fistula (AVF). Sixty-nine femoral catheters were positioned in 61 patients (mean age 70.8 yrs): 307 observational months/patients (mean duration 4.45 months) demonstrated the following results: a) no incidents during catheter positioning; b) four iliac-femoral thromboses (in three cases complete recanalization with heparin treatment); c) two catheters were removed due to an infection of the tunnel; d) no generalized, life-threatening sepsis. Therefore, we recommend this solution as a 'bridge-access' between the immediate need for HD and the successive best strategy for the treatment of end-stage renal disease (ESRD). PMID:16596552

  3. Current-induced switching of magnetic tunnel junctions: Effects of field-like spin-transfer torque, pinned-layer magnetization orientation, and temperature

    SciTech Connect

    Tiwari, R. K.; Jhon, M. H.; Ng, N.; Gan, C. K.; Srolovitz, D. J.

    2014-01-13

    We study current-induced switching in magnetic tunnel junctions in the presence of a field-like spin-transfer torque and titled pinned-layer magnetization in the high current limit at finite temperature. We consider both the Slonczewski and field-like torques with coefficients a{sub J} and b{sub J}, respectively. At finite temperatures, σ=b{sub J}/a{sub J}=±1 leads to a smaller mean switching time compared that with σ=0. The reduction of switching time in the presence of the field-like term is due to the alignment effect (for σ>0) and the initial torque effect.

  4. Tibial hemimelia and femoral bifurcation.

    PubMed

    Ugras, Ali Akin; Sungur, Ibrahim; Akyildiz, Mustafa Fehmi; Ercin, Ersin

    2010-02-01

    Femoral bifurcation and tibial agenesis are rare anomalies and have been described in both the Gollop-Wolfgang complex and tibial agenesis-ectrodactyly syndrome. This article presents a case of Gollop-Wolfgang complex without hand ectrodactyly. Tibial agenesis-ectrodactyly syndrome and Gollop-Wolfgang complex are variants of tibial field defect, which includes distal femoral duplication, tibial aplasia, oligo-ectrodactylous toe defects, and preaxial polydactyly, occasionally associated with hand ectrodactyly.This article describes the case of a patient with bilateral tibial hemimelia and left femoral bifurcation. The proximal tibial anlage had not been identified in the patient's left leg. After failed fibular transfer procedure, the knee was disarticulated. The other leg was treated with tibiofibular synostosis and centralization of fibula to os calcis. At 7-year follow-up, the patient ambulates with an above-knee prosthesis and uses an orthopedic boot for ankle stability.In patients with a congenital absence of the tibia, accurate diagnosis is of the utmost importance in planning future treatment. In the absence of proximal tibial anlage, especially in patients with femoral bifurcation, the knee should be disarticulated. Tibiofibular synostosis is a good choice in the presence of a proximal tibial anlage and good quadriceps function. PMID:20192156

  5. Femoral head cartilage disarticulation disorder

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Femoral head cartilage disarticulation disorder and necrosis is a major skeletal problem in broiler breeders since they are maintained for a long time in the farm. The etiology of this disease is not well understood. A field study was conducted to understand the basis of this metabolic disease. Six ...

  6. Applying Cross-Pin System in Both Femoral and Tibial Fixation in Anterior Cruciate Ligament Reconstruction Using Hamstring Tendons

    PubMed Central

    Qi, Wei; Liu, Yujie; Xue, Jing; Li, Haifeng; Wang, Junliang; Qu, Feng

    2015-01-01

    Use of the RigidFix Cross Pin System (DePuy Mitek, Raynham, MA) is a popular technique for femoral fixation of grafts in anterior cruciate ligament reconstruction (ACLR). However, tibial fixation is still limited to the use of interference screws and post fixation, and few surgeons apply the femoral RigidFix system in tibial fixation. Meanwhile, tunnel enlargement is still a problem that affects the outcome of ACLR with hamstring grafts. We have used the femoral RigidFix system in femoral and tibial fixation. The rod top of the guide frame should be placed under the level of the subchondral bone at the proximal end of the tibial tunnel to ensure that the pins will not be inserted into the joint. The pins are inserted through the center of the lateral tibia. Using our technique, the fixation points of the femur and tibia are close to the anterior cruciate ligament insertions, and full contact of the graft with the tunnel wall can be accomplished. On the basis of our preliminary observations and investigation, we are optimistic about the prospect of performing ACLR using the RigidFix system in femoral and tibial fixation. PMID:26697293

  7. Arthroscopic Suture Fixation in Femoral-Sided Avulsion Fracture of Anterior Cruciate Ligament

    PubMed Central

    Prasathaporn, Niti; Umprai, Vantawat; Laohathaimongkol, Thongchai; Kuptniratsaikul, Somsak; Kongrukgreatiyos, Kitiphong

    2015-01-01

    A femoral-sided avulsion fracture of the anterior cruciate ligament (ACL) is a rare and challenging condition. Most reported cases have occurred in childhood or adolescence. Many techniques of ACL repair have been reported, and in recent years, techniques in arthroscopic surgery have been developed and have become ever more popular with orthopaedic surgeons. We created a technique of arthroscopic ACL repair with suture anchor fixation for a femoral-sided ACL avulsion fracture. This technique saves the natural ACL stump. It is available for cases in which creation of a tibial tunnel is not allowed. Moreover, it does not require a skin incision for fixation on the far femoral cortex and, therefore, does not require a second operation to remove the fixation device. The arthroscopic technique also has a good cosmetic outcome. PMID:26258035

  8. Femoral Footprint Reconstruction With a Direct Viewing of the Posterior Insertion Using a Trans-Septal Portal in the Outside-In Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Elazab, Ashraf; Lee, Yong Seuk; Kang, Seo Goo

    2015-01-01

    We established a technique for femoral tunnel preparation through direct vision of the femoral footprint with maximum preservation to the native anterior cruciate ligament (ACL) remnant using a posterior trans-septal portal. Anterior arthroscopy is difficult for the proper tunnel placement without sacrificing the ACL remnant. Posterior arthroscopy could be helpful for viewing the posterior insertion of the ACL remnant that provides excellent femoral footprint exposure without sacrificing the native ACL remnant. Therefore, a posterolateral portal technique using a 70° arthroscope through a posterolateral portal is introduced. However, using the 70° arthroscope, an oblique view is displayed and distorted view could be seen. Therefore, to achieve the goal of posterior arthroscopy and avoid obstacles of the posterolateral view with the 70° arthroscope, we introduce this technique that uses the posterior trans-septal portal with a 30° arthroscope that provides an excellent viewing to the femoral footprint through a hole of the posterior septum. PMID:27073766

  9. Water tunnels

    NASA Technical Reports Server (NTRS)

    Bjarke, Lisa J.

    1991-01-01

    Some of the uses of water tunnels are demonstrated through the description of the NASA Ames-Dryden Flow Visualization Facility. It is concluded that water tunnels are capable of providing a quick and inexpensive means of flow visualization and can aid in the understanding of complex fluid mechanics phenomena.

  10. Arthroplasty in Femoral Head Osteonecrosis

    PubMed Central

    Nam, Dong Cheol; Jung, Kwangyoung

    2014-01-01

    Osteonecrosis of the femoral head is a destructive joint disease requiring early hip arthroplasty. The polyethylene-metal design using a 22-mm femoral head component, introduced by Charnley in 1950, has been widely used for over half a century. Since then, different materials with the capacity to minimize friction between bearing surfaces and various cement or cementless insert fixations have been developed. Although the outcome of second and third generation designs using better bearing materials and technologies has been favorable, less favorable results are seen with total hip arthroplasty in young patients with osteonecrosis. Selection of appropriate materials for hip arthroplasty is important for any potential revisions that might become inevitable due to the limited durability of a prosthetic hip joint. Alternative hip arthroplasties, which include hemiresurfacing arthroplasty and bipolar hemiarthroplasty, have not been found to have acceptable outcomes. Metal-on-metal resurfacing has recently been suggested as a feasible option for young patients with extra physical demands; however, concerns about complications such as hypersensitivity reaction or pseudotumor formation on metal bearings have emerged. To ensure successful long-term outcomes in hip arthroplasty, factors such as insert stabilization and surfaces with less friction are essential. Understanding these aspects in arthroplasty is important to selection of proper materials and to making appropriate decisions for patients with osteonecrosis of the femoral head. PMID:27536561

  11. Conservative femoral stem revision: avoiding therapeutic escalation.

    PubMed

    Pinaroli, Alban; Lavoie, Frédéric; Cartillier, Jean-Claude; Neyret, Philippe; Selmi, Tarik Ait Si

    2009-04-01

    A conservative approach to femoral revision is assessed. We report on 41 femoral revisions using an extensively coated hydroxyapatite primary femoral stem. Clinical, operative, and radiological data were gathered. Harris hip scores increased from 65/100 to 90/100 at the minimal follow-up of 1 year (P < .05). All stems showed signs of osseous integration. No significant migration was measured. No patient had to be reoperated because of problems related to the stem. Good results are reported for femoral revision with Paprosky type I and II bone defects with no significant difference between the 2 subgroups, hereby proving that conservative femoral revision is a reasonable treatment alternative. Reproducible results with such a technique may bring surgeons to be more aggressive when noticing early signs of femoral loosening. PMID:18534426

  12. Tunneling machine

    SciTech Connect

    Snyder, L.L.

    1980-02-19

    A diametrically compact tunneling machine for boring tunnels is disclosed. The machine includes a tubular support frame having a hollow piston mounted therein which is movable from a retracted position in the support frame to an extended position. A drive shaft is rotatably mounted in the hollow piston and carries a cutter head at one end. The hollow piston is restrained against rotational movement relative to the support frame and the drive shaft is constrained against longitudinal movement relative to the hollow piston. A plurality of radially extendible feet project from the support frame to the tunnel wall to grip the tunnel wall during a tunneling operation wherein the hollow piston is driven forwardly so that the cutter head works on the tunnel face. When the hollow piston is fully extended, a plurality of extendible support feet, which are fixed to the rearward and forward ends of the hollow piston, are extended, the radially extendible feet are retracted and the support frame is shifted forwardly by the piston so that a further tunneling operation may be initiated.

  13. Hip contact stress and femoral neck retroversion: a biomechanical study to evaluate implication of femoroacetabular impingement

    PubMed Central

    Satpathy, Jibanananda; Kannan, Arun; Owen, John R.; Wayne, Jennifer S.; Hull, Jason R.; Jiranek, William A.

    2015-01-01

    The current literature on femoroacetabular impingement (FAI) is focused on acetabular orientation and femoral head asphericity, with little emphasis on the effect of version of the femoral neck. A biomechanical model was developed to determine the causative effect, if any, of femoral retroversion on hip contact stress and, if present, delineate the type of FAI with femoral neck retroversion. Five pairs of cadaveric hips (n = 10) were tested by loading the hip in 90° of flexion and measured the peak joint pressure and the location of the peak joint pressure. The experiment was repeated after performing a subtrochanteric osteotomy and retroverting the proximal femur by 10°. Ten hips were successfully tested, with one hip excluded due to an outlier value for peak joint pressure. Retroversion of the proximal femur significantly increased the magnitude of mean peak joint pressure. With retroversion, the location of the peak joint pressure was shifted posteroinferiorly in all cases. In conclusion, femoral neck retroversion increases peak joint pressure in the flexed position and may act as a cause of femoroacetabular impingement. The location of peak joint pressure suggests a pincer-type impingement with retroversion. The version of femoral neck should be assessed as a possible causative factor in patients with FAI, especially those with pincer-type impingement. PMID:27011851

  14. Recognition Tunneling

    PubMed Central

    Lindsay, Stuart; He, Jin; Sankey, Otto; Hapala, Prokop; Jelinek, Pavel; Zhang, Peiming; Chang, Shuai; Huang, Shuo

    2010-01-01

    Single molecules in a tunnel junction can now be interrogated reliably using chemically-functionalized electrodes. Monitoring stochastic bonding fluctuations between a ligand bound to one electrode and its target bound to a second electrode (“tethered molecule-pair” configuration) gives insight into the nature of the intermolecular bonding at a single molecule-pair level, and defines the requirements for reproducible tunneling data. Simulations show that there is an instability in the tunnel gap at large currents, and this results in a multiplicity of contacts with a corresponding spread in the measured currents. At small currents (i.e. large gaps) the gap is stable, and functionalizing a pair of electrodes with recognition reagents (the “free analyte” configuration) can generate a distinct tunneling signal when an analyte molecule is trapped in the gap. This opens up a new interface between chemistry and electronics with immediate implications for rapid sequencing of single DNA molecules. PMID:20522930

  15. [Aneurysm of the femoral and popliteal vein].

    PubMed

    Hansen, L G; Boris, P

    1986-04-01

    Aneurysms of the popliteal and femoral veins are rare and may be seen as casual findings with no clinical manifestations whatsoever. On the other hand they may be potential source of recurrent pulmonary embolism. A case is reported, where an aneurysm of the femoral vein was found in a clinically symptomless woman aged 48. PMID:3715020

  16. Unusual presentation of a femoral stress fracture

    PubMed Central

    Ejnisman, Leandro; Wajnsztejn, Andre; Queiroz, Roberto Dantas; Ejnisman, Benno

    2013-01-01

    Stress fractures are common injuries in sports medicine. Among these fractures, femoral neck stress fractures frequently have a benign course, especially when it happens in the medial aspect of the neck. This case report describes a stress fracture of the medial aspect of the femoral neck that developed a complete fracture and underwent surgical fixation. PMID:23283621

  17. FEMORAL INSERTION OF THE POSTERIOR CRUCIATE LIGAMENT: AN ANATOMICAL STUDY

    PubMed Central

    de Paula Leite Cury, Ricardo; Severino, Nilson Roberto; Camargo, Osmar Pedro Arbix; Aihara, Tatsuo; Neto, Leopoldo Viana Batista; Goarayeb, Dedley Nelson

    2015-01-01

    Objective: To identify objective parameters to guide correct location of the posterior cruciate ligament (PCL) in the femur. Methods: The PCLs of 20 human cadavers were resected. The following portions were measured: distance from the most distal portion of the PCL, close to the roof, to the most anterior edge of the cartilage (AB); distance from the most proximal portion of the PCL, close to the roof, to the most anterior cartilage (AC); distance between the two parts of the ligament close to the roof (BC); distance from the distal edge in its posterior portion, to the more posterior joint edge (DE); distance from the distal edge of the ligament in its posterior portion, to the intercondylar roof (DF); and finally, the format of the ligament insertion and area of coverage on the femoral condyle. Results: The PCL has the shape of a quarter ellipse, with an average area of 153.5mm2. The mean distances found were: AB of 2.1mm, AC of 10.7mm, BC of 8.6mm DE of 12.4mm and DF of 16.8mm. Conclusions: The edge close to the roof of the anterolateral bundle is closer to the joint cartilage (2.1mm) than the posteromedial bundle is, which is 12.4mm from the edge proximal to the cartilage. These references should assist in better and more accurate positioning of femoral tunnels in PCL reconstruction. PMID:27027059

  18. Treatment of neglected femoral neck fracture

    PubMed Central

    Jain, Anil K; Mukunth, R; Srivastava, Amit

    2015-01-01

    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% cases

  19. The Channel Tunnel

    NASA Technical Reports Server (NTRS)

    2006-01-01

    The Channel Tunnel is a 50.5 km-long rail tunnel beneath the English Channel at the Straits of Dover. It connects Dover, Kent in England with Calais, northern France. The undersea section of the tunnel is unsurpassed in length in the world. A proposal for a Channel tunnel was first put forward by a French engineer in 1802. In 1881, a first attempt was made at boring a tunnel from the English side; the work was halted after 800 m. Again in 1922, English workers started boring a tunnel, and advanced 120 m before it too was halted for political reasons. The most recent attempt was begun in 1987, and the tunnel was officially opened in 1994. At completion it was estimated that the project cost around $18 billion. It has been operating at a significant loss since its opening, despite trips by over 7 million passengers per year on the Eurostar train, and over 3 million vehicles per year.

    With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring

  20. Spin-valley filter and tunnel magnetoresistance in asymmetrical silicene magnetic tunnel junctions

    NASA Astrophysics Data System (ADS)

    Wang, Dali; Huang, Zeyuan; Zhang, Yongyou; Jin, Guojun

    2016-05-01

    The spin and valley transports and tunnel magnetoresistance are studied in a silicene-based asymmetrical magnetic tunnel junction consisting of a ferromagnetic tunnel barrier, sandwiched between a ferromagnetic electrode and a normal electrode. For such an asymmetrical silicene junction, a general formulism is established. The numerical results show that the spin-valley resolved conductances strongly depend on the magnetization orientation of the ferromagnetic tunnel barrier, and the fully spin-valley polarized current can be realized by tuning a perpendicularly applied electric field. We also find that the tunnel magnetoresistance in this case can be effectively modified by the external electric field when the conductance is fully spin-valley polarized. In particular, the exchange field in the ferromagnetic electrode can further substantially enhance the tunnel magnetoresistance of the system. Our work provides a practical method for electric and magnetic manipulation of valley/spin polarization and tunnel magnetoresistance.

  1. Visualization of postoperative anterior cruciate ligament reconstruction bone tunnels

    PubMed Central

    2011-01-01

    Background and purpose Non-anatomic bone tunnel placement is the most common cause of a failed ACL reconstruction. Accurate and reproducible methods to visualize and document bone tunnel placement are therefore important. We evaluated the reliability of standard radiographs, CT scans, and a 3-dimensional (3D) virtual reality (VR) approach in visualizing and measuring ACL reconstruction bone tunnel placement. Methods 50 consecutive patients who underwent single-bundle ACL reconstructions were evaluated postoperatively by standard radiographs, CT scans, and 3D VR images. Tibial and femoral tunnel positions were measured by 2 observers using the traditional methods of Amis, Aglietti, Hoser, Stäubli, and the method of Benereau for the VR approach. Results The tunnel was visualized in 50–82% of the standard radiographs and in 100% of the CT scans and 3D VR images. Using the intraclass correlation coefficient (ICC), the inter- and intraobserver agreement was between 0.39 and 0.83 for the standard femoral and tibial radiographs. CT scans showed an ICC range of 0.49–0.76 for the inter- and intraobserver agreement. The agreement in 3D VR was almost perfect, with an ICC of 0.83 for the femur and 0.95 for the tibia. Interpretation CT scans and 3D VR images are more reliable in assessing postoperative bone tunnel placement following ACL reconstruction than standard radiographs. PMID:21999625

  2. Distal femoral fractures: current concepts.

    PubMed

    Gwathmey, F Winston; Jones-Quaidoo, Sean M; Kahler, David; Hurwitz, Shepard; Cui, Quanjun

    2010-10-01

    The diversity of surgical options for the management of distal femoral fractures reflects the challenges inherent in these injuries. These fractures are frequently comminuted and intra-articular, and they often involve osteoporotic bone, which makes it difficult to reduce and hold them while maintaining joint function and overall limb alignment. Surgery has become the standard of care for displaced fractures and for patients who must obtain rapid return of knee function. The goal of surgical management is to promote early knee motion while restoring the articular surface, maintaining limb length and alignment, and preserving the soft-tissue envelope with a durable fixation that allows functional recovery during bone healing. A variety of surgical exposures, techniques, and implants has been developed to meet these objectives, including intramedullary nailing, screw fixation, and periarticular locked plating, possibly augmented with bone fillers. Recognition of the indications and applications of the principles of modern implants and techniques is fundamental in achieving optimal outcomes. PMID:20889949

  3. Medial patellofemoral ligament reconstruction procedure using a suspensory femoral fixation system.

    PubMed

    Nakagawa, Shuji; Arai, Yuji; Kan, Hiroyuki; Ueshima, Keiichiro; Ikoma, Kazuya; Terauchi, Ryu; Kubo, Toshikazu

    2013-11-01

    Recurrent patellar dislocation has recently been treated with anatomic medial patellofemoral ligament (MPFL) reconstruction using a semitendinosus muscle tendon. Although it is necessary to add tension to fix the tendon graft without loading excess stress on the patellofemoral joint, adjustment of the tension can be difficult. To resolve this problem, we developed an MPFL reconstruction procedure using the ToggleLoc Fixation Device (Biomet, Warsaw, IN), in which the semitendinosus muscle tendon is folded and used as a double-bundle tendon graft and 2 bone tunnels and 1 bone tunnel are made on the patellar and femoral sides, respectively. The patellar side of the tendon graft is fixed with an EndoButton (Smith & Nephew, London, England), and the femoral side is fixed with the ToggleLoc. Stepless adjustment of tension of the tendon graft is possible by reducing the size of the loop of the ToggleLoc hung onto the tendon graft. It may be useful to position the patella in the center of the femoral sulcus by confirming the patellofemoral joint fitting. Stability can be confirmed by loading lateral stress on the patella in the extended knee joint. This procedure is less invasive because opening of the lateral side of the femur is not necessary, and it may be useful for MPFL reconstruction. PMID:24892014

  4. "Grand piano sign," a marker for proper femoral component rotation during total knee arthroplasty.

    PubMed

    Moyad, Thomas F; Hughes, Richard E; Urquhart, Andrew

    2011-07-01

    A malpositioned femoral component is an established risk factor for patellar instability and pain after total knee arthroplasty (TKA). In the assessment of femoral rotation, several axes, including the transepicondylar axis, the posterior condylar axis, and the anteroposterior axis, are useful. However, these axes are not always easily applicable, particularly when significant deformity exists. An anecdotal method used by some surgeons involves assessing the shape of the anterior femoral surface osteotomy. Our observations from saw bone models and TKA led to our hypothesis that proper femoral component placement is indicated by a bimodal peak on the anterior femur, approximately twice as high on the lateral side than on the medial side. We use the term "grand piano sign" to describe the shape of the trochlea after the osteotomy is correctly completed. To our knowledge, this common observation has not been studied either in the laboratory or in vivo. Our cadaveric models demonstrated that the grand piano sign correlated with proper femoral rotation during TKA. Surgeons who are knowledgeable about this marker should find it helpful when orienting components during knee replacement surgery. PMID:22013571

  5. Unilateral Isolated Proximal Femoral Focal Deficiency

    PubMed Central

    Doğer, Emek; Köpük, Şule Y.; Çakıroğlu, Yiğit; Çakır, Özgür; Yücesoy, Gülseren

    2013-01-01

    Objective. To discuss a patient with a prenatal diagnosis of unilateral isolated femoral focal deficiency. Case. Antenatal diagnosis of unilateral isolated femoral focal deficiency was made at 20 weeks of gestation. The length of left femur was shorter than the right, and fetal femur length was below the fifth percentile. Proximal femoral focal deficiency was diagnosed. After delivery, the diagnosis was confirmed with skeletal radiographs and magnetic resonance imaging. In prenatal ultrasonographic examination, the early recognition and exclusion of skeletal dysplasias is important; moreover, treatment plans should be initiated, and valuable information should be provided to the family. PMID:23984135

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

    PubMed

    Zhu, Qing-hua; Ye, Tian-wen; Guo, Yong-fei; Wang, Chong-li; Chen, Ai-min

    2013-01-01

    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 fracture 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 rotating 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 broken wire end was taken out, mixed with blood and bone fragments. Through the existing drilling channel, DHS fixation was easily finished. The patient had an uneventful recovery 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. PMID:23910678

  7. Meralgia Paresthetica and Femoral Acetabular Impingement: A Possible Association

    PubMed Central

    Ahmed, Aiesha

    2010-01-01

    Meralgia paresthetica consists of pain and dysesthesia in the anterolateral thigh. Etiology is divided into spontaneous and iatrogenic causes. To my knowledge this has never been attributed to femoral acetabular impingement. This case highlights the presence of lateral femoral cutaneous neuropathy in the setting of femoral acetabular impingement syndrome thus raising the possibility of an association. Keywords Femoral acetabular impingement; Lateral femoral cutaneous nerve; Dysesthesia; Nerve conduction studies PMID:22043261

  8. Flows In Model Human Femoral Arteries

    NASA Technical Reports Server (NTRS)

    Back, Lloyd H.; Kwack, Eug Y.; Crawford, Donald W.

    1990-01-01

    Flow is visualized with dye traces, and pressure measurements made. Report describes experimental study of flow in models of human femoral artery. Conducted to examine effect of slight curvature of artery on flow paths and distribution of pressure.

  9. Atypical periprosthetic femoral fracture: a case report.

    PubMed

    Woo, S B; Choi, S T; Chan, W L

    2016-08-01

    We report an 82-year-old woman who underwent fixation with a long-spanning cable-plate for a bisphosphonate-induced Vancouver B1 periprosthetic femoral fracture. Non-union and breakage of the plate occurred at 16 months and necessitated revision surgery using a long-stem femoral prosthesis augmented with a cable-plate construct. Bone union was achieved eventually after 10 months. PMID:27574277

  10. Stress changes ahead of an advancing tunnel

    USGS Publications Warehouse

    Abel, J.F.; Lee, F.T.

    1973-01-01

    Instrumentation placed ahead of three model tunnels in the laboratory and ahead of a crosscut driven in a metamorphic rock mass detected stress changes several tunnel diameters ahead of the tunnel face. Stress changes were detected 4 diameters ahead of a model tunnel drilled into nearly elastic acrylic, 2??50 diameters ahead of a model tunnel drilled into concrete, and 2 diameters ahead of a model tunnel drilled into Silver Plume Granite. Stress changes were detected 7??50 diameters ahead of a crosscut driven in jointed, closely foliated gneisses and gneissic granites in an experimental mine at Idaho Springs, Colorado. These results contrast markedly with a theoretical elastic estimate of the onset of detectable stress changes at 1 tunnel diameter ahead of the tunnel face. A small compressive stress concentration was detected 2 diameters ahead of the model tunnel in acrylic, 1.25 diameters ahead of the model tunnel in concrete, and 1 diameter ahead of the model tunnel in granite. A similar stress peak was detected about 6 diameters ahead of the crosscut. No such stress peak is predicted from elastic theory. The 3-dimensional in situ stress determined in the field demonstrate that geologic structure controls stress orientations in the metamorphic rock mass. Two of the computed principal stresses are parallel to the foliation and the other principal stress is normal to it. The principal stress orientations vary approximately as the foliation attitude varies. The average horizontal stress components and the average vertical stress component are three times and twice as large, respectively, as those predicted from the overburden load. An understanding of the measured stress field appears to require the application of either tectonic or residual stress components, or both. Laboratory studies indicate the presence of proportionately large residual stresses. Mining may have triggered the release of strain energy, which is controlled by geologic structure. ?? 1973.

  11. Clinical-radiographic correlation of the femoral insertion point of the graft in reconstruction of the medial patellofemoral ligament☆

    PubMed Central

    Pinheiro Júnior, Lúcio Flávio Biondi; Cenni, Marcos Henrique Frauendorf; Nicolai, Oscar Pinheiro; Carneiro, Guilherme Galvão Barreto; de Andrade, Rodrigo Cristiano; de Moraes, Vinícius Vidigal

    2015-01-01

    Objective To analyze the radiographic positioning of the femoral tunnel and correlate this with the postoperative clinical results among patients undergoing reconstruction of the medial patellofemoral ligament (MPFL) alone. Method This was a retrospective study in which 30 knees of 26 patients with recurrent dislocation of the patella that underwent MPFL reconstruction were evaluated. The femoral insertion point of the graft and the postoperative clinical condition were analyzed and correlated using the Kujala and Lysholm scales. Results 22 knees presented a femoral tunnel in the anatomical area (group A) and 8 outside of this location (group B). In group A, the mean score on the Kujala scale was 89.68 points and on the Lysholm scale was 92.45 points. In group B, the mean score on the Kujala scale was 84.75 points and on the Lysholm scale was 92 points. The difference between the means was not significant on either of the two scales. Conclusion Correlation with the clinical results did not show any difference in relation to the positioning of the femoral insertion of the graft. PMID:27218083

  12. Tunneling Nanotubes

    PubMed Central

    Lou, Emil; Fujisawa, Sho; Barlas, Afsar; Romin, Yevgeniy; Manova-Todorova, Katia; Moore, Malcolm A.S.; Subramanian, Subbaya

    2012-01-01

    Tunneling nanotubes are actin-based cytoplasmic extensions that function as intercellular channels in a wide variety of cell types.There is a renewed and keen interest in the examination of modes of intercellular communication in cells of all types, especially in the field of cancer biology. Tunneling nanotubes –which in the literature have also been referred to as “membrane nanotubes,” “’intercellular’ or ‘epithelial’ bridges,” or “cytoplasmic extensions” – are under active investigation for their role in facilitating direct intercellular communication. These structures have not, until recently, been scrutinized as a unique and previously unrecognized form of direct cell-to-cell transmission of cellular cargo in the context of human cancer. Our recent study of tunneling nanotubes in human malignant pleural mesothelioma and lung adenocarcinomas demonstrated efficient transfer of cellular contents, including proteins, Golgi vesicles, and mitochondria, between cells derived from several well-established cancer cell lines. Further, we provided effective demonstration that such nanotubes can form between primary malignant cells from human patients. For the first time, we also demonstrated the in vivo relevance of these structures in humans, having effectively imaged nanotubes in intact solid tumors from patients. Here we provide further analysis and discussion on our findings, and offer a prospective ‘road map’ for studying tunneling nanotubes in the context of human cancer. We hope that further understanding of the mechanisms, methods of transfer, and particularly the role of nanotubes in tumor-stromal cross-talk will lead to identification of new selective targets for cancer therapeutics. PMID:23060969

  13. Femoral intercondylar notch shape and dimensions in ACL-injured patients.

    PubMed

    van Eck, Carola F; Martins, Cesar A Q; Vyas, Shail M; Celentano, Umberto; van Dijk, C Niek; Fu, Freddie H

    2010-09-01

    The femoral intercondylar notch has been an anatomic site of interest as it houses the anterior cruciate ligament (ACL). The objective of this study was to arthroscopically evaluate the femoral notch in patients with known ACL injury. This evaluation included establishing a classification for notch shapes, identifying the shape frequency, measuring notch dimensions, and determining correlation between notch shape, notch dimensions, and demographic patient data. In this clinical cohort study, 102 consecutive patients underwent diagnostic arthroscopic evaluation of the notch. Several intra-operative photos, videos, and measurements were taken of the notch. Demographic data for each patient were recorded including age, gender, height, weight, and BMI. Three categories of notch shape were established: 1. A-shaped; 2. U-shaped; and 3. W-shaped. Two blinded independent orthopedic surgeons were asked to categorize the recorded notches. Notch shape, dimensions, and demographic factors were correlated. Of the 102 notches evaluated, 55 notches were found to be "A-shaped," 42 "U-shaped," and 5 "W-shaped." "A-shaped" notches were narrower in all width dimensions than "U-shaped" notches. Only patient height was found to influence notch shape with a positive association between taller patients and "U-shaped" and "W-shaped" notches (P = 0.011). Women had a smaller notch width at the base and middle of the notch. With this data, surgeons who enter the knee and appreciate an "A-shaped" notch should consider placing the arthroscope in the anteromedial portal and drill the femoral tunnel through an accessory medial portal to improve visualization and accuracy in anatomic femoral tunnel creation. PMID:20390246

  14. Femoral neck shortening after internal fixation of a femoral neck fracture.

    PubMed

    Zielinski, Stephanie M; Keijsers, Noël L; Praet, Stephan F E; Heetveld, Martin J; Bhandari, Mohit; Wilssens, Jean Pierre; Patka, Peter; Van Lieshout, Esther M M

    2013-07-01

    This study assesses femoral neck shortening and its effect on gait pattern and muscle strength in patients with femoral neck fractures treated with internal fixation. Seventy-six patients from a multicenter randomized controlled trial participated. Patient characteristics and Short Form 12 and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were collected. Femoral neck shortening, gait parameters, and maximum isometric forces of the hip muscles were measured and differences between the fractured and contralateral leg were calculated. Variables of patients with little or no shortening, moderate shortening, and severe shortening were compared using univariate and multivariate analyses. Median femoral neck shortening was 1.1 cm. Subtle changes in gait pattern, reduced gait velocity, and reduced abductor muscle strength were observed. Age, weight, and Pauwels classification were risk factors for femoral neck shortening. Femoral neck shortening decreased gait velocity and seemed to impair gait symmetry and physical functioning. In conclusion, internal fixation of femoral neck fractures results in permanent physical limitations. The relatively young and healthy patients in our study seem capable of compensating. Attention should be paid to femoral neck shortening and proper correction with a heel lift, as inadequate correction may cause physical complaints and influence outcome. PMID:23823040

  15. Removal of a well-fixed cementless femoral component with an extended proximal femoral osteotomy.

    PubMed

    Younger, T I; Bradford, M S; Paprosky, W G

    1995-05-01

    Removal of a stable, well-fixed cementless femoral arthroplasty component occasionally is necessary because of infection, component malposition, persistent pain, or incompatibility with a femoral revision component. Restricted access to ingrowth surfaces may make implant removal exceedingly difficult and increases the risk of iatrogenic damage to the proximal femur. A new extended proximal femoral osteotomy technique is described for use in removing well-fixed cementless femoral components. Previous techniques have been modified to allow access to the bone-implant interface and to provide straight-shot access to the femoral canal for proper sizing and positioning of the revision implant. The osteotomy can be extended to accommodate the entire length of the porous coating on the revision component. If a shorter osteotomy is desired, access to the prosthesis for transection with a metal-cutting burr is possible. The osteotomy is easily repositioned with cerclage wires or cables and reliable healing has been demonstrated. PMID:10150358

  16. Domino Tunneling.

    PubMed

    Schreiner, Peter R; Wagner, J Philipp; Reisenauer, Hans Peter; Gerbig, Dennis; Ley, David; Sarka, János; Császár, Attila G; Vaughn, Alexander; Allen, Wesley D

    2015-06-24

    Matrix-isolation experiments near 3 K and state-of-the-art quantum chemical computations demonstrate that oxalic acid [1, (COOH)2] exhibits a sequential quantum mechanical tunneling phenomenon not previously observed. Intensities of numerous infrared (IR) bands were used to monitor the temporal evolution of the lowest-energy O-H rotamers (1cTc, 1cTt, 1tTt) of oxalic acid for up to 19 days following near-infrared irradiation of the matrix. The relative energies of these rotamers are 0.0 (1cTc), 2.6 (1cTt), and 4.0 (1tTt) kcal mol(-1). A 1tTt → 1cTt → 1cTc isomerization cascade was observed with half-lives (t1/2) in different matrix sites ranging from 30 to 360 h, even though the sequential barriers of 9.7 and 10.4 kcal mol(-1) are much too high to be surmounted thermally under cryogenic conditions. A general mathematical model was developed for the complex kinetics of a reaction cascade with species in distinct matrix sites. With this model, a precise, global nonlinear least-squares fit was achieved simultaneously on the temporal profiles of nine IR bands of the 1cTc, 1cTt, and 1tTt rotamers. Classes of both fast (t(1/2) = 30-50 h) and slow (t(1/2) > 250 h) matrix sites were revealed, with the decay rate of the former in close agreement with first-principles computations for the conformational tunneling rates of the corresponding isolated molecules. Rigorous kinetic and theoretical analyses thus show that a "domino" tunneling mechanism is at work in these oxalic acid transformations. PMID:26027801

  17. Looking into Tunnel Books.

    ERIC Educational Resources Information Center

    Hinshaw, Craig

    1999-01-01

    Describes how to make tunnel books, which are viewed by looking into a "tunnel" created by accordion-folded expanding sides. Suggests possible themes. Describes how to create a walk-through tunnel book for first grade students. (CMK)

  18. Carpal tunnel release

    MedlinePlus

    Median nerve decompression; Carpal tunnel decompression; Surgery - carpal tunnel ... The median nerve and the tendons that flex (or curl) your fingers go through a passage called the carpal tunnel in ...

  19. Femoral lipectomy increases postprandial lipemia in women.

    PubMed

    Hernandez, Teri L; Bessesen, Daniel H; Cox-York, Kimberly A; Erickson, Christopher B; Law, Christopher K; Anderson, Molly K; Wang, Hong; Jackman, Matthew R; Van Pelt, Rachael E

    2015-07-01

    Femoral subcutaneous adipose tissue (SAT) appears to be cardioprotective compared with abdominal SAT, possibly through better triglyceride (TG) sequestration. We hypothesized that removal of femoral SAT would increase postprandial TG through a reduction in dietary fatty acid (FA) storage. Normal-weight (means ± SD; BMI 23.9 ± 2.6 kg/m(2)) women (n = 29; age 45 ± 6 yr) were randomized to femoral lipectomy (LIPO) or control (CON) and followed for 1 yr. Regional adiposity was measured by DEXA and CT. A liquid meal labeled with [(14)C]oleic acid was used to trace the appearance of dietary FA in plasma (6-h postprandial TG), breath (24-h oxidation), and SAT (24-h [(14)C]TG storage). Fasting LPL activity was measured in abdominal and femoral SAT. DEXA leg fat mass was reduced after LIPO vs. CON (Δ-1.4 ± 0.7 vs. 0.1 ± 0.5 kg, P < 0.001) and remained reduced at 1 yr (-1.1 ± 1.4 vs. -0.2 ± 0.5 kg, P < 0.05), as did CT thigh subcutaneous fat area (-39.6 ± 36.6 vs. 4.7 ± 14.6 cm(2), P < 0.05); DEXA trunk fat mass and CT visceral fat area were unchanged. Postprandial TG increased (5.9 ± 7.7 vs. -0.6 ± 5.3 × 10(3) mg/dl, P < 0.05) and femoral SAT LPL activity decreased (-21.9 ± 22.3 vs. 10.5 ± 26.5 nmol·min(-1)·g(-1), P < 0.05) 1 yr following LIPO vs. CON. There were no group differences in (14)C-labeled TG appearing in abdominal and femoral SAT or elsewhere. In conclusion, femoral fat remained reduced 1 yr following lipectomy and was accompanied by increased postprandial TG and reduced femoral SAT LPL activity. There were no changes in storage of meal-derived FA or visceral fat. Our data support a protective role for femoral adiposity on circulating TG independent of dietary FA storage and visceral adiposity. PMID:25968576

  20. Laparoscopic repair of an incarcerated femoral hernia

    PubMed Central

    Pillay, Yagan

    2015-01-01

    Introduction A femoral hernia is a rare, acquired condition, which has been reported in less than 5% of all abdominal wall hernias, with a female to male ratio of 4:1. Presentation of case We report a case in a female patient who had a previous open inguinal herniorrhaphy three years previously. She presented with right sided groin pain of one month duration. Ultrasound gave a differential diagnosis of a recurrent inguinal hernia or a femoral hernia. A transabdominal preperitoneal repair was performed and the patient made an uneventful recovery. Discussion Laparoscopic repair of a femoral hernia is still in its infancy and even though the outcomes are superior to an open repair, open surgery remains the standard of care. The decision to perform a laparoscopic trans abdominal preperitoneal (TAPP) repair was facilitated by the patient having previous open hernia surgery. The learning curve for laparoscopic femoral hernia repair is steep and requires great commitment from the surgeon. Once the learning curve has been breached this is a feasible method of surgical repair. This is demonstrated by the fact that this case report is from a rural hospital in Canada. Conclusion Laparoscopic femoral hernia repair involves more time and specialized laparoscopic skills. The advantages are a lower recurrence rate and lower incidence of inguinodynia. PMID:26581083

  1. Carpal tunnel biopsy

    MedlinePlus

    Calandruccio JH. Carpal tunnel syndrome, ulnar tunnel syndrome, and stenosing tenosynovitis. In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics . 12th ed. Philadelphia, PA: Elsevier Mosby; 2012: ...

  2. Tissue level microstructure and mechanical properties of the femoral head in the proximal femur of fracture patients

    NASA Astrophysics Data System (ADS)

    Lü, Linwei; Meng, Guangwei; Gong, He; Zhu, Dong; Gao, Jiazi; Fan, Yubo

    2015-04-01

    This study aims to investigate the regional variations of trabecular morphological parameters and mechanical parameters of the femoral head, as well as to determine the relationship between trabecular morphological and mechanical parameters. Seven femoral heads from patients with fractured proximal femur were scanned using a micro-CT system. Each femoral head was divided into 12 sub-regions according to the trabecular orientation. One trabecular cubic model was reconstructed from each sub-region. A total of 81 trabecular models were reconstructed, except three destroyed sub-regions from two femoral heads during the surgery. Trabecular morphological parameters, i.e. trabecular separation (Tb.Sp), trabecular thickness (Tb.Th), specific bone surface (BS/BV), bone volume fraction (BV/TV), structural model index (SMI), and degree of anisotropy (DA) were measured. Micro-finite element analyses were performed for each cube to obtain the apparent Young's modulus and tissue level von Mises stress distribution under 1 % compressive strain along three orthogonal directions, respectively. Results revealed significant regional variations in the morphological parameters (). Young's moduli along the trabecular orientation were significantly higher than those along the other two directions. In general, trabecular mechanical properties in the medial region were lower than those in the lateral region. Trabecular mechanical parameters along the trabecular orientation were significantly correlated with BS/BV, BV/TV, Tb.Th, and DA. In this study, regional variations of microstructural features and mechanical properties in the femoral head of patients with proximal femur fracture were thoroughly investigated at the tissue level. The results of this study will help to elucidate the mechanism of femoral head fracture for reducing fracture risk and developing treatment strategies for the elderly.

  3. Micromotion of cemented and uncemented femoral components.

    PubMed

    Burke, D W; O'Connor, D O; Zalenski, E B; Jasty, M; Harris, W H

    1991-01-01

    We evaluated the initial stability of cemented and uncemented femoral components within the femoral canals of cadaver femurs during simulated single limb stance and stair climbing. Both types were very stable in simulated single limb stance (maximum micromotion of 42 microns for cemented and 30 microns for uncemented components). However, in simulated stair climbing, the cemented components were much more stable than the uncemented components (76 microns as against 280 microns). There was also greater variation in the stability of uncemented components in simulated stair climbing, with two of the seven components moving 200 microns or more. Future implant designs should aim to improve the initial stability of cementless femoral components under torsional loads; this should improve the chances of bony ingrowth. PMID:1991771

  4. Guide wire migration during femoral vein catheterization.

    PubMed

    Khatami, Mohammad Reza; Abbasi, Rozita; Sadigh, Gelareh

    2010-10-01

    Central vein catheterization is a routine and relatively safe procedure in critically ill patients. Complications with this procedure depend to the site of catheterization and the skill of the operator. In addition to the common complications with femoral vein catheterization there are some rare usually preventable side effects related to guide wire and catheter. In our patient who underwent femoral catheterization for acute hemodialysis, we report migration of guide wire through the systemic circulation from the femoral vein to the jugular vein. This is a very rare complication that is a human error and is totally preventable by doing the procedure by a skilled doctor and considering the standards described for central vein catheter insertion. PMID:20852377

  5. Emergency intravenous access through the femoral vein.

    PubMed

    Swanson, R S; Uhlig, P N; Gross, P L; McCabe, C J

    1984-04-01

    A study was undertaken to assess the efficacy and safety of femoral venous catheterization for resuscitation of critically ill patients in the emergency department setting. From May 1982 to April 1983, 100 attempts were made at percutaneous insertion of a large-bore catheter into the femoral veins of patients presenting to our emergency department in cardiac arrest or requiring rapid fluid resuscitation. Eighty-nine attempts were successful. Insertion was generally considered easy, and flow rates were excellent. The only noted complications were four arterial punctures and one minor groin hematoma. This study suggests that short-term percutaneous catheterization of the femoral vein provides rapid, safe, and effective intravenous access. PMID:6703430

  6. Adventitial cystic disease of common femoral vein

    PubMed Central

    Suh, Bo-Yang

    2011-01-01

    Adventitial cystic disease (ACD) of venous system is an extremely rare condition. Very few reports of ACD in venous system have been described. In this report we discuss two cases of common femoral vein ACD that presented with a swollen leg by the obstruction of the vein. Ultrasound imaging showed the typical hypoechoic fluid filled cyst with a posterior acoustic window. Computed tomography scan and ascending venogram showed a stenosis to flow in the common femoral vein caused by an extrinsic mass. Trans-adventitial evacuation of cyst with removal of vein wall was performed for both cases. During operation we found the gelatinous material in the cysts arising in the wall of the common femoral vein and compressing the lumen. The patients were released after short hospitalization and have remained symptom free with no recurrence. PMID:22066091

  7. Optimizing Stability in Femoral Neck Fracture Fixation.

    PubMed

    Ye, Ye; Hao, Jiandong; Mauffrey, Cyril; Hammerberg, E Mark; Stahel, Philip F; Hak, David J

    2015-10-01

    Optimizing stability of femoral neck fracture fixation is important in obtaining a successful outcome. The mechanical problems and strategies for achieving optimal stability differ depending on patients' age and degree of osteoporosis. Femoral neck fractures in younger adults usually result from high-energy trauma and have a vertical fracture pattern. Strategies for optimizing fixation stability in this group include placing additional screws at right angles to the fracture plane and medial buttress plate augmentation. In elderly patients, screw position relative to the intact cortical femoral neck bone is of critical importance. Additional strategies for optimizing fixation stability in this group include the concept of length stable fixation, use of adjunctive calcium phosphate cement, and use of novel fixed angle fixation implants. PMID:26488776

  8. Reverse distal femoral locking compression plate a salvage option in nonunion of proximal femoral fractures

    PubMed Central

    Dumbre Patil, Sampat S; Karkamkar, Sachin S; Patil, Vaishali S Dumbre; Patil, Shailesh S; Ranaware, Abhijeet S

    2016-01-01

    Background: When primary fixation of proximal femoral fractures with implants fails, revision osteosynthesis may be challenging. Tracts of previous implants and remaining insufficient bone stock in the proximal femur pose unique problems for the treatment. Intramedullary implants like proximal femoral nail (PFN) or surface implants like Dynamic Condylar Screw (DCS) are few of the described implants for revision surgery. There is no evidence in the literature to choose one implant over the other. We used the reverse distal femur locking compression plate (LCP) of the contralateral side in such cases undergoing revision surgery. This implant has multiple options of fixation in proximal femur and its curvature along the length matches the anterior bow of the femur. We aimed to evaluate the efficacy of this implant in salvage situations. Materials and Methods: Twenty patients of failed primary proximal femoral fractures who underwent revision surgery with reverse distal femoral locking plate from February 2009 to November 2012 were included in this retrospective study. There were 18 subtrochanteric fractures and two ipsilateral femoral neck and shaft fractures, which exhibited delayed union or nonunion. The study included 14 males and six females. The mean patient age was 43.6 years (range 22–65 years) and mean followup period was 52.1 months (range 27–72 months). Delayed union was considered when clinical and radiological signs of union failed to progress at the end of four months from initial surgery. Results: All fractures exhibited union without any complications. Union was assessed clinically and radiologically. One case of ipsilateral femoral neck and shaft fracture required bone grafting at the second stage for delayed union of the femoral shaft fracture. Conclusions: Reverse distal femoral LCP of the contralateral side can be used as a salvage option for failed fixation of proximal femoral fractures exhibiting nonunion. PMID:27512218

  9. Management of femoral head osteonecrosis: Current concepts

    PubMed Central

    Tripathy, Sujit Kumar; Goyal, Tarun; Sen, Ramesh Kumar

    2015-01-01

    Osteonecrosis of femoral head (ONFH) is a disabling condition of young individuals with ill-defined etiology and pathogenesis. Remains untreated, about 70-80% of the patients progress to secondary hip arthritis. Both operative and nonoperative treatments have been described with variable success rate. Early diagnosis and treatment is the key for success in preserving the hip joint. Once femoral head collapses (>2 mm) or if there is secondary degeneration, hip conservation procedures become ineffective and arthroplasty remains the only better option. We reviewed 157 studies that evaluate different treatment modalities of ONFH and then a final consensus on treatment was made. PMID:25593355

  10. Intramedullary nailing of pediatric femoral shaft fracture.

    PubMed

    Hosalkar, Harish S; Pandya, Nirav K; Cho, Robert H; Glaser, Diana A; Moor, Molly A; Herman, Martin J

    2011-08-01

    Intramedullary nail fixation of pediatric long bone fracture, particularly femoral shaft fracture, has revolutionized the care and outcome of these complex injuries. Nailing is associated with a high rate of union and a low rate of complications. Improved understanding of proximal femoral vascularity has led to changes in nail insertion methodology. Multiple fixation devices are available; selection is based on fracture type, patient age, skeletal maturity, and body mass index. A thorough knowledge of anatomy and biomechanics is required to achieve optimal results without negatively affecting skeletal development. PMID:21807915

  11. Electron tunnel sensor technology

    NASA Technical Reports Server (NTRS)

    Waltman, S. B.; Kaiser, W. J.

    1989-01-01

    The recent development of Scanning Tunneling Microscopy technology allows the application of electron tunneling to position detectors for the first time. The vacuum tunnel junction is one of the most sensitive position detection mechanisms available. It is also compact, simple, and requires little power. A prototype accelerometer based on electron tunneling, and other sensor applications of this promising new technology are described.

  12. 15-Foot Spin Tunnel

    NASA Technical Reports Server (NTRS)

    1934-01-01

    Constructing the forms for the foundation of the 15-Foot Spin Tunnel. Charles Zimmerman was given the assignment to design and build a larger spin tunnel that would supplant the 5-foot Vertical Wind Tunnel. Authorization to build the tunnel using funds from the Federal Public Works Administration (PWA) came in June 1933. Construction started in late winter 1934 and the tunnel was operational in April 1935. The initial construction costs were $64,000. The first step was to pour the foundation for the tunnel and the housing which would encase the wind tunnel.

  13. History of femoral head fracture and coronal fracture of the femoral condyles.

    PubMed

    Bartoníček, Jan; Rammelt, Stefan

    2015-06-01

    The first known description of the coronal fracture of the lateral femoral condyle was published by Busch in 1869. Hoffa used Busch's drawing in the first edition of his book in 1888 and accompanied it only with one sentence. A full case history of this fracture pattern was described by Braun in 1891. However, Braun's article fell into oblivion and so the fracture was popularized only in the fourth edition of Hoffa's textbook, particularly thanks to the drawing, rather than the brief description. Therefore, a fracture of the posterior femoral condyle, or more specifically, of the lateral condyle, could properly be called "Busch-Hoffa fracture". Femoral head fracture was initially described by Birkett in 1869. Of essential importance in this respect were the publications by Christopher in 1924 and, particularly, Pipkin's study of 1957, including his classification that is still in use today. A historically correct eponym for a femoral head fracture would therefore be "Birkitt-Pipkin fracture". PMID:25787681

  14. Femoral development in chronically centrifuged rats

    NASA Technical Reports Server (NTRS)

    Smith, S. D.

    1977-01-01

    Groups of 30-d-old male and female rats were centrifuged at 2.00 G (RE, Rotation Experimental), 1.05 G (RC, Rotation Control) or exposed to the noise and wind of the centrifuge at 1.00 G (EC, Earth Control) for periods of 1, 2, 4, 8, and 16 weeks. Measurements of their femurs indicated that exposure to centrifugation a) decreased femoral length in RE animals, b) increased femoral length in RC animals, c) reduced femoral diameter in RE and RC animals, d) increased L/D ratios in RC animals, e) decreased L/D ratios in RE animals, f) increased femur length/body weight in RE animals, g) decreased cortical thickness (CT) in RE animals, h) increased relative CT in RE animals, and decreased it in RC animals, i) accelerated ossification in RC femoral heads, j) thinned and distorted RE epiphyseal plates, and k) thickened condylar cartilage in RE females. The effects tended to be strongly sexually dimorphic, with females more severely affected by the stress than males.

  15. EPIDEMIOLOGICAL STUDY OF CHILDREN DIAPHYSEAL FEMORAL FRACTURES

    PubMed Central

    Hoffmann, Cassiano Ricardo; Traldi, Eduardo Franceschini; Posser, Alexandre

    2015-01-01

    Objective: To evaluate the personal, fracture, treatment and complication characteristics among patients with pediatric femoral shaft fractures attended at the pediatric orthopedic service of the Joana de Gusmão Children's Hospital. Methods: This was a retrospective cross-sectional study on a population consisting of patients with femoral shaft fractures, aged between birth and 14 years and 11 months, who were divided into four age groups. Information was obtained from medical records and was transferred to a survey questionnaire to present personal, fracture, treatment and complication variables. Results: The study population consisted of 96 patients. Their mean age was 6.8 years. The cases were predominantly among males, comprising closed fractures on the right side, in the middle third with a single line. Regarding fracture etiology, traffic accidents predominated overall in the sample. Most of the patients (74 to 77.1%) presented femoral fractures as their only injury. Conservative treatment predominated in the group younger than six years of age, and surgical treatment in the group aged 6 to 14 years and 11 months. The complications observed until bone union were: discrepancy, infection and movement limitation. The mean time taken for consolidation was 9.6 ± 2.4 weeks, varying with age. Conclusion: The features of these fractures were similar to those described in the literature and the treatment used showed good results. The Joana de Gusmão Children's Hospital has used the treatment proposed in the literature for pediatric femoral shaft fractures. PMID:27042619

  16. Femoral neck version affects medial femorotibial loading.

    PubMed

    Papaioannou, T A; Digas, Georgios; Bikos, Ch; Karamoulas, V; Magnissalis, E A

    2013-01-01

    The aim of this study was to provide a preliminary evaluation of the possible effect that femoral version may have on the bearing equilibrium conditions developed on the medial tibiofemoral compartment. A digital 3D solid model of the left physiological adult femur was used to create morphological variations of different neck-shaft angles (varus 115, normal 125, and valgus 135 degrees) and version angles (-10, 0, and +10 degrees). By means of finite element modeling and analysis techniques (FEM-FEA), a virtual experiment was executed with the femoral models aligned in a neutral upright position, distally supported on a fully congruent tibial tray and proximally loaded with a vertical only hip joint load of 2800 N. Equivalent stresses and their distribution on the medial compartment were computed and comparatively evaluated. Within our context, the neck-shaft angle proved to be of rather indifferent influence. Reduction of femoral version, however, appeared as the most influencing parameter regarding the tendency of the medial compartment to establish its bearing equilibrium towards posteromedial directions, as a consequence of the corresponding anteroposterior changes of the hip centre over the horizontal tibiofemoral plane. We found a correlation between femoral anteversion and medial tibiofemoral compartment contact pressure. Our findings will be further elucidated by more sophisticated FEM-FEA and by clinical studies that are currently planned. PMID:24959355

  17. Scanning tunneling microscopy on graphite and gold

    NASA Astrophysics Data System (ADS)

    Guichar, G. M.; Han, B.; Morand, M.; Belkaid, M. S.

    1993-03-01

    A compact, UHV-compatible scanning tunneling microscope has been built together with the necessary controlling electronics. We report on the design, development and evaluation of this setup. Some experimental results performed on highly oriented pyrolitic graphite and gold evaporated on stainless steel samples are presented.

  18. Femoral mononeuropathy caused by a malignant sarcoma: two case reports.

    PubMed

    Montoliu, Patrícia; Pumarola, Martí; Zamora, Angels; Espada, Ivonne; Lloret, Albert; Añor, Sònia

    2008-11-01

    A 9-year old miniature poodle and a 6-year old American Staffordshire terrier were evaluated for slowly progressive lameness and atrophy of the left pelvic limb. Neurological examinations of both animals were consistent with femoral nerve lesions. In both cases, neoplastic masses were identified within the left psoas muscle, invading the left femoral nerve or, in one case, its nerve roots. Ultrasound-guided fine needle aspirate and histopathological examination of the masses revealed that these were malignant sarcomas. Femoral mononeuropathies are very rare in dogs, and most descriptions of femoral nerve lesions are caused by traumatic injuries. Descriptions of neoplastic processes affecting the femoral nerve are limited to peripheral nerve sheath tumours (PNST). These cases provide the first descriptions of malignant neoplasms other than PNSTs that infiltrate the femoral nerve or its nerve roots and cause unilateral femoral mononeuropathy and lameness of obscure origin. PMID:17889576

  19. Cryogenic wind tunnels. II

    NASA Technical Reports Server (NTRS)

    Kilgore, Robert A.

    1987-01-01

    The application of the cryogenic concept to various types of tunnels including Ludwieg tube tunnel, Evans clean tunnel, blowdown, induced-flow, and continuous-flow fan-driven tunnels is discussed. Benefits related to construction and operating costs are covered, along with benefits related to new testing capabilities. It is noted that cooling the test gas to very low temperatures increases Reynolds number by more than a factor of seven. From the energy standpoint, ambient-temperature fan-driven closed-return tunnels are considered to be the most efficient type of tunnel, while a large reduction in the required tunnel stagnation pressure can be achieved through cryogenic operation. Operating envelopes for three modes of operation for a cryogenic transonic pressure tunnel with a 2.5 by 2.5 test section are outlined. A computer program for calculating flow parameters and power requirements for wind tunnels with operating temperatures from saturation to above ambient is highlighted.

  20. Planar Quasiparticle Tunneling Spectroscopy of Bi2212 Single Crystals

    NASA Astrophysics Data System (ADS)

    Aubin, H.; Pugel, D. E.; Greene, L. H.; Jian, S.; Hinks, D.

    2000-03-01

    Using techniques of quasi-particle planar tunneling spectroscopy, the in-plane density of states of the high-Tc superconductor Bi2212 is investigated. The 0.3 mm thick single crystals used allow tunneling into crystal faces of various crystallographic orientations, and a newly-developed technique allows for exposing these crystal faces with little damage. The planar tunnel junction is fabricated with the insulating dielectric CaF2 as the tunnel barrier and a noble metal counter-electrode. The tunneling conductance measured with the current injected perpendicular to the copper-oxide planes differs substantially from that measured with the current injected parallel to the planes. The in-plane tunneling density of states exhibits a zero-bias conductance peak which is attributed to the formation of an Andreev bound state, as predicted to occur at the ab-plane oriented surface of a d-wave superconductor. Tunneling spectra as a function of temperature, magnetic field and crystallographic orientation will be presented. These results will be discussed and compared with those obtained previously on YBCO-based tunnel junctions. This research was supported by the NSF-STCS (NSF-DMR 91-20000). DGH acknowledges support by the US DOE (W-31-109-ENG-38).

  1. Anatomic Tunnel Placement in Anterior Cruciate Ligament Reconstruction.

    PubMed

    Dhawan, Aman; Gallo, Robert A; Lynch, Scott A

    2016-07-01

    The anatomic anterior cruciate ligament (ACL) reconstruction concept has developed in part from renewed interest in the insertional anatomy of the ACL, using surgical techniques that can reproduce this anatomy reliably and accurately during surgical reconstruction. Several technical tools are available to help identify and place the tibial and femoral grafts anatomically, including arthroscopic anatomic landmarks, a malleable ruler device, and intraoperative fluoroscopy. The changes in technique for anatomic tunnel placement in ACL reconstruction follow recent biomechanical and kinematic data that demonstrate improved time zero characteristics. A better re-creation of native ACL kinematics and biomechanics is achieved with independent femoral drilling techniques that re-create a central footprint single-bundle ACL reconstruction or double-bundle reconstruction. However, to date, limited short-term and long-term clinical outcome data have been reported that support using either of these techniques rather than a transtibial drilling technique. This lack of clear clinical advantage for femoral independent and/or double-bundle techniques may arise because of the potentially offsetting biologic incorporation challenges of these grafts when placed using these techniques or could result from modifications made in traditional endoscopic transtibial techniques that allow improved femoral and tibial footprint restoration. PMID:27243794

  2. Cryogenic wind tunnels. III

    NASA Technical Reports Server (NTRS)

    Kilgore, Robert A.

    1987-01-01

    Specific problems pertaining to cryogenic wind tunnels, including LN(2) injection, GN(2) exhaust, thermal insulation, and automatic control are discussed. Thermal and other physical properties of materials employed in these tunnels, properties of cryogenic fluids, storage and transfer of liquid nitrogen, strength and toughness of metals and nonmetals at low temperatures, and material procurement and qualify control are considered. Safety concerns with cryogenic tunnels are covered, and models for cryogenic wind tunnels are presented, along with descriptions of major cryogenic wind-tunnel facilities the United States, Europe, and Japan. Problems common to wind tunnels, such as low Reynolds number, wall and support interference, and flow unsteadiness are outlined.

  3. Secure fixation of femoral bone plug with a suspensory button in anatomical anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft

    PubMed Central

    TAKETOMI, SHUJI; INUI, HIROSHI; NAKAMURA, KENSUKE; YAMAGAMI, RYOTA; TAHARA, KEITARO; SANADA, TAKAKI; MASUDA, HIRONARI; TANAKA, SAKAE; NAKAGAWA, TAKUMI

    2015-01-01

    Purpose the efficacy and safety of using a suspensory button for femoral fixation in anatomical anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone (BPTB) graft have not been established. The purpose of the current study was to evaluate bone plug integration onto the femoral socket and migration of the bone plug and the EndoButton (EB) (Smith & Nephew, Andover, MA, USA) after rectangular tunnel ACL reconstruction with BPTB autograft. Methods thirty-four patients who underwent anatomical rectangular ACL reconstruction with BPTB graft using EB for femoral fixation and in whom three-dimensional (3D) computed tomography (CT) was performed one week and one year after surgery were included in this study. Bone plug integration onto the femoral socket, bone plug migration, soft tissue interposition, EB migration and EB rotation were evaluated on 3D CT. The clinical outcome was also assessed and correlated with the imaging outcomes. Results the bone plug was integrated onto the femoral socket in all cases. The incidence of bone plug migration, soft tissue interposition, EB migration and EB rotation was 15, 15, 9 and 56%, respectively. No significant association was observed between the imaging outcomes. The postoperative mean Lysholm score was 97.1 ± 5.0 points. The postoperative side-to-side difference, evaluated using a KT-2000 arthrometer, averaged 0.5 ± 1.3 mm. There were no complications associated with EB use. Imaging outcomes did not affect the postoperative KT side-to-side difference. Conclusions the EB is considered a reliable device for femoral fixation in anatomical rectangular tunnel ACL reconstruction with BPTB autograft. Level of evidence Level IV, therapeutic case series. PMID:26889465

  4. Postcatheterization Femoral Arteriovenous Fistulas: Endovascular Treatment with Stent-Grafts

    SciTech Connect

    Onal, Baran Kosar, Sule; Gumus, Terman; Ilgit, Erhan T.; Akpek, Sergin

    2004-09-15

    Purpose: To report our results of stent-graft implantation for the endovascular treatment of postcatheterization femoral arteriovenous fistulas (AVFs) occurring between the deep femoral artery and the femoral vein.Methods: Endovascular treatment of iatrogenic femoral AVFs as a result of arterial puncture for coronary angiography and/or angioplasty was attempted in 10 cases. Balloon-expandable stent-grafts, one for each lesion, were used to repair the fistulas, which were between the deep femoral artery and the femoral vein in all cases. Stent-graft implantation to the deep femoral artery was performed by a contralateral retrograde approach.Results: All stent-grafts were deployed successfully. Complete closure of the fistulas was accomplished immediately in nine of 10 cases. In one case, complete closure could not be obtained but the fact that the complaint subsided was taken to indicate clinical success. In three cases, side branch occlusion of the deep femoral artery occurred. No complications were observed after implantation. Follow-up for 8-31 months (mean 18.5 months) with color Doppler ultrasonography revealed patency of the stented arterial segments without recurrent arteriovenous shunting in those nine patients who had successful immediate closure of their AVFs.Conclusion: Our results with a mean follow-up 18.5 months suggest that stent-graft implantation for the closure of postcatheterization femoral AVFs originating from the deep femoral artery is an effective, minimally invasive alternative procedure.

  5. 4. 'Ring Stones & Tunnel Sections, Tunnel #33,' Southern Pacific ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. 'Ring Stones & Tunnel Sections, Tunnel #33,' Southern Pacific Standard Double-Track Tunnel, ca. 1913. Compare to photos in documentation sets for Tunnel 18 (HAER No. CA-197), Tunnel 34 (HAER No. CA-206), and Tunnel 1 (HAER No. CA-207). - Central Pacific Transcontinental Railroad, Sacramento to Nevada state line, Sacramento, Sacramento County, CA

  6. Spontaneous stress fractures of the femoral neck

    SciTech Connect

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

    1985-02-01

    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.

  7. Atypical femoral fracture following zoledronic acid treatment.

    PubMed

    Ataoğlu, Baybars; Kaptan, Ahmet Yiğit; Eren, Toygun Kağan; Yapar, Ali Ekber; Berkay, Ahmet Fırat

    2016-04-01

    A 68-year-old female patient admitted to our clinic with right anterior thigh pain ongoing for six months and which increased in last two months. The patient had no trauma history. The patient had been followed-up for 15 years because of osteoporosis and administrated alendronate and ibandronate treatment for 10 years. Patient had three shots of zoledronate once a year during the last three years. Her pain was increasing when she was walking. Physical examination revealed pain in her right thigh. Radiogram showed thickened lateral cortex of the subtrochanteric area. Magnetic resonance imaging also showed thickening and edema of the same area. These images were correlated with atypical fracture in right femoral subthrochanteric zone. Dual energy X-ray absorptiometry revealed that T score was -3.3 in lumbar region and -2.5 in femoral neck. Zoledronate treatment was ended. Prophylactic surgical fixation was performed with titanium elastic nails. PMID:26874637

  8. Tunneling spectroscopy of anisotropic superconductors

    SciTech Connect

    Kashiwaya, Satoshi; Koyanagi, Masao; Kajimura, Koji; Tanaka, Yukio

    1996-12-31

    Tunneling spectroscopy of normal-insulator-superconductor junction is investigated theoretically. In anisotropic superconductors, differently from the case of isotropic superconductor, the effective pair potentials felt by quasiparticles depend on the direction of their motion. By taking this effect into account, it is shown that the conductance spectra strongly depend on the crystal orientation. Using Green`s function method, local density of states (LDOS) in superconductor is also calculated. The close relation between conductance spectra and LDOS is presented. The calculation is compared with experimental spectra of high-{Tc} superconductors.

  9. Femoral midshaft fractures: expandable versus locked nailing.

    PubMed

    Zhou, Zhen-Tao; Song, Yu-Chen; Zhou, Xiao-Zhong; Zhou, Hai-Bin; Luo, Zong-Ping; Dong, Qi-Rong

    2015-04-01

    Femoral midshaft fracture is one of the most common clinical injuries and is often caused by high-energy traffic accidents. Intramedullary nailings, plates, and external fixators are all used as treatment alternatives for a variety of patients depending on fracture location, displacement, comminution, soft tissue condition, and local tradition. Locked intramedullary nailing is currently the preferred treatment method for most diaphyseal fractures and has good clinical results. The goal of this study was to compare expandable and locked intramedullary nailing for the treatment of AO type 32A and 32B1 femoral midshaft fractures. The authors performed a retrospective analysis of 46 patients (33 men and 13 women; mean age, 32.3 years; range, 22-52 years) with femoral midshaft fractures who were divided into 2 groups-one treated with an expandable intramedullary nailing method and the other with a conventional locked intramedullary nailing. The 2 groups were compared with respect to operation time, fluoroscopic time, amount of estimated blood loss, hospitalization time, healing time, and complications. Patients were followed for at least 1 year. The results of this study showed that all of the patients achieved bone union within 12 to 24 months. Expandable nailing performed better than locked nailing in operation time, fluoroscopic time, amount of estimated blood loss, and healing time (P<.001). There was no difference in hospitalization time and no visible shortening or severe complications were observed in either group. Based on the results of this study, the expandable intramedullary nailing is an easy and effective treatment for AO type 32A and 32B1 diaphyseal femoral fractures. PMID:25901625

  10. Subtrochanteric fractures after retrograde femoral nailing.

    PubMed

    Mounasamy, Varatharaj; Mallu, Sathya; Khanna, Vishesh; Sambandam, Senthil

    2015-10-18

    Secondary fractures around femoral nails placed for the management of hip fractures are well known. We report, two cases of a fracture of the femur at the interlocking screw site in the subtrochanteric area after retrograde femoral nailing of a femoral shaft fracture. Only a few reports in the existing literature have described these fractures. Two young men after sustaining a fall presented to us with pain, swelling and deformity in the upper thigh region. On enquiring, examining and radiographing them, peri-implant fractures of subtrochanteric nature through the distal interlocking screws were revealed in both patients who also had histories of previous falls for which retrograde intramedullary nailing was performed for their respective femora. Both patients were managed with similar surgical routines including removal of the existing hardware, open reduction and ace cephallomedullary antegrade nailing. The second case did show evidence of delayed healing and was additionally stabilized with cerclage wires. Both patients had uneventful postoperative outcomes and union was evident at the end of 6 mo postoperatively with a good range of motion at the hip and knee. Our report suggests that though seldom reported, peri-implant fractures around the subtrochanteric region can occur and pose a challenge to the treating orthopaedic surgeon. We suggest these be managed, after initial stabilization and resuscitation, by implant removal, open reduction and interlocking intramedullary antegrade nailing. Good results and progression to union can be expected in these patients by adhering to basic principles of osteosynthesis. PMID:26495251

  11. Major SSC tunneling begins

    SciTech Connect

    Not Available

    1993-01-11

    In Texas, work has been completed on the first on the Superconducting Supercollider's major shafts. Now a boring machine has started driving the fifty-four mile elliptical accelerator tunnel. To date, contracts let for the tunnel have come in far below preliminary estimates. Five of the main fourteen foot diameter tunnel contracts have been awarded for a total of 107.4 million dollars, about forty million dollars below estimates. These contracts represent %60 percent of the total tunneling project.

  12. The Tunnels of Samos

    NASA Technical Reports Server (NTRS)

    Apostol, Tom M. (Editor)

    1995-01-01

    This 'Project Mathematics' series video from CalTech presents the tunnel of Samos, a famous underground aquaduct tunnel located near the capital of Pithagorion (named after the famed Greek mathematician, Pythagoras, who lived there), on one of the Greek islands. This tunnel was constructed around 600 BC by King Samos and was built under a nearby mountain. Through film footage and computer animation, the mathematical principles and concepts of why and how this aquaduct tunnel was built are explained.

  13. Squeezable electron tunneling junctions

    NASA Astrophysics Data System (ADS)

    Moreland, J.; Alexander, S.; Cox, M.; Sonnenfeld, R.; Hansma, P. K.

    1983-09-01

    We report a versatile new technique for constructing electron tunneling junctions with mechanically-adjusted artificial barriers. I-V curves are presented for tunneling between Ag electrodes with vacuum, gas, liquid or solid in the barrier. An energy gap is apparent in the measured I-V curve when tunneling occurs between superconducting Pb electrodes.

  14. Variable Density Tunnel

    NASA Technical Reports Server (NTRS)

    1931-01-01

    Variable Density Tunnel in operation. Man at far right is probably Harold J. 'Cannonball' Tuner, longtime safety officer, who started with Curtiss in the teens. This view of the Variable Density Tunnel clearly shows the layout of the Tunnel's surroundings, as well as the plumbing and power needs of the this innovative research tool.

  15. Incomplete transposition of the common femoral artery and vein.

    PubMed

    Leite, J O; Carvalho Ventura, I; Botelho, F E; Costa Galvao, W

    2010-02-01

    Anatomical variations of the great saphenous vein, femoral artery and femoral vein at the inguinal level are rare. Modifications in the anatomical relationships among theses vessel can cause technical difficulties. There are two reports in the literature of the complete transposition of the femoral artery and vein. Both patients had large varicose veins only in the limb that presented the variation, which suggested an extrinsic compression. In the present paper, we report a case study of a patient with an incomplete transposition of the femoral artery and vein. Specifically, the common femoral vein and the saphenofemoral junction were completely overlapped by the common femoral artery. Although this anatomical variation did not present any clinical signs, it required a more complex surgical procedure. PMID:20224538

  16. Autologous Hamstring Anterior Cruciate Ligament Graft Failure Using the Anteromedial Portal Technique With Suspensory Femoral Fixation

    PubMed Central

    Galdi, Balazs; Reyes, Allan; Brabston, Eugene W.; Levine, William N.

    2015-01-01

    Background: The anteromedial portal technique for drilling of the femoral tunnel during anterior cruciate ligament (ACL) reconstruction has been advocated by many surgeons as allowing improved access to the anatomical footprint. Furthermore, suspensory fixation of soft tissue grafts has become popularized because of complications associated with cross-pin fixation. Concerns regarding the use of both have recently arisen. Purpose: To raise awareness of the increased risk of graft failure when using the anteromedial portal technique with suspensory femoral fixation during ACL reconstruction. Study Design: Cohort study; Level of evidence, 3. Methods: From November 1998 to August 2012, a total of 465 primary ACL reconstructions were performed using quadrupled hamstring autograft tendons, with drilling of the femoral tunnel performed via the transtibial portal. Graft fixation on the femur was achieved with cross-pin fixation, while interference screw fixation was used on the tibia. From September 2012 to October 2013, there were 69 reconstructions performed through an anteromedial portal. While there was no change in graft choice, a change was made to using suspensory femoral fixation. No other surgical or postoperative rehabilitation changes were made. Results: During the 14-year period in which ACL reconstructions were performed via the transtibial portal and with cross-pin fixation, 2 graft failures (0.4% failure rate) were reported. After switching to the anteromedial portal with suspensory fixation, 7 graft failures (10.1% failure rate) were reported over a 13-month period. These were 5 male and 2 female patients, with a mean age of 18.8 years—all elite athletes. The same surgical technique was used in all patients, and all patients had at least an 8 mm–diameter graft. Patients were cleared to return to sport at an average of 8.4 months postoperatively, after completing functional performance tests. Of the 7 patients, 6 sustained a rerupture of the graft within

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

    PubMed Central

    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. Femoral neck structure and function in early hominins.

    PubMed

    Ruff, Christopher B; Higgins, Ryan

    2013-04-01

    All early (Pliocene-Early Pleistocene) hominins exhibit some differences in proximal femoral morphology from modern humans, including a long femoral neck and a low neck-shaft angle. In addition, australopiths (Au. afarensis, Au. africanus, Au. boisei, Paranthropus boisei), but not early Homo, have an "anteroposteriorly compressed" femoral neck and a small femoral head relative to femoral shaft breadth. Superoinferior asymmetry of cortical bone in the femoral neck has been claimed to be human-like in australopiths. In this study, we measured superior and inferior cortical thicknesses at the middle and base of the femoral neck using computed tomography in six Au. africanus and two P. robustus specimens. Cortical asymmetry in the fossils is closer overall to that of modern humans than to apes, although many values are intermediate between humans and apes, or even more ape-like in the midneck. Comparisons of external femoral neck and head dimensions were carried out for a more comprehensive sample of South and East African australopiths (n = 17) and two early Homo specimens. These show that compared with modern humans, femoral neck superoinferior, but not anteroposterior breadth, is larger relative to femoral head breadth in australopiths, but not in early Homo. Both internal and external characteristics of the australopith femoral neck indicate adaptation to relatively increased superoinferior bending loads, compared with both modern humans and early Homo. These observations, and a relatively small femoral head, are consistent with a slightly altered gait pattern in australopiths, involving more lateral deviation of the body center of mass over the stance limb. PMID:23341246

  19. Operative Management of Crossover Femoral-femoral Graft Erosion into Bladder: A Case Report.

    PubMed

    Motiani, Karan; Mahdy, Ayman

    2016-09-01

    Erosion of vascular grafts is not uncommon as seen in the recent literature. There have been many case reports documenting the work up and management of erosion of these grafts into bowel. We report a case of a crossover femoral-femoral graft that eroded into the anterior bladder wall and was incidentally found as an adherent bladder stone during cystoscopy. We demonstrate the importance of having a high level of clinical suspicion for eroding vascular grafts when preoperative imaging shows close proximity of graft to bladder. PMID:27462547

  20. Confocal Annular Josephson Tunnel Junctions

    NASA Astrophysics Data System (ADS)

    Monaco, Roberto

    2016-04-01

    The physics of Josephson tunnel junctions drastically depends on their geometrical configurations and here we show that also tiny geometrical details play a determinant role. More specifically, we develop the theory of short and long annular Josephson tunnel junctions delimited by two confocal ellipses. The behavior of a circular annular Josephson tunnel junction is then seen to be simply a special case of the above result. For junctions having a normalized perimeter less than one, the threshold curves in the presence of an in-plane magnetic field of arbitrary orientations are derived and computed even in the case with trapped Josephson vortices. For longer junctions, a numerical analysis is carried out after the derivation of the appropriate motion equation for the Josephson phase. We found that the system is modeled by a modified and perturbed sine-Gordon equation with a space-dependent effective Josephson penetration length inversely proportional to the local junction width. Both the fluxon statics and dynamics are deeply affected by the non-uniform annulus width. Static zero-field multiple-fluxon solutions exist even in the presence of a large bias current. The tangential velocity of a traveling fluxon is not determined by the balance between the driving and drag forces due to the dissipative losses. Furthermore, the fluxon motion is characterized by a strong radial inward acceleration which causes electromagnetic radiation concentrated at the ellipse equatorial points.

  1. Autonomous Robotic Inspection in Tunnels

    NASA Astrophysics Data System (ADS)

    Protopapadakis, E.; Stentoumis, C.; Doulamis, N.; Doulamis, A.; Loupos, K.; Makantasis, K.; Kopsiaftis, G.; Amditis, A.

    2016-06-01

    In this paper, an automatic robotic inspector for tunnel assessment is presented. The proposed platform is able to autonomously navigate within the civil infrastructures, grab stereo images and process/analyse them, in order to identify defect types. At first, there is the crack detection via deep learning approaches. Then, a detailed 3D model of the cracked area is created, utilizing photogrammetric methods. Finally, a laser profiling of the tunnel's lining, for a narrow region close to detected crack is performed; allowing for the deduction of potential deformations. The robotic platform consists of an autonomous mobile vehicle; a crane arm, guided by the computer vision-based crack detector, carrying ultrasound sensors, the stereo cameras and the laser scanner. Visual inspection is based on convolutional neural networks, which support the creation of high-level discriminative features for complex non-linear pattern classification. Then, real-time 3D information is accurately calculated and the crack position and orientation is passed to the robotic platform. The entire system has been evaluated in railway and road tunnels, i.e. in Egnatia Highway and London underground infrastructure.

  2. Confocal Annular Josephson Tunnel Junctions

    NASA Astrophysics Data System (ADS)

    Monaco, Roberto

    2016-09-01

    The physics of Josephson tunnel junctions drastically depends on their geometrical configurations and here we show that also tiny geometrical details play a determinant role. More specifically, we develop the theory of short and long annular Josephson tunnel junctions delimited by two confocal ellipses. The behavior of a circular annular Josephson tunnel junction is then seen to be simply a special case of the above result. For junctions having a normalized perimeter less than one, the threshold curves in the presence of an in-plane magnetic field of arbitrary orientations are derived and computed even in the case with trapped Josephson vortices. For longer junctions, a numerical analysis is carried out after the derivation of the appropriate motion equation for the Josephson phase. We found that the system is modeled by a modified and perturbed sine-Gordon equation with a space-dependent effective Josephson penetration length inversely proportional to the local junction width. Both the fluxon statics and dynamics are deeply affected by the non-uniform annulus width. Static zero-field multiple-fluxon solutions exist even in the presence of a large bias current. The tangential velocity of a traveling fluxon is not determined by the balance between the driving and drag forces due to the dissipative losses. Furthermore, the fluxon motion is characterized by a strong radial inward acceleration which causes electromagnetic radiation concentrated at the ellipse equatorial points.

  3. Clinical Results of Internal Fixation of Subcapital Femoral Neck Fractures

    PubMed Central

    Moon, Kyoung Ho; Shin, Joong Sup; Shin, Eun Ho; Ahn, Chi Hoon; Choi, Geon Hong

    2016-01-01

    Background Subcapital femoral neck is known to cause many complications, such as avascular necrosis (AVN) of the femoral head or nonunion, compared with other femoral neck fractures. The purpose of this study was to analyze the incidence of AVN and fixation failures in patients treated with internal fixation using cannulated screws for the subcapital femoral neck fractures. Methods This study targeted a total of 84 cases of subcapital femoral neck fractures that underwent internal fixation using cannulated screws. The average follow-up time after surgery was 36.8 months (range, 24 to 148 months). Results Nine hips (10.7%) showing AVN of the femoral head and 6 hips (7.1%) showing fixation failures were observed. The factors affecting the incidence of AVN of the femoral head after sustaining fractures correlated well with fracture types in the Garden classification (p = 0.030). The factors affecting fixation failure were the degree of reduction (p = 0.001) measured by the Garden alignment index and firm fixation (p = 0.009) assessed using the technique of 3-point fixation through the inferomedial cortical bone of the femoral neck. Conclusions The complication rates for subcapital femoral neck fractures were lower than those previously reported; hence, internal fixation could be a primary treatment option for these fractures. PMID:27247738

  4. [Isolated true aneurysm of the deep femoral artery].

    PubMed

    Salomon du Mont, L; Holzer, T; Kazandjian, C; Saucy, F; Corpataux, J M; Rinckenbach, S; Déglise, S

    2016-07-01

    Aneurysms of the deep femoral artery, accounting for 5% of all femoral aneurysms, are uncommon. There is a serious risk of rupture. We report the case of an 83-year-old patient with a painless pulsatile mass in the right groin due to an aneurysm of the deep femoral artery. History taking revealed no cardiovascular risk factors and no other aneurysms at other localizations. The etiology remained unclear because no recent history of local trauma or puncture was found. ACT angiography was performed, revealing a true isolated aneurysm of the deep femoral artery with a diameter of 90mm, beginning 1cm after its origin. There were no signs of rupture or distal emboli. Due to unsuitable anatomy for an endovascular approach, the patient underwent open surgery, with exclusion of the aneurysm and interposition of an 8-mm Dacron graft to preserve deep femoral artery flow. Due to their localization, the diagnosis and the management of aneurysms of the deep femoral artery can be difficult. Options are surgical exclusion or an endovascular approach in the absence of symptoms or as a bridging therapy. If possible, blood flow to the distal deep femoral artery should be maintained, the decision depending also on the patency of the superficial femoral artery. In case of large size, aneurysms of the deep femoral artery should be treated without any delay. PMID:27289256

  5. Three-dimensional analysis of alignment error in using femoral intramedullary guides in unicompartmental knee arthroplasty.

    PubMed

    Ma, Burton; Long, William; Rudan, John F; Ellis, Randy E

    2006-02-01

    We used computerized simulations with 3-dimensional models of 20 cadaver femora, calculated from computed tomographic scans, and a model of a rod measuring 200 x 5 mm to study femoral alignment accuracy for unicompartmental knee arthroplasty via minimally invasive reconstruction. The anatomical axis and insertion site were identified on each femur. A simulation of all feasible flexion-extension and varus-valgus orientations was performed. The average rod orientation was 3.2 degrees flexion and 2.5 degrees valgus. The range of orientation was 3.2 degrees extension to 9.7 degrees flexion and 4.5 degrees varus to 8.9 degrees valgus. The study suggests that a short narrow intramedullary rod inserted according to the manufacturer's specifications does not accurately find the anatomical axis and may lead to poor alignment of the femoral prosthesis. Given our finding of consistent bias toward excessive flexion and valgus alignment, we recommend that the operating surgeon carefully plan the insertion point of the intramedullary rod during surgery to compensate for this bias. PMID:16520218

  6. Validation of the femoral anteversion measurement method used in imageless navigation.

    PubMed

    Turley, Glen A; Ahmed, Shahbaz M Y; Williams, Mark A; Griffin, Damian R

    2012-01-01

    Total hip arthroplasty restores lost mobility to patients suffering from osteoarthritis and acute trauma. In recent years, navigated surgery has been used to control prosthetic component placement. Furthermore, there has been increasing research on what constitutes correct placement. This has resulted in the definition of a safe-zone for acetabular cup orientation. However, there is less definition with regard to femoral anteversion and how it should be measured. This study assesses the validity of the femoral anteversion measurement method used in imageless navigation, with particular attention to how the neutral rotation of the femur is defined. CT and gait analysis methodologies are used to validate the reference which defines this neutral rotation, i.e., the ankle epicondyle piriformis (AEP) plane. The findings of this study indicate that the posterior condylar axis is a reliable reference for defining the neutral rotation of the femur. In imageless navigation, when these landmarks are not accessible, the AEP plane provides a useful surrogate to the condylar axis, providing a reliable baseline for femoral anteversion measurement. PMID:22681336

  7. Anatomic Double Bundle single tunnel Foreign Material Free ACL-Reconstruction – a technical note

    PubMed Central

    Felmet, Gernot

    2011-01-01

    Summary The anterior cruciate ligament (ACL) consists of two bundles, the anteromedial (AM) and posterolateral bundle (PM). Double bundle reconstructions appear to give better rotational stability. The usual technique is to make two tunnels in the femur and two in the tibia. This is difficult and in small knees may not even be possible. We have developed a foreign material free press fit fixation for double bundle ACL reconstruction using a single femoral tunnel (R). This is based on the ALL PRESS FIT ACL reconstruction. It is suitable for the most common medium and, otherwise difficult, small sizes of knees. Method: Using diamond edged wet grinding hollow reamers, bone cylinders in different diameters are harvested from the implantation tunnels of the tibia and femur and used for the press fit fixation. Using the press fit technique the graft is first fixed in tibia. It is then similarly fixed under tension in the femoral side with the knee in 120 degree flexion. This is called Bottom To Top Fixation (BTT). On extending the knee the graft tension is self adapting. Depending on the size of the individual knee, the diameter of the femoral bone plug is varied from 8 to 13 mm to achieve an anatomic spread with a double bundle-like insertion. The tibia tunnel can be applied with two 7 or 8 mm diameter tunnels overlapping to a semi oval tunnel between 10 to 13 mm. Results: Since May 2003 we have carried out ACL-reconstructions with Hamstring grafts without foreign material using the ALL PRESS FIT technique. Initially, an 8 mm press fit fixation was used proximally with good results. Since April 2008, the range of diameters was increased up to 13 mm. The results of the Lachman tests have been good to excellent. Results of the Pivot shift test suggested more stability with femoral broader diameters of 9,5 to 13 mm. Conclusions: The foreign material free fixation of ham-string in the ALL PRESS FIT Bottom To Top Fixation is a successful method for ACL Reconstruction. The

  8. Effectiveness of Fulkerson Osteotomy with Femoral Nerve Stimulation for Patients with Severe Femoral Trochlear Dysplasia

    PubMed Central

    Crebs, D.T.; Anthony, C.A.; McCunniff, P.T.; Nieto, M.J.; Beckert, M.W.; Albright, J.P.

    2015-01-01

    Background Patients with femoral trochlear dysplasia are at risk for chronic recurrent patellofemoral dislocations, with extreme cases often requiring a surgical procedure. Anteromedialization of the tibial tubercle with intraoperative femoral nerve stimulation and concurrent medial patella-femoral ligament (MPFL) reconstruction is a previously reported method of maximizing patello-femoral congruency. We hypothesize the Fulkerson osteotomy with intraoperative femoral nerve stimulation and concurrent MPFL reconstruction in patients with severe trochlear dysplasia provides equivalent postoperative clinical outcomes to the same procedure in patients with low level trochlear dysplasia. Methods 48 knees underwent Fulkerson osteotomy with intraoperative femoral nerve stimulation and concurrent MPFL reconstruction for recurrent lateral patellar dislocations. MRI, surgeon intraoperative assessment, and X-ray were used to assess degrees of trochlear dysplasia; inter-observer and intra-observer error were measured. The knees positive for severe dysplasia on MRI, intraoperative assessment, and X-ray were considered as a comparison cohort to the rest of the study population. We considered postoperative dislocation events and patellar tracking kinematics as outcome measures. Independent student t tests and Fisher exact tests were used to evaluate differences between groups. Significance was set at P<0.05. Results 11 knees were positive for severe dysplasia (SD) by combined MRI, surgeon intraoperative assessment, and X-ray with the remaining 37 knees categorized as low dysplasia (LD). No patients in either group exhibited apprehension or required re-operation. Mean sulcus angle in the SD group was 175.8 +−2.45 degrees (95% CI 171.0–180.6); the LD group mean sulcus angle was 154.3 +− 0.98 degrees (95% CI 152.4–156.2) (P<.001). Postoperatively there was no significant difference in dislocation events between the SD group (0/11) and the LD group (2/37) (P>0.999). Patellar

  9. Slipped capital femoral epiphysis: what's new?

    PubMed

    Peck, Kathryn; Herrera-Soto, José

    2014-01-01

    Slipped capital femoral epiphysis (SCFE) is a common hip disorder among adolescents, whereby the epiphysis is displaced posteriorly and inferiorly to the metaphysis. Treatment modalities aim to stabilize the epiphysis, prevent further slippage, and avoid complications associated with long-term morbidity, such as osteonecrosis and chondrolysis. Controversy exists with SCFE regarding prophylactic fixation of the contralateral, painless, normal hip, the role of femoroacetabular impingement with SCFE, and whether in situ fixation is the best treatment method for SCFE. This article presents and discusses the latest diagnostic and treatment modalities for SCFE. PMID:24267209

  10. Correlation Between Asymmetric Resection of Posterior Femoral Condyles and Femoral Component Rotation in Total Knee Arthroplasty

    PubMed Central

    Güngör, Harun Reşit; Ök, Nusret; Ağladıoğlu, Kadir; Akkaya, Semih; Kıter, Esat

    2014-01-01

    Objectives: Pertaining to peculiar designs of current knee prostheses, more bone is removed from posteromedial femoral condyle than posterolateral condyle to obtain desired femoral component rotation. The aim of our study was to evaluate whether there is a correlation between the asymmetry of the cuts and the femoral component rotation in total knee arthroplasty. Methods: We built a model to simulate anterior chamfer cut (ACC) performed during total knee arthroplasty for measuring posterior condylar offset (PCO). Right knee axial MRI slices of a total 290 consecutive patients (142 male, 138 female, and mean age 31.39 ± 6.6) were examined. A parallel line to surgical transepiphyseal axis was drawn, and placed at the deepest part of trochlear groove. Posteromedial and posterolateral condylar offsets were measured by drawing perpendicular lines to ACC beginning from the intersection points of both anteromedial and anterolateral cortices to posterior joint line (PJL), respectively. Differences between posteromedial and posterolateral PCO were calculated, and femoral rotation angles (FRA) relative to PJL were measured. Results: The mean surgical FRA was 4.76 ± 1.16 degrees and the mean PCO differencesss- was 4.35 ± 1.04 mm for the whole group and there was no statistically significant difference between genders. There was a strong correlation between surgical FRA and PCO difference (p<0.0001, r=0.803). Linear regression analyses revealed that 0.8 mm of difference between the anteroposterior dimensions of medial and lateral PCO corresponds to 1 degree of surgical FRA (p<0.0001, R2=0.645). Conclusion: Correlation between the asymmetry of posterior chamfer cuts and achieved femoral component rotation can verify the accuracy of desired rotation, intraoperatively. However, further clinical investigations should be planned to test the results of our morphometric study.

  11. The effect of accelerated, brace free, rehabilitation on bone tunnel enlargement after ACL reconstruction using hamstring tendons: a CT study.

    PubMed

    Vadalà, Antonio; Iorio, Raffaele; De Carli, Angelo; Argento, Giuseppe; Di Sanzo, Vincenzo; Conteduca, Fabio; Ferretti, Andrea

    2007-04-01

    The mechanism of bone tunnel enlargement following anterior cruciate ligament (ACL) reconstruction is not yet clearly understood. Many authors hypothesized that aggressive rehabilitation protocols may be a potential factor for bone tunnel enlargement, especially in reconstructions performed with hamstrings autograft. The purpose of this study was to evaluate the effect of a brace free rehabilitation on the tunnel enlargement after ACL reconstruction using doubled semitendinosus and gracilis tendons (DGST): our hypothesis was that early post-operative knee motion increase the diameters of the tibial and femoral bone tunnels. Forty-five consecutive patients undergoing ACL reconstruction for chronic ACL deficiency were selected. All patients were operated by the same surgeon using autologous DGST and the same fixation devices. Patients with associated ligaments injuries and or severe chondral damage were excluded. The patients were randomly assigned to enter the control group (group A, standard post-operative rehabilitation) and the study group (group B, brace free accelerated rehabilitation). A CT scan was used to exactly determine the diameters of both femoral and tibial tunnels at various levels of lateral femoral condyle and proximal tibia, using a previously described method [17]. Measurements were done by an independent radiologist in a blinded fashion the day after the operation and at a mean follow-up of 10 months (range 9-11). Statistical analysis was performed using paired t-test. The mean femoral tunnel diameter increased significantly from 9.04 +/- 0.05 (post-operative) to 9.30 +/- 0.8 mm (follow-up) in group A and from 9.04 +/- 0.03 to 9.94 +/- 1.12 mm in group B. The mean tibial tunnel diameter increased significantly from 9.03 +/- 0.04 to 10.01 +/- 0.80 mm in group A and from 9.04 +/- 0.03 to 10.60 +/- 0.78 mm in group B. The increase in femoral and tunnel diameters observed in the study group was significantly higher than that observed in the control

  12. [The changes of bone architecture in atypical femoral fracture].

    PubMed

    Yamamoto, Noriaki; Shimakura, Taketoshi; Takahash, Hideaki

    2013-07-01

    The feature of atypical femoral fracture is stress induced cortical bone reaction. It was considered to be the accumulation of microdamage which come from increasing of mechanical stress by femoral lateral bowing, and the decreased of ability of microdamage repair system. PMID:23811584

  13. Simulator of Road Tunnel

    NASA Astrophysics Data System (ADS)

    Danišovič, Peter; Schlosser, František; Šrámek, Juraj; Rázga, Martin

    2015-05-01

    A Tunnel Traffic & Operation Simulator is a device of the Centre of Transport Research at the University of Žilina. The Simulator allows managing technological equipment of virtual two-tube highway tunnel, which is interconnected with simulation of vehicle traffic in tunnel. Changes of the traffic-operation states and other equipment are reflecting at the simulated traffic, as well as simulations of various emergency events in traffic initiate changes in tunnel detecting and measuring devices. It is thus possible to simulate emergency states, which can be affected by various faults of technology as well as by climatic conditions. The solutions can be found in irreplaceable experiences of Slovak road tunnel operators, changes of trafficoperation states, visualizations of operator technological display screens, technological devices labelling in order to increase operational safety of road tunnels.

  14. The cryogenic wind tunnel

    NASA Technical Reports Server (NTRS)

    Kilgore, R. A.

    1976-01-01

    Based on theoretical studies and experience with a low speed cryogenic tunnel and with a 1/3-meter transonic cryogenic tunnel, the cryogenic wind tunnel concept was shown to offer many advantages with respect to the attainment of full scale Reynolds number at reasonable levels of dynamic pressure in a ground based facility. The unique modes of operation available in a pressurized cryogenic tunnel make possible for the first time the separation of Mach number, Reynolds number, and aeroelastic effects. By reducing the drive-power requirements to a level where a conventional fan drive system may be used, the cryogenic concept makes possible a tunnel with high productivity and run times sufficiently long to allow for all types of tests at reduced capital costs and, for equal amounts of testing, reduced total energy consumption in comparison with other tunnel concepts.

  15. Current concepts in total femoral replacement

    PubMed Central

    Ramanathan, Deepak; Siqueira, Marcelo BP; Klika, Alison K; Higuera, Carlos A; Barsoum, Wael K; Joyce, Michael J

    2015-01-01

    Total femoral replacement (TFR) is a salvage arthroplasty procedure used as an alternative to lower limb amputation. Since its initial description in the mid-20th century, this procedure has been used in a variety of oncologic and non-oncologic indications. The most compelling advantage of TFR is the achievement of immediate fixation which permits early mobilization. It is anticipated that TFR will be increasingly performed as the rate of revision arthroplasty rises worldwide. The existing literature is mainly composed of a rather heterogeneous mix of retrospective case series and a wide assortment of case reports. Numerous TFR prostheses are currently available and the surgeon must understand the unique implications of each implant design. Long-term functional outcomes are dependent on adherence to proper technique and an appropriate physical therapy program for postoperative rehabilitation. Revision TFR is mainly performed for periprosthetic infection and the severe femoral bone loss associated with aseptic revisions. Depending on the likelihood of attaining infection clearance, it may sometimes be advisable to proceed directly to hip disarticulation without attempting salvage of the TFR. Other reported complications of TFR include hip joint instability, limb length discrepancy, device failure, component loosening, patellar maltracking and delayed wound healing. Further research is needed to better characterize the long-term functional outcomes and complications associated with this complex procedure. PMID:26716087

  16. Continuous blood gas monitoring in femoral arteries

    NASA Astrophysics Data System (ADS)

    Schlain, Les A.; Spar, Steven M.; Dellinger, Bart

    1995-05-01

    Continuous intra-arterial blood gas monitoring is a potentially valuable tool in the surgical and intensive care arenas. Patient oxygenation and acid base status can change rapidly and without warning. The ability to monitor pHa, PaCO2 and PaO2 in arterial blood will be a major medical advance for the anesthesiologist and intensivist. Intra-arterial blood gas sensors are typically placed in radial arteries. In certain patient populations accurate monitoring is not possible in radial arteries due to arterial environmental factors such as hypotension, vasoconstriction and atherosclerotic disease. These same factors can make radial cannulation difficult resulting in traumatic catheter insertion, thereby further compromising flow conditions. In situations where radial artery flow is expected to be compromised, selecting a large vessel for sensor placement is desirable. We report an initial feasibility study of our blood gas monitoring system using the femoral artery as the sensing site. Clinical results are presented as well as potential advantages and disadvantages associated with monitoring in the femoral artery.

  17. Complete guidewire retention after femoral vein catheterization.

    PubMed

    Cat, Bahar Gulcay; Guler, Sertac; Soyuduru, Murat; Guven, Ibrahim; Ramadan, Hayri

    2015-01-01

    Central venous catheters (CVCs) are often used for various purposes in the emergency departments (ED). The main uses of CVCs in the EDs are emergent hemodialysis, in situations where peripheral vein catheterization cannot be achieved, and continuous invasive hemodynamic monitoring. The complications related to CVC insertion are usually mechanical and observed in the near term after the procedure. Retained CVC guidewire after catheterization is a rare complication in the published reports and usually related with intra- or postoperative settings and jugular or subclavian vein. The present study reported a young female patient who underwent left femoral vein catheterization 6 months earlier in an intensive care unit of another hospital and was diagnosed with complete guidewire retention in the ED. To the best of the authors' knowledge, this is the first case in published reports with a diagnosis of retained CVC guidewire with retrograde migration into the femoral vein. Surprisingly, the patient developed no thrombotic or embolic complication during this 6-month period. PMID:26657235

  18. Inelastic tunnel diodes

    NASA Technical Reports Server (NTRS)

    Anderson, L. M. (Inventor)

    1984-01-01

    Power is extracted from plasmons, photons, or other guided electromagnetic waves at infrared to midultraviolet frequencies by inelastic tunneling in metal-insulator-semiconductor-metal diodes. Inelastic tunneling produces power by absorbing plasmons to pump electrons to higher potential. Specifically, an electron from a semiconductor layer absorbs a plasmon and simultaneously tunnels across an insulator into metal layer which is at higher potential. The diode voltage determines the fraction of energy extracted from the plasmons; any excess is lost to heat.

  19. Charge Islands Through Tunneling

    NASA Technical Reports Server (NTRS)

    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.

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

    PubMed Central

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

    2015-01-01

    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. PMID:25793165

  1. The Design of Wind Tunnels and Wind Tunnel Propellers

    NASA Technical Reports Server (NTRS)

    Warner, Edward P; Norton, F H; Hebbert, C M

    1919-01-01

    Report discusses the theory of energy losses in wind tunnels, the application of the Drzewiecki theory of propeller design to wind tunnel propellers, and the efficiency and steadiness of flow in model tunnels of various types.

  2. Occult fracture of the femoral neck associated with extensive osteonecrosis of the femoral head: A case report

    PubMed Central

    Fukui, Kiyokazu; Kaneuji, Ayumi; Matsumoto, Tadami

    2015-01-01

    Introduction Although the subchondral portion of the femoral head is a common site for collapse in osteonecrosis of the femoral head (ONFH), femoral-neck fracture rarely occurs during the course of ONFH. We report a case of occult insufficiency fracture of the femoral neck without conditions predisposing to insufficiency fractures, occurring in association with ONFH. Presentation of case We report a case of occult fracture of the femoral neck due to extensive ONFH in a 60-year-old man. No abnormal findings suggestive of ONFH were identified on radiographs, and the fracture occurred spontaneously without any trauma or unusual increase in activity. The patient’s medical history, age, and good bone quality suggested ONFH as a possible underlying cause. Contrast-enhanced magnetic resonance imaging was useful in determining whether the fracture was caused by ONFH or was instead a simple insufficiency fracture caused by steroid use. Discussion The patient was treated with bipolar hemiarthroplasty, but if we had not suspected ONFH as a predisposing condition, the undisplaced fracture might have been treated by osteosynthesis, and this would have led to nonunion or collapse of the femoral head. To avoid providing improper treatment, clinicians should consider ONFH as a predisposing factor in pathologic fractures of the femoral neck. Conclusion ONFH should be included in the differential diagnosis of insufficiency fracture of the femoral neck. PMID:26275737

  3. Atom Tunneling in Chemistry.

    PubMed

    Meisner, Jan; Kästner, Johannes

    2016-04-25

    Quantum mechanical tunneling of atoms is increasingly found to play an important role in many chemical transformations. Experimentally, atom tunneling can be indirectly detected by temperature-independent rate constants at low temperature or by enhanced kinetic isotope effects. In contrast, the influence of tunneling on the reaction rates can be monitored directly through computational investigations. The tunnel effect, for example, changes reaction paths and branching ratios, enables chemical reactions in an astrochemical environment that would be impossible by thermal transition, and influences biochemical processes. PMID:26990917

  4. Development of Background-Oriented Schlieren for NASA Langley Research Center Ground Test Facilities

    NASA Technical Reports Server (NTRS)

    Bathel, Brett F.; Borg, Stephen; Jones, Stephen; Overmeyer, Austin; Walker, Eric; Goad, William; Clem, Michelle; Schairer, Edward T.; Mizukaki, Toshiharu

    2015-01-01

    This paper provides an overview of recent wind tunnel tests performed at the NASA Langley Research Center where the Background-Oriented Schlieren (BOS) technique was used to provide information pertaining to flow-field density disturbances. The facilities in which the BOS technique was applied included the National Transonic Facility (NTF), Transonic Dynamics Tunnel (TDT), 31-Inch Mach 10 Air Tunnel, 15-Inch Mach 6 High-Temperature Air Tunnel, Rotor Test Cell at the 14 by 22 Subsonic Tunnel, and a 13-Inch Low-Speed Tunnel.

  5. Tunneling Magnetothermopower in Magnetic Tunnel Junction Nanopillars

    NASA Astrophysics Data System (ADS)

    Liebing, N.; Serrano-Guisan, S.; Rott, K.; Reiss, G.; Langer, J.; Ocker, B.; Schumacher, H. W.

    2011-10-01

    We study tunneling magnetothermopower (TMTP) in CoFeB/MgO/CoFeB magnetic tunnel junction nanopillars. Thermal gradients across the junctions are generated by an electric heater line. Thermopower voltages up to a few tens of μV between the top and bottom contact of the nanopillars are measured which scale linearly with the applied heating power and hence the thermal gradient. The thermopower signal varies by up to 10μV upon reversal of the relative magnetic configuration of the two CoFeB layers from parallel to antiparallel. This signal change corresponds to a large spin-dependent Seebeck coefficient of the order of 100μV/K and a large TMTP change of the tunnel junction of up to 90%.

  6. Tunneling magnetothermopower in magnetic tunnel junction nanopillars.

    PubMed

    Liebing, N; Serrano-Guisan, S; Rott, K; Reiss, G; Langer, J; Ocker, B; Schumacher, H W

    2011-10-21

    We study tunneling magnetothermopower (TMTP) in CoFeB/MgO/CoFeB magnetic tunnel junction nanopillars. Thermal gradients across the junctions are generated by an electric heater line. Thermopower voltages up to a few tens of μV between the top and bottom contact of the nanopillars are measured which scale linearly with the applied heating power and hence the thermal gradient. The thermopower signal varies by up to 10  μV upon reversal of the relative magnetic configuration of the two CoFeB layers from parallel to antiparallel. This signal change corresponds to a large spin-dependent Seebeck coefficient of the order of 100  μV/K and a large TMTP change of the tunnel junction of up to 90%. PMID:22107572

  7. Morphological Study of the Newly Designed Cementless Femoral Stem

    PubMed Central

    Baharuddin, Mohd Yusof; Salleh, Sh-Hussain; Zulkifly, Ahmad Hafiz; Lee, Muhammad Hisyam; Mohd Noor, Alias

    2014-01-01

    A morphology study was essential to the development of the cementless femoral stem because accurate dimensions for both the periosteal and endosteal canal ensure primary fixation stability for the stem, bone interface, and prevent stress shielding at the calcar region. This paper focused on a three-dimensional femoral model for Asian patients that applied preoperative planning and femoral stem design. We measured various femoral parameters such as the femoral head offset, collodiaphyseal angle, bowing angle, anteversion, and medullary canal diameters from the osteotomy level to 150 mm below the osteotomy level to determine the position of the isthmus. Other indices and ratios for the endosteal canal, metaphyseal, and flares were computed and examined. The results showed that Asian femurs are smaller than Western femurs, except in the metaphyseal region. The canal flare index (CFI) was poorly correlated (r < 0.50) to the metaphyseal canal flare index (MCFI), but correlated well (r = 0.66) with the corticomedullary index (CMI). The diversity of the femoral size, particularly in the metaphyseal region, allows for proper femoral stem design for Asian patients, improves osseointegration, and prolongs the life of the implant. PMID:25025068

  8. Orienteering injuries

    PubMed Central

    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. Imagesp236-ap237-ap237-bp238-ap239-ap240-a PMID:7159815

  9. Whose Orientations?

    ERIC Educational Resources Information Center

    Gutoff, Joshua

    2010-01-01

    This article presents the author's response to Jon A. Levisohn's article entitled "A Menu of Orientations in the Teaching of Rabbinic Literature." While the "menu" Levisohn describes in his groundbreaking work on orientations to the teaching of rabbinic texts will almost certainly be refined over time, even as it stands this article should be of…

  10. Shotcrete in tunnel design

    SciTech Connect

    Golser, J.; Galler, R.; Schubert, P.; Rabensteiner, K.

    1995-12-31

    Shotcrete is an important structural element for tunnel support. Green shotcrete is exposed to compression strain rates and tunnel design requires a realistic material law for shotcrete. A modified rate of flow method simulates shotcrete behavior very well and can be incorporated in Finite Element calculations.

  11. Electron-Tunneling Magnetometer

    NASA Technical Reports Server (NTRS)

    Kaiser, William J.; Kenny, Thomas W.; Waltman, Steven B.

    1993-01-01

    Electron-tunneling magnetometer is conceptual solid-state device operating at room temperature, yet offers sensitivity comparable to state-of-art magnetometers such as flux gates, search coils, and optically pumped magnetometers, with greatly reduced volume, power consumption, electronics requirements, and manufacturing cost. Micromachined from silicon wafer, and uses tunneling displacement transducer to detect magnetic forces on cantilever-supported current loop.

  12. Micromachined Tunneling Accelerometer

    NASA Technical Reports Server (NTRS)

    Kenny, Thomas W.; Waltman, Stephen B.; Kaiser, William J.; Reynolds, Joseph K.

    1993-01-01

    Separation of tunneling electrodes adjusted by varying electrostatic force. Major components of tunneling transducer formed on two silicon chips by microfabrication techniques. Use of electrostatic deflection reduces sensitivity of transducer to thermal drift and simplifies design. Sensitivity suitable for applications in which larger acceleration-sensing instruments required.

  13. Comparison of the Sliding and Femoral Head Rotation among Three Different Femoral Head Fixation Devices for Trochanteric Fractures

    PubMed Central

    Chinzei, Nobuaki; Niikura, Takahiro; Tsuji, Mitsuo; Kuroda, Ryosuke; Doita, Minoru; Kurosaka, Masahiro

    2015-01-01

    Background Recently, various femoral head fixation devices (HFDs) for trochanteric fractures have become available. However, there are some cases in which femoral head rotation with excessive sliding of the HFD is observed and it is often followed by cutout. The purpose of this study is to compare the ability of the three types of HFDs to prevent femoral head rotation. Methods Between July 2005 and December 2009, 206 patients aged over 60 years with trochanteric fractures who had undergone surgical treatment using a short femoral nail in our institution were enrolled into the study. We used the gamma 3 nail (GMN) as the screw-type HFD in 66 cases, the gliding nail (GLN) as a non-cylindrical blade in 76 cases, and the proximal femoral nail antirotation (PFNA) as a cylindrical blade in 64 cases. The sliding length of HFDs and the occurrence of femoral head rotation were evaluated by assessing radiographs as the main outcome, and the results were compared among these devices. Results A comparison of the degree of sliding in the GMN group showed that femoral head rotation was observed significantly more frequently in cases with rotation. Further, it appeared that femoral head rotation occurred more frequently in comminuted fractures. However, no significant differences between the sliding lengths of the different HFDs were observed among three groups. Femoral head rotation was observed in 15 cases of GMN (22.7%), 0 case of GLN, and 5 case of PFNA (7.8%). Significant differences with regard to the occurrence of femoral head rotation were observed among the three groups. Furthermore, significant differences were also observed between GLN and PFNA with respect to the occurrence of femoral head rotation. Conclusions The ability to stabilize femoral head appears to be greater with blade-type materials than with screw-type materials. Furthermore, we believe that a non-cylindrical blade is preferable to a cylindrical blade for the surgical treatment of comminuted, unstable

  14. Three-dimensional characterization of the anterior cruciate ligament's femoral footprint.

    PubMed

    Westermann, Robert; Sybrowsky, Christian; Ramme, Austin; Amedola, Annuziati; Wolf, Brian R

    2014-02-01

    There is increasing use of three-dimensional (3D) computed tomography (CT) for researching anterior cruciate ligament (ACL) reconstructions and tunnel placement. However, there is limited 3D CT data on the ACL footprint. The purpose of this study is to define the native ACL femoral footprint using 3D surface reconstructions of computed tomography (CT) imaging of cadaveric knees. The femoral insertion of the ACL was meticulously dissected and marked with drill holes in seven cadaveric knees. CT scans were performed on each specimen, and 3D computer models were created. Distance from the condyle edges to the margins of the footprint were referenced to the total condylar size. This was performed both parallel and perpendicular to the femoral axis as well as the intercondylar notch. The mean condylar depth (c/C) ratios along the axis of the femur were 0.45 ± 0.06 for the anterior border, 0.44 ± 0.08 for the posterior border, 0.26 ± 0.07 for the proximal border, and 0.63 ± 0.08 for the distal border. The mean notch (n/N) ratios for the four margins were 0.37 ± 0.04 for the anterior border, 0.67 ± 0.08 for the posterior border, 0.49 ± 0.07 for the proximal margin, and 0.50 ± 0.06 for the distal border. The mean c/C ratios parallel the intercondylar notch measured 0.23 ± 0.03 for the anterior border, 0.27 ± 0.04 for the posterior border, 0.37 ± 0.04 for the proximal border, and 0.12 ± 0.02 for the distal border. The mean n/N ratios perpendicular to the intercondylar notch measured 0.11 ± 0.06 for the anterior border, 0.52 ± 0.09 the posterior border, 0.29 ± 0.06 for the proximal border, and 0.30 ± 0.06 for the distal border. This study provides reference measures of the femoral footprint of the ACL using 3D CT. It will assist future studies that use advanced imaging to evaluate accuracy of ACL reconstruction. PMID:23765876

  15. The impact of proximal femoral morphology on failure strength with a mid-head resection short-stem hip arthroplasty.

    PubMed

    Olsen, Michael; Al Saied, Mohamed; Morison, Zachary; Sellan, Michael; Waddell, James P; Schemitsch, Emil H

    2014-12-01

    Mid-head resection short-stem hip arthroplasty is a conservative alternative to conventional total hip replacement and addresses proximal fixation challenges in patients not suitable for hip resurfacing. It is unclear whether proximal femoral morphology impacts the ultimate failure load of mid-head resection implanted femurs, thus the aim of this study was to investigate the effect of native neck-shaft angle (NSA) and coronal implant alignment on proximal femoral strength. In total, 36 synthetic femurs with two different proximal femoral morphologies were utilized in this study. Of them, 18 femurs with a varus NSA of 120° and 18 femurs with a valgus NSA of 135° were each implanted with a mid-head resection prosthesis. Femurs within the two different femoral morphology groups were divided into three equal coronal implant alignment groups: 10° valgus, 10° varus or neutral alignment. Prepared femurs were tested for stiffness and to failure in axial compression. There was no significant difference in stiffness nor failure load between femurs implanted with valgus-, varus- or neutrally aligned implants in femurs with a NSA of 120° (p = 0.396, p = 0.111, respectively). Femurs implanted in valgus orientation were significantly stiffer and failed at significantly higher loads than those implanted in varus alignment in femurs with a NSA of 135° (p = 0.001, p = 0.007, respectively). A mid-head resection short-stem hip arthroplasty seems less sensitive to clinically relevant variations of coronal implant alignment and may be more forgiving upon implantation in some femoral morphologies, however, a relative valgus component alignment is recommended. PMID:25515228

  16. Painful Spastic Hip Dislocation: Proximal Femoral Resection

    PubMed Central

    Albiñana, Javier; Gonzalez-Moran, Gaspar

    2002-01-01

    The dislocated hip in a non-ambulatory child with spastic paresis tends to be a painful interference to sleep, sitting upright, and perineal care. Proximal femoral resection-interposition arthroplasty is one method of treatment for this condition. We reviewed eight hips, two bilateral cases, with a mean follow-up of 30 months. Clinical improvement was observed in all except one case, with respect to pain relief and sitting tolerance. Some proximal migration was observed in three cases, despite routine post-operative skeletal traction in all cases and careful soft tissue interposition. One case showed significant heterotopic ossification which restricted prolonged sitting. This patient needed some occasional medication for pain. PMID:12180614

  17. Coherent revival of tunneling

    NASA Astrophysics Data System (ADS)

    Hsu, Liang-Yan; Rabitz, Herschel

    2015-07-01

    We introduce a tunneling effect by a driving field, referred to as coherent revival of tunneling (CRT), corresponding to complete tunneling (transmission coefficient =1 ) that is revived from the circumstance of total reflection (transmission coefficient ≈0 ) through application of an appropriate perpendicular high-frequency ac field. To illustrate CRT, we simulate electron transport through fish-bone-like quantum-dot arrays by using single-particle Green's functions along with Floquet theory, and we explore the corresponding current-field amplitude characteristics as well as current-polarization characteristics. In regard to the two characteristics, we show that CRT exhibits entirely different features than coherent destruction of tunneling and photon-assisted tunneling. We also discuss two practical conditions for experimental realization of CRT.

  18. Femoral lengthening with a motorized intramedullary nail

    PubMed Central

    Horn, Joachim; Grimsrud, Øyvind; Dagsgard, Anita Hoddevik; Huhnstock, Stefan; Steen, Harald

    2015-01-01

    Purpose We assessed whether an intramedullary lengthening device would reduce the problems normally associated with the external fixation technique. We also wanted to determine whether it is a reliable construct for limb lengthening and deformity correction in the femur. Patients and methods We conducted a matched-pair comparison of 30 femoral lengthenings, 15 with a motorized intramedullary nail (the nail group) and 15 lengthenings with an external ring fixator (the fixator group). The patients were matched based on age, sex, amount of lengthening, and the etiology of leg length discrepancy. Mean lengthening was 35 (25–55) mm in the nail group and 38 (15–75) mm in the fixator group. Outcome measures were: lengthening and alignment achieved, consolidation index, knee range of motion (ROM), and complications. Results The pairs in this matched-pair study were similar in terms of age, sex, diagnosis, and amount of lengthening. The planned amount of lengthening was achieved in all patients in both groups and axis correction was considered sufficient. The mean radiographic consolidation index in the nail group, at 1.5 (0.9–3.0) months/cm, was better than the mean value for the fixator group (1.9 (0.9–3.4) months/cm) (p = 0.01). Knee ROM was better in the nail group during the lengthening, 6 weeks after lengthening was completed, and 6 months after lengthening was completed (p < 0.001). A larger number of complications were observed in the fixator group than in the nail group. Interpretation A lengthening nail may be superior to external fixation in femoral lengthening, when the anatomical conditions and the complexity of the deformity allow the use of an intramedullary nail. PMID:25191936

  19. Risk of Anterior Femoral Notching in Navigated Total Knee Arthroplasty

    PubMed Central

    Lee, Ju Hong

    2015-01-01

    Background We retrospectively investigated the prevalence of femoral anterior notching and risk factors after total knee arthroplasty (TKA) using an image-free navigation system. Methods We retrospectively reviewed 148 consecutive TKAs in 130 patients beginning in July 2005. Seventy knees (62 patients) underwent conventional TKA, and 78 knees (68 patients) received navigated TKA. We investigated the prevalence of femoral anterior notching and measured notching depth by conventional and navigated TKA. Additionally, the navigated TKA group was categorized into two subgroups according to whether anterior femoral notching had occurred. The degree of preoperative varus deformity, femoral bowing, and mediolateral suitability of the size of the femoral component were determined by reviewing preoperative and postoperative radiographs. The resection angle on the sagittal plane and the angle of external rotation that was set by the navigation system were checked when resecting the distal femur. Clinical outcomes were compared using range of motion (ROM) and the Hospital for Special Surgery (HSS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAX) scores between the two groups. Results The prevalence of anterior femoral notching by conventional TKA was 5.7%, and that for navigated TKA was 16.7% (p = 0.037). Mean notching depth by conventional TKA was 2.92 ± 1.18 mm (range, 1.8 to 4.5 mm) and 3.32 ± 1.54 mm (range, 1.55 to 6.93 mm) by navigated TKA. Preoperative anterior femoral bowing was observed in 61.5% (p = 0.047) and both anterior and lateral femoral bowing in five cases in notching group during navigated TKA (p = 0.021). Oversized femoral components were inserted in 53.8% of cases (p = 0.035). No differences in clinical outcomes for ROM or the HSS and WOMAX scores were observed between the groups. A periprosthetic fracture, which was considered a notching-related side effect, occurred in one case each in the conventional and navigated TKA groups

  20. Significantly lower femoral neck growth in screw fixation of the asymptomatic contralateral hip in unilateral slipped capital femoral epiphysis.

    PubMed

    Wölfle-Roos, Julia V; Urlaub, Stefanie; Reichel, Heiko; Taurman, Rita

    2016-05-01

    There is an ongoing debate on which fixation technique should be preferred for the prophylactic fixation of the asymptomatic contralateral hip in slipped capital femoral epiphysis (SCFE). In the case of Kirschner-wire (K-wire) fixation, there is a possibility of secondary loss of fixation because of longitudinal growth of the physis, whereas in screw fixation, physeal growth of the femoral neck might be impaired. The aim of this matched-pair study was to compare the longitudinal growth of the femoral neck in screw fixation versus K-wire fixation of the asymptomatic contralateral hip in SCFE. All 18 patients (female : male=3 : 15), who had undergone screw fixation of the asymptomatic contralateral hip between 9/2001 and 9/2011, were matched according to age, bone age, sex, and time to follow-up to another 18 patients with K-wire fixation. The length of the femoral neck of the contralateral hip was measured in parallel to either screw or K-wire from the apex of the femoral head to the opposite cortical bone. The ratio of the femoral neck length measured directly after surgery and on follow-up was defined as femoral neck growth. There was no significant difference between groups with respect to age, modified Oxford Bone age score, and time to follow-up. We found a significant difference in femoral neck growth between patients with screw fixation (5.5±4.3%) compared with K-wire fixation (8.9±5.7%, P=0.048 matched Wilcoxon test). The difference in femoral neck growth of patients with K-wire or screw fixation of the contralateral asymptomatic hip in SCFE was small, but statistically significant. Thus, despite high rates of secondary loss of fixation, K-wire fixation should still be considered, especially in very young patients. PMID:26919622

  1. Ultrafast scanning tunneling microscopy

    SciTech Connect

    Botkin, D.A. |

    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.

  2. The aeolian wind tunnel

    NASA Technical Reports Server (NTRS)

    Iversen, J. D.

    1991-01-01

    The aeolian wind tunnel is a special case of a larger subset of the wind tunnel family which is designed to simulate the atmospheric surface layer winds to small scale (a member of this larger subset is usually called an atmospheric boundary layer wind tunnel or environmental wind tunnel). The atmospheric boundary layer wind tunnel is designed to simulate, as closely as possible, the mean velocity and turbulence that occur naturally in the atmospheric boundary layer (defined as the lowest portion of the atmosphere, of the order of 500 m, in which the winds are most greatly affected by surface roughness and topography). The aeolian wind tunnel is used for two purposes: to simulate the physics of the saltation process and to model at small scale the erosional and depositional processes associated with topographic surface features. For purposes of studying aeolian effects on the surface of Mars and Venus as well as on Earth, the aeolian wind tunnel continues to prove to be a useful tool for estimating wind speeds necessary to move small particles on the three planets as well as to determine the effects of topography on the evolution of aeolian features such as wind streaks and dune patterns.

  3. [How to determine the rotation of the femoral component].

    PubMed

    Matziolis, G; Roehner, E

    2015-04-01

    The different landmarks for determination of the rotation of the femoral component are shown and specific pros and cons are discussed. The videos demonstrate how to identify them intraoperatively. PMID:25874402

  4. Analyzing Orientations

    NASA Astrophysics Data System (ADS)

    Ruggles, Clive L. N.

    Archaeoastronomical field survey typically involves the measurement of structural orientations (i.e., orientations along and between built structures) in relation to the visible landscape and particularly the surrounding horizon. This chapter focuses on the process of analyzing the astronomical potential of oriented structures, whether in the field or as a desktop appraisal, with the aim of establishing the archaeoastronomical "facts". It does not address questions of data selection (see instead Chap. 25, "Best Practice for Evaluating the Astronomical Significance of Archaeological Sites", 10.1007/978-1-4614-6141-8_25) or interpretation (see Chap. 24, "Nature and Analysis of Material Evidence Relevant to Archaeoastronomy", 10.1007/978-1-4614-6141-8_22). The main necessity is to determine the azimuth, horizon altitude, and declination in the direction "indicated" by any structural orientation. Normally, there are a range of possibilities, reflecting the various errors and uncertainties in estimating the intended (or, at least, the constructed) orientation, and in more formal approaches an attempt is made to assign a probability distribution extending over a spread of declinations. These probability distributions can then be cumulated in order to visualize and analyze the combined data from several orientations, so as to identify any consistent astronomical associations that can then be correlated with the declinations of particular astronomical objects or phenomena at any era in the past. The whole process raises various procedural and methodological issues and does not proceed in isolation from the consideration of corroborative data, which is essential in order to develop viable cultural interpretations.

  5. Circumflex femoral vein thrombosis misinterpreted as acute hamstring strain.

    PubMed

    Papastergiou, Stergios G; Koukoulias, Nikolaos E; Tsitouridis, Ioannis; Natsis, Constantinos; Parisis, Constantinos A

    2007-07-01

    The case of a 24-year-old female professional, long-distance runner who presented with acute proximal posterior thigh pain is reported. History and clinical findings were consistent with acute hamstring strain but MRI demonstrated circumflex femoral vein thrombosis. This is the first case of proximal posterior thigh pain caused by circumflex femoral vein thrombosis reported in the literature. Doctors dealing with sports injuries should be aware of this clinical entity that mimics hamstring strain. PMID:17224439

  6. Circumflex femoral vein thrombosis misinterpreted as acute hamstring strain

    PubMed Central

    Papastergiou, Stergios G; Koukoulias, Nikolaos E; Tsitouridis, Ioannis; Natsis, Constantinos; Parisis, Constantinos A

    2007-01-01

    The case of a 24‐year‐old female professional, long‐distance runner who presented with acute proximal posterior thigh pain is reported. History and clinical findings were consistent with acute hamstring strain but MRI demonstrated circumflex femoral vein thrombosis. This is the first case of proximal posterior thigh pain caused by circumflex femoral vein thrombosis reported in the literature. Doctors dealing with sports injuries should be aware of this clinical entity that mimics hamstring strain. PMID:17224439

  7. Proximal femoral reconstruction with a constrained acetabulum in oncologic patients.

    PubMed

    Jawad, Muhammad Umar; Brien, Earl W

    2014-02-01

    Metallic endoprostheses are used for oncological reconstruction around the proximal femur and hip joint. Common modes of failure with hemiarthroplasty or standard hip arthroplasty after proximal femoral replacement include dislocation, late hip pain, and infection. The authors reviewed hospital records to identify patients undergoing constrained tripolar hip arthroplasty for oncological reasons between 2002 and 2012. Inclusion criterion was at least 12-cm proximal femoral resection, including patients with total femur reconstruction. A total of 33 patients were reviewed. Information regarding demographics, length of follow-up, treatment characteristics, and patient outcomes was extracted. Average follow-up for all patients was 912.33 days (30.4 months). Average follow-up was 1396.1 days for living patients and 428.6 days for deceased patients. Average estimated blood loss was 462.12 cc: an average of 1080 cc for patients undergoing total femoral resection and replacement and 315.8 cc for patients undergoing proximal femoral resection and replacement. Average operative time was 137.7 minutes: an average of 205 minutes for patients undergoing total femoral resection and replacement and 119.1 minutes for patients undergoing proximal femoral resection and replacement. Average Musculoskeletal Tumor Society score was 21.7. There were no dislocations in the cohort. A constrained tripolar device can be safely used for oncological proximal femoral reconstructions while minimizing the risk of dislocation. Positioning of the acetabular implant in neutral anatomic version in conjunction with a neutral-placed femoral component provides the greatest range of motion, reduction of liner impingement, and improved hip stability. PMID:24679207

  8. CIRCUMFERENTIAL PROXIMAL FEMORAL ALLOGRAFTS IN TOTAL HIP ARTHROPLASTY REVISION SURGERY

    PubMed Central

    Roos, Bruno Dutra; Roos, Milton Valdomiro; Júnior, Antero Camisa; Lampert, Henrique Bonotto; da Silva, Matheus Luis

    2015-01-01

    Objective: To evaluate the clinical and radiographic results from patients who underwent femoral reconstruction secondary to loosening of total hip arthroplasty, using circumferential proximal femoral allografts and cemented implants. Methods: A retrospective study was conducted on 32 patients (33 hips) who underwent femoral reconstruction secondary to loosening of total hip arthroplasty, using circumferential proximal femoral allografts and cemented implants. Among these patients, 28 (29 hips) fulfilled all the requirements for this study. The mean follow-up was five years and two months. The clinical evaluation was done in accordance with the Harris Hip Score. Radiographically, the patients were assessed regarding reabsorption and consolidation of the allograft, migration of the greater trochanter, stability of the femoral component and heterotypic calcification. Results: The average preoperative Harris Hip Score was 32 points. At the last postoperative follow-up, the average score was 82 points. Allograft resorption of some degree was seen in nine hips (31%). Regarding consolidation, 24 cases (82.8%) showed full consolidation, three (10.3%) showed partial consolidation and two (6.9%) showed pseudarthrosis. All femoral components were stable. According to the criteria established, 27 cases (93.1%) were considered to be successful reconstructions after a mean follow-up of five years and two months. Conclusion: From the results obtained, it was concluded that use of circumferential proximal femoral allografts in selected cases of femoral reconstruction secondary to loosening of arthroplasty presented a high survival rate from the reconstruction over an average follow-up of five years and two months. PMID:27047896

  9. RADIOLOGICAL ANALYSIS OF BONE TUNNEL POSITION IN ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION SURGERY: COMPARISON BETWEEN THE OPEN TECHNIQUE AND ARTHROSCOPY VIA AN ANTEROMEDIAL PORTAL

    PubMed Central

    Dambrós, Jean Marcel; Florêncio, Rodrigo; Júnior, Osmar Valadão Lopes; Kuhn, André; Saggin, José; de Freitas Spinelli, Leandro

    2015-01-01

    Objectives: To evaluate and compare bone tunnel positioning in anterior cruciate ligament (ACL) reconstruction surgery using the arthroscopic technique and the open technique consisting of arthrotomy. Method: A comparative retrospective study on 70 patients with ACL lesions was conducted. Thirty-five patients underwent ACL reconstruction by means of the open technique and 35 by means of the arthroscopic technique using an anteromedial portal. All the patients underwent ACL reconstruction using an autologous graft from the middle third of the patellar tendon, fixed using interference screws. The postoperative radiographs were reviewed and the positioning of the femoral tunnel was evaluated using the methods proposed by Harner et al. and Aglietti et al., while the tibial tunnel was assessed using the method proposed by Rauschning and Stäubli. Results: Fifty-four of the patients were male and 16 were female. Their mean age at the time of the procedure was 34 years and 3 months, with a range from 17 to 58 years. The arthroscopic technique was shown to be more accurate than the open technique for positioning both the femoral and the tibial bone tunnels. Conclusions: Radiological analysis on the knees subjected to ACL reconstruction showed that the positioning of both the femoral and the tibial bone tunnels presented less variation when the surgery was performed arthroscopically. PMID:27027019

  10. Femoral Component Survival in Hybrid Total Knee Arthroplasty.

    PubMed

    Perry, Clayton R; Perry, Kevin I

    2016-05-01

    Although the majority of North American surgeons perform total knee arthroplasty by cementing both the femoral and the tibial components, hybrid fixation with a press-fit femur and cemented tibia is an alternative form of total knee arthroplasty performed by some. Currently, there is a paucity of literature evaluating long-term outcomes after hybrid total knee arthroplasty. As such, the purpose of the current study was to describe the long-term results of total knee arthroplasty performed using the hybrid technique. The authors retrospectively reviewed a total of 77 hybrid total knee arthroplasties with at least 12 years of follow-up. Clinical and radiographic evaluations were performed to determine patient function and the incidence of femoral component failure after hybrid total knee arthroplasty. At the time of last follow-up, 76 of 77 (99%) of the femoral components remained in place without evidence of loosening. One femoral component failed due to aseptic loosening and was ultimately revised to a cemented femoral component without further complication. In addition, 1 tibial component and 2 patellar components failed due to aseptic loosening. Four tibial polyethylene liners were revised for polyethylene wear. In conclusion, press-fit fixation of the femoral component is a reliable and durable alternative to cemented fixation. [Orthopedics. 2016; 39(3):181-186.]. PMID:27135453

  11. Carpal Tunnel Syndrome

    MedlinePlus

    ... through NIH's National Center for Complementary and Alternative Medicine are investigating the effects of acupuncture on pain, loss of median nerve function, and changes in the brain associated with carpal tunnel syndrome. In addition, a ...

  12. Carpal Tunnel Surgery

    MedlinePlus Videos and Cool Tools

    ... is the incriminating structure in carpal tunnel syndrome. As it increases in size, the pressures within the ... you can visualize the movement of the tendons as I move the fingers, the tendons are gliding ...

  13. Carpal tunnel biopsy

    MedlinePlus

    ... syndrome, ulnar tunnel syndrome, and stenosing tenosynovitis. In: Canale ST, Beaty JH, eds. Campbell's Operative ... Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, ...

  14. Carpal Tunnel Syndrome

    MedlinePlus

    ... at the base of your hand. It contains nerve and tendons. Sometimes, thickening from irritated tendons or other swelling narrows the tunnel and causes the nerve to be compressed. Symptoms usually start gradually. As ...

  15. Tarsal Tunnel Syndrome

    MedlinePlus

    ... and nerves. One of these structures is the posterior tibial nerve, which is the focus of tarsal tunnel ... syndrome is a compression, or squeezing, on the posterior tibial nerve that produces symptoms anywhere along the path ...

  16. Carpal tunnel syndrome

    MedlinePlus

    ... also need to make changes in your work duties or home and sports activities. Some of the ... Call for an appointment with your provider if: You have symptoms of carpal tunnel syndrome Your symptoms ...

  17. Tunneling anisotropic magnetoresistance in a magnetic tunnel junction with half-metallic electrodes

    NASA Astrophysics Data System (ADS)

    Burton, J. D.; Tsymbal, Evgeny Y.

    2016-01-01

    Tunneling anisotropic magnetoresistance (TAMR) is the difference in resistance of a magnetic tunnel junction due to a change in magnetization direction of one or both magnetic electrodes with respect to the flow of current. We present the results of first-principles density functional calculations of the TAMR effect in magnetic tunnel junctions with L a0.7S r0.3Mn O3 (LSMO) electrodes and a SrTi O3 (STO) tunneling barrier. We find an ˜500 % difference in resistance between magnetization in the plane and out of the plane. This large TAMR effect originates from the half-metallic nature of LSMO: When magnetization is out of plane spin-orbit coupling (SOC) contributions to the transmission come only from spin-flip scattering, which is intrinsically small due to the half-metallicity. For in-plane magnetization, however, there is a large non-spin-flip SOC contribution to the conductance. The large magnitude of the effect stems from the additional fact that there is an inherent polar discontinuity between LSMO and STO which leads to quasilocalized states at the interface whose influence on tunneling is strongly dependent on the magnetization orientation.

  18. Electron tunnel sensor technology

    NASA Technical Reports Server (NTRS)

    Kenny, T. W.; Waltman, S. B.; Reynolds, J. K.; Kaiser, W. J.

    1991-01-01

    Researchers designed and constructed a novel electron tunnel sensor which takes advantage of the mechanical properties of micro-machined silicon. For the first time, electrostatic forces are used to control the tunnel electrode separation, thereby avoiding the thermal drift and noise problems associated with piezoelectric actuators. The entire structure is composed of micro-machined silicon single crystals, including a folded cantilever spring and a tip. The application of this sensor to the development of a sensitive accelerometer is described.

  19. Tunnelling in carbonic acid.

    PubMed

    Wagner, J Philipp; Reisenauer, Hans Peter; Hirvonen, Viivi; Wu, Chia-Hua; Tyberg, Joseph L; Allen, Wesley D; Schreiner, Peter R

    2016-06-14

    The cis,trans-conformer of carbonic acid (H2CO3), generated by near-infrared radiation, undergoes an unreported quantum mechanical tunnelling rotamerization with half-lives in cryogenic matrices of 4-20 h, depending on temperature and host material. First-principles quantum chemistry at high levels of theory gives a tunnelling half-life of about 1 h, quite near those measured for the fastest rotamerizations. PMID:27248671

  20. Rupture of the Deep Femoral Artery during Proximal Femoral Nailing Following an Intertrochanteric Fracture: A Case Report

    PubMed Central

    Yoon, Han Kook; Park, Junyoung; Oyunbat, Choidog; Kim, Taehwan

    2016-01-01

    Recently, we experienced a case where the diagnosis and management of a deep femoral artery rupture was delayed. This vascular complication occurred during the insertion of a distal interlocking screw of a proximal femoral nail for the fixation of an intertrochanteric femur fracture. A 79-year-old male patient was diagnosed with a right intertrochanteric fracture after a fall. We fixed the fracture with a proximal femoral nail (Zimmer® Natural Nail™ System). One day after the procedure, the patient complained of pain and swelling on the anteromedial side of his middle thigh followed by hypotension, anemia and prolonged thigh swelling. Computed tomography angiography was performed 7 days after the procedure. We found a pseudoaneurysm of the perforating artery caused by injury to the deep femoral artery and an intramuscular hematoma in the anterior thigh muscle. We successfully treated the pseudoaneurysm using coil embolization. Throughout the management of intertrochanteric femoral fractures, it is important to be aware and monitor signs and symptoms related to the possibility of blood vessel damage. When a patient presents with swelling and pain on the middle thigh and/or unexplained anemia postoperatively, the possibility that these symptoms are caused by an injury to the femoral artery must be considered.

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

    NASA Technical Reports Server (NTRS)

    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.

  2. Seasonal variation of slipped capital femoral epiphysis.

    PubMed

    Maffulli, Nicola; Douglas, A Stuart

    2002-01-01

    During the 18-year period 1980-1997, 1103 patients were treated as in-patients for slipped capital femoral epiphysis (SCFE) in Scottish hospitals. This paper reports a significant seasonal variation, especially in male patients, with an excess admitted in the autumn. Examining the physiological seasonality of the monthly increment of growth in height and weight in childhood, we hypothesised that these physiological rhythms, while not pathogenetic, may be responsible for the timing of the seasonal features of SCFE. Previously published studies suggest that the average time between first symptoms and diagnosis is 3 to 5 months. The condition may start with the spring peak in growth and become more symptomatic with the autumn peak in weight. In conclusion, we report a new epidemiological finding, but, in accordance with other studies, we cannot provide a certain aetiological explanation. The timing, but not the pathogenesis, of admission to hospital for a SCFE might be related to the timing in the year of seasonal increments of height in spring and weight in autumn. It is tempting to draw attention to associations with environmental features. For example, in autumn there is the most rapid annual fall in temperature, and the hours of darkness are increasing from the autumn equinox to the winter solstice. However, there is no reason to conclude that these associations have anything to do with aetiology. PMID:11866078

  3. Intraosseous Lipoma of the Femor: Image Findings

    PubMed Central

    Yazdi, Hadi Rokni; Rasouli, Bahman; Borhani, Ali; Noorollahi, Mohammad Mahdi

    2014-01-01

    Introduction: Intraosseous lipoma is a rare benign bone disease. Long and cancellous bones are the most locationsthat can be affected. Almost all lesions were discovered incidentally on imaging modalities that were done during an unrelated investigation. As it is rare, it may be mistaken for nonossifying fibroma, aneurismal bone cyst, simple bone cyst, bone infarct or chondroid tumors. Recently with the high quality imaging modalities such as CT scan and/or MR imaging, the diagnosis of intramedullary lipoma and some other bone lesions can be done without the need for bone biopsy and surgery. Case Report: We’re reporting a rare case of intraosseous lipoma of the distal femur. Plain film radiography showed barely visible medullary expansion and lucency in the distal left femoral diaphysis. The patient underwent further evaluation with computed tomographic (CT) and magnetic resonance Imaging (MRI). According to the MRI and CT scan findings, intraosseous lipoma was confirmed and the need for more diagnostic tests were eliminated. Conclusion: Although Intraosseous lipoma doesn’t have any manifestations clinically but it should be considered in the differential diagnosis of bone pains. MRI has an important role in characterization of soft tissue and bone marrow lesions therefore non-surgical approach for most of the patients with intraosseous lipoma would be beneficial. PMID:27298943

  4. 'Oxide-free' tip for scanning tunneling microscopy

    NASA Technical Reports Server (NTRS)

    Colton, R. J.; Baker, S. M.; Baldeschwieler, J. D.; Kaiser, W. J.

    1987-01-01

    A new tip for scanning tunneling microscopy and a tip repair procedure that allows one to reproducibly obtain atomic images of highly oriented pyrolytic graphite with previously inoperable tips are reported. The tips are shown to be relatively oxide-free and highly resistant to oxidation. The tips are fabricated with graphite by two distinct methods.

  5. Femoral articular shape and geometry. A three-dimensional computerized analysis of the knee.

    PubMed

    Siu, D; Rudan, J; Wevers, H W; Griffiths, P

    1996-02-01

    An average, three-dimensional anatomic shape and geometry of the distal femur were generated from x-ray computed tomography data of five fresh asymptomatic cadaver knees using AutoCAD (AutoDesk, Sausalito, CA), a computer-aided design and drafting software. Each femur model was graphically repositioned to a standardized orientation using a series of alignment templates and scaled to a nominal size of 85 mm in mediolateral and 73 mm in anteroposterior dimensions. An average generic shape of the distal femur was synthesized by combining these pseudosolid models and reslicing the composite structure at different elevations using clipping and smoothing techniques in interactive computer graphics. The resulting distal femoral geometry was imported into a computer-aided manufacturing system, and anatomic prototypes of the distal femur were produced. Quantitative geometric analyses of the generic femur in the coronal and transverse planes revealed definite condylar camber (3 degrees-6 degrees) and toe-in (8 degrees-10 degrees) with an oblique patellofemoral groove (15 degrees) with respect to the mechanical axis of the femur. In the sagittal plane, each condyle could be approximated by three concatenated circular arcs (anterior, distal, and posterior) with slope continuity and a single arc for the patellofemoral groove. The results of this study may have important implications in future femoral prosthesis design and clinical applications. PMID:8648311

  6. Management of distal femoral periprosthetic fractures by distal femoral locking plate: A retrospective study.

    PubMed Central

    Thukral, Rajiv; Marya, SKS; Singh, Chandeep

    2015-01-01

    Background: Management of periprosthetic supracondylar femoral fractures is difficult. Osteoporosis, comminution and bone loss, compromise stability with delayed mobility and poor functional outcomes. Open reduction and internal fixation (ORIF) with anatomic distal femoral (DF) locking plate permits early mobilization. However, this usually necessitates bone grafting (BG). Biological fixation using minimally invasive techniques minimizes periosteal stripping and morbidity. Materials and Methods: 31 patients with comminuted periprosthetic DF fractures were reviewed retrospectively from October 2006 to September 2012. All patients underwent fixation using a DF locking compression plate (Synthes). 17 patients underwent ORIF with primary BG, whereas 14 were treated by closed reduction (CR) and internal fixation using biological minimally invasive techniques. Clinical and radiological followup were recorded for an average 36 months. Results: Mean time to union for the entire group was 5.6 months (range 3-9 months). Patients of ORIF group took longer (Mean 6.4 months, range 4.5-9 months) than the CR group (mean 4.6 months, range 3-7 months). Three patients of ORIF and one in CR group had poor results. Mean knee society scores were higher for CR group at 6 months, but nearly identical at 12 months, with similar eventual range of motion. Discussion: Locked plating of comminuted periprosthetic DF fractures permits stable rigid fixation and early mobilization. Fixation using minimally invasive biological techniques minimizes morbidity and may obviate the need for primary BG. PMID:26015610

  7. Full circle: 3D femoral mapping demonstrates age-related changes that influence femoral implant positioning.

    PubMed

    Tucker, Damien; Surup, Timm; Petersik, Andreas; Kelly, Michael

    2016-02-01

    The geometry of the femur is important in the final position of an intramedullary implant; we hypothesised that the femoral geometry changes with age and this may predispose the elderly to anterior mal-positioning of these implants. We used CT DICOM data of 919 intact left femora and specialist software that allowed us to defined landmarks for measurement reference - such as the linea aspera - on a template bone that could be mapped automatically to the entire database. We found that older (>80 years) cortical bone is up to 1.5 mm thinner anteriorly and 2 mm thinner posteriorly than younger (<40 years) bone but the rate of change of posterior to anterior cortex thickness is greater in the older bone. We also found the isthmus in the elderly to be more distal and less substantial than in the younger bone. This study has demonstrated femoral geometry changes with age that may explain our perception that the elderly are at increased risk for anterior mal-positioning of intramedullary implants. PMID:26686594

  8. Radiological assessment of the femoral bowing in Japanese population

    PubMed Central

    Abdelaal, Ahmed Hamed Kassem; Yamamoto, Norio; Hayashi, Katsuhiro; Takeuchi, Akihiko; Morsy, Ahmad Fawaz; Miwa, Shinji; Kajino, Yoshitomo; Rubio, Donnel A.; Tsuchiya, Hiroyuki

    2016-01-01

    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. PMID:27163091

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

    NASA Astrophysics Data System (ADS)

    Kirilova, I. A.; Sharkeev, Yu. P.; Podorozhnaya, V. T.; Popova, K. S.; Uvarkin, P. V.

    2015-11-01

    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%.

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

    SciTech Connect

    Kirilova, I. A. Podorozhnaya, V. T.; Sharkeev, Yu. P.; Popova, K. S. Uvarkin, P. V.

    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%.

  11. ACL mismatch reconstructions: influence of different tunnel placement strategies in single-bundle ACL reconstructions on the knee kinematics.

    PubMed

    Herbort, Mirco; Lenschow, Simon; Fu, Freddie H; Petersen, Wolf; Zantop, Thore

    2010-11-01

    To evaluate the influence of tibial and femoral tunnel position in ACL reconstruction on knee kinematics, we compared ACL reconstruction with a tibial and femoral tunnel in anteromedial (AM-AM reconstruction) and in posterolateral footprint (PL-PL reconstruction) with a reconstruction technique with tibial posterolateral and femoral anteromedial tunnel placement (PL-AM reconstruction). In 9 fresh-frozen human cadaveric knees, the knee kinematics under simulated Lachman (134 N anterior tibial load) and a simulated pivot shift test (10 N/m valgus and 4 N/m internal tibial torque) were determined at 0°, 30°, 60°, and 90° of flexion. Kinematics were recorded for intact, ACL-deficient, and single-bundle ACL reconstructed knees using three different reconstruction strategies in randomized order: (1) PL-AM, (2) AM-AM and (3) PL-PL reconstructions. Under simulated Lachman test, single-bundle PL-AM reconstruction and PL-PL reconstructions both showed significantly increased anterior tibial translation (ATT) at 60° and 90° when compared to the intact knee. At all flexion angles, AM-AM reconstruction did not show any statistical significant differences in ATT compared to the intact knee. Under simulated pivot shift, PL-AM reconstruction resulted in significantly higher ATT at 0°, 30°, and 60° knee flexion and AM-AM reconstructions showed significantly higher ATT at 30° compared to the intact knee. PL-PL reconstructions did not show any significant differences to the intact knee. AM-AM reconstructions restore the intact knee kinematics more closely when compared to a PL-AM technique resembling a transtibial approach. PL-PL reconstructions showed increased ATT at higher flexion angles, however, secured the rotational stability at all flexion angles. Due to the independent tibial and femoral tunnel location, a medial portal technique may be superior to a transtibial approach. PMID:20461359

  12. Atypical subtrochanteric and diaphyseal femoral fractures: report of a task force of the American Society for Bone and Mineral Research.

    PubMed

    Shane, Elizabeth; Burr, David; Ebeling, Peter R; Abrahamsen, Bo; Adler, Robert A; Brown, Thomas D; Cheung, Angela M; Cosman, Felicia; Curtis, Jeffrey R; Dell, Richard; Dempster, David; Einhorn, Thomas A; Genant, Harry K; Geusens, Piet; Klaushofer, Klaus; Koval, Kenneth; Lane, Joseph M; McKiernan, Fergus; McKinney, Ross; Ng, Alvin; Nieves, Jeri; O'Keefe, Regis; Papapoulos, Socrates; Sen, Howe Tet; van der Meulen, Marjolein C H; Weinstein, Robert S; Whyte, Michael

    2010-11-01

    Reports linking long-term use of bisphosphonates (BPs) with atypical fractures of the femur led the leadership of the American Society for Bone and Mineral Research (ASBMR) to appoint a task force to address key questions related to this problem. A multidisciplinary expert group reviewed pertinent published reports concerning atypical femur fractures, as well as preclinical studies that could provide insight into their pathogenesis. A case definition was developed so that subsequent studies report on the same condition. The task force defined major and minor features of complete and incomplete atypical femoral fractures and recommends that all major features, including their location in the subtrochanteric region and femoral shaft, transverse or short oblique orientation, minimal or no associated trauma, a medial spike when the fracture is complete, and absence of comminution, be present to designate a femoral fracture as atypical. Minor features include their association with cortical thickening, a periosteal reaction of the lateral cortex, prodromal pain, bilaterality, delayed healing, comorbid conditions, and concomitant drug exposures, including BPs, other antiresorptive agents, glucocorticoids, and proton pump inhibitors. Preclinical data evaluating the effects of BPs on collagen cross-linking and maturation, accumulation of microdamage and advanced glycation end products, mineralization, remodeling, vascularity, and angiogenesis lend biologic plausibility to a potential association with long-term BP use. Based on published and unpublished data and the widespread use of BPs, the incidence of atypical femoral fractures associated with BP therapy for osteoporosis appears to be very low, particularly compared with the number of vertebral, hip, and other fractures that are prevented by BPs. Moreover, a causal association between BPs and atypical fractures has not been established. However, recent observations suggest that the risk rises with increasing duration of

  13. Industrial Orientation.

    ERIC Educational Resources Information Center

    Rasor, Leslie; Brooks, Valerie

    These eight modules for an industrial orientation class were developed by a project to design an interdisciplinary program of basic skills training for disadvantaged students in a Construction Technology Program (see Note). The Drafting module overviews drafting career opportunities, job markets, salaries, educational requirements, and basic…

  14. Application of a medial buttress plate may prevent many treatment failures seen after fixation of vertical femoral neck fractures in young adults.

    PubMed

    Mir, Hassan; Collinge, Cory

    2015-05-01

    Femoral neck fractures in young adults with normal bone are mostly vertically oriented and may have variable amounts of comminution, which result from shearing forces during high-energy trauma. These factors play a role in the high rate of complications after this injury, including nonunion, malunion, failure of fixation, and avascular necrosis. These problems often occur together and inter-relate, for example, nonunion or malunion frequently result from fixation failure and varus collapse of the femoral head after reconstruction. The orthopaedic surgeon's goals of obtaining and maintaining anatomic reduction until bony union have been addressed by a number of surgical approaches and fixation constructs, however, complications are still common and no consensus exists on how these problematic fractures may be best treated. For optimal treatment of vertical femoral neck fractures, anatomic reduction must be achieved and fixation must be able to resist the high shear forces across the fracture with hip motion, weight-bearing, and muscle tone. Buttress plate fixation is a common method for stabilizing fractures that require resistance to shear forces and stands as one of the basic principles of fracture care. This technique has not been widely applied to this injury pattern. We propose that the concepts of modern fracture care should be applied together for vertical femoral neck fractures in young adults. Specifically, we propose that anatomic reduction and fixation of vertically oriented femoral neck fractures with the addition of a medial buttress plate to resist shearing forces will improve on the historically high rate of complications after these difficult injuries. PMID:25744726

  15. Single Electron Tunneling

    SciTech Connect

    Ruggiero, Steven T.

    2005-07-25

    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

  16. Carpal Tunnel Syndrome

    PubMed Central

    Zimmerman, Gregory R.

    1994-01-01

    Carpal tunnel syndrome is a neuropathy resulting from compression of the median nerve as it passes through a narrow tunnel in the wrist on its way to the hand. The lack of precise objective and clinical tests, along with symptoms that are synonymous with other syndromes in the upper extremity, cause carpal tunnel syndrome to appear to be a rare entity in athletics. However, it should not be ruled out as a possible etiology of upper extremity paralysis in the athlete. More typically, carpal tunnel syndrome is the most common peripheral entrapment neuropathy encountered in industry. Treatment may include rest and/or splinting of the involved wrist, ice application, galvanic stimulation, or iontophoresis to reduce inflammation, and then transition to heat modalities and therapeutic exercises for developing flexibility, strength, and endurance. In addition, an ergonomic assessment should be conducted, resulting in modifications to accommodate the carpal tunnel syndrome patient. ImagesFig 3.Fig 4.Fig 5.Fig 6.Fig 7. PMID:16558255

  17. 20-Foot Spin Tunnel

    NASA Technical Reports Server (NTRS)

    1947-01-01

    Construction of a typical model used in the 20-Foot Spin Tunnel. >From 'Characteristics of Nine Research Wind Tunnels of the Langley Aeronautical Laboratory': 'Dynamic models are used for free-spinning tunnel tests. A dynamic model is one for which geometric similarity between model and airplane is extended to obtain geometric similarity of the paths of motion of corresponding points by maintaining constant, in addition to the scale ratio of linear dimensions, three other ratios, that of force, mass, and time. In model testing, however, complete similarity can generally not be duplicated and some compromise is necessary. For free-spinning-model tests in the NACA 20-foot tunnel, the ratio of inertia to frictional or viscous forces (Reynolds number) is not maintained constant, but the ratio of inertia to gravity forces (Froude number) is maintained constant.' 'Models used in the spin tunnel until recently [this report was written in 1957] were made primarily of balsa and reinforced with hardwood. Now, plastic models are being used almost entirely, because they are more durable and when properly constructed are no heavier than balsa models. The models are constructed accurately to scale by pressing plastic material and class cloth into a previously constructed mold. A typical mod is shown in [this picture]. The model is swung as a torsional pendulum and is ballasted to obtain dynamic similarity by placing lead weights in suitable locations within the model wings and fuselage. Corrections are made for the effect of ambient and entrapped air.'

  18. Condensate Mixtures and Tunneling

    SciTech Connect

    Timmermans, E.

    1998-09-14

    The experimental study of condensate mixtures is a particularly exciting application of the recently developed atomic-trap Bose-Einstein condensate (BEC) technology: such multiple condensates represent the first laboratory systems of distinguishable boson superfluid mixtures. In addition, as the authors point out in this paper, the possibility of inter-condensate tunneling greatly enhances the richness of the condensate mixture physics. Not only does tunneling give rise to the oscillating particle currents between condensates of different chemical potentials, such as those studied extensively in the condensed matter Josephson junction experiments, it also affects the near-equilibrium dynamics and stability of the condensate mixtures. In particular, the stabilizing influence of tunneling with respect to spatial separation (phase separation) could be of considerable practical importance to the atomic trap systems. Furthermore, the creation of mixtures of atomic and molecular condensates could introduce a novel type of tunneling process, involving the conversion of a pair of atomic condensate bosons into a single molecular condensate boson. The static description of condensate mixtures with such type of pair tunneling suggests the possibility of observing dilute condensates with the liquid-like property of a self-determined density.

  19. [Delayed hypoxia after the surgical correction of femoral neck fracture].

    PubMed

    Goh, R; Mori, K; Abe, T; Kohyama, A; Minato, A

    1996-11-01

    We investigated perioperative blood gas changes in 26 patients scheduled for surgical correction of femoral neck fracture under epidural anesthesia. Arterial blood gases during spontaneous air respiration were measured eight times during the femoral neck prosthetic replacements (n = 16), and four times during osteosynthesis (n = 10). In the patients who received femoral neck replacements using bone cement (n = 8), arterial oxygen tension decreased significantly four hours after insertion of prosthesis, and did not recover during two postoperative days. In contrast, in the patients who received cementless femoral neck replacements (n = 8), arterial oxygen tension tended to decrease but not significantly, and returned to normal on the second postoperative day. In the patients who received osteosynthesis, arterial oxygen tension did not change. We suspected that the causes of delayed hypoxia in the femoral neck replacements were vascular endothelial cell injury in the lung by free fatty acid originating from fat embolism, and/or microthrombosis resulting from activated coagulation system. Bone cement was thought to intensify fat embolism because of elevated intramedullary pressure in the femur. PMID:8953864

  20. East portal of Tunnel No. 1292, Indigo Tunnel, showing interior ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    East portal of Tunnel No. 1292, Indigo Tunnel, showing interior timber framing, looking southwest. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  1. West portal of Tunnel No. 1292, Indigo Tunnel at milepost ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    West portal of Tunnel No. 1292, Indigo Tunnel at milepost 129.95, largely obscured by overgrowth. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  2. View of entrance tunnel. Tunnel right to Control Center, left ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of entrance tunnel. Tunnel right to Control Center, left to Antenna Silos - Titan One Missile Complex 2A, .3 miles west of 129 Road and 1.5 miles north of County Line Road, Aurora, Adams County, CO

  3. Magnetic flux tube tunneling

    NASA Astrophysics Data System (ADS)

    Dahlburg, R. B.; Antiochos, S. K.; Norton, D.

    1997-08-01

    We present numerical simulations of the collision and subsequent interaction of orthogonal magnetic flux tubes. The simulations were carried out using a parallelized spectral algorithm for compressible magnetohydrodynamics. It is found that, under a wide range of conditions, the flux tubes can ``tunnel'' through each other, a behavior not previously seen in studies of either vortex tube or magnetic flux tube interactions. Two conditions must be satisfied for tunneling to occur: the magnetic field must be highly twisted with a field line pitch >>1, and the Lundquist number must be somewhat large, >=2880. An examination of magnetic field lines suggests 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.

  4. Magnetic flux tube tunneling

    SciTech Connect

    Dahlburg, R.B.; Antiochos, S.K.; Norton, D.

    1997-08-01

    We present numerical simulations of the collision and subsequent interaction of {ital orthogonal} magnetic flux tubes. The simulations were carried out using a parallelized spectral algorithm for compressible magnetohydrodynamics. It is found that, under a wide range of conditions, the flux tubes can {open_quotes}tunnel{close_quotes} through each other, a behavior not previously seen in studies of either vortex tube or magnetic flux tube interactions. Two conditions must be satisfied for tunneling to occur: the magnetic field must be highly twisted with a field line pitch {gt}1, and the Lundquist number must be somewhat large, {ge}2880. An examination of magnetic field lines suggests that tunneling is due to a double-reconnection mechanism. Initially orthogonal field lines reconnect at two specific locations, exchange interacting sections, and {open_quotes}pass{close_quotes} through each other. The implications of these results for solar and space plasmas are discussed. {copyright} {ital 1997} {ital The American Physical Society}

  5. Femtosecond scanning tunneling microscope

    SciTech Connect

    Taylor, A.J.; Donati, G.P.; Rodriguez, G.; Gosnell, T.R.; Trugman, S.A.; Some, D.I.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). By combining scanning tunneling microscopy with ultrafast optical techniques we have developed a novel tool to probe phenomena on atomic time and length scales. We have built and characterized an ultrafast scanning tunneling microscope in terms of temporal resolution, sensitivity and dynamic range. Using a novel photoconductive low-temperature-grown GaAs tip, we have achieved a temporal resolution of 1.5 picoseconds and a spatial resolution of 10 nanometers. This scanning tunneling microscope has both cryogenic and ultra-high vacuum capabilities, enabling the study of a wide range of important scientific problems.

  6. Uncooled tunneling infrared sensor

    NASA Technical Reports Server (NTRS)

    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.

  7. View down tank tunnel (tunnel no. 2) showing pipes and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View down tank tunnel (tunnel no. 2) showing pipes and walkway of metal grating, side tunnel to tank 3 is on the left - U.S. Naval Base, Pearl Harbor, Diesel Purification Plant, North Road near Pierce Street, Pearl City, Honolulu County, HI

  8. Bilateral midshaft femoral fractures in an adolescent baseball player.

    PubMed

    Ju, D G; Mogayzel, P J; Sponseller, P D; Familiari, F; McFarland, E G

    2016-07-01

    Bone disease, specifically low bone mineral density, is a common and undertreated complication that begins during childhood in patients with cystic fibrosis (CF). This case describes a male baseball player, aged 14years, with undiagnosed CF who sustained a left midshaft femoral fracture while running toward base; 8months later, he sustained a right midshaft femoral fracture under similar conditions. After the second fracture, further evaluation revealed low bone mineral density and CF. There is no previously published report of pathologic fractures occurring in the femoral shaft in an athlete with undiagnosed CF. Patients with CF have a higher fracture rate. Low-energy fractures of major bones in athletically active individuals should be viewed with suspicion for an underlying process. PMID:26927602

  9. Emergency Stenting of a Ruptured Infected Anastomotic Femoral Pseudoaneurysm

    SciTech Connect

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

    2007-11-15

    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.

  10. Rapid resolution of femoral head osteonecrosis after rotational acetabular osteotomy.

    PubMed

    Nozawa, Masahiko; Matsuda, Keiji; Maezawa, Katsuhiko; Kim, Sungon; Maeda, Kouichi; Ikegami, Takashi; Kubota, Reiko; Hayashi, Kentaro; Nagayama, Masataka; Kaneko, Haruka

    2008-12-01

    The natural history of osteonecrosis of the femoral head is generally thought to be one of progressive deterioration if no intervention is undertaken. However, it is unknown whether surgical intervention is beneficial for patients with a small region of osteonecrosis. We observed rapid improvement of MRI findings after rotational acetabular osteotomy (RAO) was performed in a young patient with osteonecrosis of the femoral head. The band-like low signal area on T2-weighted images almost resolved by six months after surgery. He returned to work as an electrician by six months after surgery. Early surgical intervention such as RAO that alters the mechanical force acting on the necrotic region of the femoral head may accelerate the recovery of osteonecrosis and the improvement of symptoms. PMID:19384490

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

    SciTech Connect

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

    2010-10-15

    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.

  12. High-speed Wind Tunnels

    NASA Technical Reports Server (NTRS)

    Ackeret, J

    1936-01-01

    Wind tunnel construction and design is discussed especially in relation to subsonic and supersonic speeds. Reynolds Numbers and the theory of compressible flows are also taken into consideration in designing new tunnels.

  13. Two-dimensional wind tunnel

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Information on the Japanese National Aerospace Laboratory two dimensional transonic wind tunnel, completed at the end of 1979 is presented. Its construction is discussed in detail, and the wind tunnel structure, operation, test results, and future plans are presented.

  14. Wind tunnel wall interference

    NASA Technical Reports Server (NTRS)

    Newman, Perry A.; Mineck, Raymond E.; Barnwell, Richard W.; Kemp, William B., Jr.

    1986-01-01

    About a decade ago, interest in alleviating wind tunnel wall interference was renewed by advances in computational aerodynamics, concepts of adaptive test section walls, and plans for high Reynolds number transonic test facilities. Selection of NASA Langley cryogenic concept for the National Transonic Facility (NTF) tended to focus the renewed wall interference efforts. A brief overview and current status of some Langley sponsored transonic wind tunnel wall interference research are presented. Included are continuing efforts in basic wall flow studies, wall interference assessment/correction procedures, and adaptive wall technology.

  15. Instrumentation in wind tunnels

    NASA Technical Reports Server (NTRS)

    Takashima, K.

    1986-01-01

    Requirements in designing instrumentation systems and measurements of various physical quantities in wind tunnels are surveyed. Emphasis is given to sensors used for measuring pressure, temperature, and angle, and the measurements of air turbulence and boundary layers. Instrumentation in wind tunnels require accuracy, fast response, diversity and operational simplicity. Measurements of force, pressure, attitude angle, free flow, pressure distribution, and temperature are illustrated by a table, and a block diagram. The LDV (laser Doppler velocimeter) method for measuring air turbulence and flow velocity and measurement of skin friction and flow fields using laser holograms are discussed. The future potential of these techniques is studied.

  16. Biophysical stimulation in osteonecrosis of the femoral head

    PubMed Central

    Leo, Massari; Milena, Fini; Ruggero, Cadossi; Stefania, Setti; GianCarlo, Traina

    2009-01-01

    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. PMID:19753174

  17. Venting during prophylactic nailing for femoral metastases: current orthopedic practice

    PubMed Central

    Dalgorf, Dustin; Borkhoff, Cornelia M.; Stephen, David J.G.; Finkelstein, Joel; Kreder, Hans J.

    2003-01-01

    Introduction Reamed intramedullary nailing, recommended for impending fracture of a femur weakened by bone metastases, causes a rise in intramedullary pressure and increases the risk of a fat embolism syndrome. The pressure can be equalized by the technique of venting — drilling a hole into the distal cortex of the femur. Our objective was to study the current practice of orthopedic surgeons in Ontario with respect to venting during prophylactic intramedullary nailing for an impending femoral fracture due to bone metastases. Methods We mailed a questionnaire to all orthopedic surgeons from the Province of Ontario listed in the 1999 Canadian Medical Directory or on the Canadian Orthopaedic Association membership list, asking if they vent when prophylactically nailing an impending pathologic femoral fracture. The responses were modelled as a function of surgeon volume and year of graduation. Results Of the 415 surveys mailed, 223 (54%) surgeons responded. Of these, 81% reported having prophylactically treated a femoral metastatic lesion during the previous year; 67% treated 1 to 3 metastatic lesions and 14% treated more than 3; 19% did not treat a metastatic femoral lesion prophylactically. Over two-thirds of surgeons had never considered venting, whereas one-third always or sometimes vented the femoral canal. More recent graduates were 3 times more likely to vent than earlier (before 1980) graduates (odds ratio [OR] = 3.2, 95% confidence interval [CI] 1.6–6.5) as were those who treat a greater number of impending fractures (OR = 1.4, 95% CI 1.1–1.7). Conclusions Although there is a theoretical rationale for routine venting, there is disagreement among Ontario orthopedic surgeons regarding the use of this technique during prophylactic nailing for femoral metastatic lesions. Prospective evidence will be required to warrant a change in the standard of care. PMID:14680349

  18. Spontaneous modular femoral head dissociation complicating total hip arthroplasty.

    PubMed

    Talmo, Carl T; Sharp, Kinzie G; Malinowska, Magdalena; Bono, James V; Ward, Daniel M; LaReau, Justin

    2014-06-01

    Modular femoral heads have been used successfully for many years in total hip arthroplasty. Few complications have been reported for the modular Morse taper connection between the femoral head and trunnion of the stem in metal-on-polyethylene bearings. Although there has always been some concern over the potential for fretting, corrosion, and generation of particulate debris at the modular junction, this was not considered a significant clinical problem. More recently, concern has increased because fretting and corrosive debris have resulted in rare cases of pain, adverse local tissue reaction, pseudotumor, and osteolysis. Larger femoral heads, which have gained popularity in total hip arthroplasty, are suspected to increase the potential for local and systemic complications of fretting, corrosion, and generation of metal ions because of greater torque at the modular junction. A less common complication is dissociation of the modular femoral heads. Morse taper dissociation has been reported in the literature, mainly in association with a traumatic event, such as closed reduction of a dislocation or fatigue fracture of the femoral neck of a prosthesis. This report describes 3 cases of spontaneous dissociation of the modular prosthetic femoral head from the trunnion of the same tapered titanium stem because of fretting and wear of the Morse taper in a metal-on-polyethylene bearing. Continued clinical and scientific research on Morse taper junctions is warranted to identify and prioritize implant and surgical factors that lead to this and other types of trunnion failure to minimize complications associated with Morse taper junctions as hip implants and surgical techniques continue to evolve. PMID:24972443

  19. How to Minimize Rotational Conflict between Femoral & Tibial Component in Total Knee Arthroplasty: The Use of Femoro-Tibial Axial Synchronizer (Linker)

    PubMed Central

    Seo, Jai-Gon; Moon, Young-Wan; Kim, Sang-Min

    2015-01-01

    Purpose The purpose of this study was to investigate the correlation between rotational axes of femur and tibia with the use of Linker. Materials and Methods This study was carried out from August 2009 to February 2010 on 54 patients (106 knees), who were diagnosed with simultaneous bilateral total knee arthroplasty. With the use of postoperative computed tomography scans, it was investigated how much the rotational angle of femoral and tibial components matched. Results The tibial component was internally rotated for the femoral component at an angle of 0.8°. The femoral component was externally rotated for the surgical transepicondylar axis (TEA) at an angle of 1.6 (range: from 4.8° of internal rotation to 7.9° of external rotation, SD=2.2°), and the tibial component was externally rotated for the surgical TEA at an average angle of 0.9 (range: from 5.1° of internal rotation to 8.3° of external rotation, SD=3.1°). Conclusion The femoro-tibial synchronizer helped to improve the orientation and positioning of both femoral component and tibial component, and also increase the correlation of the rotational axes of the two components. PMID:25683995

  20. Parallel manipulator robot assisted femoral fracture reduction on traction table.

    PubMed

    Lin, H; Wang, J Q; Han, W

    2013-01-01

    The principle of femoral shaft fracture reduction is to restore its pre-fractured limb length and mechanical axis. The current documented treatment method with traction table reduction does not conform to the quantitative alignment and reduction. There is also a great amount of X-Ray radiation exposure to both surgeon and patient during the procedure. For this reason, we introduced an innovated Parallel Manipulator Robot (PMR) application: A Femoral Shaft Fracture Reduction with Parallel Manipulator Robot on Traction Table. With this application, the quantitative control on fracture reduction and alignment can be achieved and the radiation exposure to both surgeons and patients can be greatly reduced. PMID:24110820

  1. Intramedullary locking femoral nails. Experience with the AO nail.

    PubMed Central

    Fogarty, A. B.; Yeates, H. A.

    1991-01-01

    The AO interlocking nail was introduced to the Ulster Hospital, Dundonald in 1988 and since then has been used in over 50 patients with femoral shaft fractures. We have reviewed 45 patients with 46 femoral shaft fractures treated between June 1988 and April 1990. These included four compound fractures and 13 comminuted fractures. The results compare favourably with other series. The union rate was 98% and there were no instances of deep infection. The alternative treatment methods available are discussed along with a review of the relevant literature. Images Fig 3 Fig 5 PMID:1785145

  2. Bone SPECT/CT of Femoral Head Subchondral Insufficiency Fracture.

    PubMed

    Motomura, Goro; Yamamoto, Takuaki; Karasuyama, Kazuyuki; Iwamoto, Yukihide

    2015-09-01

    Subchondral insufficiency fracture of the femoral head may be confused with osteonecrosis, mainly because of radiological overlap. SPECT/CT with Tc-99 m hydroxymethylene diphosphonate images in 7 patients with subchondral insufficiency fracture were retrospectively reviewed and compared with those from 11 patients with symptomatic early osteonecrosis. In all of the hips with subchondral insufficiency fracture, SPECT/CT showed increased uptake at the subchondral lesions of the femoral head. On the other hand, in all of the hips with osteonecrosis, absence of uptake was confirmed at the subchondral lesions. SPECT/CT may assist in differentiating subchondral insufficiency fracture from osteonecrosis. PMID:26164176

  3. Traumatic Hip Dislocation with Associated Femoral Head Fracture

    PubMed Central

    Dortaj, H.; Emamifar, A.

    2015-01-01

    Dislocation of the hip is a critical injury that results from high-energy trauma. This paper describes a case of posterior dislocation of the right hip in a 35-year-old woman with associated ipsilateral femoral head fracture. Initial treatment included reduction of the right hip through posterior approach and fixation of the femoral head fracture with three absorbable screws. After 15-month follow-up, a full range of motion has been achieved and there are no signs of avascular necrosis, hip instability, or limping. The authors describe their method of surgery. PMID:25874147

  4. Patellofemoral dysbalance due to femoral deformities - diagnostic, therapy and results

    PubMed Central

    Dickschas, Jörg; Strecker, Wolf; Harrer, Jörg; Ferner, Felix

    2016-01-01

    Aims and Objectives: Anterior knee pain or patellofemoral instability are typical symptoms of patellofemoral dysbalance. Beside other reasons, this pathology can be caused by a femoral deformity. The two dimensions leading to this problems are torsional- and valgus deformities. This constellation often stays unrecognized. When diagnosed and analyzed, a femoral torsional or varization-osteotomy is the adequate treatment. Aim of this study was to show the diagnostic approach, the gold standard of therapy and the follow up results. Can patellofemoral stability be archived? Is the pain relief significant and how do clinical scores develop at the follow up? Materials and Methods: 33 femoral torsional osteotomies and 18 femoral varization osteotomies were included in this study, 5 of these were combined femoral varization and torsional corrections so that 46 knees are included in 41 patients, as 5 patients were operated on both legs. Major symptoms were patellofemoral dislocations in 28 cases and anterior knee pain in 26 cases. Beside clinical and radiographic evaluation full weight bearing long leg views and a torsional computertomography was always performed. Follow up examination was after 41 (6-113) months. Visual analog scala score, Japanese Knee Society Score, Tegner activity score and Lysholm score were taken before surgery and at the follow up. Results: Mechanical femorotibial valgus was on average 6,4° (5°-10°), femoral internal torsion was in average 40,9° (29°-66°; normal: 24°). Surgical treatment was performed with an arthroscopy followed by an acute femoral varization 7,2°(5°-10°) and / or external torsion osteotomy of 13.8° (5°-26°). Tegner activity score, Japanese knee society score and Lysholm score all significantly improved. Pain relief could be demonstrated as shown by a significant decrease of the VAS score. No further dislocation was reported during the follow up period. Conclusion: Valgus or torsional deformities of the femur frequently

  5. A rare case of femoral herniation of female internal genitalia

    PubMed Central

    Ambedkar, Vivek; Singh, Abhilash; Bain, Jayanta; Singh, Lal Mani

    2015-01-01

    We report a rare case with herniation of the uterus, fallopian tube, and ovary in a femoral hernia. A female patient was admitted with complain of the painful lump in the left groin. Clinical examination indicated strangulated femoral hernia, which necessitated an emergency surgery. During surgical procedure, the uterine tube, left fallopian tube and left ovary, were observed as the contents of the hernia. The contents were reduced back into the pelvic cavity, and the hernia was repaired. The patient made good recovery postsurgery. PMID:26283851

  6. Scanning tunneling microscope nanoetching method

    DOEpatents

    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.

  7. Failure load of patellar tendon grafts at the femoral side: 10- versus 20-mm-bone blocks.

    PubMed

    Meuffels, Duncan E; Niggebrugge, Marnix J N; Verhaar, Jan A N

    2009-02-01

    The aim of the study was to investigate whether use of short bone blocks is safe in anterior cruciate ligament (ACL) reconstruction. Our hypothesis was that the smaller 10-mm-length bone blocks will fail at lower loads than 20-mm-bone blocks. Ten paired human cadaver knees were randomly assigned to the 10- or 20-mm group (group 1 and 2) and underwent bone-patellar tendon-bone femoral fixation with interference screw. Tensile tests were performed using a tensile testing machine (Instron). Stiffness, failure load and failure mode were recorded. Median stiffness was 72 N/mm (16-103) for 10-mm-bone blocks and 91 N/mm (40-130) for 20-mm-bone blocks. Median failure loads were 402 N (87-546) for 10-mm-long bone block and 456 N (163-636) for 20-mm-bone blocks. There was no statistically significant difference between groups (P = 0.35). All bone-patellar tendon-bone grafts were pulled out of the femoral tunnel with interference screw, due to slippage. We concluded that a 10-mm-long bone block was not significantly weaker than a 20-mm-long bone block. Failure loads of a 10-mm-bone block exceeded loading values at passive and active extension of the knee under normal conditions. Ten millimetre bone blocks offered sufficient fixation strength in ACL reconstruction. PMID:18839146

  8. Osteochondral Autograft from the Ipsilateral Femoral Head by Surgical Dislocation for Treatment of Femoral Head Fracture Dislocation: A Case Report.

    PubMed

    Won, Yougun; Lee, Gi Soo; Kim, Sang Bum; Kim, Sun Joong; Yang, Kyu Hyun

    2016-11-01

    As anatomical reduction of the articular surface of femoral head fractures and restoration of damaged cartilage are essential for good long-term results, many treatment options have been suggested, including fixation of the fracture using various surgical exposures and implants, as well as arthroscopic irrigation and debridement, bone marrow stimulating techniques, osteochondral allograft, autograft, and autogenous chondrocyte implantation. We report a case of osteochondral autograft harvested from its own femoral articular surface through surgical hip dislocation. The osteochondral graft was harvested from the inferior non-weight-bearing articular surface and grafted to the osteochondral defect. One year later, the clinical and radiological results were good, without the collapse of the femoral head or arthritic change. This procedure introduced in our case is considered convenient and able to lessen surgical time without morbidity of the donor site associated with the harvest. PMID:27593886

  9. 21 CFR 888.3400 - Hip joint femoral (hemi-hip) metallic resurfacing prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 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...

  10. 21 CFR 888.3400 - Hip joint femoral (hemi-hip) metallic resurfacing prosthesis.

    Code of Federal Regulations, 2010 CFR

    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...