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

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

2013-06-01

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

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

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

2018-01-01

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

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

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Roberto Freire da Mota Albuquerque

2007-01-01

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

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

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

2015-07-01

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

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

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Farrow, Lutul D; Parker, Richard D

2010-06-01

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

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

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Lim Na-ra

2009-03-01

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

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

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

2014-09-01

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

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

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

2013-10-01

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

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

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

2007-01-01

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

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

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

2017-05-18

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

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

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Robin, Brett N; Lubowitz, James H

2014-10-01

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

Femoral Condyle Fracture during Anterior Cruciate Ligament Reconstruction

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Selahattin Ozyurek

2015-07-01

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

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

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

2011-11-01

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

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

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

2000-01-01

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

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

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Luites, Joan W.H.; Verdonschot, Nico

2017-01-01

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

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

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

2012-10-01

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

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

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

2012-01-01

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

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

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

2015-03-18

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

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

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

2006-10-01

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

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

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

2013-11-01

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

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

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

2014-10-01

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

Spin-polarized tunneling with GaAs tips in scanning tunneling microscopy

NARCIS (Netherlands)

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

1996-01-01

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

Femoral component rotation in patellofemoral joint replacement.

Science.gov (United States)

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

2018-06-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-12-15

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

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

International Nuclear Information System (INIS)

Hardenby, Carljohan; Sigurdsson, Oskar

2010-12-01

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

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

International Nuclear Information System (INIS)

Ohmori, Hideto; Hatori, Tomoya; Nakagawa, Shigeki

2008-01-01

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

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

Directory of Open Access Journals (Sweden)

ZHU Qing-hua

2013-08-01

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

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

International Nuclear Information System (INIS)

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

2010-01-01

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

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

International Nuclear Information System (INIS)

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

2004-01-01

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

Optical Flow for Flight and Wind Tunnel Background Oriented Schlieren Imaging

Science.gov (United States)

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

2017-01-01

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

Radiographic femoral varus measurement is affected unpredictably by femoral rotation

DEFF Research Database (Denmark)

Miles, James Edward

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

Mechanical properties of femoral trabecular bone in dogs

Directory of Open Access Journals (Sweden)

Nolte Ingo

2005-03-01

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

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

Science.gov (United States)

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

2018-04-01

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

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

Science.gov (United States)

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

2017-07-01

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

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

Directory of Open Access Journals (Sweden)

Keith A Fehring

2017-07-01

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

Tunneling anisotropic magnetoresistance via molecular π orbitals of Pb dimers

Science.gov (United States)

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

2018-01-01

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

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

Science.gov (United States)

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

2017-10-01

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

Spin-dependent transport in metal/semiconductor tunnel junctions

NARCIS (Netherlands)

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

1995-01-01

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

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

International Nuclear Information System (INIS)

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

2004-01-01

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

Femoral nerve damage (image)

Science.gov (United States)

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 ...

Femoral rotation unpredictably affects radiographic anatomical lateral distal femoral angle measurements

DEFF Research Database (Denmark)

Miles, James Edward

2016-01-01

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

Subchondral bone density distribution in the human femoral head

Energy Technology Data Exchange (ETDEWEB)

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

2012-06-15

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

Tunnelling determined superconducting energy gap of bulk single crystal aluminum

International Nuclear Information System (INIS)

Civiak, R.L.

1974-01-01

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

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

International Nuclear Information System (INIS)

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

1985-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2002-09-01

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

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

International Nuclear Information System (INIS)

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

2002-01-01

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

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

Science.gov (United States)

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

2011-03-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1985-02-15

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

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

International Nuclear Information System (INIS)

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

1999-01-01

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

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

Science.gov (United States)

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

2016-01-01

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

Treatment of neglected femoral neck fracture

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Anil K Jain

2015-01-01

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

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

Science.gov (United States)

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

2013-09-01

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

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

International Nuclear Information System (INIS)

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

2004-01-01

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

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

Science.gov (United States)

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

2014-01-01

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

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

Science.gov (United States)

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

2018-01-01

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

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

Science.gov (United States)

Suzuki, Daisuke; Hanyu, Takahiro

2018-04-01

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

Evaluation of a pig femoral head osteonecrosis model

Directory of Open Access Journals (Sweden)

Kim Harry

2010-03-01

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

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

Science.gov (United States)

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

2018-03-01

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

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

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Appleton Paul

2010-01-01

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

Silicon spintronics with ferromagnetic tunnel devices

International Nuclear Information System (INIS)

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

2012-01-01

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

Sidewall GaAs tunnel junctions fabricated using molecular layer epitaxy

Directory of Open Access Journals (Sweden)

Takeo Ohno and Yutaka Oyama

2012-01-01

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

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

Science.gov (United States)

Terjesen, Terje; Wiig, Ola; Svenningsen, Svein

2012-09-01

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

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

Science.gov (United States)

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

2015-10-01

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

[Trochanteric femoral fractures].

Science.gov (United States)

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

2013-01-01

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

In Situ Observation of Rock Spalling in the Deep Tunnels of the China Jinping Underground Laboratory (2400 m Depth)

Science.gov (United States)

Feng, Xia-Ting; Xu, Hong; Qiu, Shi-Li; Li, Shao-Jun; Yang, Cheng-Xiang; Guo, Hao-Sen; Cheng, Yuan; Gao, Yao-Hui

2018-04-01

To study rock spalling in deep tunnels at China Jinping Underground Laboratory Phase II (CJPL-II), photogrammetry method and digital borehole camera were used to quantify key features of rock spalling including orientation, thickness of slabs and the depth of spalling. The failure mechanism was analysed through scanning electron microscope and numerical simulation based on FLAC3D. Observation results clearly showed the process of rock spalling failure: a typical spalling pattern around D-shaped tunnels after top-heading and bottom bench were discovered. The orientation and thickness of the slabs were obtained. The slabs were parallel to the excavated surfaces of the tunnel and were related to the shape of the tunnel surface and orientation of the principal stress. The slabs were alternately thick and thin, and they gradually increased in thickness from the sidewall inwards. The form and mechanism of spalling at different locations in the tunnels, as influenced by stress state and excavation, were analysed. The result of this study was helpful to those rethinking the engineering design, including the excavation and support of tunnels, or caverns, at high risk of spalling.

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-09-15

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

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

International Nuclear Information System (INIS)

Kaushik, Abhishek; Sankaran, Balu; Varghese, Mathew

2010-01-01

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

Femoral head avascular necrosis

International Nuclear Information System (INIS)

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

1988-01-01

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

Femoral revision with impaction allografting and an uncemented femoral component

DEFF Research Database (Denmark)

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

2008-01-01

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

COMPARATIVE STUDY OF ARTHROSCOPIC SINGLE BUNDLE ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION AND NON-ANATOMICAL DOUBLE BUNDLE WITH SINGLE TIBIAL TUNNEL ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION WITH SEMITENDINOSUS ± GRACILIS AUTOGRAFTS USING LAXOMETRY

Directory of Open Access Journals (Sweden)

Sivananda

2016-01-01

Full Text Available BACKGROUND The knee joint is the most commonly injured of all joints and the ACL is the most commonly injured ligament. Arthroscopic reconstruction of ACL has become gold standard in treating these injuries. AIM 1. To compare the short-term results of ACL reconstruction using single bundle (one Tibial + one Femoral tunnel and non-anatomical double-bundle (one Tibial + two Femoral tunnels techniques using Hamstrings (Semitendinosus ± Gracilis graft. 2. To evaluate ACL graft reconstruction stability measured by laxometry and to find out an association with clinical findings. MATERIAL & METHODS We performed a prospective study between 2014-2015 of 20 case of ACL injuries & compared single bundle reconstruction with Non – anatomical double Bundle reconstruction with semitendinosus ± Gracilis, Autograft using laxometry. CONCLUSION Arthroscopic Non-anatomical double ACL Reconstruction is Bio-mechanically stable reconstruction resembling anatomy of the ACL.

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

Science.gov (United States)

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

2009-01-01

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

ONKALO 3D tunnel seismic investigations at Olkiluoto in 2009

International Nuclear Information System (INIS)

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

2011-02-01

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

A Morphological Insight of the Femoral Vein

Directory of Open Access Journals (Sweden)

Ferreira AH

2015-10-01

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

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

International Nuclear Information System (INIS)

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

2000-01-01

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

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

International Nuclear Information System (INIS)

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

2011-01-01

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

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

OpenAIRE

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

2013-01-01

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

Editorial Commentary: Arthroscopic Hip Ligamentum Teres Reconstruction-Reality or Mythology?

Science.gov (United States)

Bajwa, Ali S; Villar, Richard N

2018-01-01

The ligamentum teres (LT) is perceived to contribute to hip stability and proprioception. LT incompetence can lead to pain and instability, which may play a role in chondral damage. Hip arthroscopy plays a role in diagnosing and treating LT tears. Reconstruction of the LT is feasible, but careful attention needs to be paid to tunnel positioning, graft material, graft length, and fixation methods. An anatomic femoral tunnel should exit at the fovea capitis on the femoral side, whereas the location for safe placement of the acetabular attachment is thought to be in the posteroinferior part of the cotyloid fossa. On the basis of a recent study, optimization of the acetabular tunnel can potentially be achieved by drilling from the femoral tunnel aided by 15° of abduction and 15° of internal rotation. The femoral neck-shaft angle and femoral anteversion must be factored in while planning the entry point of the femoral tunnel, and this may vary based on the amount of femoral head distraction during hip arthroscopy. Copyright © 2017. Published by Elsevier Inc.

Femoral shaft fractures

International Nuclear Information System (INIS)

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

1985-01-01

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

The critical current of point symmetric Josephson tunnel junctions

International Nuclear Information System (INIS)

Monaco, Roberto

2016-01-01

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

Structure factors for tunneling ionization rates of molecules

DEFF Research Database (Denmark)

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

2013-01-01

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

Subchondral insufficiency fractures of the femoral head

Energy Technology Data Exchange (ETDEWEB)

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

2004-02-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-01-01

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

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

Science.gov (United States)

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

2016-10-07

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

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

Science.gov (United States)

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

2016-04-01

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

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

Directory of Open Access Journals (Sweden)

Pedro Miguel Dantas Costa Marques

2013-04-01

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

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

Science.gov (United States)

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.

Tunneling-recombination luminescence between Ag0 and Ag2+ in KCl:AgCl

International Nuclear Information System (INIS)

Delbecq, C.J.; Dexter, D.L.; Yuster, P.H.

1978-01-01

Appropriate treatment of a KCl:AgCl crystal results in the trapping of electrons as silver atoms, Ag 0 , and positive holes as AgCl 4 2- , Ag 2+ , centers. Optical excitation of Ag 0 in such a crystal at T 0 and Ag 2+ pairs, similar to the Ag 0 -Cl 2 - tunneling-recombination studies we previously reported. We have shown that Ag 2+ centers are involved in the emission process by preferentially orienting the anisotropic Ag 2+ at 6 K by excitation with polarized light and observing that the afterglow is polarized. Upon warming to 50 K, where the preferentially oriented Ag 2+ can change orientation, a strong reversal in the degree of polarization occurs which finally decays to zero. The characteristics of this luminescence can be understood if we assume: (i) a tunneling-recombination mechanism in which the orientation of the electric vector of the emitted radiation depends on the position of the Ag 0 relative to the Ag 2+ and (ii) the tunneling is anisotropic and depends on the location of the Ag 0 relative to the anisotropic Ag 2+ . The latter assumption is based on the tetragonal (d-like) symmetry of the Ag 2+ complex. Good quantitative agreement between theory and experiment has been obtained on the decay kinetics, the degree of polarization, and the polarization reversal

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

Science.gov (United States)

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

2015-07-01

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

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

Science.gov (United States)

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

2011-10-15

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

Slipped capital femoral epiphysis: A modern treatment protocol

Directory of Open Access Journals (Sweden)

Slavković Nemanja

2009-01-01

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

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

African Journals Online (AJOL)

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

Influence of concentration and temperature on tunneling and rotational dynamics of ammonium in Rb1-x (NH4)x I mixed crystals

International Nuclear Information System (INIS)

Natkaniec, I.; Dianoux, A.J.; Martinez-Sarrion, M.L.; Mestres, L.; Herraiz, M.; Smirnov, L.S.; Shuvalov, L.A.

2001-01-01

The Rb 1x (NH 4 ) x I mixed crystals are studied by inelastic incoherent neutron scattering using time-of-flight spectrometers in the concentration region of the x-T phase diagram 0.01≤x≤0.66 at 5≤T≤150K, where dynamic and static orientational disorder phases are generally found. It is shown that at 5 K rotational tunneling levels for ammonium concentrations x=0.01, 0.02 and 0.06 are similar. Additional tunneling levels are observed for x=0.16 which can be explained as the result of T-states splitting for account of NH 4 -NH 4 interaction. Tunneling levels are not observed for x=0.40 as the result of forming of orientational glass state. The elastic incoherent structure factors for concentrations 0.01≤x≤0.16 (dynamic orientational disordered α-phase), x=0.40 (orientational glass state) and 0.50≤x≤0.66 (orientational ordered state) have different temperature dependences

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

Science.gov (United States)

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

2005-11-01

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

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

Science.gov (United States)

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

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

Science.gov (United States)

Min, Byung-Woo; Kim, Sung-Jin

2011-05-18

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

Femoral neck buttressing: a radiographic and histologic analysis

International Nuclear Information System (INIS)

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

2000-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1991-07-15

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

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

International Nuclear Information System (INIS)

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

1991-01-01

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

Risk stratification for avascular necrosis of the femoral head after internal fixation of femoral neck fractures by post-operative SPECT/CT

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Han, Sang Won; Oh, Min Young; Yoon, Seok Ho; Kim, Jin Soo; Chang, Jae Suk; Ryu, Jin Sook [Asan Medical CenterUniversity of Ulsan College of Medicine, Seoul (Korea, Republic of); Kim, Ji Wan [Dept. of Orthopedic Surgery, Haeundae Paik Hospital, Inje University, Busan (Korea, Republic of)

2017-03-15

Avascular necrosis (AVN) of the femoral head is a major complication after internal fixation of a femoral neck fracture and determines the functional prognosis. We investigated postoperative bone single-photon emission computed tomography/computed tomography (SPECT/CT) for assessing the risk of femoral head AVN. We retrospectively reviewed 53 consecutive patients who underwent bone SPECT/CT within 2 weeks of internal fixation of a femoral neck fracture and follow-up serial hip radiographs over at least 12 months. Nine patients developed femoral head AVN. In 15 patients who showed normal uptake on immediate postoperative SPECT/CT, no AVN occurred, whereas 9 of 38 patients who showed cold defects of the femoral head later developed AVN. The negative predictive value of immediate postoperative SPECT/CT for AVN was 100 %, whereas the positive predictive value was 24 %. Among 38 patients with cold defects, 1 developed AVN 3 months postoperatively. A follow-up bone SPECT/CT was performed in the other 37 patients at 2–10 months postoperatively. The follow-up bone SPECT/CT revealed completely normalized femoral head uptake in 27, partially normalized uptake in 8, and persistent cold defects in 2 patients. AVN developed in 3.7 % (1/27), 62.5 % (5/8), and 100 % (2/2) of each group, respectively. According to the time point of imaging, radiotracer uptake patterns of the femoral head on postoperative bone SPECT/CT indicate the risk of AVN after internal fixation of femoral neck fractures differently. Postoperative bone SPECT/CT may help orthopedic surgeons determine the appropriate follow-up of these patients.

Risk stratification for avascular necrosis of the femoral head after internal fixation of femoral neck fractures by post-operative SPECT/CT

International Nuclear Information System (INIS)

Han, Sang Won; Oh, Min Young; Yoon, Seok Ho; Kim, Jin Soo; Chang, Jae Suk; Ryu, Jin Sook; Kim, Ji Wan

2017-01-01

Avascular necrosis (AVN) of the femoral head is a major complication after internal fixation of a femoral neck fracture and determines the functional prognosis. We investigated postoperative bone single-photon emission computed tomography/computed tomography (SPECT/CT) for assessing the risk of femoral head AVN. We retrospectively reviewed 53 consecutive patients who underwent bone SPECT/CT within 2 weeks of internal fixation of a femoral neck fracture and follow-up serial hip radiographs over at least 12 months. Nine patients developed femoral head AVN. In 15 patients who showed normal uptake on immediate postoperative SPECT/CT, no AVN occurred, whereas 9 of 38 patients who showed cold defects of the femoral head later developed AVN. The negative predictive value of immediate postoperative SPECT/CT for AVN was 100 %, whereas the positive predictive value was 24 %. Among 38 patients with cold defects, 1 developed AVN 3 months postoperatively. A follow-up bone SPECT/CT was performed in the other 37 patients at 2–10 months postoperatively. The follow-up bone SPECT/CT revealed completely normalized femoral head uptake in 27, partially normalized uptake in 8, and persistent cold defects in 2 patients. AVN developed in 3.7 % (1/27), 62.5 % (5/8), and 100 % (2/2) of each group, respectively. According to the time point of imaging, radiotracer uptake patterns of the femoral head on postoperative bone SPECT/CT indicate the risk of AVN after internal fixation of femoral neck fractures differently. Postoperative bone SPECT/CT may help orthopedic surgeons determine the appropriate follow-up of these patients

Comparative study on anterior cruciate ligament reconstruction: determination of isometric points with and without navigation

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Fabio J. Angelini

2010-01-01

Full Text Available OBJECTIVES: To compare the accuracy of tunnel placement and graft isometry for anterior cruciate ligament reconstruction performed using a computer-assisted navigation system (Orthopilot and using traditional instruments. METHODS: The anterior cruciate ligament was removed intact from 36 pairs of human cadaver knees. From each pair, one knee was randomized to Group 1 (conventional and the other to Group 2 (Orthopilot. An inelastic suture was then passed through the central points of the tibial and femoral tunnels. Neither of the tunnels was drilled. All knees were then dissected, and six parameters were obtained: distances from the tibial tunnel center to the 1 posterior cruciate ligament, 2 anterior horn of the lateral meniscus and 3 medial tibial spine; 4 distance from the femoral tunnel center to the posterior femoral cortex; 5 femoral tunnel coronal angle; and 6 variation of the distance from the femoral to the tibial tunnel with the knee extended and at 90 degrees of flexion. RESULTS: The variation of the distance from the femoral to the tibial tunnel during flexion and extension was smaller in the Orthopilot group (better isometry compared to the conventional group. There were no statistical differences in any other parameters between the groups, and all tunnels were considered to be in satisfactory positions. DISCUSSION: The results obtained for anterior cruciate ligament reconstruction depend on precise isometric point positioning, and a navigation system is a precision tool that can assist surgeons in tunnel positioning. CONCLUSION: No differences in tunnel position were observed between the groups. Nonetheless, better isometry was achieved in the Orthopilot group than with conventional instruments.

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

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Khairurrijal khairurrijal

2012-09-01

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

Ipsilateral femoral neck and shaft fractures: An overlooked association

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

1991-01-01

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

Ipsilateral femoral neck and shaft fractures: An overlooked association

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

1991-05-01

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

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

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Tahmasebi MN

2011-05-01

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

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

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Kaseb Mohammad Hasan

2009-05-01

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

Clinical study on 44 cases of femoral hernia

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

2012-01-01

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

MR evaluation of femoral neck version and tibial torsion

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

2012-01-15

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

Correlation between baseline femoral neck marrow status and the development of femoral head osteonecrosis in corticosteroid-treated patients: A longitudinal study by MR imaging

International Nuclear Information System (INIS)

Vande Berg, Bruno C.; Gilon, Raphael; Malghem, Jacques; Lecouvet, Frederic; Depresseux, Genevieve; Houssiau, Frederic A.

2006-01-01

Objective: To test the hypothesis that the development of corticosteroid (CS)-associated femoral head osteonecrosis (ON) is influenced by baseline femoral neck marrow status. Patients and methods: The population consisted of 20 untreated patients with a newly diagnosed rheumatic disease in whom a standardized CS regimen was planned. Before CS treatment, baseline femoral neck marrow status was determined by magnetic resonance (MR) imaging on T1-weighted images (proportion of surface area of femoral neck and intertrochanteric area occupied by fatty marrow; index of marrow conversion [IMC]) and on a quantitative MR sequence (bulk T1 values of femoral head and neck). The presence of ON was assessed by coronal T1-weighted MR images of the hips at 6 and 12 months. Results: None of the patients suffered from ON at baseline. Four patients (20%) developed bilateral femoral head ON at 6 months. The mean percentage of fat marrow in the femoral neck before treatment was significantly higher in ON-positive than in ON-negative patients (p = 0.0025). The mean baseline femoral neck IMC value, which parallels the degree of red to yellow marrow conversion, was higher in ON-positive than in ON-negative patients (p = 0.089). The mean baseline bulk T1 value of the femoral neck (but not of the femoral head), which inversely correlates with the amount of fat marrow, was significantly shorter in ON-positive than in ON-negative patients (p = 0.0298). Conclusion: The development of CS-associated femoral head ON is correlated with a high fat content in the proximal femur before CS therapy

Herniography off femoral, obturator and perineal hernias

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

1985-01-01

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

Research on position and orientation measurement method for roadheader based on vision/INS

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Yang, Jinyong; Zhang, Guanqin; Huang, Zhe; Ye, Yaozhong; Ma, Bowen; Wang, Yizhong

2018-01-01

Roadheader which is a kind of special equipment for large tunnel excavation has been widely used in Coal Mine. It is one of the main mechanical-electrical equipment for mine production and also has been regarded as the core equipment for underground tunnel driving construction. With the deep application of the rapid driving system, underground tunnel driving methods with higher automation level are required. In this respect, the real-time position and orientation measurement technique for roadheader is one of the most important research contents. For solving the problem of position and orientation measurement automatically in real time for roadheaders, this paper analyses and compares the features of several existing measuring methods. Then a new method based on the combination of monocular vision and strap down inertial navigation system (SINS) would be proposed. By realizing five degree-of-freedom (DOF) measurement of real-time position and orientation of roadheader, this method has been verified by the rapid excavation equipment in Daliuta coal mine. Experiment results show that the accuracy of orientation measurement is better than 0.1°, the standard deviation of static drift is better than 0.25° and the accuracy of position measurement is better than 1cm. It is proved that this method can be used in real-time position and orientation measurement application for roadheader which has a broad prospect in coal mine engineering.

Tunneling effects in electromagnetic wave scattering by nonspherical particles: A comparison of the Debye series and physical-geometric optics approximations

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Bi, Lei; Yang, Ping

2016-07-01

The accuracy of the physical-geometric optics (PG-O) approximation is examined for the simulation of electromagnetic scattering by nonspherical dielectric particles. This study seeks a better understanding of the tunneling effect on the phase matrix by employing the invariant imbedding method to rigorously compute the zeroth-order Debye series, from which the tunneling efficiency and the phase matrix corresponding to the diffraction and external reflection are obtained. The tunneling efficiency is shown to be a factor quantifying the relative importance of the tunneling effect over the Fraunhofer diffraction near the forward scattering direction. Due to the tunneling effect, different geometries with the same projected cross section might have different diffraction patterns, which are traditionally assumed to be identical according to the Babinet principle. For particles with a fixed orientation, the PG-O approximation yields the external reflection pattern with reasonable accuracy, but ordinarily fails to predict the locations of peaks and minima in the diffraction pattern. The larger the tunneling efficiency, the worse the PG-O accuracy is at scattering angles less than 90°. If the particles are assumed to be randomly oriented, the PG-O approximation yields the phase matrix close to the rigorous counterpart, primarily due to error cancellations in the orientation-average process. Furthermore, the PG-O approximation based on an electric field volume-integral equation is shown to usually be much more accurate than the Kirchhoff surface integral equation at side-scattering angles, particularly when the modulus of the complex refractive index is close to unity. Finally, tunneling efficiencies are tabulated for representative faceted particles.

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

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

2017-06-01

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

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

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

2016-01-01

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

Bilateral femoral neck fractures following pelvic irradiation

International Nuclear Information System (INIS)

Mitsuda, Kenji; Nishi, Hosei; Oba, Hiroshi

1977-01-01

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

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

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

2011-05-01

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

Magnetic resonance imaging of the femoral head necrosis

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

1986-06-01

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

Magnetic resonance imaging of the femoral head necrosis

International Nuclear Information System (INIS)

Narita, Shinya; Asada, Kanji; Yoshida, Kenjiro

1986-01-01

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

Femoral component loosening after hip resurfacing arthroplasty

International Nuclear Information System (INIS)

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

2010-01-01

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

Orientation-dependent imaging of electronically excited quantum dots

Science.gov (United States)

Nguyen, Duc; Goings, Joshua J.; Nguyen, Huy A.; Lyding, Joseph; Li, Xiaosong; Gruebele, Martin

2018-02-01

We previously demonstrated that we can image electronic excitations of quantum dots by single-molecule absorption scanning tunneling microscopy (SMA-STM). With this technique, a modulated laser beam periodically saturates an electronic transition of a single nanoparticle, and the resulting tunneling current modulation ΔI(x0, y0) maps out the SMA-STM image. In this paper, we first derive the basic theory to calculate ΔI(x0, y0) in the one-electron approximation. For near-resonant tunneling through an empty orbital "i" of the nanostructure, the SMA-STM signal is approximately proportional to the electron density |φi) (x0,y0)|nudge quantum dots on the surface and roll them, thus imaging excited state electronic structure of a single quantum dot at different orientations. We use density functional theory to model ODMs at various orientations, for qualitative comparison with the SMA-STM experiment. The model demonstrates that our experimentally observed signal monitors excited states, localized by defects near the surface of an individual quantum dot. The sub-nanometer super-resolution imaging technique demonstrated here could become useful for mapping out the three-dimensional structure of excited states localized by defects within nanomaterials.

Avascular necrosis of the femoral head

International Nuclear Information System (INIS)

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

1990-01-01

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

CT study of avascular necrosis of femoral head in adults

International Nuclear Information System (INIS)

Liu Jihua; Du Yuqing; Xu Aide

2000-01-01

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

Tunneling technologies for the collider ring tunnels

International Nuclear Information System (INIS)

Frobenius, P.

1989-01-01

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

Morphometric analysis of rat femoral vessels under a video magnification system

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Rui Sergio Monteiro de Barros

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

Study of the anatomical position of the femoral nerve by magnetic resonance imaging in patients with fractured neck of femur: relevance to femoral nerve block.

LENUS (Irish Health Repository)

Mehmood, Shehzad

2012-01-31

STUDY OBJECTIVE: To determine the anatomical location of the femoral nerve in patients who have sustained fracture of the neck of femur, and its relevance to femoral nerve block technique. DESIGN: Prospective, observational clinical study. SETTING: Orthopedic and Radiology departments of a regional hospital. SUBJECTS: 10 consecutive adult ASA physical status II and III patients (mean age, 78.5 yrs) and 4 adult healthy volunteers. INTERVENTIONS: A T1 magnetic resonance imaging scan was performed of both upper thighs in patients and healthy volunteers successfully. MEASUREMENTS: The distance (mm) between the midpoint of the femoral artery and the midpoint of the femoral nerve, and the distance of the femoral nerve from the skin was measured at the mid-inguinal ligament, the pubic tubercle, and at the mid-inguinal crease. Data are shown as means (SD). Differences between both sides were compared using paired Student\\'s t-tests. P < 0.05 was significant. MAIN RESULTS: In patients the mean distance (mm) between the midpoint of the femoral nerve from the midpoint of femoral artery at the mid-inguinal crease on the fractured and non-fractured sides was 10.7 and 11.0, respectively (P = 0.87). The mean distance (mm) between the midpoint of the femoral nerve from the midpoint of the femoral artery at the mid-inguinal ligament on the fractured and non-fractured sides was 9.64 and 12.5, respectively (P = 0.03). The mean distance (mm) between the midpoint of the femoral nerve from the midpoint of the femoral artery at the pubic tubercle on the fractured and non-fractured sides was 8.74 and 10.49, respectively (P = 0.18). CONCLUSIONS: Blockade of the femoral nerve may be easier to perform at the mid-inguinal crease in patients with fractured neck of femur.

Bone tunnel diameter measured with CT after anterior cruciate ligament reconstruction using double-bundle auto-hamstring tendors: Clinical implications

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Yoon, Soo Jeong; Yoon, Young Cheol; Bae, So Young; Wang, Joon Ho [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2015-12-15

To evaluate the correlation between bone tunnel diameter after anterior cruciate ligament (ACL) reconstruction measured by computed tomography (CT) using multiplanar reconstruction (MPR) and stability or clinical scores. Forty-seven patients (41 men and 6 women, mean age: 34 years) who had undergone ACL reconstruction with the double bundle technique using auto-hamstring graft and had subsequently received CT scans immediately after the surgery (T1: range, 1-4 days, mean, 2.5 days) and at a later time (T2: range, 297-644 days, mean, 410.4 days) were enrolled in this study. The diameter of each tunnel (two femoral and two tibial) at both T1 and T2 were independently measured using MPR technique by two radiologists. Stability and clinical scores were evaluated with a KT-2000 arthrometer, International Knee Documentation Committee objective scores, and the Lysholm score. Statistical analysis of the correlation between the diameter at T2 or the interval diameter change ratio ([T2 - T1] / T1) and clinical scores or stability was investigated. The tibial bone tunnels for the anteromedial bundles were significantly widened at T2 compared with T1 (observer 1, 0.578 mm to 0.698 mm, p value of < 0.001; observer 2, 0.581 mm to 0.707 mm, p value of < 0.001). There was no significant correlation between the diameter at T2 and stability or clinical scores and between the interval change ratio ([T2 - T1] / T1) and stability or clinical scores (corrected p values for all were 1.0). Intraobserver agreement for measurements was excellent (> 0.8) for both observers. Interobserver agreement for measurement was excellent (> 0.8) except for the most distal portion of the femoral bone tunnel for anterior medial bundle in immediate postoperative CT, which showed moderate agreement (concordance correlation coefficient = 0.6311).Neither the diameter nor its change ratio during interval follow-up is correlated with stability or clinical scores.

Bone tunnel diameter measured with CT after anterior cruciate ligament reconstruction using double-bundle auto-hamstring tendors: Clinical implications

International Nuclear Information System (INIS)

Yoon, Soo Jeong; Yoon, Young Cheol; Bae, So Young; Wang, Joon Ho

2015-01-01

To evaluate the correlation between bone tunnel diameter after anterior cruciate ligament (ACL) reconstruction measured by computed tomography (CT) using multiplanar reconstruction (MPR) and stability or clinical scores. Forty-seven patients (41 men and 6 women, mean age: 34 years) who had undergone ACL reconstruction with the double bundle technique using auto-hamstring graft and had subsequently received CT scans immediately after the surgery (T1: range, 1-4 days, mean, 2.5 days) and at a later time (T2: range, 297-644 days, mean, 410.4 days) were enrolled in this study. The diameter of each tunnel (two femoral and two tibial) at both T1 and T2 were independently measured using MPR technique by two radiologists. Stability and clinical scores were evaluated with a KT-2000 arthrometer, International Knee Documentation Committee objective scores, and the Lysholm score. Statistical analysis of the correlation between the diameter at T2 or the interval diameter change ratio ([T2 - T1] / T1) and clinical scores or stability was investigated. The tibial bone tunnels for the anteromedial bundles were significantly widened at T2 compared with T1 (observer 1, 0.578 mm to 0.698 mm, p value of < 0.001; observer 2, 0.581 mm to 0.707 mm, p value of < 0.001). There was no significant correlation between the diameter at T2 and stability or clinical scores and between the interval change ratio ([T2 - T1] / T1) and stability or clinical scores (corrected p values for all were 1.0). Intraobserver agreement for measurements was excellent (> 0.8) for both observers. Interobserver agreement for measurement was excellent (> 0.8) except for the most distal portion of the femoral bone tunnel for anterior medial bundle in immediate postoperative CT, which showed moderate agreement (concordance correlation coefficient = 0.6311).Neither the diameter nor its change ratio during interval follow-up is correlated with stability or clinical scores

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

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

1997-04-01

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

Simultaneous avascular necrosis of both medial and lateral femoral condyles

International Nuclear Information System (INIS)

Mansberg, R.

2002-01-01

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

Marrow pattern in the proximal femoral metaphysis of patients with osteonecrosis of femoral head and normal subjects: comparison on MR images

International Nuclear Information System (INIS)

Chun, Ho Jong; Park, Jeong Mi; Kim, Jee Young; Lim, Gye Yeon; Yang, Po Song; Kim, Euy Neyong; Kim, Choon Yul; Shinn, Kyung Sub

1996-01-01

To predict early risk of osteonecrosis of the femoral head by comparison of the bone marrow pattern of the proximal femoral metaphysis(PFM) in normal subjects and patients with osteonecrosis of the femoral head on T1-weighted magnetic resonance(MR) images. The authors retrospectively reviewed T1(TR 525/TE 25 msec) weighted coronal MR images of 67 hips with osteonecrosis and 65 normal hips in 39 patients with osteonecrosis of the femoral head and in 27 normal subjects. On the basis of bright signal intensity of fat, the proportion of remaining hematopoietic marrow in PFM was subdivided into 4 grades (0 to 3) by two radiologists. No evidence of remaining hematopoietic marrow was assigned grade 0, and grades 1, 2 and 3 represented scanty, moderate, and prominent hematopoietic marrow, respectively. Grades 0 and 1 were collectively defined as 'predominantly fatty', grades 2 and 3 as 'predominantly hematopoietic'. The frequency of the predominantly fatty marrow in PFM was analyzed in relation to three age groups (<25, 25-50, 50<) and both sexes. The overall frequency of predominantly fatty marrow in PFM was higher in hips with osteonecrosis than in normal hips (p<0.001). Especially in the male population under the age of 50, the frequency was apparently higher in hips with osteonecrosis, compared with normal hips (p<0.0001). However, the male population aged over 50 or female population showed no statistically significant difference in our series. In proximal femoral metaphysis with osteonecrosis of the femoral head, fatty marrow conversion occurs apparently earlier than in normal subject. T1-weighted MR imaging could therefore be useful in predicting early risk of osteonecrosis of the femoral head because of early fatty marrow conversion of the proximal femoral metaphysis

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

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

2013-10-01

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

Tunneling effects in electromagnetic wave scattering by nonspherical particles: A comparison of the Debye series and physical-geometric optics approximations

International Nuclear Information System (INIS)

Bi, Lei; Yang, Ping

2016-01-01

The accuracy of the physical-geometric optics (PG-O) approximation is examined for the simulation of electromagnetic scattering by nonspherical dielectric particles. This study seeks a better understanding of the tunneling effect on the phase matrix by employing the invariant imbedding method to rigorously compute the zeroth-order Debye series, from which the tunneling efficiency and the phase matrix corresponding to the diffraction and external reflection are obtained. The tunneling efficiency is shown to be a factor quantifying the relative importance of the tunneling effect over the Fraunhofer diffraction near the forward scattering direction. Due to the tunneling effect, different geometries with the same projected cross section might have different diffraction patterns, which are traditionally assumed to be identical according to the Babinet principle. For particles with a fixed orientation, the PG-O approximation yields the external reflection pattern with reasonable accuracy, but ordinarily fails to predict the locations of peaks and minima in the diffraction pattern. The larger the tunneling efficiency, the worse the PG-O accuracy is at scattering angles less than 90°. If the particles are assumed to be randomly oriented, the PG-O approximation yields the phase matrix close to the rigorous counterpart, primarily due to error cancellations in the orientation-average process. Furthermore, the PG-O approximation based on an electric field volume-integral equation is shown to usually be much more accurate than the Kirchhoff surface integral equation at side-scattering angles, particularly when the modulus of the complex refractive index is close to unity. Finally, tunneling efficiencies are tabulated for representative faceted particles. - Highlights: • Concepts of diffraction, reflection and tunneling are refined. • The diffraction together with reflection is rigorously treated. • An improved invariant imbedding method is employed to compute the Debye

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

Science.gov (United States)

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

2011-10-01

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

Femoral head vitality after intracapsular hip fracture

International Nuclear Information System (INIS)

Stroemqvist, B.

1983-01-01

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

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

International Nuclear Information System (INIS)

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

1980-01-01

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

Femoral Head Avascular Necrosis Is Not Caused by Arthroscopic Posterolateral Femoroplasty.

Science.gov (United States)

Rupp, Robert E; Rupp, Sasha N

2016-05-01

This study was conducted to identify the risk of avascular necrosis of the femoral head after arthroscopic femoroplasty extending to the posterolateral femoral neck, the source of the primary blood supply to the femoral head. Cam lesions of femoroacetabular impingement are typically anterior along the junction of the femoral head and neck. However, anatomic variations can involve the posterolateral vascular region of the femoral head and neck. Femoroplasty involving this vascular region can lead to injury to the blood supply to the femoral head, with subsequent avascular necrosis. If the posterolateral portion of the cam lesion is preserved, persistent femoroacetabular impingement may occur. A retrospective review identified 112 patients who underwent arthroscopic femoroplasty for femoroacetabular impingement over a 2-year period. Of these patients, 14 had femoroplasty that extended to the posterolateral femoral head. Of this group, 5 had undergone magnetic resonance imaging (MRI) after femoroplasty and the other 9 were contacted to undergo MRI of the hip to evaluate for avascular necrosis. A radiologist and the senior author evaluated all MRI scans specifically for avascular necrosis of the femoral head. All procedures were performed by the senior author. Mean age of the 14 patients (8 women and 6 men) with femoroplasty that extended into the posterolateral vascular region of the femoral head was 44 years (range, 23-69 years). All 14 patients underwent MRI evaluation of the affected hip a mean of 25 months (range, 7-44 months) after femoroplasty. No MRI scans showed evidence of avascular necrosis of the femoral head. Femoroplasty of the posterolateral vascular region of the femoral head is not associated with avascular necrosis. Patients with femoroacetabular impingement and a cam lesion extending to the posterolateral femoral head can undergo femoroplasty of this region without the development of avascular necrosis. [Orthopedics. 2016; 39(3):177-180.]. Copyright

Selective arteriography in femoral head fractures

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

1986-01-01

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

[Femoral artery pseudoaneurysms encountered in orthopedics and traumatology].

Science.gov (United States)

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

2015-12-01

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

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

Science.gov (United States)

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

2010-11-01

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

Comparison of 2 surgical techniques for reconstructing posterolateral corner of the knee: a cadaveric study evaluated by navigation system.

Science.gov (United States)

Ho, Eric Po-Yan; Lam, Mak-Ham; Chung, Mandy Man-Ling; Fong, Daniel Tik-Pui; Law, Billy Kan-Yip; Yung, Patrick Shu-Hang; Chan, Wood-Yee; Chan, Kai-Ming

2011-01-01

This study aimed to evaluate the immediate effect on knee kinematics by 2 different techniques of posterolateral corner (PLC) reconstruction. Five intact formalin-preserved cadaveric knees were used in this study. A navigation system was used to measure knee kinematics (posterior translation, varus angulation, and external rotation) after application of a constant force and torque to the tibia. Four different conditions of the knee were evaluated during the biomechanical test: intact knee and PLC-sectioned knee and PLC-reconstructed knee by the double-femoral tunnel technique and single-femoral tunnel technique. Sectioning of the PLC structures resulted in significant increases in external rotation at 30° of flexion from 11.2° (SD, 2.6) to 24.6° (SD, 6.2), posterior translation at 30° of flexion from 3.4 mm (SD, 1.5) to 7.4 mm (SD, 3.8), and varus angulation at 0° of flexion from 2.3° (SD, 2.1) to 7.9° (SD, 5.1). Both reconstruction techniques significantly restored the varus stability. The external rotation and posterior translation at 30° of flexion after reconstruction with the double-femoral tunnel technique were 10.2° (SD, 1.3) and 3.4° (SD, 2.7), respectively, which were significantly better than those of the single-femoral tunnel technique. Both techniques of reconstruction showed improved stability compared with PLC-sectioned knees. The double-femoral tunnel technique in PLC reconstruction showed better rotational stability and resistance to posterior translation than the single-femoral tunnel technique without compromising varus stability. PLC reconstruction by a double-femoral tunnel technique achieves better rotational control and resistance to posterior translation. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

[Midterm follow-up results on Asian femoral intramedullary nail for the treatment of segmental and comminuted femoral fractures].

Science.gov (United States)

Li, Lang; Gao, Feng; Huang, Qi; Li, Qiang; Xie, Lin; Zhang, Bin

2016-06-01

To investigate midterm follow-up results on Asian femoral intramedullary nail in treating segmental and comminuted femoral fractures. Between June 2011 and October 2012,16 patients with segmental and comminuted femoral fractures were treated with minimally invasive reset and Asian femoral intramedullary nail under extension table. Among them, there were 10 males and 6 females aged from 21 to 49 years old with an average of 34.5 years old; the time from injury to operation ranged from 3 to 24 d with an average of 9.1 d. There were 6 cases were type C1,2 cases were type C2 and 8 cases were type C3 according to AO classification. X-ray of femoral segment at 3,6 and 12 months after operation were applied for evaluating fracture healing. Harris score of hip joint and HSS score of knee joint were used to evaluate postoperative function. All patients were followed up from 24 to 36 months with an average of 28.4 months. Operative time was from 88 to 112 min with an average of 90.7 min; blood loss ranged from 150 to 200 ml with an average of 188.75 ml; the time of fracture healing was from 5 to 9 months with an average of 5.4 months. All incision were healed at stage I. No loosening, breakage of internal fixation and displacement of fracture were occurred. There were no significant differences in Harris score of hip joint at 3, 6 and 12 months after operation (F = 0.07, P = 0.893 > 0.05), 10 cases obtained excellent results, 5 good and 1 moderate. There was no obvious meaning in HSS score of knee joint (F = 0.08,P = 0.876 > 0.05), 9 cases obtained excellent results, 6 good and 1 poor. Asian femoral intramedullary nail could treat segmental and comminuted femoral fractures by using variety of less invasive ways,which has advantages of less trauma, quick recovery of function and satisfied midterm following-up results. But long term following-up effects remains to be seen.

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

Science.gov (United States)

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

2017-02-06

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

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

Science.gov (United States)

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

2017-01-01

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

Tunnelling anomalous and planar Hall effects (Conference Presentation)

Science.gov (United States)

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

2016-10-01

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

Influence of semiconductor barrier tunneling on the current-voltage characteristics of tunnel metal-oxide-semiconductor diodes

DEFF Research Database (Denmark)

Nielsen, Otto M.

1983-01-01

of multistep tunneling recombination current and injected minority carrier diffusion current. This can explain the observed values of the diode quality factor n. The results also show that the voltage drop across the oxide Vox is increased with increased NA, with the result that the lowering of the minority...... carrier diode current Jmin is greater than in the usual theory. The conclusion drawn is that the increase in Vox and lowering of Jmin is due to multistep tunneling of majority carriers through the semiconductor barrier. Journal of Applied Physics is copyrighted by The American Institute of Physics.......Current–voltage characteristics have been examined for Al–SiO2–pSi diodes with an interfacial oxide thickness of delta[approximately-equal-to]20 Å. The diodes were fabricated on and oriented substrates with an impurity concentration in the range of NA=1014–1016 cm−3. The results show that for low...

Computerized tomography in evaluation of decreased acetabular and femoral anteversion

International Nuclear Information System (INIS)

Toennis, D.; Skamel, H.J.

2003-01-01

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

Femoral neck fracture following groin irradiation

Energy Technology Data Exchange (ETDEWEB)

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

1995-04-30

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

Femoral neck fracture following groin irradiation

International Nuclear Information System (INIS)

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

1995-01-01

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

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

DEFF Research Database (Denmark)

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

2016-01-01

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

Orientation-weighted local Minkowski functionals in 3D for quantitative assessment of trabecular bone structure in the hip

Science.gov (United States)

Boehm, H. F.; Bitterling, H.; Weber, C.; Kuhn, V.; Eckstein, F.; Reiser, M.

2007-03-01

Fragility fractures or pathologic fractures of the hip, i.e. fractures with no apparent trauma, represent the worst complication in osteoporosis with a mortality close to 25% during the first post-traumatic year. Over 90% of hip fractures result from falls from standing height. A substantial number of femoral fractures are initiated in the femoral neck or the trochanteric regions which contain an internal architecture of trabeculae that are functionally highly specialized to withstand the complex pattern of external and internal forces associated with human gait. Prediction of the mechanical strength of bone tissue can be achieved by dedicated texture analysis of data obtained by high resolution imaging modalities, e.g. computed tomography (CT) or magnetic resonance tomography (MRI). Since in the case of the proximal femur, the connectivity, regional distribution and - most of all - the preferred orientation of individual trabeculae change considerably within narrow spatial limits, it seems most reasonable to evaluate the femoral bone structure on an orientation-weighted, local scale. In past studies, we could demonstrate the advantages of topological analysis of bone structure using the Minkowski Functionals in 3D on a global and on a local scale. The current study was designed to test the hypothesis that the prediction of the mechanical competence of the proximal femur by a new algorithm considering orientational changes of topological properties in the trabecular architecture is feasible and better suited than conventional methods based on the measurement of the mineral density of bone tissue (BMD).

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

Directory of Open Access Journals (Sweden)

Wen-Chuan Chen

2014-07-01

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

Spin-polarized scanning tunneling microscopy: breakthroughs and highlights.

Science.gov (United States)

Bode, Matthias

2012-01-01

The principle of scanning tunneling microscopy, an imaging method with atomic resolution capability invented by Binnig and Rohrer in 1982, can be adapted for surface magnetism studies by using magnetic probe tips. The contrast mechanism of this so-called spin-polarized scanning tunneling microscopy, or SP-STM, relies on the tunneling magneto-resistance effect, i.e. the tip-sample distance as well as the differential conductance depend on the relative magnetic orientation of tip and sample. To illustrate the working principle and the unique capabilities of SP-STM, this compilation presents some key experiments which have been performed on various magnetic surfaces, such as the topological antiferromagnet Cr(001), a double-layer of Fe which exhibits a stripe- domain pattern with about 50 nm periodicity, and the Mn monolayer on W(110), where the combination of experiment and theory reveal an antiferromagnetic spin cycloid. Recent experimental results also demonstrate the suitability of SP-STM for studies of dynamic properties, such as the spin relaxation time of single magnetic nanostructures.

A multi-modality tracking, navigation and calibration for a flexible robotic drill system for total hip arthroplasty.

Science.gov (United States)

Ahmad Fuad, Ahmad Nazmi Bin; Deep, Kamal; Yao, Wei

2018-02-01

This paper presents a novel multi-modality tracking and navigation system that provides a unique capability to guild a flexible drill tip inside the bone with accurate curved tunnelling. As the flexible drill tip cannot be tracked optically inside the bone, this research focuses on developing a hybrid tracking and navigation system for tracking a flexible drill tip by using both optical and kinematic tracking. The tracking information is used to guide the THA (total hip arthroplasty) procedure, providing a real-time virtual model of the flexible drill. The flexible and steerable drill tip system is then tested on total hip arthroplasty followed by evaluation of the positioning and orientation of femoral stem placement by femoral milling. Based on this study, we conclude that the tracking and navigation system is able to guide the flexible drill to mill inside femoral canal. Copyright © 2017 John Wiley & Sons, Ltd.

Treatment of the femoral neck peudoarthrosis in childhood: Case report

Directory of Open Access Journals (Sweden)

Vukašinović Zoran

2013-01-01

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

Continuous Mapping of Tunnel Walls in a Gnss-Denied Environment

Science.gov (United States)

Chapman, Michael A.; Min, Cao; Zhang, Deijin

2016-06-01

The need for reliable systems for capturing precise detail in tunnels has increased as the number of tunnels (e.g., for cars and trucks, trains, subways, mining and other infrastructure) has increased and the age of these structures and, subsequent, deterioration has introduced structural degradations and eventual failures. Due to the hostile environments encountered in tunnels, mobile mapping systems are plagued with various problems such as loss of GNSS signals, drift of inertial measurements systems, low lighting conditions, dust and poor surface textures for feature identification and extraction. A tunnel mapping system using alternate sensors and algorithms that can deliver precise coordinates and feature attributes from surfaces along the entire tunnel path is presented. This system employs image bridging or visual odometry to estimate precise sensor positions and orientations. The fundamental concept is the use of image sequences to geometrically extend the control information in the absence of absolute positioning data sources. This is a non-trivial problem due to changes in scale, perceived resolution, image contrast and lack of salient features. The sensors employed include forward-looking high resolution digital frame cameras coupled with auxiliary light sources. In addition, a high frequency lidar system and a thermal imager are included to offer three dimensional point clouds of the tunnel walls along with thermal images for moisture detection. The mobile mapping system is equipped with an array of 16 cameras and light sources to capture the tunnel walls. Continuous images are produced using a semi-automated mosaicking process. Results of preliminary experimentation are presented to demonstrate the effectiveness of the system for the generation of seamless precise tunnel maps.

Femoral neck fractures complicating gaucher disease in children

International Nuclear Information System (INIS)

Goldman, A.B.; Jacobs, B.

1984-01-01

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

Femoral neck fractures complicating gaucher disease in children

Energy Technology Data Exchange (ETDEWEB)

Goldman, A B; Jacobs, B

1984-09-01

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

frequency of ipsilateral femoral neck fractures in patients

African Journals Online (AJOL)

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

Sequential MRI Study of Graft Integrity and Signal Following Pediatric All-epiphyseal ACL Reconstruction: Does the “Sharp Turn” at the Socket of the Distal Femoral Aperture Matter?

Science.gov (United States)

Tuca, Maria; Greditzer, Harry Gus; Gausden, Elizabeth Bishop; Uppstrom, Tyler J.; Potter, Hollis G.; Cordasco, Frank A.; Green, Daniel W.

2017-01-01

Objectives: To analyze graft structure and signal with particular emphasis on the distal femoral socket aperture following all-epiphyseal ACLR using hamstring autografts with sequential MRI in skeletally immature athletes. Methods: Retrospective cohort study of 23 skeletally immature patients who underwent ACLR by the same surgical team at a tertiary center during 2011-2013. Athletes had at least two follow-up MRIs, the first MRI 6-12 months after surgery and the second MRI >18 months, were included. Exclusion criteria included those athletes with inMRI follow-up (6) or with a failure of their reconstructions (1). All athletes were treated with an arthroscopic all-inside, all-epiphyseal ACLR, using hamstring autograft, secured with adjustable loop cortical buttons on both tibia and femur. MRI images were analyzed independently and blinded by an orthopaedic surgery fellow and a musculoskeletal radiology fellow. Using a GE Functional Analysis Software, the signal intensity (SI) of the graft was measured in 5 different locations: 1) femoral tunnel, 2) intra-articular proximal turn, 3) midsubstance, 4) intra-articular distal turn, and 5) tibial tunnel. Values were normalized to cortical bone density. The amount of perigraft scarring and synovitis was analyzed. An intraclass correlation coefficient was used to quantify inter-rater reliability, non-parametric Wilcoxon test for perigraft scarring and synovitis, one-way ANOVA to test if significant differences of SI were seen between the different graft locations, and a 2-tailed student t-test for SI changes from 1st to 2nd MRI. Results: The study included 16 patients (5 girls and 11 boys), with an average age at surgery of 11.9 years (range 10-15). The first follow-up MRI was on average at 8.4 months (range 6-12 months), while the 2nd MRI was on average 30.7 months (range 18-40) after surgery. Intra-class correlation coefficients were above 0.7 for all measurements, indicating an excellent concordance between observers

Proximal femoral fractures

DEFF Research Database (Denmark)

Palm, Henrik; Teixidor, Jordi

2015-01-01

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

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

DEFF Research Database (Denmark)

Monaco, Roberto; Aarøe, Morten; Mygind, Jesper

2009-01-01

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

Localized cortical thickening of the femoral diaphysis captured on an X-ray before alendronate therapy in two cases of atypical femoral fracture

Energy Technology Data Exchange (ETDEWEB)

Iizuka, Yoichi [Gunma University Graduate School of Medicine, Department of Orthopedic Surgery, Maebashi, Gunma (Japan); Shibukawa General Hospital, Department of Orthopedic Surgery, Shibukawa, Gunma (Japan); Takechi, Rumi [Gunma University Graduate School of Medicine, Department of Orthopedic Surgery, Maebashi, Gunma (Japan); Gunma Cardiovascular Center, Department of Orthopaedic Surgery, Maebashi, Gunma (Japan); Iizuka, Haku; Takagishi, Kenji [Gunma University Graduate School of Medicine, Department of Orthopedic Surgery, Maebashi, Gunma (Japan); Omodaka, Takuya [Gunma University Graduate School of Medicine, Department of Orthopedic Surgery, Maebashi, Gunma (Japan); Gunma Central Hospital, Department of Orthopedic Surgery, Maebashi, Gunma (Japan)

2016-10-15

We herein report two cases of atypical femoral fracture (AFF). X-ray examinations at the first visit of these two female patients showed a complete fracture of the femoral diaphysis diagnosed as an atypical femoral fracture (AFF). X-rays of these two cases also showed localized cortical thickening of the femoral diaphysis. Both patients had been taking alendronate for more than 3 years because of postmenopausal osteoporosis. We assumed that both of the fractures were associated with the long-term use of alendronate. However, we retrospectively identified localized cortical thickening of the femoral diaphysis on an X-ray taken before the alendronate therapy in both of these cases. Therefore, we suspected a pathogenesis of AFFs in which preexisting stress or an insufficient fracture unrelated to bisphosphonate (BP) therapy and subsequent suppression of bone turnover due to BP administration led to the occurrence of an AFF. The patient underwent surgery using intramedullary nails in both of these cases, followed by the administration of teriparatide, and they were able to walk without any support at the final follow-up examination. (orig.)

Iodixanol in femoral arteriography

International Nuclear Information System (INIS)

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

1994-01-01

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

Femoral Neck Shaft Angle in Men with Fragility Fractures

Directory of Open Access Journals (Sweden)

S. P. Tuck

2011-01-01

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

Logistic regression analysis of factors associated with avascular necrosis of the femoral head following femoral neck fractures in middle-aged and elderly patients.

Science.gov (United States)

Ai, Zi-Sheng; Gao, You-Shui; Sun, Yuan; Liu, Yue; Zhang, Chang-Qing; Jiang, Cheng-Hua

2013-03-01

Risk factors for femoral neck fracture-induced avascular necrosis of the femoral head have not been elucidated clearly in middle-aged and elderly patients. Moreover, the high incidence of screw removal in China and its effect on the fate of the involved femoral head require statistical methods to reflect their intrinsic relationship. Ninety-nine patients older than 45 years with femoral neck fracture were treated by internal fixation between May 1999 and April 2004. Descriptive analysis, interaction analysis between associated factors, single factor logistic regression, multivariate logistic regression, and detailed interaction analysis were employed to explore potential relationships among associated factors. Avascular necrosis of the femoral head was found in 15 cases (15.2 %). Age × the status of implants (removal vs. maintenance) and gender × the timing of reduction were interactive according to two-factor interactive analysis. Age, the displacement of fractures, the quality of reduction, and the status of implants were found to be significant factors in single factor logistic regression analysis. Age, age × the status of implants, and the quality of reduction were found to be significant factors in multivariate logistic regression analysis. In fine interaction analysis after multivariate logistic regression analysis, implant removal was the most important risk factor for avascular necrosis in 56-to-85-year-old patients, with a risk ratio of 26.00 (95 % CI = 3.076-219.747). The middle-aged and elderly have less incidence of avascular necrosis of the femoral head following femoral neck fractures treated by cannulated screws. The removal of cannulated screws can induce a significantly high incidence of avascular necrosis of the femoral head in elderly patients, while a high-quality reduction is helpful to reduce avascular necrosis.

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

Science.gov (United States)

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

2018-01-01

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

'Femoral head necrosis' in metabolic and hormonal osteopathies

International Nuclear Information System (INIS)

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

1984-01-01

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

Femoral neck fractures complicating gaucher disease in children

Energy Technology Data Exchange (ETDEWEB)

Goldman, A.B.; Jacobs, B.

1984-09-01

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

Anatomic landmarks of fluoroscopy guided puncture of the pulseless femoral artery

International Nuclear Information System (INIS)

Jeon, Min Hee; Han, Gi Seok; Kim, Sung Jin; Park, Kil Sun; Cha, Sang Hoon; Bae, Il Hun; Lee, Seung Young

2006-01-01

We wanted to improve puncturing the pulseless femoral artery by evaluating the anatomic landmarks that suggest the course of the femoral artery on fluoroscopy. We analyzed 37 hemipelvis spot images that were centered on the arterial sheath after puncture of the femoral artery. The inguinal angles were measured between the inguinal line connecting the anterior superior iliac spine and the symphysis pubis, and the line of the arterial sheath. Inguinal ligament ratios were measured as the distance from the symphysis pubis to the arterial sheath to the length of the inguinal ligament on the inguinal line. The femoral head ratios were measured as the distance from the medial margin of the femur head to the arterial sheath to the transverse length of the femur head. The mean inguinal angle was 66.5 and the mean inguinal ligament ratio was 0.42 (± 0.03). The mean femoral head ratio was 0.08 (± 0.18). In comparing the men and women, there was no significant difference in the inguinal angle and the femoral head ratio, but the inguinal distance ratio was larger in women (men: 0.41 ± 0.033, women: 0.44 ± 0.031, ρ < 0.05). The femoral artery generally courses just lateral to the medial margin of the femur head (femoral head ratio: 0.08) and the medial 40% of the inguinal ligament (inguinal ligament ratio: 0.42). So, consideration of these relations may be helpful for puncturing the pulseless femoral artery

MRI for early diagnosis of avascular necrosis of the femoral head

International Nuclear Information System (INIS)

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

1988-01-01

Magnetic resonance imaging (MRI) was performed in forty patients on long-term oral steroid therapy for early detection of avascular necrosis (AN) of the femoral head. In 13 patients, AN was diagnosed in the unilateral femoral head from abnormal plain radiographs while the contralateral femoral head was normal radiographically. In the other 27 patients, radiographs were normal. A total of 67 femoral heads with normal radiographs is studied in this paper. In 36 of 67 femoral heads (54 %), MRI demonstrated abnormal low intensity area. The abnormal findings on MRI were divided into five patterns: whole type (type A), peripheral type (type B), ring or band type (type C), small change type (type D) and distal type (type E). Type A, B, C, D and E were found in 2, 11, 5, 16 and 2 femoral heads, respectively. In cases to be followed up over 6 months, AN was manifested radiographically in 4 femoral heads of 5 in type C and in one of 14 in type D. Meanwhile, in 6 of 41 femoral heads examined (15 %), bone scintigrams was abnormal. Followed-up study over 6 months revealed that AN was manifested radiographically in one femoral head of 6 with abnormal scintigram. However, in 4 of 30 with normal scintigram, AN was manifested subsequently. MRI was a better diagnostic modality for early AN. Ring or band-like low intensity (type C) on MRI was considered to be characteristic pattern of early AN. (author)

MRI for early diagnosis of avascular necrosis of the femoral head

Energy Technology Data Exchange (ETDEWEB)

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

1988-09-01

Magnetic resonance imaging (MRI) was performed in forty patients on long-term oral steroid therapy for early detection of avascular necrosis (AN) of the femoral head. In 13 patients, AN was diagnosed in the unilateral femoral head from abnormal plain radiographs while the contralateral femoral head was normal radiographically. In the other 27 patients, radiographs were normal. A total of 67 femoral heads with normal radiographs is studied in this paper. In 36 of 67 femoral heads (54 %), MRI demonstrated abnormal low intensity area. The abnormal findings on MRI were divided into five patterns: whole type (type A), peripheral type (type B), ring or band type (type C), small change type (type D) and distal type (type E). Type A, B, C, D and E were found in 2, 11, 5, 16 and 2 femoral heads, respectively. In cases to be followed up over 6 months, AN was manifested radiographically in 4 femoral heads of 5 in type C and in one of 14 in type D. Meanwhile, in 6 of 41 femoral heads examined (15 %), bone scintigrams was abnormal. Followed-up study over 6 months revealed that AN was manifested radiographically in one femoral head of 6 with abnormal scintigram. However, in 4 of 30 with normal scintigram, AN was manifested subsequently. MRI was a better diagnostic modality for early AN. Ring or band-like low intensity (type C) on MRI was considered to be characteristic pattern of early AN.

Is Contralateral Templating Reliable for Establishing Rotational Alignment During Intramedullary Stabilization of Femoral Shaft Fractures? A Study of Individual Bilateral Differences in Femoral Version.

Science.gov (United States)

Croom, William P; Lorenzana, Daniel J; Auran, Richard L; Cavallero, Matthew J; Heckmann, Nathanael; Lee, Jackson; White, Eric A

2018-02-01

To determine native individual bilateral differences (IBDs) in femoral version in a diverse population. Computed tomography scans with complete imaging of uninjured bilateral femora were used to determine femoral version and IBDs in version. Age, sex, and ethnicity of each subject were also collected. Femoral version and IBDs in version were correlated with demographic variables using univariate and multivariate regression models. One hundred sixty-four subjects were included in the study. The average femoral version was 9.4 degrees (±9.4 degrees). The mean IBD in femoral version was 5.4 degrees (±4.4 degrees, P alignment during intramedullary stabilization of diaphyseal femur fractures. This is also an important consideration when considering malrotation of femur fractures because most studies define malrotation as a greater than 10-15-degree difference compared with the contralateral side. Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Proximal Focal Femoral Deficiency in Ibadan a Developing ...

African Journals Online (AJOL)

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

Femoral neck radiography: effect of flexion on visualization

International Nuclear Information System (INIS)

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

2005-01-01

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

MgB2 energy gap determination by scanning tunnelling spectroscopy

International Nuclear Information System (INIS)

Heitmann, T W; Bu, S D; Kim, D M; Choi, J H; Giencke, J; Eom, C B; Regan, K A; Rogado, N; Hayward, M A; He, T; Slusky, J S; Khalifah, P; Haas, M; Cava, R J; Larbalestier, D C; Rzchowski, M S

2004-01-01

We report scanning tunnelling spectroscopy (STS) measurements of the gap properties of both ceramic MgB 2 and c-axis oriented epitaxial MgB 2 thin films. Both show a temperature dependent zero bias conductance peak and evidence for two superconducting gaps. We report tunnelling spectroscopy of superconductor-insulator-superconductor (S-I-S) junctions formed in two ways in addition to normal metal-insulator-superconductor (N-I-S) junctions. We find a gap δ = 2.2-2.8 meV, with spectral features and temperature dependence that are consistent between S-I-S junction types. In addition, we observe evidence of a second, larger gap, δ 7.2 meV, consistent with a proposed two-band model

Quantitative CT assessment of proximal femoral bone density. An experimental study concerning its correlation to breaking load for femoral neck fractures

International Nuclear Information System (INIS)

Buitrago-Tellez, C.H.; Schulze, C.; Gufler, H.; Langer, M.; Bonnaire, F.; Hoenninger, A.; Kuner, E.

1997-01-01

Purpose: In an experimental study, the correlation between the trabecular bone density of the different regions of the proximal femur and the fracture load in the setting of femoral neck fractures was examined. Methods: The bone mineral density 41 random proximal human femora was estimated by single-energy quanitative CT (SE-QCT). The trabecular bone density was measured at the greatest possible extracortical volume at midcapital, midneck and intertrochanteric level and in the 1 cm 3 volumes of the centres of these regions in a standardised 10 mm thick slice in the middle of the femoral neck axis (in mg/ml Ca-hydroxyl apatite). The proximal femora were then isolated and mounted on a compression/bending device under two-legged stand conditions and loaded up to the point when a femoral neck fracture occurred. Results: Statistical analysis revealed a linear correlation between the trabecular bone density and the fracture load for the greater regions, with the highest value in the maximal area of the head (coefficient factor r=0.76). Conclusion: According to our data, the measurement of the trabecular bone by SE-QCT at the femoral head is a more confident adjunct than the neck or trochanteric area to predict a femoral neck fracture. (orig.) [de

Tunnel - history of

International Nuclear Information System (INIS)

1998-11-01

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

Radionuclide patterns of femoral head disease

Energy Technology Data Exchange (ETDEWEB)

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

1977-12-01

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

Radiological assessment of the femoral bowing in Japanese population

Directory of Open Access Journals (Sweden)

Abdelaal Ahmed Hamed Kassem

2016-01-01

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

Mesoscopic self-organization of a self-assembled supramolecular rectangle on highly oriented pyrolytic graphite and Au(111) surfaces.

Science.gov (United States)

Gong, Jian-Ru; Wan, Li-Jun; Yuan, Qun-Hui; Bai, Chun-Li; Jude, Hershel; Stang, Peter J

2005-01-25

A self-assembled supramolecular metallacyclic rectangle was investigated with scanning tunneling microscopy on highly oriented pyrolytic graphite and Au(111) surfaces. The rectangles spontaneously adsorb on both surfaces and self-organize into well ordered adlayers. On highly oriented pyrolytic graphite, the long edge of the rectangle stands on the surface, forming a 2D molecular network. In contrast, the face of the rectangle lays flat on the Au(111) surface, forming linear chains. The structures and intramolecular features obtained through high-resolution scanning tunneling microscopy imaging are discussed.

Typical Underwater Tunnels in the Mainland of China and Related Tunneling Technologies

Directory of Open Access Journals (Sweden)

Kairong Hong

2017-12-01

Full Text Available In the past decades, many underwater tunnels have been constructed in the mainland of China, and great progress has been made in related tunneling technologies. This paper presents the history and state of the art of underwater tunnels in the mainland of China in terms of shield-bored tunnels, drill-and-blast tunnels, and immersed tunnels. Typical underwater tunnels of these types in the mainland of China are described, along with innovative technologies regarding comprehensive geological prediction, grouting-based consolidation, the design and construction of large cross-sectional tunnels with shallow cover in weak strata, cutting tool replacement under limited drainage and reduced pressure conditions, the detection and treatment of boulders, the construction of underwater tunnels in areas with high seismic intensity, and the treatment of serious sedimentation in a foundation channel of immersed tunnels. Some suggestions are made regarding the three potential great strait-crossing tunnels—the Qiongzhou Strait-Crossing Tunnel, Bohai Strait-Crossing Tunnel, and Taiwan Strait-Crossing Tunnel—and issues related to these great strait-crossing tunnels that need further study are proposed. Keywords: Underwater tunnel, Strait-crossing tunnel, Shield-bored tunnel, Immersed tunnel, Drill and blast

Large Magnetoresistance at Room Temperature in Organic Molecular Tunnel Junctions with Nonmagnetic Electrodes.

Science.gov (United States)

Xie, Zuoti; Shi, Sha; Liu, Feilong; Smith, Darryl L; Ruden, P Paul; Frisbie, C Daniel

2016-09-27

We report room-temperature resistance changes of up to 30% under weak magnetic fields (0.1 T) for molecular tunnel junctions composed of oligophenylene thiol molecules, 1-2 nm in length, sandwiched between gold contacts. The magnetoresistance (MR) is independent of field orientation and the length of the molecule; it appears to be an interface effect. Theoretical analysis suggests that the source of the MR is a two-carrier (two-hole) interaction at the interface, resulting in spin coupling between the tunneling hole and a localized hole at the Au/molecule contact. Such coupling leads to significantly different singlet and triplet transmission barriers at the interface. Even weak magnetic fields impede spin relaxation processes and thus modify the ratio of holes tunneling via the singlet state versus the triplet state, which leads to the large MR. Overall, the experiments and analysis suggest significant opportunities to explore large MR effects in molecular tunnel junctions based on widely available molecules.

Individualised distal femoral cut improves femoral component placement and limb alignment during total knee replacement in knees with moderate and severe varus deformity.

Science.gov (United States)

Palanisami, Dhanasekararaja; Iyyampillai, Geethan; Shanmugam, Sivaraj; Natesan, Rajkumar; S, Rajasekaran

2016-10-01

Our aim was to determine the variation in valgus correction angle and the influence of individualised distal femoral cut on femoral component placement and limb alignment during total knee replacement (TKR) in knees with varus deformity. The study was done prospectively in two stages. In the first stage, the valgus correction angle (VCA) was calculated in long-limb radiographs of 227 patients and correlated with pre-operative parameters of femoral bowing, neck-shaft angle and hip-knee-ankle angle. In the second part comprising of 240 knees with varus deformity, 140 (group 1) had the distal femoral cut individualised according to the calculated VCA, while the remaining 100 knees (group 1) were operated with a fixed distal femoral cut of 5°. The outcome of surgery was studied by grouping the knees as varus 15°. Of the 227 limbs analysed in stage I, 70 knees (31 %) had a VCA angle outside 5-7°. Coronal bowing (p shaft angle (p alignment when VCA was individualised in the groups of knees with varus 10-15° (p 0.002) and varus >15° (p 0.002). Valgus correction angle is highly variable and is influenced by femoral bowing, neck-shaft angle and pre-operative deformity. Individualisation of VCA is preferable in patients with moderate and severe varus deformity. Level 2.

Biophysical stimulation in osteonecrosis of the femoral head

Directory of Open Access Journals (Sweden)

Massari Leo

2009-01-01

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

One stage revision single-bundle anterior cruciate ligament reconstruction with impacted morselized bone graft following a failed double-bundle reconstruction

Directory of Open Access Journals (Sweden)

Ho Jong Ra

2017-01-01

Full Text Available Although double-bundle anterior cruciate ligament (ACL reconstruction has theoretical benefits such as more accurate reproduction of ACL anatomy, it is technically more demanding surgery. This report describes the case of a one stage revision single-bundle ACL reconstruction after primary double-bundle ACL reconstruction. A professional dancer had an ACL previously reconstructed with a double-bundle technique, but the femoral tunnels were malpositioned resulting in residual laxity and rotational instability. The previous femoral tunnel positions were vertical and widened. The previous vertical tunnels were filled with impacted bone graft and a revision single-bundle ACL reconstruction was performed via the new femoral tunnel with a 2 O'clock position between the previous two tunnels. After 10 months of postoperative rehabilitation, the patient returned to professional dancing with sound bony union and without any residual instability.

Manifestation of spin selection rules on the quantum tunneling of magnetization in a single-molecule magnet.

Science.gov (United States)

Henderson, J J; Koo, C; Feng, P L; del Barco, E; Hill, S; Tupitsyn, I S; Stamp, P C E; Hendrickson, D N

2009-07-03

We present low temperature magnetometry measurements on a new Mn3 single-molecule magnet in which the quantum tunneling of magnetization (QTM) displays clear evidence for quantum mechanical selection rules. A QTM resonance appearing only at high temperatures demonstrates tunneling between excited states with spin projections differing by a multiple of three. This is dictated by the C3 molecular symmetry, which forbids pure tunneling from the lowest metastable state. Transverse field resonances are understood by correctly orienting the Jahn-Teller axes of the individual manganese ions and including transverse dipolar fields. These factors are likely to be important for QTM in all single-molecule magnets.

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

International Nuclear Information System (INIS)

Halbritter, J.

1997-01-01

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

Avascular osteonecrosis of the femoral condyle after arthroscopic surgery

International Nuclear Information System (INIS)

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

1997-01-01

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

Research and advancement of treating avascular necrosis of the femoral head

International Nuclear Information System (INIS)

Wang Kaibing; Bai Bin; Wang Honghui; Sui Hong

2006-01-01

To undertake retrospective analysis of the research and advancement of treating avascular necrosis of the femoral head. After comparing the superiority and inferiority of different treatments and the present therapeutic status many therapeutic methods for avascular necrosis of the femoral head have been performed, commonly according to the staging of necrosis. Conservative therapy is suitable for stage 0-I, interventional therapy is suitable for stage II-III, operation is adapted for stage II-III and femoral head collapse or degenerative changes. Avascular necrosis of the femoral head is a chronic and dysfunctional illness. Comprehensive treatment according to different stage is now the most popular. Interventional therapy is the study focus of the avascular necrosis of the femoral head meanwhile. (authors)

A Method of Accurate Bone Tunnel Placement for Anterior Cruciate Ligament Reconstruction Based on 3-Dimensional Printing Technology: A Cadaveric Study.

Science.gov (United States)

Ni, Jianlong; Li, Dichen; Mao, Mao; Dang, Xiaoqian; Wang, Kunzheng; He, Jiankang; Shi, Zhibin

2018-02-01

To explore a method of bone tunnel placement for anterior cruciate ligament (ACL) reconstruction based on 3-dimensional (3D) printing technology and to assess its accuracy. Twenty human cadaveric knees were scanned by thin-layer computed tomography (CT). To obtain data on bones used to establish a knee joint model by computer software, customized bone anchors were installed before CT. The reference point was determined at the femoral and tibial footprint areas of the ACL. The site and direction of the bone tunnels of the femur and tibia were designed and calibrated on the knee joint model according to the reference point. The resin template was designed and printed by 3D printing. Placement of the bone tunnels was accomplished by use of templates, and the cadaveric knees were scanned again to compare the concordance of the internal opening of the bone tunnels and reference points. The twenty 3D printing templates were designed and printed successfully. CT data analysis between the planned and actual drilled tunnel positions showed mean deviations of 0.57 mm (range, 0-1.5 mm; standard deviation, 0.42 mm) at the femur and 0.58 mm (range, 0-1.5 mm; standard deviation, 0.47 mm) at the tibia. The accuracy of bone tunnel placement for ACL reconstruction in cadaveric adult knees based on 3D printing technology is high. This method can improve the accuracy of bone tunnel placement for ACL reconstruction in clinical sports medicine. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

First Principles Study of Electron Tunneling through Ice

KAUST Repository

Cucinotta, Clotilde S.; Rungger, Ivan; Sanvito, Stefano

2012-01-01

With the aim of understanding electrochemical scanning tunnel microscopy experiments in an aqueous environment, we investigate electron transport through ice in the coherent limit. This is done by using the nonequilibrium Greens functions method, implemented within density functional theory, in the self-interaction corrected local density approximation. In particular, we explore different ice structures and different Au electrode surface orientations. By comparing the decay coefficient for different thicknesses to the ice complex band structure, we find that the electron transport occurs via tunneling with almost one-dimensional character. The slow decay of the current with the ice thickness is largely due to the small effective mass of the conduction electrons. Furthermore, we find that the calculated tunneling decay coefficients at the Fermi energy are not sensitive to the structural details of the junctions and are at the upper end of the experimental range for liquid water. This suggests that linear response transport measurements are not capable of distinguishing between different ordered ice structures. However, we also demonstrate that a finite bias measurement may be capable of sorting polar from nonpolar interfaces due to the asymmetry of the current-voltage curves for polar interfaces. © 2012 American Chemical Society.

First Principles Study of Electron Tunneling through Ice

KAUST Repository

Cucinotta, Clotilde S.

2012-10-25

With the aim of understanding electrochemical scanning tunnel microscopy experiments in an aqueous environment, we investigate electron transport through ice in the coherent limit. This is done by using the nonequilibrium Greens functions method, implemented within density functional theory, in the self-interaction corrected local density approximation. In particular, we explore different ice structures and different Au electrode surface orientations. By comparing the decay coefficient for different thicknesses to the ice complex band structure, we find that the electron transport occurs via tunneling with almost one-dimensional character. The slow decay of the current with the ice thickness is largely due to the small effective mass of the conduction electrons. Furthermore, we find that the calculated tunneling decay coefficients at the Fermi energy are not sensitive to the structural details of the junctions and are at the upper end of the experimental range for liquid water. This suggests that linear response transport measurements are not capable of distinguishing between different ordered ice structures. However, we also demonstrate that a finite bias measurement may be capable of sorting polar from nonpolar interfaces due to the asymmetry of the current-voltage curves for polar interfaces. © 2012 American Chemical Society.

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

Science.gov (United States)

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

2013-01-01

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

Femoral head epiphysis growth and development among Chinese children aged 0-5 years.

Science.gov (United States)

Luo, Jiayou; Tang, Jin; Zhou, Libo; Zeng, Rong; Mou, Jinsong; Zhang, Lingli

2009-05-01

The aim of this study was to examine the pattern of femoral head epiphysis growth and development among Chinese children. Between January and December, 2007, we randomly sampled 1,450 healthy Chinese children (0-5 years old) from Hunan Provincial Children's Hospital in Changsha, Hunan, China. The diameter of femoral head epiphysis was measured by pelvic X-ray photography and processed by medical image processing software. The growth of femoral head epiphysis in girls was 2-3 months earlier than that in boys. The diameter of femoral head epiphysis increased with advancing age in both girls and boys, but the diameter of femoral head epiphysis in 2, 3, 4, 6, and 10-month-old girls was significantly larger than that in boys. Cubic regression equations between the diameter of femoral head epiphysis and age were created for boys and girls that could be used to predict the diameter of femoral head epiphysis. In conclusion, there was gender difference in femoral head epiphysis growth and development among Chinese children, and our prediction models will provide the guidance for early diagnosis of diseases related to the growth and development of the femoral head epiphysis.

Preoperative sup(99m)Tc-MDP scintimetry of femoral neck fractures

International Nuclear Information System (INIS)

Holmberg, S.; Thorngren, K.-G.

1984-01-01

Preoperative sup(99m)Tc-MDP-scintimetry was performed in 117 patients with femoral neck fractures. Scintimetry was shown to be superior to visual evaluation. The ratio was calculated of the uptake in the femoral head of the fractured side over that in the unfractured side, with compensation for the increased trochanteric femoral activity found on the fractured side. A ratio above 0.90 correlated well with uneventful healing in both undisplaced and displaced fractures. Preoperative scintimetry is of great value in the choice of primary treatment of femoral neck fractures. (author)

Case report - curved femoral osteotomy for management of medial patellar luxation

DEFF Research Database (Denmark)

Allpass, Maja; Miles, James Edward

2015-01-01

Medial patellaluxation kan forårsages af femoral varus hos hund. Førhen har patienter med excessiv femoralvarus været korrigeret ved en lateralt placeret femoral kile-ostektomi. Her præsenteres en case, hvor en buet osteotomi blev anvendt til behandling af medial patellaluxation.......Medial patellaluxation kan forårsages af femoral varus hos hund. Førhen har patienter med excessiv femoralvarus været korrigeret ved en lateralt placeret femoral kile-ostektomi. Her præsenteres en case, hvor en buet osteotomi blev anvendt til behandling af medial patellaluxation....

The impact of high total cholesterol and high low-density lipoprotein on avascular necrosis of the femoral head in low-energy femoral neck fractures.

Science.gov (United States)

Zeng, Xianshang; Zhan, Ke; Zhang, Lili; Zeng, Dan; Yu, Weiguang; Zhang, Xinchao; Zhao, Mingdong; Lai, Zhicheng; Chen, Runzhen

2017-02-17

Avascular necrosis of the femoral head (AVNFH) typically constitutes 5 to 15% of all complications of low-energy femoral neck fractures, and due to an increasingly ageing population and a rising prevalence of femoral neck fractures, the number of patients who develop AVNFH is increasing. However, there is no consensus regarding the relationship between blood lipid abnormalities and postoperative AVNFH. The purpose of this retrospective study was to investigate the relationship between blood lipid abnormalities and AVNFH following the femoral neck fracture operation among an elderly population. A retrospective, comparative study was performed at our institution. Between June 2005 and November 2009, 653 elderly patients (653 hips) with low-energy femoral neck fractures underwent closed reduction and internal fixation with cancellous screws (Smith and Nephew, Memphis, Tennessee). Follow-up occurred at 1, 6, 12, 18, 24, 30, and 36 months after surgery. Logistic multi-factor regression analysis was used to assess the risk factors of AVNFH and to determine the effect of blood lipid levels on AVNFH development. Inclusion and exclusion criteria were predetermined to focus on isolated freshly closed femoral neck fractures in the elderly population. The primary outcome was the blood lipid levels. The secondary outcome was the logistic multi-factor regression analysis. A total of 325 elderly patients with low-energy femoral neck fractures (AVNFH, n = 160; control, n = 165) were assessed. In the AVNFH group, the average TC, TG, LDL, and Apo-B values were 7.11 ± 3.16 mmol/L, 2.15 ± 0.89 mmol/L, 4.49 ± 1.38 mmol/L, and 79.69 ± 17.29 mg/dL, respectively; all of which were significantly higher than the values in the control group. Logistic multi-factor regression analysis showed that both TC and LDL were the independent factors influencing the postoperative AVNFH within femoral neck fractures. This evidence indicates that AVNFH was significantly

Ionic channels in Langmuir-Blodgett films imaged by a scanning tunneling microscope.

Science.gov (United States)

Kolomytkin, O V; Golubok, A O; Davydov, D N; Timofeev, V A; Vinogradova, S A; Tipisev SYa

1991-01-01

The molecular structure of channels formed by gramicidin A in a lipid membrane was imaged by a scanning tunneling microscope operating in air. The mono- and bimolecular films of lipid with gramicidin A were deposited onto a highly oriented pyrolitic graphite substrate by the Langmuir-Blodgett technique. It has been shown that under high concentration gramicidin A molecules can form in lipid films a quasi-regular, densely packed structure. Single gramicidin A molecules were imaged for the first time as well. The cavity of 0.4 +/- 0.05 nm in halfwidth was found on the scanning tunneling microscopy image of the gramicidin A molecule. The results of direct observation obtained by means of scanning tunneling microscope are in good agreement with the known molecular model of gramicidin A. It was shown that gramicidin A molecules can exist in a lipid monolayer as individual molecules or combined into clusters. The results demonstrate that scanning tunneling microscope can be used for high spatial resolution study of ionic channel structure. Images FIGURE 1 FIGURE 2 FIGURE 4 FIGURE 5 PMID:1712239

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

Directory of Open Access Journals (Sweden)

Korkmaz MF

2014-04-01

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

Is Assessment of Femoral Head Perfusion During Modified Dunn for Unstable Slipped Capital Femoral Epiphysis an Accurate Indicator of Osteonecrosis?

Science.gov (United States)

Novais, Eduardo N; Sink, Ernest L; Kestel, Lauryn A; Carry, Patrick M; Abdo, João C M; Heare, Travis C

2016-08-01

The modified Dunn procedure, which is an open subcapital realignment through a surgical dislocation approach, has gained popularity for the treatment of unstable slipped capital femoral epiphysis (SCFE). Intraoperative monitoring of the femoral head perfusion has been recommended as a method of predicting osteonecrosis; however, the accuracy of this assessment has not been well documented. We asked (1) whether intraoperative assessment of femoral head perfusion would help identify hips at risk of developing osteonecrosis; (2) whether one of the four methods of assessment of femoral head perfusion is more accurate (highest area under the curve) at identifying hips at risk of osteonecrosis; and (3) whether specific clinical features would be associated with osteonecrosis occurrence after a modified Dunn procedure for unstable SCFE. Between 2007 and 2014, we performed 29 modified Dunn procedures for unstable SCFE (16 boys, 11 girls; median age, 13 years; range, 8-17 years); two were lost to followup before 1 year. During this period, six patients with unstable SCFE were treated by other procedures. All patients undergoing modified Dunn underwent assessment of epiphyseal perfusion by the presence of active bleeding and/or by intracranial pressure (ICP) monitoring. In the initial five patients perfusion was recorded once, either before dissection of the retinacular flap or after fixation by one of the two methods. In the remaining 22 patients (81%), perfusion was systematically assessed before dissection of the retinacular flap and after fixation by both methods. Minimum followup was 1 year (median, 2.5 years; range, 1-8 years) because osteonecrosis typically develops within the first year after surgery. Patients were assessed for osteonecrosis by the presence of femoral head collapse at radiographs obtained every 3 months during the first year after surgery. Seven (26%) of the 27 patients developed osteonecrosis. Measures of diagnostic accuracy including sensitivity

Proximal focal femoral deficiency: evaluation by MR imaging

International Nuclear Information System (INIS)

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

2012-01-01

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

Proximal focal femoral deficiency: evaluation by MR imaging

Energy Technology Data Exchange (ETDEWEB)

Biko, David M. [National Naval Medical Center, Department of Radiology, Bethesda, MD (United States); Uniformed Services University of Health Sciences, Department of Radiology and Radiological Sciences, Bethesda, MD (United States); Davidson, Richard [The Children' s Hospital of Philadelphia, Department of Orthopedic Surgery, Philadelphia, PA (United States); Pena, Andres; Jaramillo, Diego [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States)

2012-01-15

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

Reoperation Rates for Laparoscopic vs Open Repair of Femoral Hernias in Denmark

DEFF Research Database (Denmark)

Andresen, Kristoffer; Bisgaard, Thue; Kehlet, Henrik

2014-01-01

IMPORTANCE: In Denmark approximately 10 000 groin hernias are repaired annually, of which 2% to 4% are femoral hernias. Several methods for repair of femoral hernias are used including sutured repair and different types of mesh repair with either open or laparoscopic techniques. The use of many...... laparoscopic vs open femoral hernia repair, analyzing data from a nationwide database. DESIGN, SETTING, AND PARTICIPANTS: A prospective cohort study was conducted. Data on femoral hernia repairs registered in the Danish Hernia Database from January 1998 until February 2012 were extracted and analyzed. All...... repairs were followed in the database and analyzed for reports of reoperation, which were used as a proxy for recurrence. Femoral hernia recurrence and inguinal hernia occurrence after the index repair were analyzed. EXPOSURE: Repair of a femoral hernia. MAIN OUTCOMES AND MEASURES: Reoperation...

Radiographic anatomy of the proximal femur: femoral neck fracture vs. transtrochanteric fracture

Directory of Open Access Journals (Sweden)

Ana Lecia Carneiro Leão de Araújo Lima

Full Text Available ABSTRACT OBJECTIVE: To evaluate the correlation between radiographic parameters of the proximal femur with femoral neck fractures or transtrochanteric fractures. METHODS: Cervicodiaphyseal angle (CDA, femoral neck width (FNW, hip axis length (HAL, and acetabular tear drop distance (ATD were analyzed in 30 pelvis anteroposterior view X-rays of patients with femoral neck fractures (n = 15 and transtrochanteric fractures (n = 15. The analysis was performed by comparing the results of the X-rays with femoral neck fractures and with transtrochanteric fractures. RESULTS: No statistically significant differences between samples were observed. CONCLUSION: There was no correlation between radiographic parameters evaluated and specific occurrence of femoral neck fractures or transtrochanteric fractures.

Evaluation of femoral head vascularization in slipped capital femoral epiphysis before and after cannulated screw fixation with use of contrast-enhanced MRI: initial results

International Nuclear Information System (INIS)

Staatz, G.; Honnef, D.; Hohl, C.; Schmidt, T.; Guenther, R.W.; Kochs, A.; Roehrig, H.

2007-01-01

In this study we used contrast-enhanced magnetic resonance imaging (MRI) to evaluate the vascularization of the femoral head in children with slipped capital femoral epiphysis (SCFE) before and after cannulated screw fixation. Eleven consecutive children with SCFE, seven boys and four girls, aged 10-15 years were included in the study. There were no preslips; four children had acute, three acute-on-chronic, and four chronic SCFE. The MRI examinations were performed in a 1.5 Tesla MR scanner with use of a coronal STIR sequence, a coronal contrast-enhanced T1-weighted spin-echo sequence, and a sagittal three-dimensional gradient-echo sequence. Morphology, signal intensities, and contrast-enhancement of the femoral head were assessed by two radiologists in consensus. Morphologic distortion of the physis, bone marrow edema within the metaphysis and epiphysis, and joint effusion were the preoperative MRI findings of SCFE in each child. In nine children, the vascularization of the femoral head before and after surgery was normal. In one child, a preoperative avascular zone in the superolateral aspect of the epiphysis revascularized completely after surgery. One child with severe SCFE developed avascular necrosis of the femoral head after open reduction of the slip. We conclude that MRI allows for accurate evaluation of the femoral head vascularization before and after surgery in children with SCFE. (orig.)

Evaluation of femoral head vascularization in slipped capital femoral epiphysis before and after cannulated screw fixation with use of contrast-enhanced MRI: initial results

Energy Technology Data Exchange (ETDEWEB)

Staatz, G. [Friedrich-Alexander-University Erlangen-Nuernberg, Department of Radiology, Division of Pediatric Radiology, Erlangen (Germany); University Hospital of the RWTH Aachen, Department of Diagnostic Radiology, Aachen (Germany); Honnef, D.; Hohl, C.; Schmidt, T.; Guenther, R.W. [University Hospital of the RWTH Aachen, Department of Diagnostic Radiology, Aachen (Germany); Kochs, A.; Roehrig, H. [University Hospital of the RWTH Aachen, Department of Orthopaedic Surgery, Aachen (Germany)

2007-01-15

In this study we used contrast-enhanced magnetic resonance imaging (MRI) to evaluate the vascularization of the femoral head in children with slipped capital femoral epiphysis (SCFE) before and after cannulated screw fixation. Eleven consecutive children with SCFE, seven boys and four girls, aged 10-15 years were included in the study. There were no preslips; four children had acute, three acute-on-chronic, and four chronic SCFE. The MRI examinations were performed in a 1.5 Tesla MR scanner with use of a coronal STIR sequence, a coronal contrast-enhanced T1-weighted spin-echo sequence, and a sagittal three-dimensional gradient-echo sequence. Morphology, signal intensities, and contrast-enhancement of the femoral head were assessed by two radiologists in consensus. Morphologic distortion of the physis, bone marrow edema within the metaphysis and epiphysis, and joint effusion were the preoperative MRI findings of SCFE in each child. In nine children, the vascularization of the femoral head before and after surgery was normal. In one child, a preoperative avascular zone in the superolateral aspect of the epiphysis revascularized completely after surgery. One child with severe SCFE developed avascular necrosis of the femoral head after open reduction of the slip. We conclude that MRI allows for accurate evaluation of the femoral head vascularization before and after surgery in children with SCFE. (orig.)

Detection and control of broken symmetries with Andreev bound state tunneling spectroscopy: effects of atomic-scale disorder

International Nuclear Information System (INIS)

Greene, L.H.; Hentges, P.J.; Aubin, H.; Aprili, M.; Badica, E.; Covington, M.; Pafford, M.M.; Westwood, G.; Klemperer, W.G.; Jian, Sha; Hinks, D.G.

2004-01-01

Quasiparticle planar tunneling spectroscopy is used to study unconventional superconductivity in YBa 2 Cu 3 O 7 (YBCO) thin films and Bi 2 Sr 2 CaCu 2 O 8 (BSCCO) single crystals. Tunneling conductances are obtained as a function of crystallographic orientation, applied magnetic field (magnitude and orientation), atomic substitution and surface damage. Our systematic studies confirm that the observed zero-bias conductance peak (ZBCP), a measure of the near-surface quasiparticle (QP) density of states (DoS), is comprised of Andreev bound states (ABS) resulting directly from the sign change of the d-wave order parameter (OP) at the Fermi surface. Our data, plus a literature search, reveals a consistency in the observation of the splitting of the ZBCP in optimally-doped materials. We note that the splitting of the ZBCP observed in applied field, and the spontaneous splitting observed at lower temperatures in zero field, occur concomitantly in a given junction, and that observation of this splitting is dependent upon two parameters: (1) the magnitude of the tunneling cone and (2) the degree of atomic-scale disorder at the interface

Delayed appearance of hypaesthesia and paralysis after femoral nerve block

OpenAIRE

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

2012-01-01

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

Theory of magnetoresistance of organic molecular tunnel junctions with nonmagnetic electrodes

Science.gov (United States)

Shi, Sha; Xie, Zuoti; Liu, Feilong; Smith, Darryl L.; Frisbie, C. Daniel; Ruden, P. Paul

2017-04-01

Large room-temperature magnetoresistance observed for devices composed of self-assembled monolayers of different oligophenylene thiols sandwiched between gold contacts has recently been reported [Z. Xie, S. Shi, F. Liu, D. L. Smith, P. P. Ruden, and C. D. Frisbie, ACS Nano 10, 8571 (2016), 10.1021/acsnano.6b03853]. The transport mechanism through the organic molecules was determined to be nonresonant tunneling. To explain this kind of magnetoresistance, we develop an analytical model based on the interaction of the tunneling charge carrier with an unpaired charge carrier populating a contact-molecule interface state. The Coulomb interaction between carriers causes the transmission coefficients to depend on their relative spin orientation. Singlet and triplet pairing of the tunneling and the interface carriers thus correspond to separate conduction channels with different transmission probabilities. Spin relaxation enabling transitions between the different channels, and therefore tending to maximize the tunneling current for a given applied bias, can be suppressed by relatively small magnetic fields, leading to large magnetoresistance. Our model elucidates how the Coulomb interaction gives rise to transmission probabilities that depend on spin and how an applied magnetic field can inhibit transitions between different spin configurations.

OUTCOME OF INTERTROCHANTERIC FRACTURES TREATED WITH SHORT FEMORAL NAIL

Directory of Open Access Journals (Sweden)

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

2015-07-01

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

Evaluation of a patient specific femoral alignment guide for hip resurfacing.

Science.gov (United States)

Olsen, Michael; Naudie, Douglas D; Edwards, Max R; Sellan, Michael E; McCalden, Richard W; Schemitsch, Emil H

2014-03-01

A novel alternative to conventional instrumentation for femoral component insertion in hip resurfacing is a patient specific, computed tomography based femoral alignment guide. A benchside study using cadaveric femora was performed comparing a custom alignment guide to conventional instrumentation and computer navigation. A clinical series of twenty-five hip resurfacings utilizing a custom alignment guide was conducted by three surgeons experienced in hip resurfacing. Using cadaveric femora, the custom guide was comparable to conventional instrumentation with computer navigation proving superior to both. Clinical femoral component alignment accuracy was 3.7° and measured within ± 5° of plan in 20 of 24 cases. Patient specific femoral alignment guides provide a satisfactory level of accuracy and may be a better alternative to conventional instrumentation for initial femoral guidewire placement in hip resurfacing. Crown Copyright © 2014. All rights reserved.

MR evaluation of the articular cartilage of the femoral head during traction. Correlation with resected femoral head

Energy Technology Data Exchange (ETDEWEB)

Nakanishi, K. [Osaka Seamens Insurance Hospital (Japan). Dept. of Radiology; Tanaka, H.; Narumi, Y.; Nakamura, H. [Osaka Univ. Medical School (Japan). Dept. of Radiology; Nishii, T.; Masuhara, K. [Osaka Univ. Medical School (Japan). Dept. of Orthopedic Surgery

1999-01-01

Objective: The purpose was to evaluate the articular cartilage of the hip joint with MR during traction and compare the findings with the resected specimen or arthroscopic findings. Material and Methods: Eight healthy volunteers, 5 patients with osteonecrosis, 5 with acetabular dysplasia, and 5 with advanced osteoarthrosis underwent MR imaging to evaluate the articular cartilage of the hip joint. Coronal fat-suppressed 3D spoiled gradient-echo (SPGR) images were obtained during traction. Identical imaging was performed of all the resected femoral heads of the osteonecrosis and advanced osteoarthrosis patients, and was correlated with the macroscopic pathological findings. Results: The traction was effective and the femoral articular cartilage was clearly identified in all 8 control subjects, and in all cases of osteonecrosis and acetabular dysplasia. In 4 cases of osteonecrosis, chondral fracture was identified in the boundary between the necrosis and the normal area. In all cases of advanced osteoarthrosis, cartilage was identified only at the medial side. The MR images of osteonecrosis and advanced osteoarthrosis corresponded well with the MR images of the resected femoral heads and the macroscopic findings. (orig.)

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

Science.gov (United States)

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

2017-04-01

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

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

NARCIS (Netherlands)

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

1999-01-01

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

Dynamic gadolinium-enhanced MRI evaluation of porcine femoral head ischemia and reperfusion

Energy Technology Data Exchange (ETDEWEB)

Schneider, T. [Clinic for Orthopaedics and Sports Traumatology, Dreifaltigkeits-Krankenhaus GmbH, Aachener Str. 445-449, 50933 Koeln (Germany); Drescher, W. [Department of Orthopaedics, Christian Albrechts University, Kiel (Germany); Becker, C. [Department of Orthopaedics, Heinrich Heine University, Duesseldorf (Germany); Sangill, R.; Stoedkilde-Joergensen, H. [Institute for Magnetic Resonance Imaging Tomography, University of Aarhus, Skejby Hospital, Aarhus (Denmark); Heydthausen, M. [Computing Center, Heinrich Heine University, Duesseldorf (Germany); Hansen, E.S.; Buenger, C. [Spine Section, Department of Orthopaedics, University of Aarhus (Denmark)

2003-02-01

To examine the potential of gadolinium (Gd)-enhanced dynamic MRI in the detection of early femoral head ischemia. Furthermore, to apply a three-compartment model to achieve a clinically applicable MR index for femoral head perfusion during the steady state and arterial hip joint tamponade.Design and materials In a porcine model femoral head perfusion was measured by radioactive tracer microspheres and by using a dynamic Gd-enhanced MRI protocol. Femoral head perfusion measurements and MRI tests were performed unilaterally before, during and after the experimentally induced ischemia of one of the hip joints. Ischemia was induced by increasing intra-articular pressure to 250 mmHg. All pigs showed ischemia of the femoral head epiphysis under hip joint tamponade followed by reperfusion to the same level as before joint tamponade. In two cases perfusion after removal of tamponade continued to be low. In dynamic MRI measurements increases in signal intensity were seen after intravenous infusion of Gd-DTPA, followed by a slow decrease in signal intensity. The signal-intensity curve during femoral head ischemia had a minor increase. Also the coefficient determined was a helpful indicator of femoral head ischemia. Femoral head blood flow as measured by microspheres fell significantly under joint tamponade. Early detection of this disturbed regional blood flow was possible using a dynamic MRI procedure. A biomathematical model resulted from the evaluation of the intervals of signal intensity over time which allows detection of bone blood flow changes at a very early stage. Using this new method earlier detection of femoral head necrosis may be possible. (orig.)

Aneurysm of the superficial femoral artery in an infant

Energy Technology Data Exchange (ETDEWEB)

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

2003-04-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Sakiyama, Mauro Yoshimitsu

1995-12-31

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

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

Energy Technology Data Exchange (ETDEWEB)

Sakiyama, Mauro Yoshimitsu

1996-12-31

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

Valgus Slipped Capital Femoral Epiphysis in Patient with Hypopituitarism

Directory of Open Access Journals (Sweden)

Yoshihiro Kotoura

2017-01-01

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

Scanning tunneling microscopy/scanning tunneling spectroscopy of the organic superconductors (TNTSF)2-PF6 and (TMTSF)2-ClO4

International Nuclear Information System (INIS)

Fainchtein, R.; Murphy, J.C.

1991-01-01

This paper reports on direct observations of the organic superconductors (tetramethyltetraselenafulvalene) (TMTSF) 2 -PF 6 and (TMTSF) 2 -ClO 4 made in air at room temperature. The samples consisted of single crystals electrochemically grown. Images revealing the molecular structural arrangement along different crystallographic orientations will be presented as well as spectroscopic data related to the electronic density of states. The images reveal a structure made up of flat molecules that stack on top of one another to form columns and are responsible for the quasi-one-dimensional nature of the electrical conductivity. Although both materials have similar crystal structure the differences in the symmetry and orientation of the counter anions are not resolved. Tunneling spectroscopy data at room temperature shows no apparent difference in the electronic density of states of both materials

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

Directory of Open Access Journals (Sweden)

David Walmsley

2014-01-01

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

[Arthroscopy-guided core decompression and bone grafting combined with selective arterial infusion for treatment of early stage avascular necrosis of femoral head].

Science.gov (United States)

Guo, Hao-Shan; Tian, Yi-Jun; Liu, Gang; An, Long; Zhou, Zhan-Guo; Liu, Huan-Zhen

2018-01-25

To observe the clinical effects of arthroscopy-guided core decompression and bone grafting combined with selective arterial infusion for early stage avascular necrosis of femoral head. From January 2010 to December 2014, 76 patients(76 hips) diagnosed as Ficat II stage avascular necrosis of femoral head were randomly divided into experimental group and control group. In the experimental group, there were 27 males and 8 females aged from 24 to 55 years old with an average of (43.96±6.81) years, treated with arthroscopic-guided core decompression and bone grafting combined with selective arterial infusion. Along the direction of the femoral neck, an 8 mm-diameter tunnel to necrotic areas was drilled, then curettage of necrotic bone was performed under arthroscope, and the iliac bone was grafted. In the control group, there were 29 males and 12 females aged from 26 to 56 years old with an average of (44.62±7.33) years, treated with percutaneous core decompression combined with selective arterial infusion. The preoperative and postoperative Harris scores were recorded and the changes of X-rays were analyzed. All the patients were followed up with an average of 30 months. Postoperative follow-up at 12 months showed that there was significant difference in imaging outcome between two groups( P 0.05), but there was significant difference in postoperative Harris score( P necrosis are effective. Using arthroscopic-guided core decompression method, the necrotic bone can be positioned and scraped more accurately, and can obtain better results. Copyright© 2018 by the China Journal of Orthopaedics and Traumatology Press.

Theoretical study of phosphorene tunneling field effect transistors

International Nuclear Information System (INIS)

Chang, Jiwon; Hobbs, Chris

2015-01-01

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

Theoretical study of phosphorene tunneling field effect transistors

Energy Technology Data Exchange (ETDEWEB)

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

2015-02-23

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

Stem cell treatment for avascular necrosis of the femoral head: current perspectives

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Houdek MT

2014-04-01

Full Text Available Matthew T Houdek,1 Cody C Wyles,2 John R Martin,1 Rafael J Sierra11Department of Orthopedic Surgery, 2School of Medicine, Mayo Clinic, Rochester, MN, USAAbstract: Avascular necrosis (AVN of the femoral head is a progressive disease that predominantly affects younger patients. Although the exact pathophysiology of AVN has yet to be elucidated, the disease is characterized by a vascular insult to the blood supply of the femoral head, which can lead to collapse of the femoral head and subsequent degenerative changes. If AVN is diagnosed in the early stages of the disease, it may be possible to attempt surgical procedures which preserve the hip joint, including decompression of the femoral head augmented with concentrated bone marrow. The use of autologous stem cells has shown promise in halting the progression of AVN of the femoral head, and subsequently preventing young patients from undergoing total hip arthroplasty. The purpose of this study was to review the current use of stem cells for the treatment of AVN of the femoral head.Keywords: avascular necrosis, femoral head, osteonecrosis, stem cells, concentrated bone marrow

MR imaging of femoral marrow in treated β-thalassemia major

International Nuclear Information System (INIS)

Shen Jun; Liang Biling; Chen Jianyu; Zhao Jiquan; Xu Honggui; Chen Chun

2006-01-01

Objective: To investigate MR imaging features of femoral marrow in treated β-thalassemia major. Methods: MR imaging of the proximal femoral marrow was performed in 35 cases of β-thalassemia major and 45 age- and sex-matched normal children as control. Coronal images of femoral marrow with the techniques of spin echo and fast field echo (FFE) were obtained. On T 1 -weighted imaging the red and yellow femoral marrow were judged and marrow distribution was classified into five groups. The hemosiderosis of marrow was judged on the basis of signal intensity of marrow on FFE imaging. The marrow distribution classification and the hemosiderosis on MR imaging were correlated with clinical features. Results: On FFE, marrow hemosiderosis occurred in 15 patients with a marked hypo-intensity signal and was related to the age (P=0.032). On T 1 -weighted imaging, the femoral marrow in 35 patients was classified as group III and IV, while the marrow distribution was group I or II in all normal children, there was statistically significant difference (P<0.001). The marrow distribution correlated positively with blood transfusion (P=0.049). Conclusion: The red marrow hyperplasia and hemosiderosis could occur in the femoral marrow of the treated β-thalassemia major. The marrow hyperplasia on MR imaging was related to the blood transfusion, and the hemosiderosis related to the age. (authors)

Osteoarthritis of the patella, lateral femoral condyle and posterior medial femoral condyle correlate with range of motion.

Science.gov (United States)

Suzuki, Takashi; Motojima, Sayaka; Saito, Shu; Ishii, Takao; Ryu, Keinosuke; Ryu, Junnosuke; Tokuhashi, Yasuaki

2013-11-01

The type of osteoarthritis and the degree of severity which causes restriction of knee range of motion (ROM) is still largely unknown. The objective of this study was to analyse the location and the degree of cartilage degeneration that affect knee range of motion and the connection, if any, between femorotibial angle (FTA) and knee ROM restriction. Four hundreds and fifty-six knees in 230 subjects with knee osteoarthritis undergoing knee arthroplasty were included. Articular surface was divided into eight sections, and cartilage degeneration was evaluated macroscopically during the operation. Cartilage degeneration was classified into four grades based on the degree of exposure of subchondral bone. A Pearson correlation was conducted between FTA and knee flexion angle to determine whether high a degree of FTA caused knee flexion restriction. A logistic regression analysis was also conducted to detect the locations and levels of cartilage degeneration causing knee flexion restriction. No correlation was found between FTA and flexion angle (r = -0.08). Flexion angle was not restricted with increasing FTA. Logistic regression analysis showed significant correlation between restricted knee ROM and levels of knee cartilage degeneration in the patella (odds ratio (OR) = 1.77; P = 0.01), the lateral femoral condyle (OR = 1.62; P = 0.03) and the posterior medial femoral condyle (OR = 1.80; P = 0.03). For clinical relevance, soft tissue release and osteophyte resection around the patella, lateral femoral condyle and posterior medial femoral condyle might be indicated to obtain a higher degree of knee flexion angle.

Three-Dimensional Analysis of the Characteristics of the Femoral Canal Isthmus: An Anatomical Study

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Xiu-yun Su

2015-01-01

Full Text Available Purpose. To establish a new approach for measuring and locating the femoral intramedullary canal isthmus in 3-dimensional (3D space. Methods. Based on the computed tomography data from 204 Chinese patients, 3D models of the whole femur and the corresponding femoral isthmus tube were reconstructed using Mimics software (Materialise, Haasrode, Belgium. The anatomical parameters of the femur and the isthmus, including the femur length and radius, and the isthmus diameter and height, were measured accordingly. Results. The mean ratio of the isthmus height versus the femoral height was 55 ± 4.8%. The mean diameter of the isthmus was 10.49 ± 1.52 mm. The femoral length, the isthmus diameter, and the isthmus tube length were significantly larger in the male group. Significant correlations were observed between the femoral length and the isthmus diameter (r=0.24, p<0.01 and between the femoral length and the isthmus height (r=0.6, p<0.01. Stepwise linear regression analyses demonstrated that the femoral length and radius were the most important factors influencing the location and dimension of the femoral canal isthmus. Conclusion. The current study developed a new approach for measuring the femoral canal and for optimization of customer-specific femoral implants.

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

African Journals Online (AJOL)

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

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

Science.gov (United States)

2010-04-01

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

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

Science.gov (United States)

2010-04-01

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

Structural and functional studies of bioobjects prepared from femoral heads

Energy Technology Data Exchange (ETDEWEB)

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

2015-11-17

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

Management of Post-Traumatic Phlegmasia Cerulea Dolens via Right-to-Left Femoral Vein to Femoral Vein Bypass (Palma Procedure).

Science.gov (United States)

Dua, Anahita; Heller, Jennifer; Lee, Cheong

2017-11-01

Phlegmasia cerulea dolens (PCD) is a rare condition resulting from venous occlusion that impairs arterial flow. We report a rare case of post-traumatic PCD after ligation of the iliac vein with successful treatment by right-to-left femoral vein to femoral vein bypass using left great saphenous vein (Palma procedure). The clinical presentation, diagnostic process, and approach to management along with a literature review on the operative management of PCD are presented in this case report.

Transvenous liver biopsy via the femoral vein

International Nuclear Information System (INIS)

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

2003-01-01

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

Hip dislocation following the treatment of femoral neck fracture: Case report

Directory of Open Access Journals (Sweden)

Vukašinović Zoran

2010-01-01

Full Text Available Introduction. Femoral neck fractures are very rare in young patients and are frequently complicated by femoral head osteonecrosis and femoral neck nonunion. Case Outline. A 19-year-old girl with hip dislocation following the treatment of the femoral neck fracture is presented. The femoral neck fracture was initially treated by open reduction and three-screw fixation. After detecting the nonunion of femoral neck, valgus osteotomy was done. Secondary, iatrogenic, hip dislocation appeared. The patient had pains, and in clinical findings a shorter leg and limited range of motion in the hip - altogether 40 degrees. She was then successfully treated by open reduction, together with Chiari pelvic osteotomy and joint transfixation. Transfixation pin was removed three weeks following the operation. After that, the patient was put into the abduction device and physical therapy was started. The mentioned regimen lasted four months after the surgery, then the abduction device was removed and walking started. Full weight bearing was allowed eight months after surgery. Conclusion. As we have not found the literature data concerning the above mentioned problem, we solved it in the way that we usually do for the treatment of developmental dislocation of the hip in adolescence.

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

DEFF Research Database (Denmark)

Olsen, Michael; Greve, Sara; Blicher, Marie

2016-01-01

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

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

Science.gov (United States)

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

2010-02-01

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

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

African Journals Online (AJOL)

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

Automated As-Built Model Generation of Subway Tunnels from Mobile LiDAR Data

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Mostafa Arastounia

2016-09-01

Full Text Available This study proposes fully-automated methods for as-built model generation of subway tunnels employing mobile Light Detection and Ranging (LiDAR data. The employed dataset is acquired by a Velodyne HDL 32E and covers 155 m of a subway tunnel containing six million points. First, the tunnel’s main axis and cross sections are extracted. Next, a preliminary model is created by fitting an ellipse to each extracted cross section. The model is refined by employing residual analysis and Baarda’s data snooping method to eliminate outliers. The final model is then generated by applying least squares adjustment to outlier-free data. The obtained results indicate that the tunnel’s main axis and 1551 cross sections at 0.1 m intervals are successfully extracted. Cross sections have an average semi-major axis of 7.8508 m with a standard deviation of 0.2 mm and semi-minor axis of 7.7509 m with a standard deviation of 0.1 mm. The average normal distance of points from the constructed model (average absolute error is also 0.012 m. The developed algorithm is applicable to tunnels with any horizontal orientation and degree of curvature since it makes no assumptions, nor does it use any a priori knowledge regarding the tunnel’s curvature and horizontal orientation.

Image features of herniation pit of the femoral neck

International Nuclear Information System (INIS)

Zhang Xuezhe; Li Guangming; Wang Cunli; Wang Guimin

2008-01-01

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

Method for stress determination in N, E, and T tunnels, Nevada Test Site, by hydraulic fracturing, with a comparison of overcoring methods

International Nuclear Information System (INIS)

Miller, C.H.

1976-01-01

Twenty-nine intervals in 10 core holes were hydraulically fractured in N, E, and T tunnels, Nevada Test Site, during 1974. Certain pressures were determined and related to the ambient stress field, but the orientation of the hydraulic fractures was not measured. These data and data from previous investigations in G tunnel indicated that both the magnitude of the hydraulic pressures and the direction of fracturing are independent of the orientation of the core holes. The maximum and minimum principal compressive stresses determined by the hydraulic fracturing methods are good approximations of those determined by nearby overcore methods. The data show that a good approximation of the magnitudes of the maximum and minimum principal stress axes can be obtained from several hydrofractured intervals in one core hole. Furthermore, if fracture orientation can be measured, then the direction of minimum principal compressive stress can be determined and the orientation of the plane of the maximum and intermediate principal compressive stresses can also be determined

Transtrochanteric rotational osteotomy for avascular necrosis of the femoral head after unstable slipped capital femoral epiphysis: 10-year clinical results.

Science.gov (United States)

Nakashima, Yasuharu; Yamamoto, Takuaki; Fukushi, Jun-Ichi; Motomura, Goro; Hamai, Satoshi; Kohno, Yusuke; Iwamoto, Yukihide

2016-11-01

Avascular necrosis of the femoral head (AVN) is the most serious complication after unstable slipped capital femoral epiphysis (SCFE), and is often unsalvageable. We report a minimum 10 years of clinical results for transtrochanteric rotational osteotomy of the femoral head (TRO) for AVN. This study included 7 patients (7 hips) with a mean age at surgery of 13.3 years, and the follow-up period was 15.8 years. All patients had prior treatment via closed reduction and pinning of the unstable SCFE, and showed severely collapsed femoral heads. The direction of rotation was anterior in 3 hips and posterior in 4. The Merle d'Aubigné-Postel score (MDPS) was used for clinical assessment, and joint degeneration was assessed with the Kellgren and Lawrence classification (KL-grade). The spherical intact area of the femoral head was moved to the weight-bearing portion, and subluxation was corrected via rotation combined with intentional varus positioning. The mean MDPS improved from 10.3 points to 15.6 points at 5 years, and it was maintained at 15.0 points by 10 years; 3 hips were excellent, 1 was good, 2 were fair, and 1 showed poor outcomes. No patient experienced re-collapse after TRO or required conversion to hip replacement or arthrodesis. After 10 years, degenerative changes became evident over time, and 2 hips progressed to KL-4 with a decreased MDPS. Although some joint degeneration is inevitable in the long-term, TRO is an effective salvage procedure for treating AVN after unstable SCFE. Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Energy gap and surface structure of superconducting diamond films probed by scanning tunneling microscopy

International Nuclear Information System (INIS)

Nishizaki, Terukazu; Takano, Yoshihiko; Nagao, Masanori; Takenouchi, Tomohiro; Kawarada, Hiroshi; Kobayashi, Norio

2007-01-01

We have performed scanning tunneling microscopy/spectroscopy (STM/STS) experiments on (1 1 1)-oriented epitaxial films of heavily boron-doped diamond at T = 0.47 K. The STM topography shows two kinds of atomic structures: a hydrogenated 1 x 1 structure, C(1 1 1)1 x 1:H, and an amorphous structure. On the C(1 1 1)1 x 1:H region, the tunneling spectra show superconducting property with the energy gap Δ = 0.83 meV. The obtained gap ratio 2Δ/k B T c = 3.57 is consistent with the weak-coupling BCS theory

Tunnel magnetoresistance in asymmetric double-barrier magnetic tunnel junctions

International Nuclear Information System (INIS)

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

2015-01-01

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

The Incidence of Atypical Femoral Fractures in Patients with Rheumatic Disease: Yamagata Prefectural Committee of Atypical Femoral Fractures (YamaCAFe) Study.

Science.gov (United States)

Takakubo, Yuya; Ohta, Daichi; Ishi, Masaji; Ito, Juji; Oki, Hiroharu; Naganuma, Yasushi; Uno, Tomohiro; Sasaki, Akiko; Akabane, Takeru; Dairaku, Katsuyuki; Goto, Shinichi; Goto, Yasuo; Kanauchi, Yumiko; Kobayashi, Shinji; Nakajima, Taku; Masuda, Keiji; Matsuda, Michiharu; Mura, Nariyuki; Takenouchi, Kenji; Tsuchida, Hiroyuki; Onuma, Yasushi; Shibuya, Junichirou; Seino, Mitsuyoshi; Yamaguchi, Osamu; Hiragami, Ken; Urayama, Yasuhiro; Furukawa, Takashi; Okuda, Shouta; Ogura, Ken; Nakamura, Takeshi; Sasaki, Kan; Konta, Tsuneo; Takagi, Michiaki

2017-08-01

Atypical femoral fractures (AFFs) have been reported to occur with minimal or spontaneous subtrochanteric and femoral shaft fractures with a characteristic transverse pattern, compared with typical femoral fractures in young patients with high-energy trauma. AFFs are related to long-term use of bisphosphonates (BPs), glucocorticoids and rheumatic diseases. We have estimated a blind analysis of AFFs in rheumatic patients receiving BPs and glucocorticoids ordinary over a long time in all Yamagata prefectural area through radiographic examination. The 123 AFFs including suspected cases over six years were collected and reviewed by two independent orthopedic surgeons. We found 86 patients with a total of 99 AFFs between 2009 and 2014 (1.43 cases/100,000 person/year). Of these 99 AFFs, 11 were in 8 rheumatic patients including three patients with bilateral AFFs. The incidence of AFFs in rheumatic patients had trend to increase from 2012. The mean age of all 8 patients was 54.9 years. All 8 patients received BPs and 7/8 received prednisolone (PSL). The mean dose of PSL was 14 mg/day. Compared to patients with unilateral AFFs, those with bilateral AFFs in rheumatic patients were on a higher dose of PSL (20 mg/day vs. 7 mg/day) and had less femoral neck-shaft angle (129° vs. 136°, p rheumatic patients showed a trend to increase from 2012 to 2014 in Yamagata prefecture. Careful management of AFFs is of particular importance in rheumatic patients who have taken high doses of PSL and have small femoral neck-shaft angle.

Development of a method for measuring femoral torsion using real-time ultrasound

International Nuclear Information System (INIS)

Hafiz, Eliza; Hiller, Claire E; Nightingale, E Jean; Eisenhuth, John P; Refshauge, Kathryn M; Nicholson, Leslie L; Clarke, Jillian L; Grimaldi, Alison

2014-01-01

Excessive femoral torsion has been associated with various musculoskeletal and neurological problems. To explore this relationship, it is essential to be able to measure femoral torsion in the clinic accurately. Computerized tomography (CT) and magnetic resonance imaging (MRI) are thought to provide the most accurate measurements but CT involves significant radiation exposure and MRI is expensive. The aim of this study was to design a method for measuring femoral torsion in the clinic, and to determine the reliability of this method. Details of design process, including construction of a jig, the protocol developed and the reliability of the method are presented. The protocol developed used ultrasound to image a ridge on the greater trochanter, and a customized jig placed on the femoral condyles as reference points. An inclinometer attached to the customized jig allowed quantification of the degree of femoral torsion. Measurements taken with this protocol had excellent intra- and inter-rater reliability (ICC 2,1  = 0.98 and 0.97, respectively). This method of measuring femoral torsion also permitted measurement of femoral torsion with a high degree of accuracy. This method is applicable to the research setting and, with minor adjustments, will be applicable to the clinical setting. (paper)

Evaluation of femoral head viability via bone scintigraphy in the postoperative pediatric patient

International Nuclear Information System (INIS)

Parikh, Ashishkumar K.; Washington, Eleby R.; Spottswood, Stephanie E.; Bobbey, Adam J.

2018-01-01

Evaluating postoperative patients with hardware is challenging following surgical intervention for hip maladies such as femoral neck fractures and slipped capital femoral epiphysis (SCFE). These children are at increased risk of developing avascular necrosis, and imaging may be requested to confirm or exclude this diagnosis. Children with Legg-Calve-Perthes disease can be monitored for restoration of blood flow to the capital femoral epiphysis to guide management and help with prognosis. Although MRI is sensitive for detecting early avascular necrosis, the presence of hardware degrades image quality. This report examines the utility of bone scans for evaluating femoral head perfusion in children who have undergone surgery for femoral neck fractures, SCFE or Legg-Calve-Perthes disease. A retrospective review of 20 patients (22 scans) after fixation for femoral neck fracture, SCFE or Legg-Calve-Perthes disease from 2012 to 2015 was performed. The bone scan findings were correlated with the intraoperative findings or clinical follow-up. Twenty-one of the 22 (95%) bone scans in 19 of the 20 (95%) patients demonstrated findings consistent with clinical outcomes and/or the intraoperative appearance of the femoral head. Four of 20 patients (20%) had bone scan features of avascular necrosis, defined as ''absent'' or ''moderately diminished'' femoral head activity, which were confirmed intraoperatively and resulted in poor outcomes. Radionuclide imaging of hips in the postoperative setting is a valuable modality for assessing the risk of avascular necrosis, a complication of femoral neck fractures and SCFE and for evaluating the restoration of flow to the capital femoral epiphyses of children with Legg-Calve-Perthes disease. (orig.)

Symmetric visualization of the femoral heads in reticuloendothelial bone marrow scanning in adults

Energy Technology Data Exchange (ETDEWEB)

Munz, D L; Hoer, G

1983-03-01

Two hundred and twenty seven consecutive patients of either sex aged 15-84 suffering from various benign and malignant disorders were studied by sup(99m)Tc-HSA-MM reticuloendothelial bone marrow scintigraphy. In all patients, symmetric findings concerning visualization or nonvisualization of the femoral heads could be seen. Femoral heads were clearly visualized in 48%, nonvisualized in 43%, and equivocally visualized in 9%. In patients with clearly visualized femoral heads, the bone marrow showed peripheral extension in 81%, whereas in patients with nonvisualized femoral heads, bone marrow extension was observed in only 42%. There was a correlation between the degree of bone marrow extension and the ability to visualize femoral heads. There was no obvious difference between males and females, nor patients with various diseases or treatments, amongst nor between different age groups. Two hypotheses are suggested to explain the correspondence between presence of bone marrow tissue in the femoral heads and peripheral extension of the bone marrow organ. Nonvisualization of the femoral heads alone is insufficient to establish the diagnosis of avascular necrosis.

Effectiveness of low-level laser therapy for patients with carpal tunnel syndrome: design of a randomized single-blinded controlled trial

Directory of Open Access Journals (Sweden)

Barbosa Rafael Inácio

2012-12-01

Full Text Available Abstract Background Carpal tunnel syndrome is the most common neuropathy in the upper extremity, resulting from the compression of the median nerve at wrist level. Clinical studies are essentials to present evidence on therapeutic resources use at early restoration on peripheral nerve functionality. Low-level laser therapy has been widely investigated in researches related to nerve regeneration. Therefore, it is suggested that the effect of low-level laser therapy associated with other conservative rehabilitation techniques may positively affect symptoms and overall hand function in compressive neuropathies such as carpal tunnel syndrome. The aim of this study is to evaluate the effectiveness of low-level laser therapy in addition to orthoses therapy and home orientations in patients with carpal tunnel syndrome. Methods/Design Patients older than 18 years old will be included, with clinical diagnosis of carpal tunnel syndrome, excluding comorbidies. A physiotherapist will conduct intervention, with a blinding evaluator. Randomization will be applied to allocate the patients in each group: with association or not to low-level laser therapy. All of them will be submitted to orthoses therapy and home orientations. Outcome will be assessed through: pain visual analogic scale, Semmes Weinstein monofilaments™ threshold sensibility test, Pinch Gauge™, Boston Carpal Tunnel Questionnaire and two point discrimination test. Discussion This paper describes the design of a randomized controlled trial, which aim to assess the effectiveness of conservative treatment added to low-level laser therapy for patients with carpal tunnel syndrome. Trial registration Brazilian Clinical Trials Registry (ReBec - 75ddtf / Universal Trial Number: U1111-1121-5184

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

Directory of Open Access Journals (Sweden)

Korhan Ozkan

2015-01-01

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

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

African Journals Online (AJOL)

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

Macroscopic and microscopic findings in avascular necrosis of the femoral head.

Science.gov (United States)

Kamal, Diana; Alexandru, D O; Kamal, C K; Streba, C T; Grecu, D; Mogoantă, L

2012-01-01

The avascular necrosis of the femoral head is an illness induced by the cutoff of blood flow to the femoral head and it affects mostly young adults between the ages of 30 and 50 years, raising therapeutic and diagnostic issues. Many risk factors are incriminated in the development of avascular necrosis of the femoral head like: trauma, chronic alcohol consumption, smoking, administration of corticosteroid drugs, most of the cases are considered to be idiopathic. The main goal of our paper is to describe the macroscopic and microscopic variations of the bone structure, which occur in patients with avascular necrosis of the femoral head. The biological material needed for our study was obtained following hip arthroplasty surgery in 26 patients between the ages of 29 and 59 years, which previously were diagnosed with avascular necrosis of the femoral head and admitted in the Orthopedics Department of the Emergency County Hospital of Craiova (Romania) between 2010 and 2011. From a macroscopic point of view, we found well defined areas of necrosis, most of which were neatly demarcated of the adjacent viable tissue by hyperemic areas, loss of shape and contour of the femoral head and transformations of the articular cartilage above the area of necrosis. When examined under the microscope, we found vast areas of fibrosis, narrow bone trabeculae, obstructed blood vessels or blood vessels with clots inside, hypertrophic fat cells, bone sequestration but also small cells and pyknotic nuclei. The microscopic and macroscopic findings on the femoral head sections varied with the patients and the stage of the disease.

Bone scintigraphy in idiopathic aseptic femoral head necrosis (IAFHN)

Energy Technology Data Exchange (ETDEWEB)

Dodig, D; Ugarkovic, B; Orlic, D

1983-01-01

Idiopathic aseptic femoral head necrosis (IAFHN) is a disease of unknown aetiology most commonly affecting adults, producing functional impairment of the hip joint and immobility. Characteristic macroscopic, microscopic and radiologic features include: (1) changes in joint cartilage, (2) subchondral necrotic area, (3) changes in fibrous tissue, and (4) osteosclerosis and vascular proliferation. The diagnosis is based on clinical and X-ray examinations. More recently scintigraphy has been used in diagnosing IAFHN. It is a very sensitive, but non-specific method. Nineteen patients aged 25-57 years were included in our study. Scintigrams were divided in four groups: (1) normal, (2) uniformly increased activity in the femoral head, (3) non-uniformly increased activity in the femoral head, and (4) a photon deficient area in the femoral head. A comparison of scintigraphy and radiological examination suggests that a photon deficient area corresponds with stage III of radiological classification, non-uniformly increased activity with stage II, and uniformly increased activity with stage I. These results indicate that scintigraphy can be used for staging of disease.

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

International Nuclear Information System (INIS)

Sakiyama, Mauro Yoshimitsu

1995-01-01

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

Magnetic tunnel junctions with monolayer hexagonal boron nitride tunnel barriers

Energy Technology Data Exchange (ETDEWEB)

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

2016-03-07

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

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

Science.gov (United States)

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

2015-11-01

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

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

OpenAIRE

Font Capó, Jordi

2012-01-01

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

Multiple bony lesions other than femoral heads on 99mTc-MDP bone scan in patients with avascular necrosis of the femoral head

International Nuclear Information System (INIS)

Choi, Yun Young; Yang, Seoung Oh; Moon, Dae Hyuk; Ryu, Jin Sook; Weon, Young Cheol; Shin, Myung Jin; Lee, Soo Ho; Lee, Hee Kyung; Chun, Hae Kyung

1997-01-01

To evaluate the clinical significance of the multiple increased uptake lesions other than in femoral heads as seen on whole body bone scan in patients with avascular necrosis of femoral heads. One hundred and seventy three patients with clinical diagnosis of avascular necrosis of the emoral head underwent a bone scan using Tc-99m MDP. Increased uptake lesions other than in femoral heads were evaluated, including frequency and common sites of in volvement, and correlated with clinical information and plain radiographic findings. Two hundred patients without AVN, who had undergone a bone scan, were included as a control group. Increased uptake lesions in extrafemoral head locations were found in 36 of 173 patients(20.8%;the location of 79 lesions was other than the femoral head, This result is statistically different from patients without avascular necrosis of femoral head(p<0.0001). The most common site of involvement was the knee joint area(62.5%). Other lesions were located in the mid-shafts of the long bones of the lower extremities, calcaneus, proximal humerus, etc., in order of decreasing frequency. Plain radiographs of 17 lesions were nonspecific, except for three lesions showing definite changes associated with avascular necrosis. The risk factors included alcoholism, the prolonged use of steroids, renal transplantation, herbal medication and working as a working as deep-sea diver. Most patients did not complain of pain, except for two with irreversible osteonecrotic changes as seen on plain radiograph. in patients with avascular necrosis of the femur, increased uptake lesions other than in the femoral head as seen on bone scan, may represent the early stage of osteonecrosis, which shows a characteristic appearance on bone scan. In order to aveid possible misdiagnoses of multiple extrafemoral lesions as bony metastasis or traumatic lesions, in patients with avascular necrosis of the femur these should be carefully evaluated

'Femoral head necrosis' in metabolic and hormonal osteopathies

Energy Technology Data Exchange (ETDEWEB)

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

1984-07-01

The pathogenesis of bone necrosis is discussed with special attention and with respect to metabolic, hormonal, and vascular factors. The influence of statics and dynamics of the hip joint bones for the development of aseptic necrosis are discussed. 45 patients with ''idiopathic femoral head necroses'' were observed, including 6 cases of renal osteopathy following renal transplantation and immune suppression therapy, 14 cases of long term corticoid therapy, and 11 cases of liver diseases of different genesis. The femoral head necrosis understood as complication of an osteopathy. In our patients there were 31 males and 14 females - which means higher involvement of males. Plain radiological findings and CT-findings of changes of the femoral heat structure in different stages of the disease are described. Early diagnosis of metabolic and hormonal osteopathies is demanded for a joint keeping therapy of the beginning femoral head necrosis. 90 refs.

Mechanical Characterization of Femoral Cartilage Under Unicompartimental Osteoarthritis

OpenAIRE

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

2014-01-01

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

Femoral head allograft disinfection system using moderate heat

International Nuclear Information System (INIS)

Knaepler, H.; Von Garrel, T.

1999-01-01

The employment of a reliable thermal viral inactivation process, which minimally manipulates tissues, for surgically retrieved femoral head allografts addresses the increased concerns with virus transmissibility while minimizing the loss of biological properties. The newest European and German surgical bone banking guidelines have incorporated the use of independently validated then-nal viral inactivation methods in place of repeat serological testing of donor. Our investigations have shown that heat treatment at 80 degree C for a minimum of 10 minutes provides safe, good quality cancellous bone allografts and increases the cost-effectiveness and simplicity of managing a hospital frozen femoral head bone bank. Human femoral head centers were contaminated with different vegetative bacterial and viral suspensions. A core temperature of 80 degree C for 10 minutes was sufficient to fully inactivate 3 x 106 ml Staphylococcus aureus and Streptococcus faecalis, and >5 loglo steps of cytomeglia (herpes group), polio (enterovirus), and yellow fever (arbovirus) viruses. A one hour treatment in a water bath set at 80 degree sufficient to fully inactivate E. coli, proteus vulgaris, and Pseudomonas aerog. vegetative suspensions; 20 minutes was sufficient to fully inactivate the D antigen (rhesus factor) but had no effect on A or B antigens. Several biomechanical and biological properties of bone following a one hour treatment in a water bath set at 80 degree C were investigated. Employing compression and tension tests, 80 degree C treated human and porcine cancellous bone blocks showed reductions in properties ranging from 8-19% compared to untreated control groups. Osteointegration at 3 months following treatment of explanted and then reimplanted autograft rat diaphyseal segment was 15% less than untreated controls. Subsequently, a thermal disinfection system for femoral heads from living donors (Lobator Marburg Bone Bank System, Telos GmbH, Hungen, Germany) was developed. A

Femoral intercondylar notch shape and dimensions in ACL-injured patients

NARCIS (Netherlands)

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

2010-01-01

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

Modular femoral component for conversion of previous hip surgery in total hip arthroplasty.

Science.gov (United States)

Goldstein, Wayne M; Branson, Jill J

2005-09-01

The conversion of previous hip surgery to total hip arthroplasty creates a durable construct that is anatomically accurate. Most femoral components with either cemented or cementless design have a fixed tapered proximal shape. The proximal femoral anatomy is changed due to previous hip surgery for fixation of an intertrochanteric hip fracture, proximal femoral osteotomy, or a fibular allograft for avascular necrosis. The modular S-ROM (DePuy Orthopaedics Inc., Warsaw, Ind) hip stem accommodates these issues and independently prepares the proximal and distal portion of the femur. In preparation and implantation, the S-ROM hip stem creates less hoop stresses on potentially fragile stress risers from screws and thin bone. The S-ROM hip stem also prepares a previously distorted anatomy by milling through cortical bone that can occlude the femoral medullar canals and recreate proper femoral anteversion and reduces the risk of intraoperative or postoperative periprosthetic fracture due to the flexible titanium-slotted stem. The S-ROM femoral stem is recommended for challenging total hip reconstructions.

Spin-polarized scanning tunneling spectroscopy of self-organized nanoscale Co islands on Au(111) surfaces.

Science.gov (United States)

Schouteden, K; Muzychenko, D A; Van Haesendonck, C

2008-07-01

Magnetic monolayer and bilayer Co islands of only a few nanometer in size were grown by atomic deposition on atomically flat Au(111) films. The islands were studied in situ by scanning tunneling microscopy (STM) and spectroscopy at low temperatures. Spin-resolved tunneling spectroscopy, using an STM tip with a magnetic coating, revealed that the Co islands exhibit a net magnetization perpendicular to the substrate surface due to the presence of spin-polarized d-states. A random distribution of islands with either upward or downward pointing magnetization was observed, without any specific correlation of magnetization orientation with island size or island height.

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

International Nuclear Information System (INIS)

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

2016-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-08-01

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

Pigmented Villonodular Synovitis Causing Osteonecrosis of the Femoral Head: A Case Report

Directory of Open Access Journals (Sweden)

Tomohiro Mimura

2013-01-01

Full Text Available We report a case of a 27-year-old man with pigmented villonodular synovitis of the hip joint with coincident osteonecrosis of the femoral head. According to our review of the English-language literature, no detailed report of osteonecrosis of the femoral head complicated with pigmented villonodular synovitis has been published. Preoperative X-ray images showed joint narrowing and severe multiple bone erosions at the acetabulum and femoral neck. Magnetic resonance imaging revealed a low-intensity band attributable to osteonecrosis of the femoral head and massive diffuse pigmented villonodular synovitis lesions. Comparison of a three-dimensional computed tomographic image of this patient with an angiographic image of a normal individual demonstrated proximity of the pigmented villonodular synovitis-induced bone erosions to the medial and lateral femoral circumflex arteries and retinacular arteries, suggesting likely the compromise of the latter by the former. We propose that the massive pigmented villonodular synovitis may have contributed to the pathogenesis of osteonecrosis of the femoral head in this patient. We performed open synovectomy and total hip arthroplasty. No operative complications occurred, and no recurrence of the pigmented villonodular synovitis was detected for 3 years after the operation.

Carpal Tunnel Syndrome

Science.gov (United States)

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

Theory of superconducting tunneling without the tunneling Hamiltonian

International Nuclear Information System (INIS)

Arnold, G.B.

1987-01-01

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

Three-dimensional measurement of femoral neck anteversion and neck shaft angle.

Science.gov (United States)

Sangeux, Morgan; Pascoe, Jessica; Graham, H Kerr; Ramanauskas, Fiona; Cain, Tim

2015-01-01

We present a three-dimensional measurement technique for femoral neck anteversion and neck shaft angles which do not require alignment of the femoral and scanner axes. Two assessors performed the measurements on 11 patients (22 femurs). Repeatability between assessors was 2.7 degrees for femoral neck anteversion and 4.8 degrees for neck shaft angle. Measurements compared with an alternative single slice method were different by 2 degrees (3 degrees) in average. The method was repeatable and appropriate for clinical practice.

Histopathology of femoral head donations: a retrospective review of 6161 cases.

Science.gov (United States)

Mackie, Katherine E; Zhou, Ziqiang; Robbins, Peter; Bulsara, Max; Zheng, Ming H

2011-08-17

Although total hip arthroplasty is one of the most common orthopaedic surgical procedures, it remains unclear whether histopathological examination of the excised femoral head adds to the quality of patient care. We propose that assessment of femoral heads resected during total hip arthroplasty and donated for allograft use may provide a profile of femoral head pathology that benefits total hip arthroplasty patients and bone donors. We retrospectively analyzed the histological findings reported for 6161 femoral heads donated for allograft use between 1993 and 2006. Specimens obtained during total hip arthroplasty and specimens donated at death were reviewed. Follow-up investigations that resulted from abnormal histopathological findings were also reviewed. The Western Australian Cancer Registry was used to determine whether patients with a suspected neoplasm were subsequently diagnosed with such a disease. A retrospective review of the histopathological findings was conducted to evaluate and reclassify all previous observations of abnormalities. One hundred and five femoral heads demonstrated abnormal or reactive histopathological features not reported prior to surgery and were rejected for allograft use. A reactive lymphocytic infiltrate, most likely due to osteoarthritis, was the most commonly identified feature (forty-five cases). Other features observed in twenty-seven cases were also most likely due to the presence of severe osteoarthritis. Ten femoral heads demonstrated plasmacytosis, which may have been related to osteoarthritis. Two patients were diagnosed with Paget's disease, and two, with rheumatoid arthritis. Nineteen patients had a suspected neoplasm. Of these nineteen, eight cases of non-Hodgkin's lymphoma or chronic lymphocytic leukemia and one case of myelodysplastic syndrome were confirmed on further investigation. One subsequently confirmed malignancy was detected per 770 femoral heads examined. Our findings indicate that, even with a detailed

Delayed appearance of hypaesthesia and paralysis after femoral nerve block

Directory of Open Access Journals (Sweden)

Stefan Landgraeber

2012-03-01

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

Delayed appearance of hypaesthesia and paralysis after femoral nerve block

Science.gov (United States)

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

2012-01-01

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

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

International Nuclear Information System (INIS)

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

1984-01-01

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

Tricrystal tunneling evidence for d-wave pairing symmetry in cuprate superconductors

International Nuclear Information System (INIS)

Tsuei, C.C.; Kirtley, J.R.

1997-01-01

Strong evidence for d-wave pairing symmetry in high-temperature superconductors such as YBa 2 Cu 3 O 7 and Tl 2 Ba 2 CuO 6+δ has been obtained by monitoring the presence or absence of the half-integer flux quantum effect in various controlled - orientation tricrystal superconducting systems. New results of a tricrystal tunneling experiment with Gd Ba 2 Cu 3 O 7 will also be presented. (orig.)

Aberrant femoral torsion presenting with frog-leg squatting mimicking gluteal muscle contracture.

Science.gov (United States)

Chiang, Chia-Ling; Tsai, Meng-Yuan; Chang, Wei-Ning; Chen, Clement Kuen-Huang

2012-04-01

Patients with frog-leg squatting have restricted internal rotation and adduction of the affected hips during sitting or squatting. In the surgical literature, the cause generally has been presumed to arise from and be pathognomonic for gluteal muscle contracture. However, we have encountered patients with frog-leg squatting but without gluteal muscle contracture. We therefore raised the following questions: What are the imaging features of patients with frog-leg squatting? Do conditions other than gluteal muscle contracture manifest frog-leg squatting? We retrospectively reviewed the MR images of 67 patients presenting with frog-leg squatting from April 1998 to July 2010. There were four females and 63 males; their mean age was 22.2 years (range, 4-50 years). During MRI readout, we observed aberrant axes of some femoral necks and obtained additional CT to measure femoral torsion angles in 59 of the 67 patients. MR images of 27 (40%) patients had signs of gluteal muscle contracture. Twenty-two (33%) patients (40 femora) had aberrant femoral torsion, including diminished anteversion (range, 6°-0°; average, 3.9°) in 11 femora of eight patients and femoral retroversion (range, muscle contracture or aberrant femoral torsion. The observation of aberrant femoral torsion was not anticipated before imaging studies. In addition to gluteal muscle contracture, aberrant femoral torsion can be a cause of frog-leg squatting. Level II, diagnostic study. See the guidelines for Authors for a complete description of levels of evidence.

Does increased femoral antetorsion predispose to cartilage lesions of the patellofemoral joint?

Science.gov (United States)

Oppermann, Johannes; Bredow, Jan; Wissusek, Boris; Spies, Christian Karl; Boese, Christoph Kolja; Chang, Shi-Min; Eysel, Peer; Dargel, Jens

2017-09-01

The purpose of this study was to investigate whether there was a relationship between femoral neck antetorsion and the presence and pattern of osteoarthritis of the patellofemoral joint. It was hypothesized that an increased femoral neck antetorsion (1) correlates with osteoarthritic changes of the lateral facet of the patellofemoral joint and (2) correlates with an increased lateral trochlear height and a decreased sulcus angle. Seventy-eight formalin-embedded cadaveric lower extremities from thirty-nine subjects with a median age of 74 years (range 60-88) were used. Surrounding soft tissues of the lower limb were removed. The femoral neck antetorsion was measured and referenced to the transepicondylar axis and the posterior condylar line. The height of the medial and lateral facet of the trochlea and the sulcus angle was measured. The location and the degree of patellofemoral cartilage degeneration were recorded. A Pearson's correlation analysis was performed to correlate the femoral neck antetorsion with the measured knee parameters. No significant correlation could be found between the femoral antetorsion and cartilage degeneration of the lateral patellofemoral joint (n.s.), the height of the lateral trochlea (n.s.) and the sulcus angle (n.s.). This study could not document that the femoral neck antetorsion and subsequent internal rotation of the distal femur correlated with the degree of degeneration of the lateral facet of the patellofemoral joint. Clinically, femoral internal rotation may play a minor role in the development of lateral patellofemoral joint degeneration.

Widening of the femoral proximal diaphysis--metaphysis angle in fetuses with achondroplasia.

Science.gov (United States)

Khalil, A; Morales-Roselló, J; Morlando, M; Bhide, A; Papageorghiou, A; Thilaganathan, B

2014-07-01

It has recently been reported that fetuses with achondroplasia have a wider than expected femoral proximal diaphysis-metaphysis angle (femoral angle). The aim of this case-control study was to investigate this finding. Cases with confirmed achondroplasia (n = 6), small-for-gestational-age fetuses (n = 70) and a group of normal fetuses (n = 377) were included in this study. The ultrasound image of the femur was examined by two independent experienced observers blinded to the diagnosis, who measured the femoral angle. These values were converted into multiples of the expected median (MoM), after adjustment for gestational age and femur length. Prevalence of various prenatal ultrasound signs of achondroplasia was determined in affected fetuses. Intra- and interobserver agreement of measurement of femoral angle was assessed using 95% limits of agreement and kappa statistics. The femoral angle can be measured accurately by ultrasound, and increases with both increasing gestational age and increasing femur length. The femoral angle-MoM was significantly higher in fetuses with achondroplasia than in the control group (1.36 vs 1.00 MoM, P achondroplasia (83.3%), which was the most consistent finding other than shortening of the long bones. The femoral angle is wider in fetuses with achondroplasia. This new ultrasound sign appears promising as an additional discriminatory marker when clinicians are faced with a case of short long bones in the third trimester. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

Rock stress orientation measurements using induced thermal spalling in slim boreholes

International Nuclear Information System (INIS)

Hakami, Eva

2011-05-01

In the planning and design of a future underground storage for nuclear waste based on the KBS-3 method, one of the aims is to optimize the layout of deposition tunnels such that the rock stresses on the boundaries of deposition holes are minimized. Previous experiences from heating of larger scale boreholes at the Aespoe Hard Rock Laboratory (AHRL) gave rise to the idea that induced borehole breakouts using thermal loading in smaller diameter boreholes, could be a possible way of determining the stress orientation. Two pilot experiments were performed, one at the Aespoe Hard Rock Laboratory and one at ONKALO research site in Finland. An acoustic televiewer logger was used to measure the detailed geometrical condition of the borehole before and after heating periods. The acoustic televiewer gives a value for each 0.7 mm large pixel size around the borehole periphery. The results from the loggers are presented as images of the borehole wall, and as curves for the maximum, mean and minimum values at each depth. Any changes in the borehole wall geometry may thus be easily detected by comparisons of the logging result images. In addition, using an optical borehole televiewer a good and detailed realistic colour picture of the borehole wall is obtained. From these images the character of the spalls identified may be evaluated further. The heating was performed in a 4 m long section, using a heating cable centred in an 8 m deep vertical borehole, drilled from the floor of the tunnels. For the borehole in the Q-tunnel of AHRL the results from the loggings of the borehole before the heating revealed that breakouts existed even before this pilot test due to previous heating experiments at the site (CAPS). Quite consistent orientation and the typical shape of small breakouts were observed. After the heating the spalling increased slightly at the same locations and a new spalling location also developed at a deeper location in the borehole. At ONKALO three very small changes

Rock stress orientation measurements using induced thermal spalling in slim boreholes

Energy Technology Data Exchange (ETDEWEB)

Hakami, Eva [Geosigma AB, Uppsala (Sweden)

2011-05-15

In the planning and design of a future underground storage for nuclear waste based on the KBS-3 method, one of the aims is to optimize the layout of deposition tunnels such that the rock stresses on the boundaries of deposition holes are minimized. Previous experiences from heating of larger scale boreholes at the Aespoe Hard Rock Laboratory (AHRL) gave rise to the idea that induced borehole breakouts using thermal loading in smaller diameter boreholes, could be a possible way of determining the stress orientation. Two pilot experiments were performed, one at the Aespoe Hard Rock Laboratory and one at ONKALO research site in Finland. An acoustic televiewer logger was used to measure the detailed geometrical condition of the borehole before and after heating periods. The acoustic televiewer gives a value for each 0.7 mm large pixel size around the borehole periphery. The results from the loggers are presented as images of the borehole wall, and as curves for the maximum, mean and minimum values at each depth. Any changes in the borehole wall geometry may thus be easily detected by comparisons of the logging result images. In addition, using an optical borehole televiewer a good and detailed realistic colour picture of the borehole wall is obtained. From these images the character of the spalls identified may be evaluated further. The heating was performed in a 4 m long section, using a heating cable centred in an 8 m deep vertical borehole, drilled from the floor of the tunnels. For the borehole in the Q-tunnel of AHRL the results from the loggings of the borehole before the heating revealed that breakouts existed even before this pilot test due to previous heating experiments at the site (CAPS). Quite consistent orientation and the typical shape of small breakouts were observed. After the heating the spalling increased slightly at the same locations and a new spalling location also developed at a deeper location in the borehole. At ONKALO three very small changes

Tunneling works. Tunnel koji

Energy Technology Data Exchange (ETDEWEB)

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

1991-10-25

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

Isolated femoral hypoplasia: an intrauterine differential diagnosis to campomelia

Energy Technology Data Exchange (ETDEWEB)

Koerber, Friederike; Benz-Bohm, Gabriele [University of Cologne, Department of Paediatric Radiology, Cologne (Germany); Schoenau, Eckard [University of Cologne, Department of Paediatrics, Cologne (Germany); Horwitz, A.Eldad [Klinikum Krefeld, Department of Paediatric Radiology, Krefeld (Germany)

2005-06-01

The isolated form of femoral bowing is an important differential diagnosis of campomelia. Therefore, knowledge of isolated anomalies is fundamental for prenatal diagnosis, especially for the differential diagnosis from severe syndromes. Four cases are presented to discuss the differential diagnosis of femoral bowing including a review of the literature. We report four newborn babies with unilateral bowing and shortening of the femur. Three had no further anomaly; one child had additional abnormalities due to coumarin embryopathy. The radiological findings were shortened femora with bowing and varus deformity and cortical thickening on the concave side. All other parts showed normal bone structure. The aetiology of femoral bowing is unknown. Early damage of the cartilaginous model followed by remodelling with thickening on the concave side of the bone similar to the healing of malaligned fractures is suspected. The isolated form of femoral bowing without any other anomalies has to be differentiated from complex and more often severe congenital syndromes such as campomelia. Postpartum radiological examination should be reduced to a single exposure of the affected limb and follow-up should be done by clinical examination. (orig.)

Transfer of obturator nerve for femoral nerve injury: an experiment study in rats.

Science.gov (United States)

Meng, Depeng; Zhou, Jun; Lin, Yaofa; Xie, Zheng; Chen, Huihao; Yu, Ronghua; Lin, Haodong; Hou, Chunlin

2018-07-01

Quadriceps palsy is mainly caused by proximal lesions in the femoral nerve. The obturator nerve has been previously used to repair the femoral nerve, although only a few reports have described the procedure, and the outcomes have varied. In the present study, we aimed to confirm the feasibility and effectiveness of this treatment in a rodent model using the randomized control method. Sixty Sprague-Dawley rats were randomized into two groups: the experimental group, wherein rats underwent femoral neurectomy and obturator nerve transfer to the femoral nerve motor branch; and the control group, wherein rats underwent femoral neurectomy without nerve transfer. Functional outcomes were measured using the BBB score, muscle mass, and histological assessment. At 12 and 16 weeks postoperatively, the rats in the experimental group exhibited recovery to a stronger stretch force of the knee and higher BBB score, as compared to the control group (p nerve with myelinated and unmyelinated fibers was observed in the experimental group. No significant differences were observed between groups at 8 weeks postoperatively (p > 0.05). Obturator nerve transfer for repairing femoral nerve injury was feasible and effective in a rat model, and can hence be considered as an option for the treatment of femoral nerve injury.

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

Science.gov (United States)

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

2014-01-01

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

Multiple bony lesions other than femoral heads on {sup 99m}Tc-MDP bone scan in patients with avascular necrosis of the femoral head

Energy Technology Data Exchange (ETDEWEB)

Choi, Yun Young; Yang, Seoung Oh; Moon, Dae Hyuk; Ryu, Jin Sook; Weon, Young Cheol; Shin, Myung Jin; Lee, Soo Ho; Lee, Hee Kyung [Asan Medical Center, Ulsan Univ. College of Medicine, Ulsan (Korea, Republic of); Chun, Hae Kyung [St. Francisco Hospital, Seoul (Korea, Republic of)

1997-03-01

To evaluate the clinical significance of the multiple increased uptake lesions other than in femoral heads as seen on whole body bone scan in patients with avascular necrosis of femoral heads. One hundred and seventy three patients with clinical diagnosis of avascular necrosis of the emoral head underwent a bone scan using Tc-99m MDP. Increased uptake lesions other than in femoral heads were evaluated, including frequency and common sites of in volvement, and correlated with clinical information and plain radiographic findings. Two hundred patients without AVN, who had undergone a bone scan, were included as a control group. Increased uptake lesions in extrafemoral head locations were found in 36 of 173 patients(20.8%); the location of 79 lesions was other than the femoral head. This result is statistically different from patients without avascular necrosis of femoral head(p<0.0001). The most common site of involvement was the knee joint area(62.5%). Other lesions were located in the mid-shafts of the long bones of the lower extremities, calcaneus, proximal humerus, etc., in order of decreasing frequency. Plain radiographs of 17 lesions were nonspecific, except for three lesions showing definite changes associated with avascular necrosis. The risk factors included alcoholism, the prolonged use of steroids, renal transplantation, herbal medication and working as a working as deep-sea diver. Most patients did not complain of pain, except for two with irreversible osteonecrotic changes as seen on plain radiograph. in patients with avascular necrosis of the femur, increased uptake lesions other than in the femoral head as seen on bone scan, may represent the early stage of osteonecrosis, which shows a characteristic appearance on bone scan. In order to aveid possible misdiagnoses of multiple extrafemoral lesions as bony metastasis or traumatic lesions, in patients with avascular necrosis of the femur these should be carefully evaluated.

Traumatic subchondral fracture of the femoral head in a healed trochanteric fracture.

Science.gov (United States)

Lee, Sang Yang; Niikura, Takahiro; Iwakura, Takashi; Kurosaka, Masahiro

2014-07-11

An 82-year-old woman sustained a trochanteric fracture of the left femur after a fall. Fracture fixation was performed using proximal femoral nail antirotation (PFNA) II, and she was able to walk with a T-cane after 3 months. Eleven months following the operation, the patient presented with left hip pain after a fall. Radiographs showed a subchondral collapse of the femoral head located above the blade tip. The authors removed the PFNA-II and subsequently performed cemented bipolar hemiarthroplasty. Histological evaluation of the femoral head showed osteoporosis with no evidence of osteonecrosis. Repair tissue, granulation tissue and callus formation were seen at the collapsed subchondral area. Based on these findings, a traumatic subchondral fracture of the femoral head in a healed trochanteric fracture was diagnosed. A traumatic subchondral fracture of the femoral head may need to be considered as a possible diagnosis after internal fixation of the trochanteric fracture. 2014 BMJ Publishing Group Ltd.

Macroscopic quantum tunneling in Mn12-acetat

International Nuclear Information System (INIS)

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

2004-01-01

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

Ipsilateral femoral shaft and vertical patella fracture: a case report

Science.gov (United States)

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

2009-01-01

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

Morphometric findings in avascular necrosis of the femoral head.

Science.gov (United States)

Kamal, Diana; Trăistaru, Rodica; Alexandru, D O; Kamal, C K; Pirici, D; Pop, O T; Mălăescu, D Gh

2012-01-01

Avascular necrosis of the femoral head is an illness with a controversial etiology, the trigger event being the suppression of blood flow to the femoral head. The disease affects mostly young adults within their third and fifth decade, the majority of the patients being men. The main risk factors are trauma, chronic alcohol consumption, smoking, corticotherapy. The main goal of our study is to describe the morphometric changes found in the bone tissue of patients diagnosed with avascular necrosis of the femoral head, with different risk factors, by comparing the area of bone trabeculae inside the area of necrosis with that from the adjacent viable tissue. The morphometric study used biological material from 16 patients with ages between 29 and 57 years, who underwent surgery for avascular necrosis of the femoral head. They were admitted in the Orthopedics Department at the Emergency County Hospital in Craiova between 2010 and 2011 and were split into four groups. Group I presented trauma as the main risk factor, Group II had corticotherapy as the defining risk factor, Group III presented chronic alcohol consumption and Group IV was represented by the patients who smoked and exhibited chronic alcohol consumption. There was not a significant statistical difference between the areas of bone trabeculae of the four groups when we compared viable bone tissue to the necrotized one. Knowing the risk factors of the avascular necrosis of the femoral head is critical to the management of the disease, because diagnosing it in an early stage is a necessity for obtaining a good result for conservative treatment.

Tunneling junction as an open system. Normal tunneling

International Nuclear Information System (INIS)

Ono, Y.

1978-01-01

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

Incidence and predictors of post-catheterization femoral artery pseudoaneurysms

OpenAIRE

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

2013-01-01

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

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

Science.gov (United States)

Minato, Izumi

2011-03-01

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

Avascular necrosis of femoral head: findings of contrast-enhanced MR imaging

International Nuclear Information System (INIS)

Shin, Yong Moon; Kang, Heung Sik; Kim, Chu Wan; Kim, Hee Joong; Kim, Young Min

1995-01-01

To evaluate the findings and the role of contrast enhanced magnetic resonance imaging in avascular necrosis of femoral head. Sixteen patients with avascular necorsis of femoral head were examined with MRI. T1-weighted and T2-weighted image and contrast-enhanced T1-weighted images were obtained. Enhancing characteristics of the necrotic area and synovium were determined. Also a change of the disease extent after enhancement was assessed. Twenty seven avascular necrosis of the femoral head including 11 cases of bilateral lesion were detected. Fifteen cases revealed collapse of the femoral head. The portions of the lesion with low signal intensity on T1-weighted images and high signal intensity on T2-weighted images showed contrast enhancement in 15 cases. However, the potions with low signal intensities both on T1 and T2-weighted images showed enhancement in one case. There was no significant change of the disease extent after enhancement. Synovium showed enhancement in 18 cases, and joint effusion was detected in 23 cases. Contrast enhanced MR images may be helpful in predicting histopathologic findings of avascular necrosis of the femoral head, but not useful for evaluating the extent of disease

Avascular necrosis of femoral head: findings of contrast-enhanced MR imaging

Energy Technology Data Exchange (ETDEWEB)

Shin, Yong Moon; Kang, Heung Sik; Kim, Chu Wan; Kim, Hee Joong; Kim, Young Min [Seoul National University College of Medicine, Seoul (Korea, Republic of)

1995-06-15

To evaluate the findings and the role of contrast enhanced magnetic resonance imaging in avascular necrosis of femoral head. Sixteen patients with avascular necorsis of femoral head were examined with MRI. T1-weighted and T2-weighted image and contrast-enhanced T1-weighted images were obtained. Enhancing characteristics of the necrotic area and synovium were determined. Also a change of the disease extent after enhancement was assessed. Twenty seven avascular necrosis of the femoral head including 11 cases of bilateral lesion were detected. Fifteen cases revealed collapse of the femoral head. The portions of the lesion with low signal intensity on T1-weighted images and high signal intensity on T2-weighted images showed contrast enhancement in 15 cases. However, the potions with low signal intensities both on T1 and T2-weighted images showed enhancement in one case. There was no significant change of the disease extent after enhancement. Synovium showed enhancement in 18 cases, and joint effusion was detected in 23 cases. Contrast enhanced MR images may be helpful in predicting histopathologic findings of avascular necrosis of the femoral head, but not useful for evaluating the extent of disease.

Avascular necrosis of the femoral head in HIV infected patients

Directory of Open Access Journals (Sweden)

Marcos Almeida Matos

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

Tunneling time, exit time and exit momentum in strong field tunnel ionization

International Nuclear Information System (INIS)

Teeny, Nicolas

2016-01-01

Tunnel ionization belongs to the fundamental processes of atomic physics. It is still an open question when does the electron tunnel ionize and how long is the duration of tunneling. In this work we solve the time-dependent Schroedinger equation in one and two dimensions and use ab initio quantum calculations in order to answer these questions. Additionally, we determine the exit momentum of the tunnel ionized electron from first principles. We find out results that are different from the assumptions of the commonly employed two-step model, which assumes that the electron ionizes at the instant of electric field maximum with a zero momentum. After determining the quantum final momentum distribution of tunnel ionized electrons we show that the two-step model fails to predict the correct final momentum. Accordingly we suggest how to correct the two-step model. Furthermore, we determine the instant at which tunnel ionization starts, which turns out to be different from the instant usually assumed. From determining the instant at which it is most probable for the electron to enter the tunneling barrier and the instant at which it exits we determine the most probable time spent under the barrier. Moreover, we apply a quantum clock approach in order to determine the duration of tunnel ionization. From the quantum clock we determine an average tunneling time which is different in magnitude and origin with respect to the most probable tunneling time. By defining a probability distribution of tunneling times using virtual detectors we relate both methods and explain the apparent discrepancy. The results found have in general an effect on the interpretation of experiments that measure the spectra of tunnel ionized electrons, and specifically on the calibration of the so called attoclock experiments, because models with imprecise assumptions are usually employed in order to interpret experimental results.

Tunneling time, exit time and exit momentum in strong field tunnel ionization

Energy Technology Data Exchange (ETDEWEB)

Teeny, Nicolas

2016-10-18

Tunnel ionization belongs to the fundamental processes of atomic physics. It is still an open question when does the electron tunnel ionize and how long is the duration of tunneling. In this work we solve the time-dependent Schroedinger equation in one and two dimensions and use ab initio quantum calculations in order to answer these questions. Additionally, we determine the exit momentum of the tunnel ionized electron from first principles. We find out results that are different from the assumptions of the commonly employed two-step model, which assumes that the electron ionizes at the instant of electric field maximum with a zero momentum. After determining the quantum final momentum distribution of tunnel ionized electrons we show that the two-step model fails to predict the correct final momentum. Accordingly we suggest how to correct the two-step model. Furthermore, we determine the instant at which tunnel ionization starts, which turns out to be different from the instant usually assumed. From determining the instant at which it is most probable for the electron to enter the tunneling barrier and the instant at which it exits we determine the most probable time spent under the barrier. Moreover, we apply a quantum clock approach in order to determine the duration of tunnel ionization. From the quantum clock we determine an average tunneling time which is different in magnitude and origin with respect to the most probable tunneling time. By defining a probability distribution of tunneling times using virtual detectors we relate both methods and explain the apparent discrepancy. The results found have in general an effect on the interpretation of experiments that measure the spectra of tunnel ionized electrons, and specifically on the calibration of the so called attoclock experiments, because models with imprecise assumptions are usually employed in order to interpret experimental results.

Chemistry at molecular junctions: Rotation and dissociation of O2 on the Ag(110) surface induced by a scanning tunneling microscope.

Science.gov (United States)

Roy, Sharani; Mujica, Vladimiro; Ratner, Mark A

2013-08-21

The scanning tunneling microscope (STM) is a fascinating tool used to perform chemical processes at the single-molecule level, including bond formation, bond breaking, and even chemical reactions. Hahn and Ho [J. Chem. Phys. 123, 214702 (2005)] performed controlled rotations and dissociations of single O2 molecules chemisorbed on the Ag(110) surface at precise bias voltages using STM. These threshold voltages were dependent on the direction of the bias voltage and the initial orientation of the chemisorbed molecule. They also observed an interesting voltage-direction-dependent and orientation-dependent pathway selectivity suggestive of mode-selective chemistry at molecular junctions, such that in one case the molecule underwent direct dissociation, whereas in the other case it underwent rotation-mediated dissociation. We present a detailed, first-principles-based theoretical study to investigate the mechanism of the tunneling-induced O2 dynamics, including the origin of the observed threshold voltages, the pathway dependence, and the rate of O2 dissociation. Results show a direct correspondence between the observed threshold voltage for a process and the activation energy for that process. The pathway selectivity arises from a competition between the voltage-modified barrier heights for rotation and dissociation, and the coupling strength of the tunneling electrons to the rotational and vibrational modes of the adsorbed molecule. Finally, we explore the "dipole" and "resonance" mechanisms of inelastic electron tunneling to elucidate the energy transfer between the tunneling electrons and chemisorbed O2.

Quantum theory of tunneling

CERN Document Server

Razavy, Mohsen

2014-01-01

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

Manipulating individual dichlorotin phthalocyanine molecules on Cu(100) surface at room temperature by scanning tunneling microscopy

International Nuclear Information System (INIS)

Li, Chao; Xiang, Feifei; Wang, Zhongping; Liu, Xiaoqing; Jiang, Danfeng; Wang, Li; Wang, Guang; Zhang, Xueao; Chen, Wei

2014-01-01

Single molecule manipulations have been achieved on dichlorotin phthalocyanine(SnCl 2 Pc) molecules adsorbed on Cu (100) at room temperature. Scanning tunneling microscopy observations directly demonstrate that the individual SnCl 2 Pc molecules can be moved along the [100] direction on Cu(100) surface by employing a scanning tunneling microscope tip fixed at the special position of the molecules. The orientation of the molecule can be switched between two angles of ±28° with respect to the [011] surface direction in the same way. Dependences of the probability of molecular motion on the distances between the tip and the molecules reveal that the mechanism for such manipulation of a SnCl 2 Pc molecule is dominated by the repulsive interactions between the tip and the molecules. With the assistance of this manipulation process, a prototype molecular storage array with molecular orientation as information carrier and an artificial hydrogen bonded supramolecular structure have been constructed on the surface. (paper)

Emergency Stenting of a Ruptured Infected Anastomotic Femoral Pseudoaneurysm

International Nuclear Information System (INIS)

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

2007-01-01

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

Femoral Artery Stenosis Following Percutaneous Closure Using a Starclose Closure Device

International Nuclear Information System (INIS)

Bent, Clare Louise; Kyriakides, Constantinos; Matson, Matthew

2008-01-01

Starclose (Abbott Vascular Devices, Redwood City, CA) is a new arterial closure device that seals a femoral puncture site with an extravascular star-shaped nitinol clip. The clip projects small tines into the arterial wall which fold inward, causing the arterial wall to pucker, producing a purse-string-like seal closing the puncture site. The case history is that of a 76-year-old female patient who underwent day-case percutaneous diagnostic coronary angiography. A Starclose femoral artery closure device was used to achieve hemostasis with subsequent femoral artery stenosis.

[Growth and deformity after in situ fixation of slipped capital femoral epiphysis].

Science.gov (United States)

Druschel, C; Placzek, R; Funk, J F

2013-08-01

For mild to moderate slipped capital femoral epiphysis (SCFE) in situ fixation is the current treatment standard. However, concerning the implant selection (screw versus k-wires) as well as the prophylactic stabilisation of the non-affected hip, controversies still exist. The aim of this study was to analyse femoral residual growth and femoral deformities after in situ fixation of SCFE either with k-wires or screws. We conducted a retrospective analysis of the radiographs of adolescents treated for SCFE in our department between 01/2003 and 02/2011. To evaluate femoral growth the articulo-trochanteric distance, centro-trochanteric distance, caput-collum-diaphyseal angle, pin-joint ratio and pin-physis ratio were determined. The femoral deformity was assessed by measuring the sphericity of the femoral head. Degenerative changes were evaluated in the final radiographs. Statistical analysis was performed concerning differences between therapeutically and prophylactically treated hips as well as stabilisations with k-wires and screws. A total of 22 patients (female : male = 14 : 8, mean age girls: 11 ± 1 years, boys: 13 ± 2 years) with 26 slipped capital femoral epiphyses was analysed. K-wires were used for fixation in 4 hips each therapeutically and prophylactically, 22 hips with SCFE and 14 non-affected hips were stabilised with screws. Treatment with screws did not lead to significantly earlier physeal closure than k-wire pinning. Regarding the femoral growth parameters a significant decrease in the articulo-trochanteric distance and CCD angle was detectable in all groups. The pin-joint ratio revealed an adequate residual growth in 58 % of the therapeutically and in 72 % of the prophylactically treated hips without significant difference between k-wires and screws. The pin-physis ratio demonstrated similar values. Regarding the femoral deformity the SCFE hips resulted in a significantly reduced sphericity, which remained unchanged during follow-up. The

A modified Larson’s method of posterolateral corner reconstruction of the knee reproducing the physiological tensioning pattern of the lateral collateral and popliteofibular ligaments

Directory of Open Access Journals (Sweden)

Niki Yasuo

2012-06-01

Full Text Available Abstract Background Consensus has been lacking as to how to reconstruct the posterolateral corner (PLC of the knee in patients with posterolateral instability. We describe a new reconstructive technique for PLC based on Larson's method, which reflects the physiological load-sharing pattern of the lateral collateral ligament (LCL and popliteofibular ligament (PFL. Findings Semitendinosus graft is harvested, and one limb of the graft comprises PFL and the other comprises LCL. Femoral bone tunnels for the LCL and popliteus tendon are made at their anatomical insertions. Fibular bone tunnel is prepared from the anatomical insertion of the LCL to the proximal posteromedial portion of the fibular head, which corresponds to the insertion of the PFL. The graft end for popliteus tendon is delivered into the femoral bone tunnel and secured on the medial femoral condyle. The other end for LCL is passed through the fibular tunnel from posterior to anterior. While the knee is held in 90 of flexion, the graft is secured in the fibular tunnel using a 5 mm interference screw. Then, the LCL end is passed into the femoral bone tunnel and secured at the knee in extension. Conclusions Differential tension patterns between LCL and PFL is critical when securing these graft limbs. Intrafibular fixation of the graft using a small interference screw allows us to secure these two graft limbs independently with intended tension at the intended flexion angle of the knee.

Prognostic value of dynamic MRI in assessing post-traumatic femoral head vascularity

Energy Technology Data Exchange (ETDEWEB)

Kaushik, Abhishek; Varghese, Mathew [St Stephen' s Hospital, Department of Orthopaedics, Delhi, New Delhi (India); Sankaran, Balu [St Stephen' s Hospital, Delhi, New Delhi (India)

2009-06-15

The vascular status of femoral heads in the post-traumatic period of intracapsular femoral neck fracture (ICFNF) remains uncertain until the patient actually develops avascular necrosis (AVN). Several methods for predicting the viability of femoral head have been reported, that are not effective or widely used because of unreliability, potential complications, and technical difficulties. The present study involved the use of Dynamic MRI (DMRI) in assessing femoral head vascularity to predict AVN. The role of DMRI was studied prospectively in 30 patients with 31 ICFNF. Fractures were divided in to three types (Type A, B, or C) based on the femoral head vascularity shown by dynamic curve patterns on MRI evaluation. Type A was preserved vascularity, Type B was some decrease in vascularity but still viable while Type C was significantly reduced vascularity. These were followed-up for 6 months to 2 years to observe the final outcome in terms of union, non-union, or AVN. We found that Type A curves correlate well with vascular status and Type C curves correlate well with poor vascularity of the femoral heads. No AVN was seen in any of Type A (13/31) or Type B (eight out of 31). Five cases showed AVN and all of them were of Type C dynamic curves. Dynamic MRI is a reliable tool to evaluate vascularity of femoral heads and thus reduces the uncertainty of outcome of treatment of ICFNFs. DMRI can be a useful tool to formulate a treatment algorithm in management of ICFNF. (orig.)

Arthroscopic treatment of femoral nerve paresthesia caused by an acetabular paralabral cyst.

Science.gov (United States)

Kanauchi, Taira; Suganuma, Jun; Mochizuki, Ryuta; Uchikawa, Shinichi

2014-05-01

This report describes a rare case of femoral nerve paresthesia caused by an acetabular paralabral cyst of the hip joint. A 68-year-old woman presented with a 6-month history of right hip pain and paresthesia along the anterior thigh and radiating down to the anterior aspect of the knee. Radiography showed osteoarthritis with a narrowed joint space in the right hip joint. Magnetic resonance imaging showed a cyst with low T1- and high T2-weighted signal intensity arising from a labral tear at the anterior aspect of the acetabulum. The cyst was connected to the joint space and displaced the femoral nerve to the anteromedial side. The lesion was diagnosed as an acetabular paralabral cyst causing femoral neuropathy. Because the main symptom was femoral nerve paresthesia and the patient desired a less invasive procedure, arthroscopic labral repair was performed to stop synovial fluid flow to the paralabral cyst that was causing the femoral nerve paresthesia. After surgery, the cyst and femoral nerve paresthesia disappeared. At the 18-month follow-up, the patient had no recurrence. There have been several reports of neurovascular compression caused by the cyst around the hip joint. To the authors' knowledge, only 3 cases of acetabular paralabral cysts causing sciatica have been reported. The current patient appears to represent a rare case of an acetabular paralabral cyst causing femoral nerve paresthesia. The authors suggest that arthroscopic labral repair for an acetabular paralabral cyst causing neuropathy can be an option for patients who desire a less invasive procedure. Copyright 2014, SLACK Incorporated.

Prognostic value of dynamic MRI in assessing post-traumatic femoral head vascularity

International Nuclear Information System (INIS)

Kaushik, Abhishek; Varghese, Mathew; Sankaran, Balu

2009-01-01

The vascular status of femoral heads in the post-traumatic period of intracapsular femoral neck fracture (ICFNF) remains uncertain until the patient actually develops avascular necrosis (AVN). Several methods for predicting the viability of femoral head have been reported, that are not effective or widely used because of unreliability, potential complications, and technical difficulties. The present study involved the use of Dynamic MRI (DMRI) in assessing femoral head vascularity to predict AVN. The role of DMRI was studied prospectively in 30 patients with 31 ICFNF. Fractures were divided in to three types (Type A, B, or C) based on the femoral head vascularity shown by dynamic curve patterns on MRI evaluation. Type A was preserved vascularity, Type B was some decrease in vascularity but still viable while Type C was significantly reduced vascularity. These were followed-up for 6 months to 2 years to observe the final outcome in terms of union, non-union, or AVN. We found that Type A curves correlate well with vascular status and Type C curves correlate well with poor vascularity of the femoral heads. No AVN was seen in any of Type A (13/31) or Type B (eight out of 31). Five cases showed AVN and all of them were of Type C dynamic curves. Dynamic MRI is a reliable tool to evaluate vascularity of femoral heads and thus reduces the uncertainty of outcome of treatment of ICFNFs. DMRI can be a useful tool to formulate a treatment algorithm in management of ICFNF. (orig.)

A new method for measurement of femoral anteversion using 3D imaging technique

International Nuclear Information System (INIS)

Kim, S.I.; Lee, Y.H.; Park, S.-B.; Lee, K.-M.

1996-01-01

Conventional methods that use cross-sectional computed tomography (CT) images to estimate femoral anteversion have several problems because of the complex 3 dimensional structure of the femur. These are the ambiguity of defining the femoral neck axis and condylar line, and the dependence on patient positioning. Especially, the femoral neck axis that is known as a major source of error is hard to determine from a single or multiple 2-dimensional transverse CT images. In this study, we are presenting a new method that we have devised form the measurement of femoral anteversion by utilizing the 3 dimensional imaging technique. Poster 176. (author)

Long-term functional outcome following intramedullary nailing of femoral shaft fractures

NARCIS (Netherlands)

el Moumni, Mostafa; Voogd, Emma Heather; ten Duis, Henk Jan; Wendt, Klaus Wilhelm

Background: The management of femoral shaft fractures using intramedullary nailing is a popular method. The purpose of this study was to evaluate the long-term functional outcome after antegrade or retrograde intramedullary nailing of traumatic femoral shaft fractures. We further determined

Epitaxial NbN/AlN/NbN tunnel junctions on Si substrates with TiN buffer layers

Directory of Open Access Journals (Sweden)

Rui Sun

2016-06-01

Full Text Available We have developed epitaxial NbN/AlN/NbN tunnel junctions on Si (100 substrates with a TiN buffer layer. A 50-nm-thick (200-oriented TiN thin film was introduced as the buffer layer for epitaxial growth of NbN/AlN/NbN trilayers on Si substrates. The fabricated NbN/AlN/NbN junctions demonstrated excellent tunneling properties with a high gap voltage of 5.5 mV, a large IcRN product of 3.8 mV, a sharp quasiparticle current rise with a ΔVg of 0.4 mV, and a small subgap leakage current. The junction quality factor Rsg/RN was about 23 for the junction with a Jc of 47 A/cm2 and was about 6 for the junction with a Jc of 3.0 kA/cm2. X-ray diffraction and transmission electron microscopy observations showed that the NbN/AlN/NbN trilayers were grown epitaxially on the (200-orientated TiN buffer layer and had a highly crystalline structure with the (200 orientation.

Epitaxial NbN/AlN/NbN tunnel junctions on Si substrates with TiN buffer layers

Energy Technology Data Exchange (ETDEWEB)

Sun, Rui [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences (CAS), Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Makise, Kazumasa; Terai, Hirotaka [Advanced ICT Research Institute, National Institute of Information and Communications Technology (Japan); Zhang, Lu [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences (CAS), Shanghai 200050 (China); Wang, Zhen, E-mail: zwang@mail.sim.ac.cn [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences (CAS), Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Shanghai Tech University, Shanghai 201210 (China)

2016-06-15

We have developed epitaxial NbN/AlN/NbN tunnel junctions on Si (100) substrates with a TiN buffer layer. A 50-nm-thick (200)-oriented TiN thin film was introduced as the buffer layer for epitaxial growth of NbN/AlN/NbN trilayers on Si substrates. The fabricated NbN/AlN/NbN junctions demonstrated excellent tunneling properties with a high gap voltage of 5.5 mV, a large I{sub c}R{sub N} product of 3.8 mV, a sharp quasiparticle current rise with a ΔV{sub g} of 0.4 mV, and a small subgap leakage current. The junction quality factor R{sub sg}/R{sub N} was about 23 for the junction with a J{sub c} of 47 A/cm{sup 2} and was about 6 for the junction with a J{sub c} of 3.0 kA/cm{sup 2}. X-ray diffraction and transmission electron microscopy observations showed that the NbN/AlN/NbN trilayers were grown epitaxially on the (200)-orientated TiN buffer layer and had a highly crystalline structure with the (200) orientation.

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

African Journals Online (AJOL)

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

Benefit of cup medialization in total hip arthroplasty is associated with femoral anatomy.

Science.gov (United States)

Terrier, Alexandre; Levrero Florencio, Francesc; Rüdiger, Hannes A

2014-10-01

Medialization of the cup with a respective increase in femoral offset has been proposed in THA to increase abductor moment arms. Insofar as there are potential disadvantages to cup medialization, it is important to ascertain whether the purported biomechanical benefits of cup medialization are large enough to warrant the downsides; to date, studies regarding this question have disagreed. The purpose of this study was to quantify the effect of cup medialization with a compensatory increase in femoral offset compared with anatomic reconstruction for patients undergoing THA. We tested the hypothesis that there is a (linear) correlation between preoperative anatomic parameters and muscle moment arm increase caused by cup medialization. Fifteen patients undergoing THA were selected, covering a typical range of preoperative femoral offsets. For each patient, a finite element model was built based on a preoperative CT scan. The model included the pelvis, femur, gluteus minimus, medius, and maximus. Two reconstructions were compared: (1) anatomic position of the acetabular center of rotation, and (2) cup medialization compensated by an increase in the femoral offset. Passive abduction-adduction and flexion-extension were simulated in the range of normal gait. Muscle moment arms were evaluated and correlated to preoperative femoral offset, acetabular offset, height of the greater trochanter (relative to femoral center of rotation), and femoral antetorsion angle. The increase of muscle moment arms caused by cup medialization varied among patients. Muscle moment arms increase by 10% to 85% of the amount of cup medialization for abduction-adduction and from -35% (decrease) to 50% for flexion-extension. The change in moment arm was inversely correlated (R(2) = 0.588, p = 0.001) to femoral antetorsion (anteversion), such that patients with less femoral antetorsion gained more in terms of hip muscle moments. No linear correlation was observed between changes in moment arm and

Spin-dependent tunnelling in magnetic tunnel junctions

International Nuclear Information System (INIS)

Tsymbal, Evgeny Y; Mryasov, Oleg N; LeClair, Patrick R

2003-01-01

The phenomenon of electron tunnelling has been known since the advent of quantum mechanics, but continues to enrich our understanding of many fields of physics, as well as creating sub-fields on its own. Spin-dependent tunnelling (SDT) in magnetic tunnel junctions (MTJs) has recently aroused enormous interest and has developed in a vigorous field of research. The large tunnelling magnetoresistance (TMR) observed in MTJs garnered much attention due to possible applications in non-volatile random-access memories and next-generation magnetic field sensors. This led to a number of fundamental questions regarding the phenomenon of SDT. In this review article we present an overview of this field of research. We discuss various factors that control the spin polarization and magnetoresistance in MTJs. Starting from early experiments on SDT and their interpretation, we consider thereafter recent experiments and models which highlight the role of the electronic structure of the ferromagnets, the insulating layer, and the ferromagnet/insulator interfaces. We also discuss the role of disorder in the barrier and in the ferromagnetic electrodes and their influence on TMR. (topical review)

Femoral artery recanalisation with percutaneous angioplasty and segmentally enclosed plasminogen activator

DEFF Research Database (Denmark)

Jørgensen, B; Tønnesen, K H; Bülow, J

1989-01-01

To establish whether re-occlusion of the femoral artery could be prevented, in 6 consecutive patients undergoing percutaneous transluminal angioplasty (PTA) for superficial femoral artery occlusion the recanalised segment was isolated, with a 7-French double-balloon catheter. 5 mg recombined huma...

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

NARCIS (Netherlands)

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

2006-01-01

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

Computer tomographic determination of femoral anteversion

International Nuclear Information System (INIS)

Jend, H.H.

1986-01-01

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

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

International Nuclear Information System (INIS)

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

2011-01-01

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

Rotation of intramedullary alignment rods affects distal femoral cutting plane in total knee arthroplasty.

Science.gov (United States)

Maderbacher, Günther; Matussek, Jan; Keshmiri, Armin; Greimel, Felix; Baier, Clemens; Grifka, Joachim; Maderbacher, Hermann

2018-02-17

Intramedullary rods are widely used to align the distal femoral cut in total knee arthroplasty. We hypothesised that both coronal (varus/valgus) and sagittal (extension/flexion) cutting plane are affected by rotational changes of intramedullary femoral alignment guides. Distal femoral cuts using intramedullary alignment rods were simulated by means of a computer-aided engineering software in 4°, 6°, 8°, 10°, and 12° of valgus in relation to the femoral anatomical axis and 4° extension, neutral, as well as 4°, 8°, and 12° of flexion in relation to the femoral mechanical axis. This reflects the different angles between anatomical and mechanical axis in coronal and sagittal planes. To assess the influence of rotation of the alignment guide on the effective distal femoral cutting plane, all combinations were simulated with the rod gradually aligned from 40° of external to 40° of internal rotation. Rotational changes of the distal femoral alignment guides affect both the coronal and sagittal cutting planes. When alignment rods are intruded neutrally with regards to sagittal alignment, external rotation causes flexion, while internal rotation causes extension of the sagittal cutting plane. Simultaneously the coronal effect (valgus) decreases resulting in an increased varus of the cutting plane. However, when alignment rods are intruded in extension or flexion partly contradictory effects are observed. Generally the effect increases with the degree of valgus preset, rotation and flexion. As incorrect rotation of intramedullary alignment guides for distal femoral cuts causes significant cutting errors, exact rotational alignment is crucial. Coronal cutting errors in the distal femoral plane might result in overall leg malalignment, asymmetric extension gaps and subsequent sagittal cutting errors.

Variant Branching of the Common Femoral Artery in a Black Kenyan ...

African Journals Online (AJOL)

Branching pattern of common femoral artery is important during artery catheterization, orthopaedic, plastic and general surgery in the proximal thigh. Frequency of variant branching shows ethnic variation but there are no data for black African populations. Since atherosclerotic diseases are increasing and femoral artery ...

Analysis of hemodynamic characteristics in anastomotic sites of femoral artery implantation

Energy Technology Data Exchange (ETDEWEB)

Roh, H.W. [Graduate School, Soongsil University, Seoul (Korea); Suh, S.H. [SoongsSil University, Seoul (Korea); Yoo, S.S. [Hankuk Aviation University, Kyonggi-do (Korea); Kim, D.I.; Lee, B.B. [Samsung Medical Center (Korea)

1998-11-01

The objective of the present study is to obtain information on the hemodynamic characteristics in the anastomotic sites of femoral artery through the vascular implantation. Three dimensional steady and physiological blood flows in the femoral artery are simulated using the finite volume method. The geometrical shape of the anastomotic sites is made based on the vascular anatomy of a white rabbit. Wall shear stress distributions in the anastomotic sites for the physiological flow are compared with those for steady flow. Blood flow phenomena in the anastomotic sites of the femoral artery are discussed extensively. (author). 9 refs., 11 figs., 1 tab.

The application of bilateral femoral vein approaches in interventional treatment of deep venous thrombosis of left lower extremity

International Nuclear Information System (INIS)

Wang Xiuping; Liu Jian; Wang Bin; Yao Zhongqiang; Zhang Yan; Li Chen

2011-01-01

Objective: To investigate the feasibility of interventional catheterization with bilateral femoral vein approaches for performing the thrombolytic treatment of acute deep venous thrombosis of left lower extremity. Methods: Antegrade puncturing into the left femoral vein was carried out in eighteen patients with acute deep vein thrombosis in the left lower extremity after left iliac-femoral vein catheterization via the right femoral vein or the right jugular vein access failed. When the puncturing of the left femoral vein was successfully done and was confirmed by angiography, the guide wire was inserted into the inferior vena cava and was pulled out through the right femoral vein or right jugular vein, and a wire track was thus established. Then, retrograde insertion of the catheter was conducted along the wire from the right to the left until the catheter was placed into the left iliac-femoral vein for thrombolysis. Results: Of 18 cases,successful puncturing into the left femoral vein was achieved in 16, and an effective wire track was established between the left and right femoral veins, based on which the catheter was smoothly inserted into the left iliac-femoral vein via the right femoral vein or jugular vein. Catheter thrombolysis was employed for 3 to 14 days, the thrombus was completely dissolved and the lower extremity swelling subsided. During the course of thrombolysis, no obvious congestion or hematoma occurred at the puncturing site of the left femoral vein. Conclusion: For patients with deep vein thrombosis of left lower extremity, when left iliac-femoral vein catheterization via the right femoral vein or the right jugular vein access failed, the establishment of wire track by using bilateral femoral vein approaches for further catheterization of left iliac-femoral vein and subsequent thrombolysis is feasible in clinical practice. This technique is safe and minimally-invasive with higher success rate. (authors)

The application of PRP combined with TCP in repairing avascular necrosis of the femoral head after femoral neck fracture in rabbit.

Science.gov (United States)

Zhang, X-L; Wang, Y-M; Chu, K; Wang, Z-H; Liu, Y-H; Jiang, L-H; Chen, X; Zhou, Z-Y; Yin, G

2018-02-01

In view of the high occurrence of avascular necrosis of the femoral head (ANFH) after femoral neck fracture and the difficulties in the treatment, our work aimed to explore the effects of platelet-rich plasma (PRP) combined with tri-calcium phosphate (TCP) on the repair of ANFH after femoral neck fracture and to provide reference for clinical treatment. Thirty New Zealand white rabbits were randomly divided into control group, TCP group, and PRP+TCP group. The rabbit ANFH model was established and femoral head tissues were collected. HE staining was used for histological observation. Image analysis and statistical analysis were used to calculate the New Bone Area fraction (NBA %). The levels of bone morphogenetic protein (BMP)-7, transforming growth factor (TGF)-β1, basic fibroblast growth factor (bFGF), interleukin (IL)-6 and tumor necrosis factor (TNF)-a in serum were detected by Enzyme-Linked ImmunoSorbent Assay (ELISA). The new bone area of TCP group was significantly lower than that of PRP+TCP group (pPRP+TCP groups (pPRP+TCP group was higher than that in TCP group. TCP and PRP+TCP can both significantly reduce the content of IL-6 and TNF-a (pPRP+TCP group compared with the TCP group at 8 weeks after injection. PRP combined with TCP, which can promote new bone formation and inhibit inflammatory response, showed higher efficiency in repairing ANFH than internal fixation alone.

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

Science.gov (United States)

2010-04-01

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

Radiation-induced femoral head necrosis

African Journals Online (AJOL)

2011-03-25

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

Disparities in correlating microstructural to nanostructural preservation of dinosaur femoral bones

Science.gov (United States)

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

2017-03-01

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

Tunnel fire dynamics

CERN Document Server

Ingason, Haukur; Lönnermark, Anders

2015-01-01

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

Proton tunneling in solids

Energy Technology Data Exchange (ETDEWEB)

Kondo, J.

1998-10-01

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

Proton tunneling in solids

International Nuclear Information System (INIS)

Kondo, J.

1998-01-01

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

Valsalva and gravitational variability of the internal jugular vein and common femoral vein: Ultrasound assessment

Energy Technology Data Exchange (ETDEWEB)

Beddy, P. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland)]. E-mail: pbeddy@eircom.net; Geoghegan, T. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); Ramesh, N. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); Buckley, O. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); O' Brien, J. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); Colville, J. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); Torreggiani, W.C. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland)

2006-05-15

Purpose: Central venous cannulation via the common femoral vein is an important starting point for many interventions. The purpose of this study was to determine the optimum conditions for cannulation of the femoral vein and to compare these with the relative changes in the internal jugular vein. Methods: High-resolution 2D ultrasound was utilised to determine variability of the calibre of the femoral and internal jugular veins in 10 healthy subjects. Venous diameter was assessed during the Valsalva manoeuvre and in different degrees of the Trendelenburg position. Results: The Valsalva manoeuvre significantly increased the size of the femoral and internal jugular veins. There was a relatively greater increase in femoral vein diameter when compared with the internal jugular vein of 40 and 29%, respectively. Changes in body inclination (Trendelenburg position) did not significantly alter the luminal diameter of the femoral vein. However, it significantly increased internal jugular vein diameter. Conclusions: Femoral vein cannulation is augmented by the Valsalva manoeuvre but not significantly altered by the gravitational position of the subject.

Underground anemotactic orientation in leaf-cutting ants: perception of airflow and experience-dependent choice of airflow direction during digging

Science.gov (United States)

Halboth, Florian; Roces, Flavio

2017-10-01

Air exchange between the large nests of Atta vollenweideri leaf-cutting ants and the environment strongly relies on a passive, wind-induced ventilation mechanism. Air moves through nest tunnels and airflow direction depends on the location of the tunnel openings on the nest mound. We hypothesized that ants might use the direction of airflow along nest tunnels as orientation cue in the context of climate control, as digging workers might prefer to broaden or to close tunnels with inflowing or outflowing air in order to regulate nest ventilation. To investigate anemotactic orientation in Atta vollenweideri, we first tested the ants' ability to perceive air movements by confronting single workers with airflow stimuli in the range 0 to 20 cm/s. Workers responded to airflow velocities ≥ 2 cm/s, and the number of ants reacting to the stimulus increased with increasing airflow speed. Second, we asked whether digging workers use airflow direction as an orientation cue. Workers were exposed to either inflow or outflow of air while digging in the nest and could subsequently choose between two digging sites providing either inflow or outflow of air, respectively. Workers significantly chose the side with the same airflow direction they experienced before. When no airflow was present during initial digging, workers showed no preference for airflow directions. Workers developed preferences for airflow direction only after previous exposure to a given airflow direction. We suggest that experience-modified anemotaxis might help leaf-cutting ants spatially organize their digging activity inside the nest during tasks related to climate control.

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-12-15

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

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

Science.gov (United States)

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

2017-08-01

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

Outcome of the geological mapping of the ONKALO underground research facility access tunnel, chainage 1980-3116

International Nuclear Information System (INIS)

Nordbaeck, N.

2010-06-01

This report describes the lithology and geological structures of the ONKALO underground rock characterization facility access tunnel in chainage 1980-3116. This part of the tunnel was excavated and mapped from spring 2007 to autumn 2008. The bedrock is very heterogeneous and mainly composed of veined gneiss and diatexitic gneiss, but many felsic dykes and sections of pegmatitic granite also occur. In addition, small sections of mica gneiss and K-feldspar porphyry are present. There are also numerous inclusions of mica gneiss, quartz gneiss and skarn. The foliation dips moderately towards SE. 14 fold axes and axial planes were measured from the ONKALO tunnel in chainage 1980-3116 and all have been interpreted to belong to deformation phase D 3 . The measured fold axes have various orientations, but most have moderate plunges and ENE- or WSW-trending ones dominate. The axial planes typically dip moderately towards SE. An almost vertical lineation was also measured from mica gneiss on two locations. A total of 7668 fractures were measured. Three main fracture sets were distinguished from the measured orientations: set 1 fractures are vertical and strike approximately NS, set 2 fractures are more or less horizontal and set 3 fractures are vertical and ENEWSW- striking. The most common filling minerals are calcite, pyrite, chlorite, kaolinite, epidote, muscovite, quartz, biotite, and illite. Of the measured fractures, 579 were slickensided. The slickensided fractures are mainly either sub-vertical N-S-trending (set 1) or sub-vertical NE-SW-trending, with dip to SE. Slickenside surfaces show N-S- and NE-SW-trending lineations, with shallow dip. The slickensided fractures are mostly strike-slip faults with both sinistral and dextral sense of movement. The chainage 1980- 3116 contains 170 tunnel-crosscutting fractures. The orientation is mostly vertical N-Sstriking, sub-horizontal or vertical E-W- trending. 27 deformation zone intersections were also observed, 23 brittle

Avascularity of the femoral head following intracapsular fracture: a comparative scintigraphic and bioptic study

Energy Technology Data Exchange (ETDEWEB)

Hoilund-Carlsen, P F; Widding, A; Uhrenholdt, A; Christoffersen, P; Grieff, J [Copenhagen Univ. (Denmark)

1980-03-01

Bioptic and scintigraphic methods of diagnosing avascular necrosis of the femoral head following intracapsular fracture of the femoral neck were compared. During operative treatment of patients, biospy samples of bone marrow were taken from the femoral head about 2 hours after the intravenous injection of sup(99m)Tc-Sn-pyrophosphate; histological examination of the biopsies were also performed. Scintigrams of the femoral head using sup(99m)Tc-pyrophosphate were performed 2 days, 7 days and 6 weeks post-operatively. The biopsies confirmed no morphological changes being apparent in the first few days. The biopsy samples indicated two groups of patients with either high or low activity in the femoral head. However, it was concluded that the use of bone-seeking radionuclides with this technique might be more reliable. Scintigraphic trends divided the patients into three groups, one with persistently normal, another with varying, and a third with decreased activity in the femoral head. It was concluded that very early scintigraphy is probably not the method of choice since the images were often difficult to interpret. For the present, assessment of the viability of the femoral head should rest upon scintigraphic examinations performed about 6 weeks or 3 months after the injury.

Alterations of the blood pool in the femoral head before and after renal transplantation

International Nuclear Information System (INIS)

Hamaguchi, Hiroyuki; Fujioka, Mikihiro; Inoue, Shigehiro; Shibatani, Masahiko; Kubo, Toshikazu; Kubota, Takao; Ushijima, Yo; Nishimura, Tsunehiko

2003-01-01

The pathogenesis of idiopathic osteonecrosis of the femoral head (ION) is thought to be an ischemic event. The purpose of this study is to investigate alterations of the blood pool in the femoral head before and after renal transplantation. After renal transplantation, all patients received the same immunosuppressive therapy: corticosteroids, cyclosporin-A, and azathioprine. We performed 3-phase bone scintigraphy on 16 renal allograft recipients within 1 week before renal transplantation, and between week 4 and 9 after renal transplantation. Regions of interest (ROI) were assigned bilaterally in the femoral head, diaphysis, and soft tissue. The head-to-diaphysis ratios (HD ratios) were then calculated. Idiopathic osteonecrosis of the femoral head occurred in 2 femoral heads of 1 patient. The HD ratio before renal transplantation (mean HD±SD, 1.52±0.30) and the HD ratio after renal transplantation (1.28±0.30) were significantly different (P=0.000024). The HD ratios before and after renal transplantation were significantly different, indicating that the administration of steroids diminished the blood pool in the femoral head. A low HD ratio before renal transplantation revealed a poor blood pool in the femoral head, which may be a risk factor for ION. (author)

Technique and results of femoral bifurcation endarterectomy by eversion.

Science.gov (United States)

Dufranc, Julie; Palcau, Laura; Heyndrickx, Maxime; Gouicem, Djelloul; Coffin, Olivier; Felisaz, Aurélien; Berger, Ludovic

2015-03-01

This study evaluated, in a contemporary prospective series, the safety and efficacy of femoral endarterectomy using the eversion technique and compared our results with results obtained in the literature for the standard endarterectomy with patch closure. Between 2010 and 2012, 121 patients (76% male; mean age, 68.7 years; diabetes, 28%; renal insufficiency, 20%) underwent 147 consecutive femoral bifurcation endarterectomies using the eversion technique, associating or not inflow or outflow concomitant revascularization. The indications were claudication in 89 procedures (60%) and critical limb ischemia in 58 (40%). Primary, primary assisted, and secondary patency of the femoral bifurcation, clinical improvement, limb salvage, and survival were assessed using Kaplan-Meier life-table analysis. Factors associated with those primary end-points were evaluated with univariate analysis. The technical success of eversion was of 93.2%. The 30-day mortality was 0%, and the complication rate was 8.2%; of which, half were local and benign. Median follow-up was 16 months (range, 1.6-31.2 months). Primary, primary assisted, and secondary patencies were, respectively, 93.2%, 97.2%, and 98.6% at 2 years. Primary, primary assisted, and secondary maintenance of clinical improvement were, respectively, 79.9%, 94.6%, and 98.6% at 2 years. The predictive factors for clinical degradation were clinical stage (Rutherford category 5 or 6, P = .024), platelet aggregation inhibitor treatment other than clopidogrel (P = .005), malnutrition (P = .025), and bad tibial runoff (P = .0016). A reintervention was necessary in 18.3% of limbs at 2 years: 2% involving femoral bifurcation, 6.1% inflow improvement, and 9.5% outflow improvement. The risk factors of reintervention were platelet aggregation inhibitor (other than clopidogrel, P = .049) and cancer (P = .011). Limb preservation at 2 years was 100% in the claudicant population. Limb salvage was 88.6% in the critical limb ischemia population

Fluctuation Dominated Josephson Tunneling with a Scanning Tunneling Microscope

International Nuclear Information System (INIS)

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

2001-01-01

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

The ISI Tunnel

Science.gov (United States)

1993-10-01

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

Osteochondral lesion of the bilateral femoral heads in a young athletic patient

Energy Technology Data Exchange (ETDEWEB)

Lee, Jung Eun; Ryu, Kyung Nam; Park, Ji Seon; Cho, Yoon Je [Kyung Hee University Hospital, Seoul (Korea, Republic of); Yoon, So Hee; Park, So Young; Jin, Wook [Dept. of Radiology, Kyung Hee University Hospital at Gangdong, Kyung Hee University College of Medicine, Seoul (Korea, Republic of); Lee, Kyung Ryeol [Dept. of Radiology, Jeju National University Hospital, Jeju (Korea, Republic of)

2014-12-15

Osteochondral lesions of the femoral head are uncommon and few studies have reported their imaging findings. Since joints are at risk of early degeneration after osteochondral damage, timely recognition is important. Osteochondral lesions of femoral head may often be necessary to differentiate from avascular necrosis. Here, we report a case of osteochondral lesions on bilateral femoral heads. This lesion manifested as subchondral cysts in initial radiographs, which led to further evaluation by computed tomography arthrography and magnetic resonance imaging, which revealed overlying cartilage defects.

Resonant tunnel magnetoresistance in a double magnetic tunnel junction

KAUST Repository

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

2011-01-01

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

Assessment of femoral head perfusion by dynamic MR imaging

International Nuclear Information System (INIS)

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

2004-01-01

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

Valley polarization due to trigonal warping on tunneling electrons in graphene

International Nuclear Information System (INIS)

Pereira Jr, J M; Peeters, F M; Costa Filho, R N; Farias, G A

2009-01-01

The effect of trigonal warping on the transmission of electrons tunneling through potential barriers in graphene is investigated. We present calculations of the transmission coefficient for single and double barriers as a function of energy, incidence angle and barrier heights. The results show remarkable valley-dependent directional effects for barriers oriented parallel to the armchair or parallel to the zigzag direction. These results indicate that electrostatic gates can be used as valley filters in graphene-based devices.

Tunneling through landsliding zone; Jisuberi chitainai no tunnel seko

Energy Technology Data Exchange (ETDEWEB)

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

1994-08-01

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

Finite Element Analysis of Patella Alta: A Patellofemoral Instability Model.

Science.gov (United States)

Watson, Nicole A; Duchman, Kyle R; Grosland, Nicole M; Bollier, Matthew J

2017-01-01

This study aims to provide biomechanical data on the effect of patella height in the setting of medial patellofemoral ligament (MPFL) reconstruction using finite element analysis. The study will also examine patellofemoral joint biomechanics using variable femoral insertion sites for MPFL reconstruction. A previously validated finite element knee model was modified to study patella alta and baja by translating the patella a given distance to achieve each patella height ratio. Additionally, the models were modified to study various femoral insertion sites of the MPFL (anatomic, anterior, proximal, and distal) for each patella height model, resulting in 32 unique scenarios available for investigation. In the setting of patella alta, the patellofemoral contact area decreased, resulting in a subsequent increase in maximum patellofemoral contact pressures as compared to the scenarios with normal patellar height. Additionally, patella alta resulted in decreased lateral restraining forces in the native knee scenario as well as following MPFL reconstruction. Changing femoral insertion sites had a variable effect on patellofemoral contact pressures; however, distal and anterior femoral tunnel malpositioning in the setting of patella alta resulted in grossly elevated maximum patellofemoral contact pressures as compared to other scenarios. Patella alta after MPFL reconstruction results in decreased lateral restraining forces and patellofemoral contact area and increased maximum patellofemoral contact pressures. When the femoral MPFL tunnel is malpositioned anteriorly or distally on the femur, the maximum patellofemoral contact pressures increase with severity of patella alta. When evaluating patients with patellofemoral instability, it is important to recognize patella alta as a potential aggravating factor. Failure to address patella alta in the setting of MPFL femoral tunnel malposition may result in even further increases in patellofemoral contact pressures, making it

MYCOTIC FEMORAL PSEUDOANEURYSMS FROM INTRAVENOUS DRUG ABUSE

Directory of Open Access Journals (Sweden)

Vojko Flis

2004-04-01

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

Femoral anteversion assessment: Comparison of physical examination, gait analysis, and EOS biplanar radiography.

Science.gov (United States)

Westberry, David E; Wack, Linda I; Davis, Roy B; Hardin, James W

2018-05-01

Multiple measurement methods are available to assess transverse plane alignment of the lower extremity. This study was performed to determine the extent of correlation between femoral anteversion assessment using simultaneous biplanar radiographs and three-dimensional modeling (EOS imaging), clinical hip rotation by physical examination, and dynamic hip rotation assessed by gait analysis. Seventy-seven patients with cerebral palsy (GMFCS Level I and II) and 33 neurologically typical children with torsional abnormalities completed a comprehensive gait analysis with same day biplanar anterior-posterior and lateral radiographs and three-dimensional transverse plane assessment of femoral anteversion. Correlations were determined between physical exam of hip rotation, EOS imaging of femoral anteversion, and transverse plane hip kinematics for this retrospective review study. Linear regression analysis revealed a weak relationship between physical examination measures of hip rotation and biplanar radiographic assessment of femoral anteversion. Similarly, poor correlation was found between clinical evaluation of femoral anteversion and motion assessment of dynamic hip rotation. Correlations were better in neurologically typical children with torsional abnormalities compared to children with gait dysfunction secondary to cerebral palsy. Dynamic hip rotation cannot be predicted by physical examination measures of hip range of motion or from three-dimensional assessment of femoral anteversion derived from biplanar radiographs. Copyright © 2018 Elsevier B.V. All rights reserved.

Optimization of Ecg Gating in Quantitative Femoral Angiography

International Nuclear Information System (INIS)

Nilsson, S.; Berglund, I.; Erikson, U.; Johansson, J.; Walldius, G.

2003-01-01

Purpose: To determine which phase of the heart cycle would yield the highest reproducibility in measuring atherosclerosis-related variables such as arterial lumen volume and edge roughness. Material and Methods: 35 patients with hypercholesterolemia underwent select ive femoral angiography, repeated four times at 10-min intervals. The angiographies were performed with Ecg-gated exposures. In angiographies 1 and 2 the delay from R-wave maximum to each exposure was 0.1 s, in angiographies 3 and 4 the delay was 0.1, 0.3, 0.5 or 0.7 s or the exposures were performed 1/s without Ecg gating. Arterial lumen volume and edge roughness were measured in a 20-cm segment of the superficial femoral artery using a computer-based densitometric method. Measurement reproducibility was determined by comparing angiographies 1-2 and angiographies 3-4. Results: When measuring arterial lumen volume and edge roughness of a 20-cm segment of the femoral artery, reproducibility was not dependent on Ecg gating. In measuring single arterial diameters and cross-sectional areas, the reproducibility was better when exposures were made 0.1 s after the R-wave maximum than when using other settings of the Ecg gating device or without Ecg gating. Conclusion: The influence of pulsatile flow upon quantitative measurement in femoral angiograms seems to be the smallest possible in early systole, as can be demonstrated when measuring single diameters and cross-sectional areas. In variables based on integration over longer segments, measurement reproducibility seems to be independent of phase

Optimization of Ecg Gating in Quantitative Femoral Angiography

Energy Technology Data Exchange (ETDEWEB)

Nilsson, S.; Berglund, I.; Erikson, U. [Univ. Hospital, Uppsala (Sweden). Dept. of Oncology, Radiology and Clinical Immunology; Johansson, J.; Walldius, G. [Karolinska Hospital, Stockholm (Sweden). King Gustav V Research Inst.

2003-09-01

Purpose: To determine which phase of the heart cycle would yield the highest reproducibility in measuring atherosclerosis-related variables such as arterial lumen volume and edge roughness. Material and Methods: 35 patients with hypercholesterolemia underwent select ive femoral angiography, repeated four times at 10-min intervals. The angiographies were performed with Ecg-gated exposures. In angiographies 1 and 2 the delay from R-wave maximum to each exposure was 0.1 s, in angiographies 3 and 4 the delay was 0.1, 0.3, 0.5 or 0.7 s or the exposures were performed 1/s without Ecg gating. Arterial lumen volume and edge roughness were measured in a 20-cm segment of the superficial femoral artery using a computer-based densitometric method. Measurement reproducibility was determined by comparing angiographies 1-2 and angiographies 3-4. Results: When measuring arterial lumen volume and edge roughness of a 20-cm segment of the femoral artery, reproducibility was not dependent on Ecg gating. In measuring single arterial diameters and cross-sectional areas, the reproducibility was better when exposures were made 0.1 s after the R-wave maximum than when using other settings of the Ecg gating device or without Ecg gating. Conclusion: The influence of pulsatile flow upon quantitative measurement in femoral angiograms seems to be the smallest possible in early systole, as can be demonstrated when measuring single diameters and cross-sectional areas. In variables based on integration over longer segments, measurement reproducibility seems to be independent of phase.

Titanium elastic nailing in pediatric femoral diaphyseal fractures

Directory of Open Access Journals (Sweden)

Singh Roop

2006-01-01

Full Text Available Background: The need for operative fixation of pediatric femoral fractures is increasingly being recognised in the present decade. The conventional traction and casting method for management of pediatric femoral fractures is giving way for the operative stabilisation of the fracture. Methods : Thirty five pediatric patients in age group 6-14 years with diaphyseal femoral fractures were stabilised with two titanium nails. Patients were followed up clinically and radiologically for two years. The final results were evaluated using the criteria of Flynn et al. Technical problems and complications associated with the procedure were also analysed. Results : Overall results observed were excellent in 25, satisfactory in 8 and poor in 2 patients. Hospital time averaged 12.30 days in the series. All the fractures healed with an average time to union of 9.6 (6-14.4 weeks. Return to school was early with an average of 7.8 weeks. The soft tissue discomfort near the knee produced by the nails ends was the most common problem encountered. Shortening was observed in three cases and restriction of knee flexion in 5 patients. There was no delayed union, infection or refractures. Per operative technical problems included failure of closed reduction in 2 cases and cork screwing of nails in one case. Conclusion : We believe that with proper operative technique and aftercare TENs may prove to be an ideal implant for pediatric femoral fracture fixation. The most of the complication associated with the procedure are infact features of inexact technique and can be eliminated by strictly adhering to the basic principles and technical aspects.

Clinical application of interventional therapy for avascular necrosis of the femoral head

International Nuclear Information System (INIS)

Han Xu; Jin Kesi; Liu Wei; Ma Jun; Shen Jianming; Aziken

2004-01-01

Objective: To evaluate the possibility of interventional therapy for avascular necrosis of the femoral head, with different curing methods, way of introduction and cultural heritages. Methods: Vasodilator, thrombolytics and promoting microcirculatory drug were directly injected into the feeding arteries of the avascular necrotic femoral heads, under the condition of applying the blood stoppage belt at the root of thigh with pressure before the drug injection into the femoral pronator and extension arteries. The treatment was repeated 45 d later. Urokinase 10 5 unite/d x 10 were administrated with venous infusion ipsilaterally on the 15th day after the beginning of the therapy. Imaging features and clinical symptoms were recorded and correlatively studied before and after the treament. Results: Symptoms relief especially the pain reached 100% after the treatment with various degrees of bony repair and new bone formation. Furthermore, increase caliber of feeding small arteries for femoral head and multiplicity of microvasculature, shortening of opacification time were revealed by DSA. IV stage bony change showed mild or inconspicuous. Conclusions: Interventional catheterization treatment for avascular femoral head necrosis, especially the patients of fore III stage, is safe and effective. (authors)

[RESEARCH PROGRESS OF EXPERIMENTAL ANIMAL MODELS OF AVASCULAR NECROSIS OF FEMORAL HEAD].

Science.gov (United States)

Yu, Kaifu; Tan, Hongbo; Xu, Yongqing

2015-12-01

To summarize the current researches and progress on experimental animal models of avascular necrosis of the femoral head. Domestic and internation literature concerning experimental animal models of avascular necrosis of the femoral head was reviewed and analyzed. The methods to prepare the experimental animal models of avascular necrosis of the femoral head can be mainly concluded as traumatic methods (including surgical, physical, and chemical insult), and non-traumatic methods (including steroid, lipopolysaccharide, steroid combined with lipopolysaccharide, steroid combined with horse serum, etc). Each method has both merits and demerits, yet no ideal methods have been developed. There are many methods to prepare the experimental animal models of avascular necrosis of the femoral head, but proper model should be selected based on the aim of research. The establishment of ideal experimental animal models needs further research in future.

Development of the tunneling junction simulation environment for scanning tunneling microscope evaluation

International Nuclear Information System (INIS)

Gajewski, Krzysztof; Piasecki, Tomasz; Kopiec, Daniel; Gotszalk, Teodor

2017-01-01

Proper configuration of scanning tunneling microscope electronics plays an important role in the atomic scale resolution surface imaging. Device evaluation in the tunneling contact between scanning tip and sample may be prone to the surface quality or mechanical disturbances. Thus the use of tunneling junction simulator makes electronics testing more reliable and increases its repeatability. Here, we present the theoretical background enabling the proper selection of electronic components circuitry used as a tunneling junction simulator. We also show how to simulate mechanics related to the piezoelectric scanner, which is applied in real experiments. Practical use of the proposed simulator and its application in metrological characterization of the developed scanning tunneling microscope is also shown. (paper)

Mortality Following Periprosthetic Proximal Femoral Fractures Versus Native Hip Fractures.

Science.gov (United States)

Boylan, Matthew R; Riesgo, Aldo M; Paulino, Carl B; Slover, James D; Zuckerman, Joseph D; Egol, Kenneth A

2018-04-04

The number of periprosthetic proximal femoral fractures is expected to increase with the increasing prevalence of hip arthroplasties. While native hip fractures have a well-known association with mortality, there are currently limited data on this outcome among the subset of patients with periprosthetic proximal femoral fractures. Using the New York Statewide Planning and Research Cooperative System, we identified patients from 60 to 99 years old who were admitted to a hospital in the state with a periprosthetic proximal femoral fracture (n = 1,655) or a native hip (femoral neck or intertrochanteric) fracture (n = 97,231) between 2006 and 2014. Within the periprosthetic fracture cohort, the indication for the existing implant was not available in the data set. We used mixed-effects regression models to compare mortality at 1 and 6 months and 1 year for periprosthetic compared with native hip fractures. The risk of mortality for patients who sustained a periprosthetic proximal femoral fracture was no different from that for patients who sustained a native hip fracture at 1 month after injury (3.2% versus 4.6%; odds ratio [OR], 0.90; 95% confidence interval [CI], 0.68 to 1.19; p = 0.446), but was lower at 6 months (3.8% versus 6.5%; OR, 0.74; 95% CI, 0.57 to 0.95; p = 0.020) and 1 year (9.7% versus 15.9%; OR, 0.71; 95% CI, 0.60 to 0.85; p accounting for age and comorbidities. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Avascular necrosis of the femoral head; Chronological change of MR images

Energy Technology Data Exchange (ETDEWEB)

Kokubo, Takeshi; Takatori, Yoshio; Kamogawa, Morihide; Nakamura, Toshitaka; Ninomiya, Setsuo; Yoshikawa, Kohki; Itai, Yuji; Iio, Masahiro; Mitamura, Tadayuki [Tokyo Univ. (Japan). Faculty of Medicine

1990-04-01

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

Repair of femoral trochanteric osteotomy in the dog

International Nuclear Information System (INIS)

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

1997-01-01

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

Case of slipped capital femoral epiphysis following radiation

Energy Technology Data Exchange (ETDEWEB)

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

1987-06-01

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

Comparison of anatomic vs. straight femoral stem design in total hip replacement - femoral canal fill in vivo.

Science.gov (United States)

de Boer, Friso A; Sariali, Elhadi

2017-05-12

The femoral canal fill between an anatomic and a straight prosthesis design in cementless total hip arthroplasty (THA) was compared. We hypothesised that the anatomic SPS stem has higher proximal fill and lesser distal fill than the straight stem. The femoral canal fill was measured on 3 months routine postoperative x-rays at 5 levels of the stem in 50 consecutive patients, aged 35-83 years, who underwent 56 THA procedures by a single surgeon in this hospital. 22 patients received a straight design Ceramconcept Global stem, 34 patients received an anatomic design Symbios SPS stem. Both anteroposterior (AP) and lateral x-rays were combined to suggest a 3-D measurement. On the AP x-rays, the canal fill was significantly higher using the anatomic design stem at the proximal measurement levels, and was significantly higher at the distal levels using the straight stem. With the AP and lateral x-rays combined, the canal fill at the proximal levels was also significantly higher in the anatomic groups, nonsignificantly lower at the central level and significantly lower at the distal levels. In THA surgery, achieving high fill at the metaphysis of the femur and less fill at the diaphysis has been suggested to result in satisfactory outcome and high stability of the prosthesis. This study demonstrated that, compared to straight stem design, an anatomically designed stem has a significantly higher metaphyseal femoral canal fill.

Treatment of osteonecrosis of the femoral head by free vascularized fibular grafting: an analysis of surgical outcome and patient health status

Science.gov (United States)

Louie, Brian E.; McKee, Michael D.; Richards, Robin R.; Mahoney, James L.; Waddell, James P.; Beaton, Dorcas E.; Schemitsch, Emil H.; Yoo, Daniel J.

1999-01-01

Objective To evaluate the limb-specific outcome and general health status of patients with osteonecrosis of the femoral head treated with vascularized fibular grafting. Design A retrospective review. Setting A single tertiary care centre. Patients Fifty-five consecutive patients with osteonecrosis of the femoral head who underwent fibular grafting (8 bilaterally). Intervention Vascularized fibular grafting. Outcome measures Limb-specific scores (Harris Hip Score, St. Michael’s Hospital Hip Score), general health status (Nottingham Health Profile, SF-36 health status survey) and radiographic outcome measures (Steinberg stage). Results Patients were young (mean age 34 years, range from 18 to 52 years) and 80% had advanced osteonecrosis (Steinberg stages IV and V). Fifty-nine hips were followed up for an average of 50 months (range from 24 to 117 months) after vascularized fibular grafting. Sixteen hips (27%) were converted to total hip arthroplasty (THA). To date, 73% of hips treated with vascularized fibular grafting have required no further surgery. Preoperative and postoperative Harris Hip Scores were 57.3 and 83.6 respectively (p < 0.001). As measured by patient-oriented health status questionnaires (SF-36, Nottingham Health Profile) and compared with population controls, patients had normal mental health scores and only slight decreases in physical component scores. Conclusions Free vascularized fibular grafting for osteonecrosis of the femoral head provides satisfactory pain relief, functional improvement and general health status and halts the progression of symptomatic disease. PMID:10459327

3D MRI findings of anterior cruciate ligament reconstruction at follow-up

International Nuclear Information System (INIS)

Deng Jun; Liang Biling; Chen Jianyu; Huang Suiqiao; Zhong Jinglian; Li Xiao

2011-01-01

Objective: To investigate the postoperative 3D MRI appearances and their evolvement patterns of ACL grafts and bone tunnels at follow-up. Methods: There were 2,6 double bundles ACL reconstructions and 16 single bundle ACL reconstructions, and a total of 56 follow-up 3D MR Imaging. MR images were reconstructed with MPR technique to evaluate grafts, bone tunnels, fixers and associated complications. Proportions of grafts with hypointensity or hyperintensity and occurrence rates of marrow edema around bone tunnels were calculated respectively among groups of different periods after operation. Results: There were 2, 4 grafts of hypointensity and 32 grafts of hyperintensity. Grafts of 2 cases were suspended with cross pins within femoral tunnels, graft of 1 case was suspended with an endobutton within the femoral tunnel, and grafts of other sites were fixed with interference screws. In the three periods as 3 months, 6 to 9 months and over 12 months after cruciate ligament reconstruction, proportions of hypointensive grafts were 20/25, 0/14 and 4/10 respectively, while proportions of hyperintensive grafts were 5/25, 14/14 and 6/10 respectively, occurrence proportions of marrow edema around bone tunnels were 54/54, 10/32 and 4/26 respectively. There was 1 tear graft, 4 tibial tunnels placed anteriorly with ACL graft impingement on the intercondylar roof, 3 femoral tunnels placed anteriorly, and 2 bone tunnels with mismatching interference screws. Conclusion: 3D MRI can accurately demonstrate the state of ACL grafts, bone tunnels, fixers and associated complications. Intensity of grafts presented a rise and reduce pattern after operation. (authors)

Electronic single-molecule identification of carbohydrate isomers by recognition tunnelling

Science.gov (United States)

Im, Jongone; Biswas, Sovan; Liu, Hao; Zhao, Yanan; Sen, Suman; Biswas, Sudipta; Ashcroft, Brian; Borges, Chad; Wang, Xu; Lindsay, Stuart; Zhang, Peiming

2016-12-01

Carbohydrates are one of the four main building blocks of life, and are categorized as monosaccharides (sugars), oligosaccharides and polysaccharides. Each sugar can exist in two alternative anomers (in which a hydroxy group at C-1 takes different orientations) and each pair of sugars can form different epimers (isomers around the stereocentres connecting the sugars). This leads to a vast combinatorial complexity, intractable to mass spectrometry and requiring large amounts of sample for NMR characterization. Combining measurements of collision cross section with mass spectrometry (IM-MS) helps, but many isomers are still difficult to separate. Here, we show that recognition tunnelling (RT) can classify many anomers and epimers via the current fluctuations they produce when captured in a tunnel junction functionalized with recognition molecules. Most importantly, RT is a nanoscale technique utilizing sub-picomole quantities of analyte. If integrated into a nanopore, RT would provide a unique approach to sequencing linear polysaccharides.

Postoperative hemoglobin level in patients with femoral neck fracture

OpenAIRE

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

2018-01-01

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

Resonant tunneling via spin-polarized barrier states in a magnetic tunnel junction

NARCIS (Netherlands)

Jansen, R.; Lodder, J.C.

2000-01-01

Resonant tunneling through states in the barrier of a magnetic tunnel junction has been analyzed theoretically for the case of a spin-polarized density of barrier states. It is shown that for highly spin-polarized barrier states, the magnetoresistance due to resonant tunneling is enhanced compared

Trombose aguda de aneurisma de artéria femoral isolado: relato de caso Acute thrombosis of isolated femoral artery aneurysm: case report

Directory of Open Access Journals (Sweden)

André Hideo Motoki

2008-12-01

Full Text Available Aneurismas de artéria femoral são raros, porém são o segundo tipo mais freqüente de aneurismas periféricos, sendo o aneurisma de artéria poplítea o mais comum. Normalmente, são de etiologia aterosclerótica. As complicações deste aneurisma são representadas por embolia, trombose e, mais raramente, a rotura. O objetivo deste trabalho é relatar um caso de um paciente com 59 anos, masculino, com queixa de dor súbita em membro inferior esquerdo associado à frialdade, palidez e ausência de pulsos. O ecocolordoppler evidenciou a presença de aneurisma trombosado da artéria femoral comum. O paciente foi submetido, com sucesso, à ressecção do aneurisma, com reconstrução do leito arterial.Common femoral artery aneurysms are rare; however, they are the second most frequent type of peripheral aneurysm, popliteal artery aneurysms being the most common. They usually have atherosclerotic ethiology. The complications of this aneurysm are thromboembolism and, more rarely, rupture. This article aimed at reporting the case of a 59-year-old male patient with complaint of sudden pain in his left leg associated with coldness, paleness and absence of pulses. Color Doppler ultrasound showed a thrombosed aneurysm of the common femoral artery. The patient was successfully submitted to aneurysm resection with reconstruction of the arterial bed.

Quantum tunneling time

International Nuclear Information System (INIS)

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

2004-01-01

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

Femoral arteriographic finding in acute ergotism: Report of A Case

Energy Technology Data Exchange (ETDEWEB)

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

1971-10-15

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

Femoral arteriographic finding in acute ergotism: Report of A Case

International Nuclear Information System (INIS)

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

1971-01-01

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

Postoperative hemoglobin level in patients with femoral neck fracture.

Science.gov (United States)

Nagra, Navraj S; Van Popta, Dmitri; Whiteside, Sigrid; Holt, Edward M

2016-01-01

The aim of this study was to analyze the changes of hemoglobin levels in patients undergoing fixation for femoral neck fracture. Peroperative hemoglobin levels of patients who underwent either dynamic hip screw (DHS) fixation (n=74; mean age: 80 years) or hip hemiarthroplasty (n=104; mean age: 84 years) for femoral neck fracture was monitored. There was a statistically and clinically significant mean drop of 31.1 g/L between the preoperative (D0) and postoperative Day 5 Hb levels (pmeasurement, DHS patients had lower hemoglobin values over hemiarthroplasty patients (p=0.046). The decrease in hemoglobin in the first 24-hour postoperative period (D0 to Day 1) is an underestimation of the ultimate lowest value in hemoglobin found at Day 2. Relying on the Day 1 hemoglobin level could be detrimental to patient care. We propose a method of predicting patients likely to be transfused and recommend a protocol for patients undergoing femoral neck fracture surgery to standardize postoperative hemoglobin monitoring.

Does femoral offset recover and affect the functional outcome of patients with displaced femoral neck fracture following hemiarthroplasty?

Science.gov (United States)

Ji, Hyung-Min; Won, Seok-Hyung; Han, Jun; Won, Ye-Yeon

2017-06-01

Restoring preoperative horizontal femoral offset (FO) promised good functional outcome in patients receiving total hip arthroplasty. However, relatively little was known regarding the clinical relevance of restoring the offset in patients with bipolar hemiarthroplasty to treat displaced femoral neck fracture. Therefore, the objective of this study was to evaluate postoperative FO accurately and verify its relation with functional outcome. One hundred elderly patients who received bipolar hemiarthroplasty to treat displaced femoral neck fracture were identified. Preoperative CT scanning of contralateral hip joint and reconstruction of images led to rotation-free FO. By referencing postoperative implant specification and comparing to measured values in Picture Archive and Communication System, rotation-free postoperative FO and the amount of change were acquired. Postoperative Harris Hip Score (HHS) and Modified Barthel Index (MBI) were evaluated to measure functional outcome at 12-month after the surgery. Patients with significant FO change were identified. Multiple regression analysis was conducted to determine if the FO change might independently affect the outcome regardless of confounding factors. The mean preoperative offset was 37.4±2.5 increased by 12.7±9.6% after the surgery. Only 25.0% of postoperative offset after hemiarthroplasty was changed within ±5% of preoperative offset. A total of 45.0% of postoperative offset changed within ±10% while 77.0% of postoperative offset changed within ±20%. 23% of patients whose FO changed more than 20% showed significantly worse outcome score than the patients whose FO change remained within ±20% of initial value. Mean MBI and HHS were negatively correlated with FO change. After adjusting for confounding factors, significant correlation remained between modification of FO and MBI, but not between FO change and HHS (B=4.576; β=0.235; 95% confidence interval of B: 0.534 to 8.135). FO was not properly restored in 23

Nontraumatic femoral head necrosis. Classification of bone scintigraphic findings and diagnostic value of SPECT following planar imaging

Energy Technology Data Exchange (ETDEWEB)

Minoshima, Satoshi; Uchida, Yoshitaka; Anzai, Yoshimi; Uno, Kimiichi; Arimizu, Noboru [Chiba Univ. (Japan). School of Medicine

1994-09-01

This study was conducted to determine bone scintigraphic findings in nontraumatic femoral head avascular necrosis and diagnostic value of SPECT imaging following a conventional planar imaging. Forty-three femoral heads in twenty-six cases with idiopathic femoral head necrosis (n=2), systemic lupus erythematosus (n=22), aplastic anemia (n=1), and renal transplantation (n=1) were studied. The diagnosis for femoral head necrosis was based on magnetic resonance imaging as well as other diagnostic studies in all cases. Scintigraphic findings of planar and SPECT images were classified into six categories: normal (N); cold or decrease (C); partial increase with cold or decrease (PH+C); ring-like increase with a cold center (RH+C); partial increase (PH); diffuse and/or irregular increase (DH). Avascular necrosis was confirmed in twenty-four femoral heads, in which planar and SPECT images showed scintigraphic findings of N (n=3, 2), C (n=1, 3), PH+C (n=2, 8), RH+C (n=2, 3), PH (n=9, 2), and DH (n=7, 6), respectively. Femoral heads without avascular necrosis demonstrated planar and SPECT findings of N (n=16, 12), C (n=0, 6), and DH (n=3, 1), respectively. When considering C, PH+C, and RH+C as diagnostic findings for avascular necrosis, sensitivities of planar and SPECT images were 21% and 58%, and specificities were 100% and 68%, respectively. In nineteen femoral heads with normal planar findings (N), SPECT correctly identified avascular necrosis in two femoral heads and misidentified six normal femoral heads as avascular necrosis. In nineteen femoral heads with nondiagnostic abnormalities (PH, DH), SPECT correctly identified avascular necrosis in seven femoral heads and showed no false positive. Diagnostic planar findings in five femoral heads were concordant with SPECT diagnosis. These results indicate that SPECT imaging is most valuable when planar images show nondiagnostic abnormalities based on the proposed classification of scintigraphic findings. (author).

Nontraumatic femoral head necrosis. Classification of bone scintigraphic findings and diagnostic value of SPECT following planar imaging

International Nuclear Information System (INIS)

Minoshima, Satoshi; Uchida, Yoshitaka; Anzai, Yoshimi; Uno, Kimiichi; Arimizu, Noboru

1994-01-01

This study was conducted to determine bone scintigraphic findings in nontraumatic femoral head avascular necrosis and diagnostic value of SPECT imaging following a conventional planar imaging. Forty-three femoral heads in twenty-six cases with idiopathic femoral head necrosis (n=2), systemic lupus erythematosus (n=22), aplastic anemia (n=1), and renal transplantation (n=1) were studied. The diagnosis for femoral head necrosis was based on magnetic resonance imaging as well as other diagnostic studies in all cases. Scintigraphic findings of planar and SPECT images were classified into six categories: normal (N); cold or decrease (C); partial increase with cold or decrease (PH+C); ring-like increase with a cold center (RH+C); partial increase (PH); diffuse and/or irregular increase (DH). Avascular necrosis was confirmed in twenty-four femoral heads, in which planar and SPECT images showed scintigraphic findings of N (n=3, 2), C (n=1, 3), PH+C (n=2, 8), RH+C (n=2, 3), PH (n=9, 2), and DH (n=7, 6), respectively. Femoral heads without avascular necrosis demonstrated planar and SPECT findings of N (n=16, 12), C (n=0, 6), and DH (n=3, 1), respectively. When considering C, PH+C, and RH+C as diagnostic findings for avascular necrosis, sensitivities of planar and SPECT images were 21% and 58%, and specificities were 100% and 68%, respectively. In nineteen femoral heads with normal planar findings (N), SPECT correctly identified avascular necrosis in two femoral heads and misidentified six normal femoral heads as avascular necrosis. In nineteen femoral heads with nondiagnostic abnormalities (PH, DH), SPECT correctly identified avascular necrosis in seven femoral heads and showed no false positive. Diagnostic planar findings in five femoral heads were concordant with SPECT diagnosis. These results indicate that SPECT imaging is most valuable when planar images show nondiagnostic abnormalities based on the proposed classification of scintigraphic findings. (author)

Effect of Olfactory Stimulus on the Flight Course of a Honeybee, Apis mellifera, in a Wind Tunnel

Directory of Open Access Journals (Sweden)

Hidetoshi Ikeno

2013-12-01

Full Text Available It is known that the honeybee, Apis mellifera, uses olfactory stimulus as important information for orienting to food sources. Several studies on olfactory-induced orientation flight have been conducted in wind tunnels and in the field. From these studies, optical sensing is used as the main information with the addition of olfactory signals and the navigational course followed by these sensory information. However, it is not clear how olfactory information is reflected in the navigation of flight. In this study, we analyzed the detailed properties of flight when oriented to an odor source in a wind tunnel. We recorded flying bees with a video camera to analyze the flight area, speed, angular velocity and trajectory. After bees were trained to be attracted to a feeder, the flight trajectories with or without the olfactory stimulus located upwind of the feeder were compared. The results showed that honeybees flew back and forth in the proximity of the odor source, and the search range corresponded approximately to the odor spread area. It was also shown that the angular velocity was different inside and outside the odor spread area, and trajectories tended to be bent or curved just outside the area.

Measuring fire size in tunnels

International Nuclear Information System (INIS)

Guo, Xiaoping; Zhang, Qihui

2013-01-01

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

Arterial Ligation for Infected Femoral Psuedo-Aneurysm in Drug Injecting Abusers

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Mohammadzade Mohammad Ali

2009-10-01

Full Text Available Pseudo-aneurysm of the femoral artery is the most common arterial complication in drug injecting abusers. Scholars in vascular surgery have published debating statements regarding techniques of successful surgical management during last two decades. We present the results of simple arterial ligation in a series of 32 patients presenting with infected femoral pseudo-aneurysm. Most of the patients were males (89%. Young persons in the age group of 15-44 years were mostly affected. Site of lesion included common femoral artery in 65% , superficial femoral artery 28% and at bifurcation 6.2%. celulitis in 14 (53%, abscess & "ncelulitis in 6 (19%, necrosing fasciitis in 2 (6.2% and vascular abscess in 7 (22% cases were the forms of associated local infection. There was no hemorrhage, vascular thrombosis, amputation, or mortality. Claudicating were the only complications identified in 2 patients with Tripe ligation. Ligation is the optimal management for infected pseudo-aneurysms because it is easy, cost-effective, and safe. Early reconstruction is not recommended, since there is an extended infection in the location of the pseudo-aneurysm.

Magnetic resonance imaging (MRI) of avascular necrosis of the femoral head

International Nuclear Information System (INIS)

Kokubo, Takashi; Yoshikawa, Kohki; Aoki, Shigeki

1987-01-01

Thirty-seven patients with the clinical diagnosis of or suspicious of avascular necrosis (AN) of the femoral head were examined by magnetic resonance imaging (MRI). In all patients with AN confirmed from clinical symptoms, past history and plain radiographs, MRI demonstrated abnormal low intensity area in the necrosed femoral head. The abnormal findings on MRI were divided into three patterns: low signal intensity occupying the greater part of the femoral head (type A), low signal intensity localized in the periphery (type B), ring-shaped or band-like low signal intensity (type C). No correlation was found among MRI patterns, radiographic findings and radionuclide bone scan images, except that the type C was not found in the stage IV determined radiographically. In the patients suspicious of AN, the positive rate of MRI was higher than that of radionuclide scan. Abnormal findings on only MRI may not necessarily indicate AN. However, such a patient must be kept under observation, because the possibility exists that only MRI detects early or asymptomatic AN of the femoral head. (author)

Magnetic resonance imaging (MRI) of avascular necrosis of the femoral head

Energy Technology Data Exchange (ETDEWEB)

Kokubo, Takashi; Yoshikawa, Kohki; Aoki, Shigeki

1987-05-01

Thirty-seven patients with the clinical diagnosis of or suspicious of avascular necrosis (AN) of the femoral head were examined by magnetic resonance imaging (MRI). In all patients with AN confirmed from clinical symptoms, past history and plain radiographs, MRI demonstrated abnormal low intensity area in the necrosed femoral head. The abnormal findings on MRI were divided into three patterns: low signal intensity occupying the greater part of the femoral head (type A), low signal intensity localized in the periphery (type B), ring-shaped or band-like low signal intensity (type C). No correlation was found among MRI patterns, radiographic findings and radionuclide bone scan images, except that the type C was not found in the stage IV determined radiographically. In the patients suspicious of AN, the positive rate of MRI was higher than that of radionuclide scan. Abnormal findings on only MRI may not necessarily indicate AN. However, such a patient must be kept under observation, because the possibility exists that only MRI detects early or asymptomatic AN of the femoral head.

Fracture of the acetabulum with femoral artery injury presenting late: A case report

Directory of Open Access Journals (Sweden)

Sivaprasad Kalyanasundaram

2016-02-01

Full Text Available This study reports a rare case of both column acetabulum fracture with femoral artery injury that presented late and was managed with arterial reconstruction and fracture fixation.A thirty-one year old man sustained both column acetabular fracture on the left in a motor vehicle accident. On admission there was no obvious neuro-vascular deficit. During surgery for the fracture after 7 days of the injury the femoral artery was found to be severely crushed with no blood flow. The anterior column of the acetabulum was stabilised followed by resection and reconstruction of the femoral artery. The post-operative period was uneventful and he was discharged normally. At 6 months from injury the fractures had united well with excellent limb circulation and good lower limb function.Femoral artery injury with acetabular fracture is rare and late presentations are unreported hitherto. The results of fracture stabilisation and vessel reconstruction seem to be excellent. Literature of similar injuries is reviewed. Keywords: Acetabular fractures, Both column fractures, Anterior column fractures, Vascular injury, Femoral artery injury

Microwave-induced co-tunneling in single electron tunneling transistors

DEFF Research Database (Denmark)

Ejrnaes, M.; Savolainen, M.; Manscher, M.

2002-01-01

on rubber bellows. Cross-talk was minimized by using individual coaxial lines between the sample and the room temperature electronics: The co-tunneling experiments were performed at zero DC bias current by measuring the voltage response to a very small amplitude 2 Hz current modulation with the gate voltage......The influence of microwaves on the co-tunneling in single electron tunneling transistors has been investigated as function of frequency and power in the temperature range from 150 to 500 mK. All 20 low frequency connections and the RF line were filtered, and the whole cryostat was suspended...

Femoral neck pseudoarthrosis in a polio patient treated with closed reduction and cell therapy

Directory of Open Access Journals (Sweden)

M.A. Codesido

2017-04-01

Full Text Available Poliomyelitis disease affects the anterior horns cells of the spinal cord and certain motor nuclei of the brain stem. Paralysis type is flaccid and asymmetrical and result in muscular imbalance.Due to this, in case of having a hip muscles involvement, degenerative or posttraumatic, total hip arthroplasty is normally contraindicated because of the excessive risk of hip dislocation. In cases of subcapital femoral neck fractures the femoral head vascularization is a main concern, and in cases of neglected fracture with pseudoarthrosis the vascular status to the head must be investigated prior to further decisions.We report the case of a femoral neck fracture non-union after a missed femoral neck fracture in a polio affected leg treated with cannulated screws and percutaneous autologous injection of processed total nuclear cells (TNC mixed with putty demineralized bone matrix. Keywords: Pseudoarthrosis, Poliomyelitis, Cell therapy, Femoral neck

Influence of trap-assisted tunneling on trap-assisted tunneling current in double gate tunnel field-effect transistor

International Nuclear Information System (INIS)

Jiang Zhi; Zhuang Yi-Qi; Li Cong; Wang Ping; Liu Yu-Qi

2016-01-01

Trap-assisted tunneling (TAT) has attracted more and more attention, because it seriously affects the sub-threshold characteristic of tunnel field-effect transistor (TFET). In this paper, we assess subthreshold performance of double gate TFET (DG-TFET) through a band-to-band tunneling (BTBT) model, including phonon-assisted scattering and acoustic surface phonons scattering. Interface state density profile (D it ) and the trap level are included in the simulation to analyze their effects on TAT current and the mechanism of gate leakage current. (paper)

Threading the Needle: Intrapelvic Displacement of a Femoral Neck Fracture through the Obturator Foramen

Directory of Open Access Journals (Sweden)

Gautham Prabhakar

2018-01-01

Full Text Available Despite timely and appropriate management, displaced femoral neck fractures are often devastating injuries for the young patient. The risk of negative sequelae is further amplified with increasing displacement and vertical fracture patterns. Open anatomic reduction with rigid internal fixation is essential to maximize the healing potential in displaced fractures of the femoral neck. Successful primary osteosynthesis of significantly displaced femoral neck fractures in the young patient has been reported in the literature. We present a unique case of open reduction and internal fixation of a high-energy femoral neck fracture with extrusion of the head through the obturator foramen into the pelvis without associated acetabular or pelvic injury.

21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint femoral (hemi-hip) metal/polymer... § 888.3390 Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis is a two-part...

21 CFR 888.3380 - Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint femoral (hemi-hip) trunnion-bearing... Devices § 888.3380 Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis is a two...

Atomic-scale structure of dislocations revealed by scanning tunneling microscopy and molecular dynamics

DEFF Research Database (Denmark)

Christiansen, Jesper; Morgenstern, K.; Schiøtz, Jakob

2002-01-01

The intersection between dislocations and a Ag(111) surface has been studied using an interplay of scanning tunneling microscopy (STM) and molecular dynamics. Whereas the STM provides atomically resolved information about the surface structure and Burgers vectors of the dislocations, the simulati......The intersection between dislocations and a Ag(111) surface has been studied using an interplay of scanning tunneling microscopy (STM) and molecular dynamics. Whereas the STM provides atomically resolved information about the surface structure and Burgers vectors of the dislocations......, the simulations can be used to determine dislocation structure and orientation in the near-surface region. In a similar way, the subsurface structure of other extended defects can be studied. The simulations show dislocations to reorient the partials in the surface region leading to an increased splitting width...

Morfología femoral proximal en fracturas de cadera

OpenAIRE

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

2003-01-01

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

Excavation damage zone tracer experiment in the floor of the room 415 test tunnel

International Nuclear Information System (INIS)

Frost, L.H.; Everitt, R.A.

1997-03-01

A 3.5-m-diameter test tunnel was constructed on the 420 Level of AECL's Underground Research Laboratory using a mechanical excavation technique. The orientation of the tunnel was chosen to maximize the stress ratio in the plane perpendicular to the tunnel axis in order to promote and study stress-induced excavation damage. The resulting excavation damage zone (EDZ) is characterized by a distinct breakout notch in both the floor and roof of the tunnel. In the floor of the tunnel, the main flow pathway within the EDZ is within a zone of intense grain-size fracturing (process zone) located at the tip of the breakout notch; virtually no flow occurs outside this region. A tracer experiment was performed within the EDZ in the floor of the tunnel to characterize the solute transport properties (permeability, transport porosity and dispersivity) within the process zone, as well as to develop and demonstrate methods for determining the transport properties within EDZs of underground tunnels. The experiment was performed as a constant head test by continuously injecting a constant concentration of iodide tracer into a region of the process zone, and by monitoring tracer breakthrough from the zone at a distance 1.5 m away. An equivalent-porous-media approach was taken in analysing fluid flow and solute transport through the process zone. Based on mass flux calculations, the hydraulic conductivity and transport porosity of the process zone are estimated to be 7.4 x 10 -7 m/s and 2.7 % respectively. Based on an analytic solution that represents tracer transport within the process zone as one-dimensional advective diffusive transport in a finite homogeneous porous medium, the longitudinal dispersivity and transport porosity of the zone are estimated to be 0.60 m and 3.3 % respectively. The transport porosity values estimated by both the mass flux and analytic calculations compare quite well. (author)

Thermovoltages in vacuum tunneling investigated by scanning tunneling microscopy

OpenAIRE

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

1995-01-01

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

Recruitment order of quadriceps motor units: femoral nerve vs. direct quadriceps stimulation.

Science.gov (United States)

Rodriguez-Falces, Javier; Place, Nicolas

2013-12-01

To investigate potential differences in the recruitment order of motor units (MUs) in the quadriceps femoris when electrical stimulation is applied over the quadriceps belly versus the femoral nerve. M-waves and mechanical twitches were evoked using femoral nerve stimulation and direct quadriceps stimulation of gradually increasing intensity from 20 young, healthy subjects. Recruitment order was investigated by analysing the time-to-peak twitch and the time interval from the stimulus artefact to the M-wave positive peak (M-wave latency) for the vastus medialis (VM) and vastus lateralis (VL) muscles. During femoral nerve stimulation, time-to-peak twitch and M-wave latency decreased consistently (P  0.05). For the VM muscle, M-wave latency decreased with increasing stimulation level for both femoral nerve and direct quadriceps stimulation, whereas, for the VL muscle, the variation of M-wave latency with stimulus intensity was different for the two stimulation geometries (P recruitment order during direct quadriceps stimulation was more complex, depending ultimately on the architecture of the peripheral nerve and its terminal branches below the stimulating electrodes for each muscle. For the VM, MUs were orderly recruited for both stimulation geometries, whereas, for the VL muscle, MUs were orderly recruited for femoral nerve stimulation, but followed no particular order for direct quadriceps stimulation.

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

Science.gov (United States)

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

2015-05-01

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

Macroscopic quantum tunneling in Josephson tunnel junctions and Coulomb blockade in single small tunnel junctions

International Nuclear Information System (INIS)

Cleland, A.N.

1991-04-01

Experiments investigating the process of macroscopic quantum tunneling in a moderately-damped, resistively shunted, Josephson junction are described, followed by a discussion of experiments performed on very small capacitance normal-metal tunnel junctions. The experiments on the resistively-shunted Josephson junction were designed to investigate a quantum process, that of the tunneling of the Josephson phase variable under a potential barrier, in a system in which dissipation plays a major role in the dynamics of motion. All the parameters of the junction were measured using the classical phenomena of thermal activation and resonant activation. Theoretical predictions are compared with the experimental results, showing good agreement with no adjustable parameters; the tunneling rate in the moderately damped (Q ∼ 1) junction is seen to be reduced by a factor of 300 from that predicted for an undamped junction. The phase is seen to be a good quantum-mechanical variable. The experiments on small capacitance tunnel junctions extend the measurements on the larger-area Josephson junctions from the region in which the phase variable has a fairly well-defined value, i.e. its wavefunction has a narrow width, to the region where its value is almost completely unknown. The charge on the junction becomes well-defined and is predicted to quantize the current through the junction, giving rise to the Coulomb blockade at low bias. I present the first clear observation of the Coulomb blockade in single junctions. The electrical environment of the tunnel junction, however, strongly affects the behavior of the junction: higher resistance leads are observed to greatly sharpen the Coulomb blockade over that seen with lower resistance leads. I present theoretical descriptions of how the environment influences the junctions; comparisons with the experimental results are in reasonable agreement

The surgical treatment of ilio-femoral venous obstruction.

Science.gov (United States)

Illuminati, G; Caliò, F G; D'Urso, A; Mancini, P; Papaspyropoulos, V; Ceccanei, G; Lorusso, R; Vietri, F

2004-01-01

A series of 9 patients of a mean age of 48 years, operated on for compression of the ilio-femoral venous axis is reported. The cause of obstruction was external compression in 3 cases, a retroperitoneal sarcoma in 1 case, and an infrarenal aortic aneurysm in 2. Two patients presented with a Cockett's syndrome, 3 with a chronic ilio-femoral thrombosis, and one with a post-traumatic segmentary stenosis. Treatment consisted in a resection/Dacron grafting of 2 infrarenal aortic aneurysms, one femoro-caval bypass graft, 2 transpositions of the right common iliac artery in the left hypogastric artery for Cockett's syndrome, 3 Palma's operations for chronic thrombosis, and one internal jugular vein interposition for segmentary stenosis. There were no postoperative deaths and no early thromboses of venous reconstructions performed. All the patients were relieved of symptoms during the follow-up period, whose mean length was 38 months. The cause of venous obstruction and the presence of symptoms which are resistant to medical treatment are the main indications to ilio-femoral venous revascularization. The choice of the optimal treatment in each single case yields satisfactory results.

MR imaging findings of the femoral marrow in myelodysplastic syndrome

International Nuclear Information System (INIS)

Tanaka, Osamu; Takagi, Shojiro; Matsuura, Katsuhiko; Ichikawa, Tamaki; Kobayashi, Yasuyuki; Nagai, Jun

1995-01-01

MR imaging of the femoral marrow was performed in 30 patients with myelodysplastic syndrome (MDS), 11 cases of which evolved to acute myeloid leukemia (AML). The MRI appearance was classified into five patterns: fatty marrow; faint signal; nodular pattern; heterogeneous infiltration; and diffuse infiltration. For each type of MDS, MRI patterns of the femoral marrow were evaluated and compared with those in normal subjects as well as in patients with aplastic anemia. Signal intensity alteration, a low signal on T1-weighted SE image and a high signal on STIR image, began in the proximal femoral marrow almost symmetrically in patients with MDS. The area of abnormal signal intensity tended to gradually extend towards the distal portion of the femur as the disease progressed. MRI patterns of the femoral marrow correlated with marrow cellularity, and diffuse marrow infiltration was noted in patients with a more advanced type of MDS or with severe anemia. There were limitations to making an accurate diagnosis of the MDS type on the basis of the MRI pattern. Progression of the MRI appearance in the course of MDS was thought to be a sign suggesting evolution to AML. It was difficult to differentiate hypoplastic MDS from aplastic anemia, although the nodular pattern was commonly seen in the latter disease. (author)

MR imaging findings of the femoral marrow in myelodysplastic syndrome

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Osamu; Takagi, Shojiro; Matsuura, Katsuhiko; Ichikawa, Tamaki; Kobayashi, Yasuyuki; Nagai, Jun [Jichi Medical School, Minamikawachi, Tochigi (Japan)

1995-10-01

MR imaging of the femoral marrow was performed in 30 patients with myelodysplastic syndrome (MDS), 11 cases of which evolved to acute myeloid leukemia (AML). The MRI appearance was classified into five patterns: fatty marrow; faint signal; nodular pattern; heterogeneous infiltration; and diffuse infiltration. For each type of MDS, MRI patterns of the femoral marrow were evaluated and compared with those in normal subjects as well as in patients with aplastic anemia. Signal intensity alteration, a low signal on T1-weighted SE image and a high signal on STIR image, began in the proximal femoral marrow almost symmetrically in patients with MDS. The area of abnormal signal intensity tended to gradually extend towards the distal portion of the femur as the disease progressed. MRI patterns of the femoral marrow correlated with marrow cellularity, and diffuse marrow infiltration was noted in patients with a more advanced type of MDS or with severe anemia. There were limitations to making an accurate diagnosis of the MDS type on the basis of the MRI pattern. Progression of the MRI appearance in the course of MDS was thought to be a sign suggesting evolution to AML. It was difficult to differentiate hypoplastic MDS from aplastic anemia, although the nodular pattern was commonly seen in the latter disease. (author).

Radionuclide scintimetry for diagnosis of complications following femoral neck fracture

International Nuclear Information System (INIS)

Alberts, K.A.; Dahlborn, M.; Hindmarsh, J.; Soederborg, B.; Ringertz, H.

1984-01-01

A scintimetric study using Tc-99m MDP was made of 54 patients with delayed union, nonunion, or late segmental collapse of the femoral head, 4-92 months after femoral neck fracture. In radiographically verified collapse, the radionuclide uptake ratio between the femoral head on the fractured and on the intact side (HHR) was significantly higher than in fractures resulting in delayed union or nonunion. On the basis of scintimetric and radiographic findings, the patients with healing disturbances could be divided into three groups, characterized by the following features: (1) Satisfactory post-reduction position of the fracture without subsequent redisplacement and a high HHR, which as a rule turned out to be delayed union; (2) The same radiographic pattern but with a lower HHR, which in most cases resulted in nonunion; (3) Inadequate reduction or early redisplacement of the fracture with a high HHR, which resulted in nonunion. The fractional precision in discriminating between different types of disturbed fracture healing by means of skeletal scintimetry was 0.86 in this study. This non-invasive and technically simple method would therefore be a valuable complement to radiography in the assessment of healing, more than 4 months after fracture of the femoral neck. (author)

Differences in Femoral Geometry and Structure Due to Immobilization

Science.gov (United States)

Kiratli, Beatrice Jenny; Yamada, M.; Smith, A.; Marcus, R. M.; Arnaud, S.; vanderMeulen, M. C. H.; Hargens, Alan R. (Technical Monitor)

1996-01-01

Reduction in bone mass of the lower extremity is well documented in individuals with paralysis resulting from spinal cord injury (SCI). The consequent osteopenia leads to elevated fracture risk with fractures occurring more commonly in the femoral shaft and supracondylar regions than the hip. A model has recently been described to estimate geometry and structure of the femoral midshaft from whole body scans by dual X-ray absorptiometry (DXA). Increases in femoral geometric and structural properties during growth were primarily related to mechanical loading as reflected by body mass. In this study, we investigate the relationship between body mass and femoral geometry and structure in adults with normal habitual mechanical loading patterns and those with severely reduced loading. The subjects were 78 ambulatory men (aged 20-72 yrs) and 113 men with complete paralysis from SCI of more than 4 years duration (aged 21 73 yrs). Subregional analysis was performed on DXA whole body scans to obtain bone mineral content (BMC, g), cortical thickness (cm), crosssectional moment of inertia (CSMI, cm4), and section modulus (cm3) of the femoral midshaft. All measured bone variables were significantly lower in SCI compared with ambulatory subjects: -29% (BMC), -33% (cortical thickness), -23% (CSMI), and -22% (section modulus) while body mass was not significantly different. However, the associations between body mass and bone properties were notably different; r2 values were higher for ambulatory than SCI subjects in regressions of body mass on BMC (0.48 vs 0.20), CSMI (0.59 vs 0.32), and section modulus (0.59 vs 0.31). No association was seen between body mass and cortical thickness for either group. The greatest difference between groups is in the femoral cortex, consistent with reduced bone mass via endosteal expansion. The relatively lesser difference in geometric and structural properties implies that there is less effect on mechanical integrity than would be expected from

Delineation of tunnel valley across the North Sea coastline, Denmark based on reflection seismic data, boreholes, TEM and Schlumberger soundings

DEFF Research Database (Denmark)

Andersen, Theis Raaschou; Jørgensen, Flemming; Christensen, Steen

Buried tunnel valleys are elongated depressions eroded into the substratum during the Pleistocene glaciations. Nine such valleys are mapped on- and offshore in a 300 km2 area located at the Danish North Sea coast. The delineation of the buried valleys is based on an extensive data set consisting......, preferred orientations, and morphology support that three of the tunnel valleys cross the North Sea coastline. It is suggested that the nine valleys were formed during at least six events that occurred through one or more pre-Weichselian glaciations. Key words: Pleistocene valleys, geophysical mapping...

Delineation of tunnel valleys across the North Sea coastline, Denmark based on reflection seismic data, boreholes, TEM and Schlumberger soundings

DEFF Research Database (Denmark)

Andersen, Theis Raaschou; Jørdensen, Flemming; Christensen, Steen

Buried tunnel valleys are elongated depressions eroded into the substratum during the Pleistocene glaciations. Nine such valleys are mapped on- and offshore in a 300 km2 area located at the Danish North Sea coast. The delineation of the buried valleys is based on an extensive data set consisting......, preferred orientations, and morphology support that three of the tunnel valleys cross the North Sea coastline. It is suggested that the nine valleys were formed during at least six events that occurred through one or more pre-Weichselian glaciations...

About tunnelling times

International Nuclear Information System (INIS)

Olkhovsky, V.S.; Recami, E.

1991-08-01

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

Starclose SE® hemostasis after 6F direct antegrade superficial femoral artery access distal to the femoral head for peripheral endovascular procedures in obese patients.

Science.gov (United States)

Spiliopoulos, Stavros; Kitrou, Panagiotis; Christeas, Nikolaos; Karnabatidis, Dimitris

2016-01-01

Direct superficial femoral artery (SFA) antegrade puncture is a valid alternative to common femoral artery (CFA) access for peripheral vascular interventions. Data investigating vascular closure device (VCD) hemostasis of distant SFA 6F access are limited. We aimed to investigate the safety and effectiveness of the Starclose SE® VCD for hemostasis, following direct 6F antegrade SFA access distal to the femoral head. This prospective, single-center study included patients who were not suitable for CFA puncture and were scheduled to undergo peripheral endovascular interventions using direct antegrade SFA 6F access, at least 2 cm below the inferior edge of femoral head. Hemostasis was obtained with the Starclose SE® VCD (Abbott Laboratories). Primary endpoints were successful hemostasis rate and periprocedural (30-day) major complication rate. Secondary endpoint was the rate of minor complications. Clinical and Doppler ultrasound follow-up was performed at discharge and at one month. Between September 2014 and August 2015, a total of 30 patients (21 male; 70.0%) with a mean body mass index of 41.2 kg/m2 were enrolled. Mean age was 72±9 years (range, 67-88 years). Most patients suffered from critical limb ischemia (87.1%) and diabetes (61.3%). Calcifications were present in eight cases (26.6%). Reason for direct SFA puncture was obesity (100%). Successful hemostasis was achieved in 100% of the cases. No major complications were noted after one-month follow-up. Minor complications included two <5 cm hematomas (6.6%) not necessitating treatment. In this prospective study, Starclose SE® VCD was safe and effective for hemostasis of antegrade direct SFA puncture. Uncomplicated hemostasis was achieved even in cases of puncturing 2 to 7 cm below the inferior edge of the femoral head.

ediatric femoral shaft fractures treated by flexible intramedullary nailing.

Science.gov (United States)

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

2015-01-01

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

Corticosteroid Reduces Blood Flow to Femoral Heads in Rabbits.

Science.gov (United States)

Hou, S.M.; Liu, T.K.; Kao, M.C.

1994-12-01

Avascular necrosis of the femoral head is one of the common problems in orthopedic practice in Taiwan. The subchondral bone loses its blood supply which weakens its biomechanical support. Steroid overuse is one of many possible etiologies in reducing blood flow to the femoral head. Laser Doppler velocimeter is a precise monitor of regional blood flow of bone which is expressed in perfusion units (PU). In the control group the rabbits were injected with normal saline and there were no statistical differences between blood flow to the right hip (39.26 +/- 5.64 PU) and left hip (38.58 +/- 4.35 PU). In group B a weekly injection of methylprednisolone into rabbits for 6 weeks demonstrated the reduction of blood flow of femoral head (24.74 +/- 3.13 PU) by the laser Doppler velocimeter. The flow decreased further (15.93 +/- 2.33 PU) by 12 weeks of steroid treatment. In group C after a weekly injection of steroid for 6 weeks the flow became 31.63 +/- 4.79 PU. The steroid was then discontinued for 3 weeks and the flow was 34.6 +/- 1.34 PU. In group D the blood flow was 25.89 +/- 4.01 PU after 6 weeks of steroid treatment and we stopped the steroid for 6 weeks, the blood flow became 29.86 +/- 2.59 PU. The merit of our experiment established a model of study in avascular necrosis of the femoral head in rabbits. Copyright 1994 S. Karger AG, Basel

London forces in highly oriented pyrolytic graphite

Directory of Open Access Journals (Sweden)

L.V. Poperenko

2017-07-01

Full Text Available Surface of highly oriented pyrolytic graphite with terrace steps was studied using scanning tunneling microscopy with high spatial resolution. Spots with positive and negative charges were found in the vicinity of the steps. Values of the charges depended both on the microscope needle scan velocity and on its motion direction. The observed effect was theoretically explained with account of London forces that arise between the needle tip and the graphite surface. In this scheme, a terrace step works as a nanoscale diode for surface electric currents.

Femoral Hernia At Mulago Hospital, Uganda

African Journals Online (AJOL)

user

2004-12-02

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

Ultrasound-guided approach for axillary brachial plexus, femoral nerve, and sciatic nerve blocks in dogs.

Science.gov (United States)

Campoy, Luis; Bezuidenhout, Abraham J; Gleed, Robin D; Martin-Flores, Manuel; Raw, Robert M; Santare, Carrie L; Jay, Ariane R; Wang, Annie L

2010-03-01

To describe an ultrasound-guided technique and the anatomical basis for three clinically useful nerve blocks in dogs. Prospective experimental trial. Four hound-cross dogs aged 2 +/- 0 years (mean +/- SD) weighing 30 +/- 5 kg and four Beagles aged 2 +/- 0 years and weighing 8.5 +/- 0.5 kg. Axillary brachial plexus, femoral, and sciatic combined ultrasound/electrolocation-guided nerve blocks were performed sequentially and bilaterally using a lidocaine solution mixed with methylene blue. Sciatic nerve blocks were not performed in the hounds. After the blocks, the dogs were euthanatized and each relevant site dissected. Axillary brachial plexus block Landmark blood vessels and the roots of the brachial plexus were identified by ultrasound in all eight dogs. Anatomical examination confirmed the relationship between the four ventral nerve roots (C6, C7, C8, and T1) and the axillary vessels. Three roots (C7, C8, and T1) were adequately stained bilaterally in all dogs. Femoral nerve block Landmark blood vessels (femoral artery and femoral vein), the femoral and saphenous nerves and the medial portion of the rectus femoris muscle were identified by ultrasound in all dogs. Anatomical examination confirmed the relationship between the femoral vessels, femoral nerve, and the rectus femoris muscle. The femoral nerves were adequately stained bilaterally in all dogs. Sciatic nerve block. Ultrasound landmarks (semimembranosus muscle, the fascia of the biceps femoris muscle and the sciatic nerve) could be identified in all of the dogs. In the four Beagles, anatomical examination confirmed the relationship between the biceps femoris muscle, the semimembranosus muscle, and the sciatic nerve. In the Beagles, all but one of the sciatic nerves were stained adequately. Ultrasound-guided needle insertion is an accurate method for depositing local anesthetic for axillary brachial plexus, femoral, and sciatic nerve blocks.

Tunneling current between graphene layers

OpenAIRE

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

2013-01-01

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

Validation of a new classification system for interprosthetic femoral fractures.

Science.gov (United States)

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

2017-07-01

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

Microstructure analysis and wear behavior of titanium cermet femoral head with hard TiC layer.

Science.gov (United States)

Luo, Yong; Ge, Shirong; Liu, Hongtao; Jin, Zhongmin

2009-12-11

Titanium cermet was successfully synthesized and formed a thin gradient titanium carbide coating on the surface of Ti6Al4V alloy by using a novel sequential carburization under high temperature, while the titanium cermet femoral head was produced. The titanium cermet phase and surface topography were characterized with X-ray diffraction (XRD) and backscattered electron imaging (BSE). And then the wear behavior of titanium cermet femoral head was investigated by using CUMT II artificial joint hip simulator. The surface characterization indicates that carbon effectively diffused into the titanium alloys and formed a hard TiC layer on the Ti6Al4V alloys surface with a micro-porous structure. The artificial hip joint experimental results show that titanium cermet femoral head could not only improve the wear resistance of artificial femoral head, but also decrease the wear of UHMWPE joint cup. In addition, the carburized titanium alloy femoral head could effectively control the UHMWPE debris distribution, and increase the size of UHMWPE debris. All of the results suggest that titanium cermet is a prospective femoral head material in artificial joint.

Automatic quantification of tibio-femoral contact area and congruity

DEFF Research Database (Denmark)

Tummala, Sudhakar; Nielsen, Mads; Lillholm, Martin

2012-01-01

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

Avascular necrosis associated with nailing of femoral neck fracture

International Nuclear Information System (INIS)

Stroemqvist, B.; Hansson, L.I.

1983-01-01

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

Avascular necrosis associated with nailing of femoral neck fracture

Energy Technology Data Exchange (ETDEWEB)

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

1983-01-01

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

Relationship of femoral artery ultrasound measures of atherosclerosis with chronic kidney disease.

Science.gov (United States)

Hsu, Simon; Rifkin, Dena E; Criqui, Michael H; Suder, Natalie C; Garimella, Pranav; Ginsberg, Charles; Marasco, Antoinette M; McQuaide, Belinda J; Barinas-Mitchell, Emma J; Allison, Matthew A; Wassel, Christina L; Ix, Joachim H

2017-12-22

Chronic kidney disease (CKD) is strongly associated with peripheral artery disease (PAD). Detection of subclinical PAD may allow early interventions for or prevention of PAD in persons with CKD. Whether the presence of atherosclerotic plaque and femoral intima-media thickness (IMT) are associated with kidney function is unknown. We performed a cross-sectional observational study of 1029 community-living adults. We measured superficial and common femoral artery IMT and atherosclerotic plaque presence by ultrasound. Estimated glomerular filtration rate (eGFR; continuous) and eGFR <60 mL/min/1.73 m 2 (binary) were evaluated as outcomes. Mean age was 70 ± 10 years, mean eGFR was 78 ± 17 mL/min/1.73 m 2 , and 156 (15%) individuals had eGFR <60 mL/min/1.73 m 2 ; 260 (25%) had femoral artery plaque. In models adjusted for demographics and cardiovascular risk factors, individuals with femoral artery plaque had mean eGFR approximately 3.0 (95% confidence interval, -5.3 to -0.8) mL/min/1.73 m 2 lower than those without plaque (P < .01). The presence of plaque was also associated with a 1.7-fold higher odds of eGFR <60 mL/min/1.73 m 2 (95% confidence interval, 1.1-2.8; P < .02). Associations were similar in persons with normal ankle-brachial index. The directions of associations were similar for femoral IMT measures with eGFR and CKD but were rendered no longer statistically significant with adjustment for demographic variables and cardiovascular disease risk factors. Femoral artery plaque is significantly associated with CKD prevalence in community-living individuals, even among those with normal ankle-brachial index. Femoral artery ultrasound may allow evaluation of relationships and risk factors linking PAD and kidney disease earlier in its course. Copyright © 2017 Society for Vascular Surgery. All rights reserved.

Single Electron Tunneling

International Nuclear Information System (INIS)

Ruggiero, Steven T.

2005-01-01

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

Drill and blast tunnelling; Konvensjonell drift av tunneler

Energy Technology Data Exchange (ETDEWEB)

Roenn, Paal-Egil

1997-12-31

This thesis treats drill and blast tunnelling. The rapid technological advance necessitates revised and updated design criteria, quality requirements and quality control. In situ blast experiments were carried out in order to test new methods and improve the basis for calculation and design. The main topics of the experiments were (1) longer rounds and increased drillhole diameter, (2) emulsion slurry as explosives in tunnelling, and (3) electronic detonators in contour blasting. The experiments show that it is technically feasible to blast rounds of up to 8.6 m length. Using current technology, the economical optimum round length is substantially shorter. Dust, low visibility, noise and toxic fumes are occupational environmental strains for the tunnel workers. Several of the environmental factors are strongly influenced by the type of explosives used. For example, emulsion slurry resulted in 4 to 5 times better visibility than Anolit and the concentration of respirable dust and total dust was reduced by 30-50 %. Electronic detonators were tested and found to give a higher percentage of remaining drillholes in the contour than Nonel detonators. The thesis includes a chapter on economic design of hydropower tunnels. 42 refs., 83 figs., 45 tabs.

Resonant tunnel magnetoresistance in double-barrier planar magnetic tunnel junctions

KAUST Repository

Useinov, A. N.

2011-08-24

We present a theoretical approach to calculate the spin-dependent current and tunnel magnetoresistance (TMR) in a double-barrier magnetic tunnel junction (DMTJ), in which the magnetization of the middle ferromagnetic metal layer can be aligned parallel or antiparallel in relation to the fixed magnetizations of the left and right ferromagnetic electrodes. The electron transport through the DMTJ is considered as a three-dimensional problem, taking into account all transmitting electron trajectories as well as the spin-dependent momentum conservation law. The dependence of the transmission coefficient and spin-polarized currents on the applied voltage is derived as an exact solution to the quantum-mechanical problem for the spin-polarized transport. In the range of the developed physical model, the resonant tunneling, nonresonant tunneling, and enhanced spin filtering can be explained; the simulation results are in good agreement with experimental data.

Resonant tunnel magnetoresistance in double-barrier planar magnetic tunnel junctions

KAUST Repository

Useinov, A. N.; Kosel, Jü rgen; Useinov, N. Kh.; Tagirov, L. R.

2011-01-01

We present a theoretical approach to calculate the spin-dependent current and tunnel magnetoresistance (TMR) in a double-barrier magnetic tunnel junction (DMTJ), in which the magnetization of the middle ferromagnetic metal layer can be aligned parallel or antiparallel in relation to the fixed magnetizations of the left and right ferromagnetic electrodes. The electron transport through the DMTJ is considered as a three-dimensional problem, taking into account all transmitting electron trajectories as well as the spin-dependent momentum conservation law. The dependence of the transmission coefficient and spin-polarized currents on the applied voltage is derived as an exact solution to the quantum-mechanical problem for the spin-polarized transport. In the range of the developed physical model, the resonant tunneling, nonresonant tunneling, and enhanced spin filtering can be explained; the simulation results are in good agreement with experimental data.

In situ control of As dimer orientation on Ge(100) surfaces

International Nuclear Information System (INIS)

Brückner, Sebastian; Döscher, Henning; Supplie, Oliver; Luczak, Johannes; Barrigón, Enrique; Rey-Stolle, Ignacio; Kleinschmidt, Peter; Hannappel, Thomas

2012-01-01

We investigated the preparation of single domain Ge(100):As surfaces in a metal-organic vapor phase epitaxy reactor. In situ reflection anisotropy spectra (RAS) of vicinal substrates change when arsenic is supplied either by tertiarybutylarsine or by background As 4 during annealing. Low energy electron diffraction shows mutually perpendicular orientations of dimers, scanning tunneling microscopy reveals distinct differences in the step structure, and x-ray photoelectron spectroscopy confirms differences in the As coverage of the Ge(100):As samples. Their RAS signals consist of contributions related to As dimer orientation and to step structure, enabling precise in situ control over preparation of single domain Ge(100):As surfaces.

In situ control of As dimer orientation on Ge(100) surfaces

Energy Technology Data Exchange (ETDEWEB)

Brueckner, Sebastian; Doescher, Henning [Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Technische Universitaet Ilmenau, Institut fuer Physik, Postfach 10 05 65, 98684 Ilmenau (Germany); Supplie, Oliver; Luczak, Johannes [Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Barrigon, Enrique; Rey-Stolle, Ignacio [Instituto de Energia Solar, Universidad Politecnica de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Kleinschmidt, Peter [Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); CiS Forschungsinstitut fuer Mikrosensorik und Photovoltaik GmbH, Konrad-Zuse-Strasse 14, 99099 Erfurt (Germany); Hannappel, Thomas [Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Technische Universitaet Ilmenau, Institut fuer Physik, Postfach 10 05 65, 98684 Ilmenau (Germany); CiS Forschungsinstitut fuer Mikrosensorik und Photovoltaik GmbH, Konrad-Zuse-Strasse 14, 99099 Erfurt (Germany)

2012-09-17

We investigated the preparation of single domain Ge(100):As surfaces in a metal-organic vapor phase epitaxy reactor. In situ reflection anisotropy spectra (RAS) of vicinal substrates change when arsenic is supplied either by tertiarybutylarsine or by background As{sub 4} during annealing. Low energy electron diffraction shows mutually perpendicular orientations of dimers, scanning tunneling microscopy reveals distinct differences in the step structure, and x-ray photoelectron spectroscopy confirms differences in the As coverage of the Ge(100):As samples. Their RAS signals consist of contributions related to As dimer orientation and to step structure, enabling precise in situ control over preparation of single domain Ge(100):As surfaces.

Outcome of pinning in patients with slipped capital femoral epiphysis: risk factors associated with avascular necrosis, chondrolysis, and femoral impingement.

Science.gov (United States)

Ulici, Alexandru; Carp, Madalina; Tevanov, Iulia; Nahoi, Catalin Alexandru; Sterian, Alin Gabriel; Cosma, Dan

2018-06-01

Objective This study aimed to assess the principal risk factors that could lead to the most common long-term complications of slipped capital femoral epiphysis, such as avascular necrosis, chondrolysis, and hip impingement. Methods We conducted a single-centre, retrospective study and evaluated patients (70 patients, 81 hips) who were treated for slipped capital femoral epiphysis from 2010 to 2015 and who underwent pinning. We measured the severity of displacement radiologically using the Southwick angle. Postoperative radiographs were evaluated for the most frequent long-term complications of avascular necrosis (AVN), chondrolysis, and femoral acetabular impingement (FAI). Results We found seven cases of AVN, 14 cases of chondrolysis, and 31 hips had an α angle of 60°. Sex, ambulation, and symptoms did not affect development of these complications. Patients with a normal weight were almost two times more likely to develop FAI. Patients with moderate and severe slips had a similar percentage of AVN. In severe slips, 85.7% of patients had an α angle higher than 60°. Conclusions This study shows that severe slips have a higher risk of developing AVN and hip impingement. Every patient who suffers from SCFE (even the mildest forms) should be regularly checked for FAI.

a Novel Image Acquisition and Processing Procedure for Fast Tunnel Dsm Production