Benefit from NASA

NASA Image and Video Library

1998-01-01

The Ultra 500 Series golf balls, introduced in 1995 by Wilson Sporting Goods Company, has 500 dimples arranged in a pattern of 60 spherical triangles. The design employs NASA's aerodynamics technology analysis of air loads of the tank and Shuttle orbiter that was performed under the Space Shuttle External Tank program. According to Wilson, this technology provides "the most symmetrical ball surface available, sustaining initial velocity longer and producing the most stable ball flight for unmatched accuracy and distance." The dimples are in three sizes, shapes and depths mathematically positioned for the best effect. The selection of dimples and their placement optimizes the interaction of opposing forces of lift and drag. Large dimples reduce air drag, enhance lift, and maintain spin for distance. Small dimples prevent excessive lift that destabilizes the ball flight and the medium size dimples blend the other two.

Improved systemic delivery of insulin by condensed drug loading in a dimpled suppository.

PubMed

Matsumoto, Akihiro; Murakami, Kayoko; Watanabe, Chie; Murakami, Masahiro

2017-01-01

The development of peptide therapeutics owing to the advances in biotechnology has overcome some unmet medical needs; however, the route of administration is still limited to injections. Systemic delivery of insulin via an enteral route remains a great challenge due to its instability and low mucosal permeability. In this study, we investigated the effect of drug condensation in a suppository on the efficacy of insulin after rectal administration. Suppositories with dimples are prepared by a mold method using a hard fat (Suppocire ® AM). Insulin or fluorescein isothiocyanate-dextran (molecular weight: 3,000-5,000) (FD4) as a model of a hydrophilic macromolecule was loaded in the dimples, and sealed with other lipids with different melting points. The in vitro release test showed that the time to 50% drug release depends on the melting point of the lipid for sealing but not on the number of dimples. The suppositories with one-, or three-dimple containing insulin and caprylocaproyl macrogol-8 glyceride (Labrasol ® ) were administered to rats at 0.5 U/head. The reduction in plasma glucose level was more significant for the one-dimple-type suppository than for the three-dimple-type although the one-dimple-type suppository contained less amount of Labrasol by one-third compared to the three-dimple-type. These results suggest that condensation of an insulin dose in a limited surface area of a suppository improves systemic availability via the rectal route with a reduced amount of an absorption enhancer.

Design of Tools for Press-countersinking or Dimpling 0.040-inch-thick-24S-T Sheet

NASA Technical Reports Server (NTRS)

Templin, R L; Fogwell, J W

1942-01-01

A set of dimpling tools was designed for 0.040-inch 24S-T sheet and flush-type rivets 1/8 inch in diameter with 100 degree countersunk heads. The dimples produced under different conditions of pressure, sheet thickness, and drill diameter are presented as cross-sectional photographs magnified 20 times. The most satisfactory values for the dimpling tools were found to be: maximum punch diameter, 0.231 inch; maximum die diameter, 0.223 inch; maximum mandrel diameter, 0.128 inch; dimple angle, 100 degree; punch springback angle, 1 1/2 degree; and die springback angle, 2 degree.

Perforator-based island flap with a peripheral muscle patch for coverage of sacral sores.

PubMed

Chang, Jung Woo; Lee, Jang Hyun; Choi, Matthew Seung Suk

2016-06-01

Despite numerous therapeutic advances, the treatment of pressure sores remains a challenge. The increased use of perforator flaps enables surgeons to minimize donor-site morbidity by sparing the underlying muscle. In the presence of focal deep spaces, however, the inclusion of muscle would be beneficial. The goal of this study was to introduce a method for including a muscle patch at the periphery of a perforator-based island flap for coverage of sacral pressure sores. Between March 2010 and February 2015, 26 patients with stage IV sacral sores underwent perforator-based island flap reconstruction with a peripheral muscle patch. Patient characteristics, including sex, age, defect size, and postoperative complications, were recorded. All flaps survived without major complications. No flap necrosis was noted. The present study shows that a muscle patch incorporated into the periphery of a perforator-based flap can be transferred safely. This can be a good surgical option in cases where infection control or more volume is needed. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

CFD Investigation of Effect of Depth to Diameter Ratio on Dimple Flow Dynamics

DTIC Science & Technology

2007-06-01

contained dynamic vortical flow structures with behavior varying between each dimple studied. This dynamic vortex activity was observed to be linked... 1 1.1 Research Goals . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Motivation for Research . . . . . . . . . . . . . . . . . . 1 1.3...59 F. 1 . Pressure tap for ReD 20500 Rex 5000 0.05 h/D dimple . . . . . 66 F.2. Pressure tap for ReD 20500 Rex 77000 0.05 h/D dimple

Experimental study of micro dimple fabrication based on laser shock processing

NASA Astrophysics Data System (ADS)

Li, Kangmei; Hu, Yongxiang; Yao, Zhenqiang

2013-06-01

Micro-dimple array has been generally considered as a valuable texture for sliding surfaces. It can improve lubrication and reduce wear by acting as reservoirs of lubricants and grinding debris. Laser shock processing (LSP) is an innovative process which can not only improve fatigue, corrosion and wearing resistance but also shape metallic parts accurately. In this study, a new process for the fabrication of micro dimples based on LSP was proposed, which was named as laser peen texturing (LPT). Experiments were performed on 2024 aluminum alloy, Oxygen-Free High Conductivity (OFHC) copper and SUS304 stainless steel to study the effects of processing parameters of LPT on surface integrity of the specimen. Surface morphology, micro hardness and microstructure of the micro dimples were investigated under various laser power densities, laser spot diameters and repeated shock numbers. It was found that the depth of the micro dimples induced by LPT is strongly dependent on material properties. The diameter, depth as well as aspect ratio of micro dimples were increased with the laser power density and the repeated shock number under the conditions in this study. But when the laser spot diameter changed, the variation laws of the diameter, depth and aspect ratio of the dimple were different from each other. The results of micro hardness measurements suggested that LPT is beneficial for the improvement of the micro hardness beneath the dimple. Grain refinement was found significantly on 2024 aluminum alloy and OFHC copper but not clearly on SUS304 stainless steel. Both the hardening effect and the grain refinement have close relationship with the depth of the micro dimple.

Investigation of the Effect of Dimple Bionic Nonsmooth Surface on Tire Antihydroplaning.

PubMed

Zhou, Haichao; Wang, Guolin; Ding, Yangmin; Yang, Jian; Zhai, Huihui

2015-01-01

Inspired by the idea that bionic nonsmooth surfaces (BNSS) reduce fluid adhesion and resistance, the effect of dimple bionic nonsmooth structure arranged in tire circumferential grooves surface on antihydroplaning performance was investigated by using Computational Fluid Dynamics (CFD). The physical model of the object (model of dimple bionic nonsmooth surface distribution, hydroplaning model) and SST k - ω turbulence model are established for numerical analysis of tire hydroplaning. By virtue of the orthogonal table L16(4(5)), the parameters of dimple bionic nonsmooth structure design compared to the smooth structure were analyzed, and the priority level of the experimental factors as well as the best combination within the scope of the experiment was obtained. The simulation results show that dimple bionic nonsmooth structure can reduce water flow resistance by disturbing the eddy movement in boundary layers. Then, optimal type of dimple bionic nonsmooth structure is arranged on the bottom of tire circumferential grooves for hydroplaning performance analysis. The results show that the dimple bionic nonsmooth structure effectively decreases the tread hydrodynamic pressure when driving on water film and increases the tire hydroplaning velocity, thus improving tire antihydroplaning performance.

Investigation of the Effect of Dimple Bionic Nonsmooth Surface on Tire Antihydroplaning

PubMed Central

Zhou, Haichao; Wang, Guolin; Ding, Yangmin; Yang, Jian; Zhai, Huihui

2015-01-01

Inspired by the idea that bionic nonsmooth surfaces (BNSS) reduce fluid adhesion and resistance, the effect of dimple bionic nonsmooth structure arranged in tire circumferential grooves surface on antihydroplaning performance was investigated by using Computational Fluid Dynamics (CFD). The physical model of the object (model of dimple bionic nonsmooth surface distribution, hydroplaning model) and SST k − ω turbulence model are established for numerical analysis of tire hydroplaning. By virtue of the orthogonal table L16(45), the parameters of dimple bionic nonsmooth structure design compared to the smooth structure were analyzed, and the priority level of the experimental factors as well as the best combination within the scope of the experiment was obtained. The simulation results show that dimple bionic nonsmooth structure can reduce water flow resistance by disturbing the eddy movement in boundary layers. Then, optimal type of dimple bionic nonsmooth structure is arranged on the bottom of tire circumferential grooves for hydroplaning performance analysis. The results show that the dimple bionic nonsmooth structure effectively decreases the tread hydrodynamic pressure when driving on water film and increases the tire hydroplaning velocity, thus improving tire antihydroplaning performance. PMID:27018311

Three-dimensional topographies of water surface dimples formed by superhydrophobic water strider legs

NASA Astrophysics Data System (ADS)

Yin, W.; Zheng, Y. L.; Lu, H. Y.; Zhang, X. J.; Tian, Y.

2016-10-01

A water strider has a remarkable capability to stand and walk freely on water. Supporting forces of a water strider and a bionic robot have been calculated from the side view of pressed depth of legs to reconstruct the water surface dimples. However, in situ measurements of the multiple leg forces and significantly small leg/water contact dimples have not been realized yet. In this study, a shadow method was proposed to reconstruct the in situ three-dimensional topographies of leg/water contact dimples and their corresponding supporting forces. Results indicated that the supporting forces were affected by the depth, width, and length of the dimple, and that the maximum dimple depth was not proportional to the supporting forces. The shadow method also has advantages in disclosing tiny supporting force of legs in their subtle actions. These results are helpful for understanding the locomotion principles of water-walking insects and the design of biomimetic aquatic devices.

A cookbook for building a high-current dimpled H – magnetron source for accelerators

DOE PAGES

Bollinger, Daniel S.; Karns, Patrick R.; Tan, Cheng -Yang

2015-10-30

A high-current (>50 mA) dimpled H – magnetron source has been built at Fermilab for supplying H – beam to the entire accelerator complex. Despite many decades of expertise with slit H – magnetron sources at Fermilab, we were faced with many challenges from the dimpled H – magnetron source, which needed to be overcome in order to make it operational. Dimpled H – sources for high-energy physics are not new: Brookhaven National Laboratory has operated a dimpled H- source for more than two decades. However, the transference of that experience to Fermilab took about two years because a cookbookmore » for building this type of source did not exist and seemingly innocuous or undocumented choices had a huge impact on the success or failure for this type of source. Moreover, it is the goal of this paper to document the reasons for these choices and to present a cookbook for building and operating dimpled H – magnetron sources.« less

Key-lock colloids in a nematic liquid crystal.

PubMed

Silvestre, Nuno M; Tasinkevych, M

2017-01-01

The Landau-de Gennes free energy is used to study theoretically the effective interaction of spherical "key" and anisotropic "lock" colloidal particles. We assume identical anchoring properties of the surfaces of the key and of the lock particles, and we consider planar degenerate and perpendicular anchoring conditions separately. The lock particle is modeled as a spherical particle with a spherical dimple. When such a particle is introduced into a nematic liquid crystal, it orients its dimple at an oblique angle θ_{eq} with respect to the far field director n_{∞}. This angle depends on the depth of the dimple. Minimization results show that the free energy of a pair of key and lock particles exhibits a global minimum for the configuration when the key particle is facing the dimple of the lock colloidal particle. The preferred orientation ϕ_{eq} of the key-lock composite doublet relative to n_{∞} is robust against thermal fluctuations. The preferred orientation θ_{eq}^{(2)} of the dimple particle in the doublet is different from the isolated situation. This is related to the "direct" interaction of defects accompanying the key particle with the edge of the dimple. We propose that this nematic-amplified key-lock interaction can play an important role in self-organization and clustering of mixtures of colloidal particles with dimple colloids present.

A novel tribological study on DLC-coated micro-dimpled orthopedics implant interface.

PubMed

Choudhury, Dipankar; Urban, Filip; Vrbka, Martin; Hartl, Martin; Krupka, Ivan

2015-05-01

This study investigates a tribological performance of diamond like carbon (DLC) coated micro dimpled prosthesis heads against ceramic cups in a novel pendulum hip joint simulator. The simulator enables determining friction coefficient and viscous effects of a concave shaped specimen interface (conformal contact). Two types of DLC such as hydrogenated amorphous carbon (a-C:H) and tetrahedral amorphous carbon (Ta-C) and one set of micro dimple (diameter of 300µm, depth of 70µm, and pitch of 900µm) were fabricated on metallic prosthesis heads. The experiment results reveal a significant friction coefficient reduction to the 'dimpled a-C:H/ceramic' prosthesis compared to a 'Metal (CoCr)/ceramic' prosthesis because of their improved material and surface properties and viscous effect. The post-experiment surface analysis displays that the dimpled a-C:H yielded a minor change in the surface roughness, and generated a larger sizes of wear debris (40-200nm sized, equivalent diameter), a size which could be certainly stored in the dimple, thus likely to reducing their possible third body abrasive wear rate. Thus, dimpled a:C-H can be used as a 'metal on ceramic hip joint interface', whereas the simulator can be utilized as an advanced bio-tribometer. Copyright © 2015 Elsevier Ltd. All rights reserved.

Insulating effectiveness of self-spacing dimpled foil

NASA Technical Reports Server (NTRS)

Bond, J. A.

1972-01-01

Experimental data are graphed for determining conductive heat losses of multilayer insulation as function of number of foil layers. Foil was 0.0051 cm thick Nb, 1% Zr refractory alloy, dimpled to 0.0254 cm with approximately 28 dimples/sq cm. Heat losses were determined at 0.1 microtorr between 700 and 1089 K.

Polymer nanoimprinting using an anodized aluminum mold for structural coloration

NASA Astrophysics Data System (ADS)

Kikuchi, Tatsuya; Nishinaga, Osamu; Natsui, Shungo; Suzuki, Ryosuke O.

2015-06-01

Polymer nanoimprinting of submicrometer-scale dimple arrays with structural coloration was demonstrated. Highly ordered aluminum dimple arrays measuring 530-670 nm in diameter were formed on an aluminum substrate via etidronic acid anodizing at 210-270 V and subsequent anodic oxide dissolution. The nanostructured aluminum surface led to bright structural coloration with a rainbow spectrum, and the reflected wavelength strongly depends on the angle of the specimen and the period of the dimple array. The reflection peak shifts gradually with the dimple diameter toward longer wavelength, reaching 800 nm in wavelength at 670 nm in diameter. The shape of the aluminum dimple arrays were successfully transferred to a mercapto-ester ultra-violet curable polymer via self-assembled monolayer coating and polymer replications using a nanoimprinting technique. The nanostructured polymer surfaces with positively and negatively shaped dimple arrays also exhibited structural coloration based on the periodic nanostructure, and reflected light mostly in the visible region, 400-800 nm. This nanostructuring with structural coloration can be easily realized by simple techniques such as anodizing, SAM coating, and nanoimprinting.

Examination of the effect of blowing on the near-surface flow structure over a dimpled surface

NASA Astrophysics Data System (ADS)

Borchetta, C. G.; Martin, A.; Bailey, S. C. C.

2018-03-01

The near surface flow over a dimpled surface with flow injection through it was documented using time-resolved particle image velocimetry. The instantaneous flow structure, time-averaged statistics, and results from snapshot proper orthogonal decomposition were used to examine the coherent structures forming near the dimpled surface. In particular, the modifications made to the flow structures by the addition of flow injection through the surface were studied. It was observed that without flow injection, inclined flow structures with alternating vorticity from neighboring dimples are generated by the dimples and advect downstream. This behavior is coupled with fluid becoming entrained inside the dimples, recirculating and ejecting away from the surface. When flow injection was introduced through the surface, the flow structures became more disorganized, but some of the features of the semi-periodic structures observed without flow injection were preserved. The structures with flow injection appear in multiple wall-normal layers, formed from vortical structures shed from upstream dimples, with a corresponding increase in the size of the advecting structures. As a result of the more complex flow field observed with flow injection, there was an increase in turbulent kinetic energy and Reynolds shear stress, with the Reynolds shear stress representing an increase in vertical transport of momentum by sweeping and ejecting motions that were not present without flow injection.

Locomotion on the water surface: hydrodynamic constraints on rowing velocity require a gait change

PubMed

Suter; Wildman

1999-10-01

Fishing spiders, Dolomedes triton (Araneae, Pisauridae), propel themselves across the water surface using two gaits: they row with four legs at sustained velocities below 0.2 m s(-)(1) and they gallop with six legs at sustained velocities above 0.3 m s(-)(1). Because, during rowing, most of the horizontal thrust is provided by the drag of the leg and its associated dimple as both move across the water surface, the integrity of the dimple is crucial. We used a balance, incorporating a biaxial clinometer as the transducer, to measure the horizontal thrust forces on a leg segment subjected to water moving past it in non-turbulent flow. Changes in the horizontal forces reflected changes in the status of the dimple and showed that a stable dimple could exist only under conditions that combined low flow velocity, shallow leg-segment depth and a long perimeter of the interface between the leg segment and the water. Once the dimple disintegrated, leaving the leg segment submerged, less drag was generated. Therefore, the disintegration of the dimple imposes a limit on the efficacy of rowing with four legs. The limited degrees of freedom in the leg joints (the patellar joints move freely in the vertical plane but allow only limited flexion in other planes) impose a further constraint on rowing by restricting the maximum leg-tip velocity (to approximately 33 % of that attained by the same legs during galloping). This confines leg-tip velocities to a range at which maintenance of the dimple is particularly important. The weight of the spider also imposes constraints on the efficacy of rowing: because the drag encountered by the leg-cum-dimple is proportional to the depth of the dimple and because dimple depth is proportional to the supported weight, only spiders with a mass exceeding 0.48 g can have access to the full range of hydrodynamically possible dimple depths during rowing. Finally, the maximum velocity attainable during rowing is constrained by the substantial drag experienced by the spider during the glide interval between power strokes, drag that is negligible for a galloping spider because, for most of each inter-stroke interval, the spider is airborne. We conclude that both hydrodynamic and anatomical constraints confine rowing spiders to sustained velocities lower than 0.3 m s(-)(1), and that galloping allows spiders to move considerably faster because galloping is free of these constraints.

Fully localized post-buckling states of cylindrical shells under axial compression

NASA Astrophysics Data System (ADS)

Kreilos, Tobias; Schneider, Tobias M.

2017-09-01

We compute nonlinear force equilibrium solutions for a clamped thin cylindrical shell under axial compression. The equilibrium solutions are dynamically unstable and located on the stability boundary of the unbuckled state. A fully localized single dimple deformation is identified as the edge state-the attractor for the dynamics restricted to the stability boundary. Under variation of the axial load, the single dimple undergoes homoclinic snaking in the azimuthal direction, creating states with multiple dimples arranged around the central circumference. Once the circumference is completely filled with a ring of dimples, snaking in the axial direction leads to further growth of the dimple pattern. These fully nonlinear solutions embedded in the stability boundary of the unbuckled state constitute critical shape deformations. The solutions may thus be a step towards explaining when the buckling and subsequent collapse of an axially loaded cylinder shell is triggered.

Investigation of thermo-fluid behavior of mixed convection heat transfer of different dimples-protrusions wall patterns to heat transfer enhancement

NASA Astrophysics Data System (ADS)

Sobhani, M.; Behzadmehr, A.

2018-05-01

This study is a numerical investigation of the effect of improving heat transfer namely, modified rough (dimples and protrusions) surfaces on the mixed convective heat transfer of a turbulent flow in a horizontal tube. The effects of different dimples-protrusions arrangements on the improving the thermal performance of a rough tube are investigated at various Richardson numbers. Three dimensional governing equations are discretized by the finite-volume technique. Based on the obtained results the dimples-protrusions arrangements are modified to find a suitable configuration for which heat transfer coefficient and pressure drop to be balanced. Modified dimples-protrusions arrangements that shows higher performance is presented. Its average thermal performance 18% and 11% is higher than the other arrangements. In addition, the results show that roughening a smooth tube is more effective at the higher Richardson number.

Precision-Trimming 2D Inverse-Opal Lattice on Elastomer to Ordered Nanostructures with Variable Size and Morphology.

PubMed

Zhan, Haoran; Chen, Yanqiu; Liu, Yu; Lau, Woonming; Bao, Chao; Li, Minggan; Lu, Yunlong; Mei, Jun; Hui, David

2017-05-23

A low-cost and scalable method is developed for producing large-area elastomer surfaces having ordered nanostructures with a variety of lattice features controllable to nanometer precision. The method adopts the known technique of molding a PDMS precursor film with a close-packed monolayer of monodisperse submicron polystyrene beads on water to form an inverse-opal dimple lattice with the dimple size controlled by the bead selection and the dimple depth by the molding condition. The subsequent novel precision engineering of the inverse-opal lattice comprises trimming the PDMS precursor by a combination of polymer curing temperature/time and polymer dissolution parameters. The resultant ordered surface nanostructures, fabricated with an increasing degree of trimming, include (a) submicron hemispherical dimples with nanothin interdimple rims and walls; (b) nanocones with variable degrees of tip-sharpness by trimming off the top part of the nanothin interdimple walls; and (c) soup-plate-like submicron shallow dimples with interdimple rims and walls by anisotropically trimming off the nanocones and forming close-packed shallow dimples. As exemplars of industrial relevance of these lattice features, tunable Young's modulus and wettability are demonstrated.

Tribological investigation of diamond-like carbon coated micro-dimpled surface under bovine serum and osteoarthritis oriented synovial fluid

NASA Astrophysics Data System (ADS)

Ghosh, Subir; Choudhury, Dipankar; Roy, Taposh; Mamat, Azuddin Bin; Masjuki, H. H.; Pingguan-Murphy, Belinda

2015-06-01

Osteoarthritis-oriented synovial fluid (OASF), i.e., that typical of a patient with osteoarthritis, has different physical and biological characteristics than bovine serum (BS), a lubricant widely used in biotribological investigations. Micro-dimpled and diamond-like carbon- (DLC) coated surfaces are key emerging interfaces for orthopedic implants. In this study, tribological performances of dimpled surfaces, with and without DLC coating, have been investigated under both BS and OASF. The friction tests were performed utilizing a pin on a disk tribometer, whereas contact pressure, speed, and temperature were simulated to a ‘medium walking gait’ of hip joint conditions. The mechanical properties of the specimen and the physical properties of the lubricant were characterized before the friction test. Raman analysis was conducted to identify the coating condition both before and after the test. The DLC-coated dimpled surface showed maximum hardness and residual stress. A DLC-coated dimpled surface under an OASF lubricated condition yielded a lower friction coefficient and wear compared to those of plain and dimpled specimens. The higher graphitization of coated materials with increasing load was confirmed by Raman spectroscopy.

Tribological investigation of diamond-like carbon coated micro-dimpled surface under bovine serum and osteoarthritis oriented synovial fluid

PubMed Central

Ghosh, Subir; Choudhury, Dipankar; Roy, Taposh; Bin Mamat, Azuddin; Masjuki, H H; Pingguan-Murphy, Belinda

2015-01-01

Osteoarthritis-oriented synovial fluid (OASF), i.e., that typical of a patient with osteoarthritis, has different physical and biological characteristics than bovine serum (BS), a lubricant widely used in biotribological investigations. Micro-dimpled and diamond-like carbon- (DLC) coated surfaces are key emerging interfaces for orthopedic implants. In this study, tribological performances of dimpled surfaces, with and without DLC coating, have been investigated under both BS and OASF. The friction tests were performed utilizing a pin on a disk tribometer, whereas contact pressure, speed, and temperature were simulated to a ‘medium walking gait’ of hip joint conditions. The mechanical properties of the specimen and the physical properties of the lubricant were characterized before the friction test. Raman analysis was conducted to identify the coating condition both before and after the test. The DLC-coated dimpled surface showed maximum hardness and residual stress. A DLC-coated dimpled surface under an OASF lubricated condition yielded a lower friction coefficient and wear compared to those of plain and dimpled specimens. The higher graphitization of coated materials with increasing load was confirmed by Raman spectroscopy. PMID:27877803

Study of Dimple Effect on the Friction Characteristics of a Journal Bearing using Taguchi Method

NASA Astrophysics Data System (ADS)

Murthy, A. Amar; Raghunandana, Dr.

2018-02-01

The effect of producing dimples using chemically etched techniques or by machining process on the surface of a journal bearing bushing to reduce the friction using Taguchi method is investigated. The data used in the present analysis is based on the results obtained by the series of experiments conducted to study the dimples effect on the Stribeck curve. It is statistically proved that producing dimples on the bushing surface of a journal bearing has significant effect on the friction coefficient when used with light oils. Also it is seen that there is an interaction effect between speeds-load and load-dimples. Hence the interaction effect, which are usually neglected should be considered during actual experiments that significantly contributes in reducing the friction in mixed lubrication regime. The experiments, if were conducted after Taguchi method, then the number of experiments would have been reduced to half of the actual set of experiments that were essentially conducted.

Spring/dimple instrument tube restraint

DOEpatents

DeMario, Edmund E.; Lawson, Charles N.

1993-01-01

A nuclear fuel assembly for a pressurized water nuclear reactor has a spring and dimple structure formed in a non-radioactive insert tube placed in the top of a sensor receiving instrumentation tube thimble disposed in the fuel assembly and attached at a top nozzle, a bottom nozzle, and intermediate grids. The instrumentation tube thimble is open at the top, where the sensor or its connection extends through the cooling water for coupling to a sensor signal processor. The spring and dimple insert tube is mounted within the instrumentation tube thimble and extends downwardly adjacent the top. The springs and dimples restrain the sensor and its connections against lateral displacement causing impact with the instrumentation tube thimble due to the strong axial flow of cooling water. The instrumentation tube has a stainless steel outer sleeve and a zirconium alloy inner sleeve below the insert tube adjacent the top. The insert tube is relatively non-radioactivated inconel alloy. The opposed springs and dimples are formed on diametrically opposite inner walls of the insert tube, the springs being formed as spaced axial cuts in the insert tube, with a web of the insert tube between the cuts bowed radially inwardly for forming the spring, and the dimples being formed as radially inward protrusions opposed to the springs.

Spring/dimple instrument tube restraint

DOEpatents

DeMario, E.E.; Lawson, C.N.

1993-11-23

A nuclear fuel assembly for a pressurized water nuclear reactor has a spring and dimple structure formed in a non-radioactive insert tube placed in the top of a sensor receiving instrumentation tube thimble disposed in the fuel assembly and attached at a top nozzle, a bottom nozzle, and intermediate grids. The instrumentation tube thimble is open at the top, where the sensor or its connection extends through the cooling water for coupling to a sensor signal processor. The spring and dimple insert tube is mounted within the instrumentation tube thimble and extends downwardly adjacent the top. The springs and dimples restrain the sensor and its connections against lateral displacement causing impact with the instrumentation tube thimble due to the strong axial flow of cooling water. The instrumentation tube has a stainless steel outer sleeve and a zirconium alloy inner sleeve below the insert tube adjacent the top. The insert tube is relatively non-radioactivated inconel alloy. The opposed springs and dimples are formed on diametrically opposite inner walls of the insert tube, the springs being formed as spaced axial cuts in the insert tube, with a web of the insert tube between the cuts bowed radially inwardly for forming the spring, and the dimples being formed as radially inward protrusions opposed to the springs. 7 figures.

On the origin of the drag force on golf balls

NASA Astrophysics Data System (ADS)

Balaras, Elias; Beratlis, Nikolaos; Squires, Kyle

2017-11-01

It is well establised that dimples accelerate the drag-crisis on a sphere. The result of the early drag-crisis is a reduction of the drag coefficient by more than a factor of two when compared to a smooth sphere at the same Reynolds number. However, when the drag coefficients for smooth and dimpled spheres in the supercritical regime are compared, the latter is higher by a factor of two to three. To understand the origin of this behavior we conducted direct numerical simulations of the flow around a dimpled sphere, which is similar to commercially available golf balls, in the supercritical regime. By comparing the results to those for a smooth sphere it is found that dimples, although effective in accelerating the drag crisis, impose a local drag-penalty, which contributes significantly to the overall drag force. This finding challenges the broadly accepted view, that the dimples only indirectly affect the drag force on a golf ball by manipulating the structure of the turbulent boundary layer near the wall and consequently affect global separation. Within this view, typically the penalty on the drag force imposed by the dimples is assumed to be small and coming primarily from skin friction. The direct numerical simulations we will report reveal a very different picture.

Characterisation of group behaviour surface texturing with multi-layers fitting method

NASA Astrophysics Data System (ADS)

Kang, Zhengyang; Fu, Yonghong; Ji, Jinghu; Wang, Hao

2016-07-01

Surface texturing was widely applied in improving the tribological properties of mechanical components, but study of measurement of this technology was still insufficient. This study proposed the multi-layers fitting (MLF) method to characterise the dimples array texture surface. Based on the synergistic effect among the dimples, the 3D morphology of texture surface was rebuilt by 2D stylus profiler in the MLF method. The feasible regions of texture patterns and sensitive parameters were confirmed by non-linear programming, and the processing software of MLF method was developed based on the Matlab®. The characterisation parameters system of dimples was defined mathematically, and the accuracy of MLF method was investigated by comparison experiment. The surface texture specimens were made by laser surface texturing technology, in which high consistency of dimples' size and distribution was achieved. Then, 2D profiles of different dimples were captured by employing Hommel-T1000 stylus profiler, and the data were further processed by MLF software to rebuild 3D morphology of single dimple. The experiment results indicated that the MLF characterisation results were similar to those of Wyko T1100, the white light interference microscope. It was also found that the stability of MLF characterisation results highly depended on the number of captured cross-sections.

Recombination of an intrachromosomal paracentric insertion of chromosome 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Best, R.G.; Burnett, W.J.; Brock, J.K.

1994-09-01

Cytogenetic studies were initiated on a newborn female due to multiple congenital anomalies including microcephaly, clinodactyly, abnormal positioning of hands, left facial palsy, heart defect, sacral dimple, and facial dysmorphic features. Facial features were described as low set rotated ears, nystagmus, and a small, flattened nose. A structural rearrangement of the long arm of chromosome 3 was observed with a complex banding pattern. Study of parental chromosomes revealed a normal male pattern for the father, and an intrachromosomal insertion on the long arm of chromosome 3 for the mother described as 46,XX,dir ins(3)(q21q23q26.2). Further characterization of the proband`s structurally abnormalmore » chromosome 3 revealed a karyotype best described as: 46,XX,rec(3),dupq23{r_arrow}q26.2::q21{r_arrow}q23,dir ins(3)(q21q23q26.2), which is a partial duplication of both the inserted segment as well as the intervening segment between the inserted segment and the insertion site. This would appear to be the result of a three-strand double cross-over within the insertion loop. Molecular cytogenetic studies are presently underway to further elucidate chromosome structure of the proband and her mother.« less

The Effect of Offloading Heels on Sacral Pressure.

PubMed

Al-Majid, Sadeeka; Vuncanon, Barbara; Carlson, Nika; Rakovski, Cyril

2017-09-01

Offloading a patient's heels during supine surgical procedures is a common practice to prevent heel pressure injuries. This practice may increase sacral pressure and jeopardize sacral skin integrity, but prophylactic dressings may help protect sacral skin. The purpose of this study was to examine the effects of offloading the heels and of multilayered silicone foam dressings on sacral pressure. We measured the sacral pressure of 50 healthy volunteers using a pressure-mapping system under four conditions: heels not offloaded and sacral dressing applied, heels offloaded and dressing applied, heels not offloaded and no dressing, and heels offloaded and no dressing. We used linear mixed-effects modeling to compare the effects of these conditions on sacral pressure. Offloading the heels significantly increased sacral pressure (P < .001), whereas the dressing had no effect on sacral pressure (P = .49). Offloading a patient's heels may increase the risk of sacral pressure injuries. Copyright © 2017 AORN, Inc. Published by Elsevier Inc. All rights reserved.

Evaluation of Wear on Macro-Surface Textures Generated by ns Fiber Laser

NASA Astrophysics Data System (ADS)

Harish, V.; Soundarapandian, S.; Vijayaraghavan, L.; Bharatish, A.

2018-03-01

The demand for improved performance and long term reliability of mechanical systems dictate the use of advanced materials and surface engineering techniques. A small change in the surface topography can lead to substantial improvements in the tribological behaviour of the contact surfaces. One way of altering the surface topography is by surface texturing by introducing dimples or channels on the surfaces. Surface texturing is already a successful technique which finds a wide area of applications ranging from heavy industries to small scale devices. This paper reports the effect of macro texture shapes generated using a nanosecond fiber laser on wear of high carbon chromium steel used in large size bearings having rolling contacts. Circular and square shaped dimples were generated on the surface to assess the effect of sliding velocities on friction coefficient. Graphite was used as solid lubricant to minimise the effect of wear on textured surfaces. The laser parameters such as power, scan speed and passes were optimised to obtain macro circular and square dimples which was characterised using a laser confocal microscope. The friction coefficients of the circular and square dimples were observed to lie in the same range due to minimum wear on the surface. On the contrary, at medium and higher sliding velocities, square dimples exhibited lower friction coefficient values compared to circular dimples. The morphology of textured specimen was characterised using Scanning Electron Microscope.

Simulations of laminar boundary-layer flow encountering large-scale surface indentions

NASA Astrophysics Data System (ADS)

Beratlis, N.; Balaras, E.; Squires, K.; Vizard, A.

2016-03-01

The transition from laminar to turbulent flow over dimples and grooves has been investigated through a series of direct numerical simulations. Emphasis has been given to the mechanism of transition and the momentum transport in the post-dimple boundary layer. It has been found that the dimple geometry plays an important role in the evolution of the turbulent boundary layer downstream. The mechanism of transition in all cases is that of the reorientation of the spanwise vorticity into streamwise oriented structures resembling hairpin vortices commonly encountered in wall bounded turbulent flows. Although qualitatively the transition mechanism amongst the three different cases is similar, important quantitative differences exist. It was shown that two-dimensional geometries like a groove are more stable than three-dimensional geometries like a dimple. In addition, it was found that the cavity geometry controls the initial thickness of the boundary layer and practically results in a shift of the virtual origin of the turbulent boundary layer. Important differences in the momentum transport downstream of the dimples exist but in all cases the boundary layer grows in a self-similar manner.

Pilonidal dimple

MedlinePlus

... cancer. Pilonidal dimple may appear as: A pilonidal abscess , in which the hair follicle becomes infected and ... or hole forms if there has been an abscess for a long time A pilonidal sinus, in ...

Surface Texturing of Polyimide Composite by Micro-Ultrasonic Machining

NASA Astrophysics Data System (ADS)

Qu, N. S.; Zhang, T.; Chen, X. L.

2018-03-01

In this study, micro-dimples were prepared on a polyimide composite surface to obtain the dual benefits of polymer materials and surface texture. Micro-ultrasonic machining is employed for the first time for micro-dimple fabrication on polyimide composite surfaces. Surface textures of simple patterns were fabricated successfully with dimple depths of 150 μm, side lengths of 225-425 μm, and area ratios of 10-30%. The friction coefficient of the micro-dimple surfaces with side lengths of 325 or 425 μm could be increased by up to 100% of that of non-textured surfaces, alongside a significant enhancement of wear resistance. The results show that surface texturing of polyimide composite can be applied successfully to increase the friction coefficient and reduce wear, thereby contributing to a large output torque.

Muscle-splitting approach to superior and inferior gluteal vessels: versatile source of recipient vessels for free-tissue transfer to sacral, gluteal, and ischial regions.

PubMed

Park, S

2000-07-01

The superior gluteal vessel has been reported as a recipient in free-tissue transfer for the coverage of complex soft-tissue defects in the lumbosacral region, where a suitable recipient vessel is difficult to find. The characteristics of proximity, vessel caliber, and constancy make the superior gluteal vessel preferable to previously reported recipient vessels. However, there are technical difficulties in microsurgery (e.g., short pedicle length and deep location) and muscle injury (transection of the muscle) associated with use of the superior gluteal vessel. The purpose of this article is to present a modification of an approach to the gluteal vessel to alleviate technical difficulties and minimize muscle injury. From August of 1997 to January of 1999, six patients received microvascular transfer of the latissimus dorsi muscle or myocutaneous flap to the sacral (4) and ischial (2) regions. The causes of defects were tumor (1), trauma (1), and pressure sores (4). A muscle-splitting approach was used on the superior gluteal vessel and was later applied to the inferior gluteal vessel. The gluteus maximus muscle was split as needed in the direction of its fibers, and the perforators were dissected down to the superior or inferior gluteal artery and vein deep into the muscle. The follow-up period ranged from 6 to 22 months, and all of the flaps survived with complete recovery of the lesion. The major drawbacks of using the superior and inferior gluteal vessels can be overcome with the muscle-splitting approach, which provides increased accessibility and additional length to the vascular pedicle while causing minimal injury to the muscle itself. It also proves to be an easy, safe, and reliable method of dissection. When free-tissue transfer to sacral, gluteal, and ischial regions is indicated, the muscle-splitting approach to the superior and inferior gluteal vessels is a recommended option in the selection of a recipient vessel.

Design modification of airfoil by integrating sinusoidal leading edge and dimpled surface

NASA Astrophysics Data System (ADS)

Masud, M. H.; Naim-Ul-Hasan, Arefin, Amit Md. Estiaque; Joardder, Mohammad U. H.

2017-06-01

Airfoil is widely used for aircraft wings and blades of helicopters, turbines, propellers, fans and compressors. Many researches have been conducted on focusing the leading edge, surface and trailing edge of airfoil in order to maximize airfoil lift and to reduce drag. Literature shows that using protuberances along the leading edge of NACA 2412, it is possible to attain better performance from the baseline. Besides, the inward dimpled surface of NACA 0018 produces lesser drag at a positive angle of attacks. However, there is no literature that integrates sinusoidal leading edge and dimpled to attain the benefits of the both. In this study, simulation has been done for design improvement of airfoil by integrating sinusoidal leading edge and dimpled surface. Simulations have been run using finite element method environment. Significant improvement has been observed from the simulation results.

The impact of surface and geometry on coefficient of friction of artificial hip joints.

PubMed

Choudhury, Dipankar; Vrbka, Martin; Mamat, Azuddin Bin; Stavness, Ian; Roy, Chanchal K; Mootanah, Rajshree; Krupka, Ivan

2017-08-01

Coefficient of friction (COF) tests were conducted on 28-mm and 36-mm-diameter hip joint prostheses for four different material combinations, with or without the presence of Ultra High Molecular Weight Polyethylene (UHMWPE) particles using a novel pendulum hip simulator. The effects of three micro dimpled arrays on femoral head against a polyethylene and a metallic cup were also investigated. Clearance played a vital role in the COF of ceramic on polyethylene and ceramic on ceramic artificial hip joints. Micro dimpled metallic femoral heads yielded higher COF against a polyethylene cup; however, with metal on metal prostheses the dimpled arrays significantly reduced the COF. In situ images revealed evidence that the dimple arrays enhanced film formation, which was the main mechanism that contributed to reduced friction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Flight trajectory of a rotating golf ball with grooves

NASA Astrophysics Data System (ADS)

Baek, Moonheum; Kim, Jooha; Choi, Haecheon

2014-11-01

Dimples are known to reduce drag on a sphere by the amount of 50% as compared to a smooth surface. Despite the advantage of reducing drag, dimples deteriorate the putting accuracy owing to their sharp edges. To minimize this putting error but maintain the same flight distance, we have devised a grooved golf ball (called G ball hereafter) for several years. In this study, we modify the shape and pattern of grooves, and investigate the flow characteristics of the G ball by performing wind-tunnel experiments at the Reynolds numbers of 0 . 5 ×105 - 2 . 5 ×105 and the spin ratios (ratio of surface velocity to the free-stream velocity) of 0 - 0.6 that include the real golf-ball velocity and rotational speed. We measure the drag and lift forces on the rotating G ball and compare them with those of a smooth ball and two well-known dimpled balls. The lift-to-drag ratio of the G ball is much higher than that of a smooth ball and is in between those of the two dimpled balls. The trajectories of flying golf balls are computed. The flight distance of G ball is almost the same as that of one dimpled ball but slightly shorter than that of the other dimpled ball. The fluid-dynamic aspects of these differences will be discussed at the talk. Supported by 2011-0028032, 2014M3C1B1033980.

Anatomic parameters of the sacral lamina for osteosynthesis in transverse sacral fractures.

PubMed

Katsuura, Yoshihiro; Lorenz, Eileen; Gardner, Warren

2018-05-01

To analyze the morphometric parameters of the dorsal sacral lamina and pedicles to determine if there is adequate bony architecture to support plate osteosynthesis. Two reviewers performed measurements on 98 randomly selected high-resolution CT scans of the pelvis to quantify the bony anatomy of the sacral lamina. Measurements included the depths of the lamina at each sacral level, the trajectory and depth of the sacral pedicles from the sacral lamina, and the width of the sacral canal. A bone mineral density analysis was performed on the sacral lamina using Hounsfield units (HU) and compared to the L1 and S1 vertebral bodies. The sacral lamina were found to form peaks and troughs which we refered to as major and minor sections. On average, the thickness was > 4 mm at all major screw starting points, indicating adequate geometry for screw fixation. The sacral pedicle depths were 27, 18, 16, and 14 mm at S2-S5, respectively. The average angulation from midline of this screw path directed laterally to avoid the sacral canal was 20°, 17°, 8°, and - 8° for the S2-5 pedicles, respectively. Average sacral canal diameter was 11 mm for S2 and 8 mm for S3-5. The sacral lamina had an average bone mineral density of 635 HU, which was significantly different from the density of the L5 (220 HU) and S1 (165 HU) vertebral bodies (p < 0.005). This morphometric data was used to pilot a new plating technique. The sacral lamina offers a novel target for screw fixation and meets the basic geometric and compositional criteria for screw purchase. To our knowledge, this study represents the first morphometric analysis performed on the sacral lamina and pedicles for plate application.

Effectiveness of fins formed by dimples in the form of ball segments

NASA Astrophysics Data System (ADS)

Gabdrakhmanov, E. A.; Afonin, G. N.; Glazov, V. S.

2017-11-01

One of the famous ways to improve efficiency of a heat exchanger is associated with the topography of the surfaces being in contact with coolants. So, use of hemispherical dimples leads to progressive growth of the relative heat transfer coefficient compared to increase of the relative resistance coefficient. Usually a plate having the spherical dimple intensifiers for heat transfer is considered as a flat one with embedded cavities. However, such a plate can be also considered as the plate with inbuilt fins which are formed by dimples in the form of ball segments. Given that for the flow of fluid (gas) from left to right, the minimum local heat transfer enhancement occurs in the first (left) half of the dimples, and the maximum falls on the edge of the second (right) half, we obtained an analytical solution describing the temperature distribution along the height of the fin. In the solution we used the Harper-Brown approach. Presented are the results of the calculation of the efficiency of the surface on the parameters of the considered fin and on a known value of the average heat transfer coefficient corresponding to the stage of the fluid flow steady state.

Identification of Viral MicroRNAs Expressed in Human Sacral Ganglia Latently Infected with Herpes Simplex Virus 2▿

PubMed Central

Umbach, Jennifer L.; Wang, Kening; Tang, Shuang; Krause, Philip R.; Mont, Erik K.; Cohen, Jeffrey I.; Cullen, Bryan R.

2010-01-01

Deep sequencing of small RNAs isolated from human sacral ganglia latently infected with herpes simplex virus 2 (HSV-2) was used to identify HSV-2 microRNAs (miRNAs) expressed during latent infection. This effort resulted in the identification of five distinct HSV-2 miRNA species, two of which, miR-H3/miR-I and miR-H4/miR-II, have been previously reported. Three novel HSV-2 miRNAs were also identified, and two of these, miR-H7 and miR-H9, are derived from the latency-associated transcript (LAT) and are located antisense to the viral transcript encoding transactivator ICP0. A third novel HSV-2 miRNA, miR-H10, is encoded within the unique long (UL) region of the genome, 3′ to the UL15 open reading frame, and is presumably excised from a novel, latent HSV-2 transcript distinct from LAT. PMID:19889786

Identification of viral microRNAs expressed in human sacral ganglia latently infected with herpes simplex virus 2.

PubMed

Umbach, Jennifer L; Wang, Kening; Tang, Shuang; Krause, Philip R; Mont, Erik K; Cohen, Jeffrey I; Cullen, Bryan R

2010-01-01

Deep sequencing of small RNAs isolated from human sacral ganglia latently infected with herpes simplex virus 2 (HSV-2) was used to identify HSV-2 microRNAs (miRNAs) expressed during latent infection. This effort resulted in the identification of five distinct HSV-2 miRNA species, two of which, miR-H3/miR-I and miR-H4/miR-II, have been previously reported. Three novel HSV-2 miRNAs were also identified, and two of these, miR-H7 and miR-H9, are derived from the latency-associated transcript (LAT) and are located antisense to the viral transcript encoding transactivator ICP0. A third novel HSV-2 miRNA, miR-H10, is encoded within the unique long (U(L)) region of the genome, 3' to the U(L)15 open reading frame, and is presumably excised from a novel, latent HSV-2 transcript distinct from LAT.

Laser dimpling process parameters selection and optimization using surrogate-driven process capability space

NASA Astrophysics Data System (ADS)

Ozkat, Erkan Caner; Franciosa, Pasquale; Ceglarek, Dariusz

2017-08-01

Remote laser welding technology offers opportunities for high production throughput at a competitive cost. However, the remote laser welding process of zinc-coated sheet metal parts in lap joint configuration poses a challenge due to the difference between the melting temperature of the steel (∼1500 °C) and the vapourizing temperature of the zinc (∼907 °C). In fact, the zinc layer at the faying surface is vapourized and the vapour might be trapped within the melting pool leading to weld defects. Various solutions have been proposed to overcome this problem over the years. Among them, laser dimpling has been adopted by manufacturers because of its flexibility and effectiveness along with its cost advantages. In essence, the dimple works as a spacer between the two sheets in lap joint and allows the zinc vapour escape during welding process, thereby preventing weld defects. However, there is a lack of comprehensive characterization of dimpling process for effective implementation in real manufacturing system taking into consideration inherent changes in variability of process parameters. This paper introduces a methodology to develop (i) surrogate model for dimpling process characterization considering multiple-inputs (i.e. key control characteristics) and multiple-outputs (i.e. key performance indicators) system by conducting physical experimentation and using multivariate adaptive regression splines; (ii) process capability space (Cp-Space) based on the developed surrogate model that allows the estimation of a desired process fallout rate in the case of violation of process requirements in the presence of stochastic variation; and, (iii) selection and optimization of the process parameters based on the process capability space. The proposed methodology provides a unique capability to: (i) simulate the effect of process variation as generated by manufacturing process; (ii) model quality requirements with multiple and coupled quality requirements; and (iii) optimize process parameters under competing quality requirements such as maximizing the dimple height while minimizing the dimple lower surface area.

A stereological analysis of ductile fracture by microvoid coalescence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steele, J.H., Jr.

A stereological analysis for ductile fracture by microvoid coalescence is presented based upon the model of Widgery and Knott which postulates that microvoids link with a propagating crack if they lie within a certain interaction distance of its plane. A 3- dimensional analytical expression for dimple density and shape is developed from this model using projected image relationships for a thin slab. Void nucleation and growth are incorporated into the analysis using numerical integration of the Rice-Tracey growth equation over the appropriate strain range. An evaluation of the stereological approach is given using tensile data from a spheroidized 1045 steelmore » to predict the effect of hydrostatic pressure upon the dimple density. The analysis, which is consistent with observed correlations between dimple density and second phase particle density, is shown to provide an estimate of dimple size and microroughness parameter used in local stain models for microvoid coalescence. 24 refs., 10 figs.« less

Use of DES in mildly separated internal flow: dimples in a turbulent channel

NASA Astrophysics Data System (ADS)

Tay, Chien Ming Jonathan; Khoo, Boo Cheong; Chew, Yong Tian

2017-12-01

Detached eddy simulation (DES) is investigated as a means to study an array of shallow dimples with depth to diameter ratios of 1.5% and 5% in a turbulent channel. The DES captures large-scale flow features relatively well, but is unable to predict skin friction accurately due to flow modelling near the wall. The current work instead relies on the accuracy of DES to predict large-scale flow features, as well as its well-documented reliability in predicting flow separation regions to support the proposed mechanism that dimples reduce drag by introducing spanwise flow components near the wall through the addition of streamwise vorticity. Profiles of the turbulent energy budget show the stabilising effect of the dimples on the flow. The presence of flow separation however modulates the net drag reduction. Increasing the Reynolds number can reduce the size of the separated region and experiments show that this increases the overall drag reduction.

Sacral Fractures and Associated Injuries

PubMed Central

Kurd, Mark F.; Schroeder, Gregory D.; Kepler, Christopher K.; Krieg, James C.; Holstein, Jörg H.; Bellabarba, Carlo; Firoozabadi, Reza; Oner, F. Cumhur; Kandziora, Frank; Dvorak, Marcel F.; Kleweno, Conor P.; Vialle, Luiz R.; Rajasekaran, S.; Schnake, Klause J.; Vaccaro, Alexander R.

2017-01-01

Study Design: Literature review. Objective: The aim of this review is to describe the injuries associated with sacral fractures and to analyze their impact on patient outcome. Methods: A comprehensive narrative review of the literature was performed to identify the injuries associated with sacral fractures. Results: Sacral fractures are uncommon injuries that result from high-energy trauma, and that, due to their rarity, are frequently underdiagnosed and mistreated. Only 5% of sacral fractures occur in isolation. Injuries most often associated with sacral fractures include neurologic injuries (present in up to 50% of sacral fractures), pelvic ring disruptions, hip and lumbar spine fractures, active pelvic/ abdominal bleeding and the presence of an open fracture or significant soft tissue injury. Diagnosis of pelvic ring fractures and fractures extending to the lumbar spine are key factors for the appropriate management of sacral fractures. Importantly, associated systemic (cranial, thoracic, and abdominopelvic) or musculoskeletal injuries should be promptly assessed and addressed. These associated injuries often dictate the management and eventual outcome of sacral fractures and, therefore, any treatment algorithm should take them into consideration. Conclusions: Sacral fractures are complex in nature and often associated with other often-missed injuries. This review summarizes the most relevant associated injuries in sacral fractures and discusses on their appropriate management. PMID:28989838

Retrospective approach to methylenetetrahydrofolate reductase mutations in children.

PubMed

Özer, Işıl; Özçetin, Mustafa; Karaer, Hatice; Kurt, Semiha G; Şahin, Şemsettin

2011-07-01

Methylenetetrahydrofolate reductase reduces methyltetrahydrofolate, a cosubstrate in the remethylation of homocysteine, from methylenetetrahydrofolate. Congenital defects, hematologic tumors, and intrauterine growth retardation can occur during childhood. This study evaluated clinical and laboratory treatment approaches in children diagnosed with methylenetetrahydrofolate reductase mutations. Our group included 23 boys and 14 girls, aged 103.4 ± 70.8 months S.D. Clinical findings of patients and homocysteine, vitamin B12, folate, hemogram, electroencephalography, cranial magnetic resonance imaging, and echocardiography data were evaluated in terms of treatment approach. Our patients' findings included vitamin B12 at 400.4 ± 224.6 pg/mL S.D. (normal range, 300-700 pg/mL), folate at 10.1 ± 4.5 ng/mL S.D. (normal range, 1.8-9 ng/mL), and homocysteine at 8.4 ± 4.7 μmol/L S.D. (normal range, 5.5-17 μmol/L). Eighty-eight percent of patients demonstrated clinical findings. In comparisons involving categorical variables between groups, χ(2) tests were used. No relationship was evident between mutation type, laboratory data, and clinical severity. All mothers who had MTHFR mutations and had babies with sacral dimples had taken folate supplements during pregnancy. To avoid the risk of neural tube defects, pregnant women with a MTHFR mutation may require higher than normally recommended doses of folic acid supplementation for optimum health. Copyright © 2011 Elsevier Inc. All rights reserved.

Follow-up of an intelligent odd-mannered teenager with del(3)(p26). Remarks on authorship and ethical commitment.

PubMed

Rivera, H; Domínguez, M G; Matute, E

2006-01-01

A male teenager formerly found to have a 46,XY,del(3)(p26)de novo karyotype was restudied. At the age of 14(8/12) yr, he attends the last grade of middle school and was a cooperating teenager with slender habitus, severe myopia, prominent nose, sacral dimples, pubertal stage Tanner III, and multiple surgical scars. Neuropsychological studies revealed a full scale IQ of 95 with slow performance (WISC-IV Spanish test) as well as an internalizing behavioral profile, poor social skills, a mild attention deficit, somatic complaints, and a feminized gender role. FISH with the 3p subtelomeric probe revealed that the deleted chromosome actually lacked the specific signal (n=10 cells). The patient's average intelligence confirms that euchromatic imbalances do not necessarily cause mental retardation and suggests that his deletion actually included the CALL gene, the Contactin 4 gene and other 3p26 genes related to intellectual capabilities; yet, the resulting hemizygosity either did not lead to haploinsufficiency or was minimally expressed. Moreover, the patient's peculiar cognitive and behavioral profile suggests that the 3p26 deletion is associated with a distinctive neuropsychological phenotype. Incidentally we comment on authorship and publication ethics in order to urge our institutional ethics committee to arbitrate authorship conflicts and thereby be consistent with its ethical commitment.

Numerical study on the lubrication performance of compression ring-cylinder liner system with spherical dimples

PubMed Central

Liu, Cheng; Zhang, Yong-Fang; Li, Sha; Müller, Norbert

2017-01-01

The effects of surface texture on the lubrication performance of a compression ring-cylinder liner system are studied in this paper. By considering the surface roughness of the compression ring and cylinder liner, a mixed lubrication model is presented to investigate the tribological behaviors of a barrel-shaped compression ring-cylinder liner system with spherical dimples on the liner. In order to determine the rupture and reformulation positions of fluid film accurately, the Jacoboson-Floberg-Olsson (JFO) cavitation boundary condition is applied to the mixed lubrication model for ensuring the mass-conservative law. On this basis, the minimum oil film thickness and average friction forces in the compression ring-cylinder liner system are investigated under the engine-like conditions by changing the dimple area density, radius, and depth. The wear load, average friction forces, and power loss of the compression ring-cylinder liner system with and without dimples are also compared for different compression ring face profiles. The results show that the spherical dimples can produce a larger reduction of friction in mixed lubrication region, and reduce power loss significantly in the middle of the strokes. In addition, higher reduction percentages of average friction forces and wear are obtained for smaller crown height or larger axial width. PMID:28732042

Study of the flow field past dimpled aerodynamic surfaces: numerical simulation and experimental verification

NASA Astrophysics Data System (ADS)

Binci, L.; Clementi, G.; D'Alessandro, V.; Montelpare, S.; Ricci, R.

2017-11-01

This work presents the study of the flow field past of dimpled laminar airfoil. Fluid dynamic behaviour of these elements has been not still deeply studied in the scientific community. Therefore Computational Fluid-Dynamics (CFD) is here used to analyze the flow field induced by dimples on the NACA 64-014A laminar airfoil at Re = 1.75 · 105 at α = 0°. Reynolds Averaged Navier-Stokes (RANS) equations and Large-Eddy Simulations (LES) were compared with wind tunnel measurements in order to evaluate their effectiveness in the modeling this kind of flow field. LES equations were solved using a specifically developed OpenFOAM solver adopting an L-stable Singly Diagonally Implicit Runge-Kutta (SDIRK) technique with an iterated PISO-like procedure for handling pressure-velocity coupling within each RK stage. Dynamic Smagorinsky subgrid model was employed. LES results provided good agreement with experimental data, while RANS equations closed with \\[k-ω -γ -\\overset{}{\\mathop{{{\\operatorname{Re}}θ, \\text{t}}}} \\] approach overstimates laminar separation bubble (LSB) extension of dimpled and un-dimpled configurations. Moreover, through skin friction coefficient analysis, we found a different representation of the turbulent zone between the numerical models; indeed, with RANS model LSB seems to be divided in two different parts, meanwhile LES model shows a LSB global reduction.

Radiosurgery and radiotherapy for sacral tumors.

PubMed

Gibbs, Iris C; Chang, Steven D

2003-08-15

Sacral tumors represent a small subset of spinal lesions and typically include chordomas, metastases, other primary bone tumors, and benign schwannomas. Resection is the standard treatment for many sacral tumors, but many types of sacral lesions have the potential for recurrence after excision. In these cases, adjuvant radiotherapy is often beneficial. Although conventional radiotherapy plays an important role in the management of spinal lesions, the radiation doses required for adequate local control of many sacral lesions generally exceed the tolerance doses of normal tissues, thus limiting its definitive role in the management of sacral tumors. Recent advances in the field of stereotactic radiosurgery have allowed precise targeting of the sacrum. In this report the authors review the use of these two forms of radiation treatment and their role in managing sacral tumors.

The evaluation of the micro-tracks and micro-dimples on the tribological characteristics of thrust ball bearings.

PubMed

Amanov, Auezhan; Pyoun, Young-Shik; Cho, In-Shik; Lee, Chang-Soon; Park, In-Gyu

2011-01-01

One of the primary remedies for tribological problems is surface modification. The reduction of the friction between the ball and the raceway of bearings is a very important goal of the development of bearing technology. A low friction has a positive effect in terms of the extension of the fatigue life, avoidance of a temperature rise, and prevention of premature failure of bearings. Therefore, this research sought to investigate the effects of micro-tracks and micro-dimples on the tribological characteristics at the contact point between the ball and the raceway of thrust ball bearings (TBBs). The ultrasonic nanocrystal surface modification (UNSM) technology was applied using different intervals (feed rates) to the TBB raceway surface to create micro-tracks and micro-dimples. The friction coefficient after UNSM at 50 microm intervals showed marked sensitivity and a significant reduction of 30%. In this study, the results showed that more micro-dimples yield a lower friction coefficient.

Latissimus dorsi free flap for coverage of sacral radiodermatitis in the ambulatory patient

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stark, D.; Tofield, J.J.; Terranova, W.

1987-07-01

Ambulatory patients with large sacral ulcers can represent extremely challenging coverage problems. Technical options become fewer when sacral ulcers are coupled with radiation dermatitis. Latissimus dorsi free flap transfer, with direct anastomoses to sacral vessels, is described in 2 patients.

Analysis of the Surface of Deposited Copper After Electroerosion Treatment

NASA Astrophysics Data System (ADS)

Ablyaz, T. R.; Simonov, M. Yu.; Shlykov, E. S.

2018-03-01

An electron microscope analysis of the surface of deposited copper is performed after a profiling-piercing electroerosion treatment. The deposited copper is treated with steel, duralumin, and copper electrode tools at different pulse energies. The treatment with the duralumin electrode produces on the treated surface a web-like structure and cubic-morphology polyhedral dimples about 10 μm in size. The main components of the surface treated with the steel electrode are developed polyhedral dimples with a size of 10 - 50 μm. After the treatment with the copper electrode the main components of the treated surface are large polyhedral dimples about 30 - 80 μm in size.

The receptor tyrosine kinase RET regulates hindgut colonization by sacral neural crest cells.

PubMed

Delalande, Jean-Marie; Barlow, Amanda J; Thomas, Aaron J; Wallace, Adam S; Thapar, Nikhil; Erickson, Carol A; Burns, Alan J

2008-01-01

The enteric nervous system (ENS) is formed from vagal and sacral neural crest cells (NCC). Vagal NCC give rise to most of the ENS along the entire gut, whereas the contribution of sacral NCC is mainly limited to the hindgut. This, and data from heterotopic quail-chick grafting studies, suggests that vagal and sacral NCC have intrinsic differences in their ability to colonize the gut, and/or to respond to signalling cues within the gut environment. To better understand the molecular basis of these differences, we studied the expression of genes known to be essential for ENS formation, in sacral NCC within the chick hindgut. Our results demonstrate that, as in vagal NCC, Sox10, EdnrB, and Ret are expressed in sacral NCC within the gut. Since we did not detect a qualitative difference in expression of these ENS genes we performed DNA microarray analysis of vagal and sacral NCC. Of 11 key ENS genes examined from the total data set, Ret was the only gene identified as being highly differentially expressed, with a fourfold increase in expression in vagal versus sacral NCC. We also found that over-expression of RET in sacral NCC increased their ENS developmental potential such that larger numbers of cells entered the gut earlier in development, thus promoting the fate of sacral NCC towards that of vagal NCC.

Risk factors for explantation due to infection after sacral neuromodulation: a multicenter retrospective case-control study.

PubMed

Myer, Emily N B; Petrikovets, Andrey; Slocum, Paul D; Lee, Toy Gee; Carter-Brooks, Charelle M; Noor, Nabila; Carlos, Daniela M; Wu, Emily; Van Eck, Kathryn; Fashokun, Tola B; Yurteri-Kaplan, Ladin; Chen, Chi Chiung Grace

2018-04-07

Sacral neuromodulation is an effective therapy for overactive bladder, urinary retention, and fecal incontinence. Infection after sacral neurostimulation is costly and burdensome. Determining optimal perioperative management strategies to reduce the risk of infection is important to reduce this burden. We sought to identify risk factors associated with sacral neurostimulator infection requiring explantation, to estimate the incidence of infection requiring explantation, and identify associated microbial pathogens. This is a multicenter retrospective case-control study of sacral neuromodulation procedures completed from Jan. 1, 2004, through Dec. 31, 2014. We identified all sacral neuromodulation implantable pulse generator implants as well as explants due to infection at 8 participating institutions. Cases were patients who required implantable pulse generator explantation for infection during the review period. Cases were included if age ≥18 years old, follow-up data were available ≥30 days after implantable pulse generator implant, and the implant was performed at the institution performing the explant. Two controls were matched to each case. These controls were the patients who had an implantable pulse generator implanted by the same surgeon immediately preceding and immediately following the identified case who met inclusion criteria. Controls were included if age ≥18 years old, no infection after implantable pulse generator implant, follow-up data were available ≥180 days after implant, and no explant for any reason <180 days from implant. Controls may have had an explant for reasons other than infection at >180 days after implant. Fisher exact test (for categorical variables) and Student t test (for continuous variables) were used to test the strength of the association between infection and patient and surgery characteristics. Significant variables were then considered in a multivariable logistic regression model to determine risk factors independently associated with infection. Over a 10-year period at 8 academic institutions, 1930 sacral neuromodulator implants were performed by 17 surgeons. In all, 38 cases requiring device explant for infection and 72 corresponding controls were identified. The incidence of infection requiring explant was 1.97%. Hematoma formation (13% cases, 0% controls; P = .004) and pocket depth of ≥3 cm (21% cases, 0% controls; P = .031) were independently associated with an increased risk of infection requiring explant. On multivariable regression analysis controlling for significant variables, both hematoma formation (P = .006) and pocket depth ≥3 cm (P = .020, odds ratio 3.26; 95% confidence interval, 1.20-8.89) remained significantly associated with infection requiring explant. Of the 38 cases requiring explant, 32 had cultures collected and 24 had positive cultures. All 5 cases with a hematoma had a positive culture (100%). Of the 4 cases with a pocket depth ≥3 cm, 2 had positive cultures, 1 had negative cultures, and 1 had a missing culture result. The most common organism identified was methicillin-resistant Staphylococcus aureus (38%). Infection after sacral neuromodulation requiring device explant is low. The most common infectious pathogen identified was methicillin-resistant S aureus. Demographic and health characteristics did not predict risk of explant due to infection, however, having a postoperative hematoma or a deep pocket ≥3 cm significantly increased the risk of explant due to infection. These findings highlight the importance of meticulous hemostasis as well as ensuring the pocket depth is <3 cm at the time of device implant. Copyright © 2018 Elsevier Inc. All rights reserved.

Complex sacral abscess 8 years after abdominal sacral colpopexy.

PubMed

Collins, Sarah A; Tulikangas, Paul K; LaSala, Christine A; Lind, Lawrence R

2011-08-01

Sacral colpopexy is an effective, durable repair for women with apical vaginal or uterovaginal prolapse. There are few reports of serious complications diagnosed in the remote postoperative period. A 74-year-old woman presented 8 years after undergoing posthysterectomy abdominal sacral colpopexy using polypropylene mesh. Posterior vaginal mesh erosion had been diagnosed several months before presentation. She suffered severe infectious complications including an infected thrombus in the inferior vena cava, sacral osteomyelitis, and a complex abscess with presacral and epidural components. Surgical exploration revealed an abscess cavity surrounding the mesh. Although minor complications commonly occur after sacral colpopexy using abdominal mesh, serious and rare postoperative infectious complications may occur years postoperatively.

Bilateral chronic sacral neuromodulation for treatment of lower urinary tract dysfunction.

PubMed

Hohenfellner, M; Schultz-Lampel, D; Dahms, S; Matzel, K; Thüroff, J W

1998-09-01

Chronic sacral neuromodulation aims at functional restoration of selected forms of nonneurogenic and neurogenic bladder dysfunction. The original technique, as described by Tanagho and Schmidt, provides unilateral sacral nerve stimulation via an implanted stimulator powering an electrode inserted into a sacral foramen. Its drawback was that the implant failed unpredictably in some patients despite previous successful percutaneous test stimulation. Therefore, we modified the stimulation technique to improve the efficacy of chronic sacral neuromodulation. Guarded bipolar electrodes powered by an implantable neurostimulator were attached bilaterally directly to the S3 nerves through a sacral laminectomy in 9 women and 2 men (mean age 43.4 years). Of the patients 5 had urinary incontinence due to detrusor hyperactivity and 6 had urinary retention from detrusor hypocontractility. Mean followup with repeated urodynamics was 13 months (range 9 to 28). Four significant complications were encountered in 4 patients. In 10 patients the urological sequelae of the neurological disorder were alleviated significantly (50% or more), including 5 who experienced complete relief of symptoms. The efficacy of chronic sacral neuromodulation can be improved by bilateral attachment of electrodes directly to the sacral nerves.

Diagnosis and treatment of posterior sacroiliac complex pain: a systematic review with comprehensive analysis of the published data.

PubMed

King, Wade; Ahmed, Shihab U; Baisden, Jamie; Patel, Nileshkumar; Kennedy, David J; Duszynski, Belinda; MacVicar, John

2015-02-01

To assess the evidence on the validity of sacral lateral branch blocks and the effectiveness of sacral lateral branch thermal radiofrequency neurotomy in managing sacroiliac complex pain. Systematic review with comprehensive analysis of all published data. Six reviewers searched the literature on sacral lateral branch interventions. Each assessed the methodologies of studies found and the quality of the evidence presented. The outcomes assessed were diagnostic validity and effectiveness of treatment for sacroiliac complex pain. The evidence found was appraised in accordance with the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system of evaluating scientific evidence. The searches yielded two primary publications on sacral lateral branch blocks and 15 studies of the effectiveness of sacral lateral branch thermal radiofrequency neurotomy. One study showed multisite, multidepth sacral lateral branch blocks can anesthetize the posterior sacroiliac ligaments. Therapeutic studies show sacral lateral branch thermal radiofrequency neurotomy can relieve sacroiliac complex pain to some extent. The evidence of the validity of these blocks and the effectiveness of this treatment were rated as moderate in accordance with the GRADE system. The literature on sacral lateral branch interventions is sparse. One study demonstrates the face validity of multisite, multidepth sacral lateral branch blocks for diagnosis of posterior sacroiliac complex pain. Some evidence of moderate quality exists on therapeutic procedures, but it is insufficient to determine the indications and effectiveness of sacral lateral branch thermal radiofrequency neurotomy, and more research is required. Wiley Periodicals, Inc.

Neurovascular risks of sacral screws with bicortical purchase: an anatomical study.

PubMed

Ergur, Ipek; Akcali, Omer; Kiray, Amac; Kosay, Can; Tayefi, Hamid

2007-09-01

The aim of this cadaver study is to define the anatomic structures on anterior sacrum, which are under the risk of injury during bicortical screw application to the S1 and S2 pedicles. Thirty formaldehyde-preserved human male cadavers were studied. Posterior midline incision was performed, and soft tissues and muscles were dissected from the posterior part of the lumbosacral region. A 6 mm pedicle screw was inserted between the superior facet of S1 and the S1 foramen. The entry point of the S2 pedicle screw was located between S1 and S2 foramina. S1 and S2 screws were placed on both right and the left sides of all cadavers. Then, all cadavers were turned into supine position. All abdominal and pelvic organs were moved away and carefully observed for any injury. The tips of the sacral screws were marked and the relations with the anatomic structures were defined. The position of the sacral screws relative to the middle and lateral sacral arteries and veins, and the sacral sympathetic trunk were measured. There was no injury to the visceral organs. In four cases, S1 screw tip was in direct contact with middle sacral artery. In two cases, S1 screw tip was in direct contact with middle sacral vein. It was observed that the S1 screw tips were in close proximity to sacral sympathetic trunk on both right and the left sides. The tip of the S2 screw was in contact with middle sacral artery on the left side only in one case. It is found that the tip of the S2 screw was closely located with the middle sacral vein in two cases. The tip of the S2 pedicle screw was in contact with the sacral sympathetic trunk in eight cases on the right side and seven cases on the left side. Lateral sacral vein was also observed to be disturbed by the S1 and S2 screws. As a conclusion, anterior cortical penetration during sacral screw insertion carries a risk of neurovascular injury. The risk of sacral sympathetic trunk and minor vascular structures together with the major neurovascular structures and viscera should be kept in mind.

Dimpled elastic sheets: a new class of non-porous negative Poisson’s ratio materials

NASA Astrophysics Data System (ADS)

Javid, Farhad; Smith-Roberge, Evelyne; Innes, Matthew C.; Shanian, Ali; Weaver, James C.; Bertoldi, Katia

2015-12-01

In this study, we report a novel periodic material with negative Poisson’s ratio (also called auxetic materials) fabricated by denting spherical dimples in an elastic flat sheet. While previously reported auxetic materials are either porous or comprise at least two phases, the material proposed here is non-porous and made of a homogeneous elastic sheet. Importantly, the auxetic behavior is induced by a novel mechanism which exploits the out-of-plane deformation of the spherical dimples. Through a combination of experiments and numerical analyses, we demonstrate the robustness of the proposed concept, paving the way for developing a new class of auxetic materials that significantly expand their design space and possible applications.

Dropwise condensation on hydrophobic bumps and dimples

NASA Astrophysics Data System (ADS)

Yao, Yuehan; Aizenberg, Joanna; Park, Kyoo-Chul

2018-04-01

Surface topography plays an important role in promoting or suppressing localized condensation. In this work, we study the growth of water droplets on hydrophobic convex surface textures such as bumps and concave surface textures such as dimples with a millimeter scale radius of curvature. We analyze the spatio-temporal droplet size distribution under a supersaturation condition created by keeping the uniform surface temperature below the dew point and show its relationship with the sign and magnitude of the surface curvature. In particular, in contrast to the well-known capillary condensation effect, we report an unexpectedly less favorable condensation on smaller, millimeter-scale dimples where the capillary condensation effect is negligible. To explain these experimental results, we numerically calculated the diffusion flux of water vapor around the surface textures, showing that its magnitude is higher on bumps and lower on dimples compared to a flat surface. We envision that our understanding of millimetric surface topography can be applied to improve the energy efficiency of condensation in applications such as water harvesting, heating, ventilation, and air conditioning systems for buildings and transportation, heat exchangers, thermal desalination plants, and fuel processing systems.

Direct Numerical Simulation of Flow Over Passive Geometric Disturbances

NASA Astrophysics Data System (ADS)

Vizard, Alexander

It is well understood that delaying flow separation on a bluff body allows significant drag reduction, which is attractive in many applications. With this in mind, many separation control mechanisms, both active and passive, have been developed and tested to optimize the effects of this phenomenon. Although this idea is generally accepted, the physical occurrences in the near-wall region during transition that lead to separation delay are not well understood. The current study evaluates the impact of both spherical dimples, and sandgrain style roughness on downstream flow by performing direct numerical simulations over such geometries on a zero pressure gradient flat plate. It is shown that although dimples and random roughness of similar characteristic length scales exhibit similar boundary layer characteristics, dimples are more successful in developing high momentum in the vicinity of the wall. Additionally it is shown that increasing the relative size of the rough elements does not increase the near-wall momentum, and is undesirable in controlling separation. Finally, it is shown that the impact of roughness elements on the flow is more immediate, and that, for the case of one row of dimples and an equivalent area of roughness, the roughness patch is more successful in transitioning the near-wall region to a non-laminar state. It can be concluded from variation in the span of the flowfield for a single row of dimples that the size and orientation of the disturbance region is significant to the results.

Mechanisms underlying recurrent inhibition in the sacral parasympathetic outflow to the urinary bladder.

PubMed Central

de Groat, W C

1976-01-01

1. In cats with the sacral dorsal roots cut on one side electrical stimulation (15-40 c/s) of the central end of the transected ipsilateral pelvic nerve depressed spontaneous bladder contractions. The depression was abolished by transecting the ipsilateral sacral ventral roots. 2. Electrical stimulation of acutely or chronically transected ('deafferented') sacral ventral roots depressed spontaneous bladder contractions and the firing of sacral parasympathetic preganglionic neurones innervating the bladder. The depression of neuronal firing occurred ipsilateral and contralateral to the point of stimulation, but only occurred with stimulation of sacral roots containing preganglionic axons and only with stimulation of sacral roots containing preganglionic axons and only at intensities of stimulation (0-7-4V) above the threshold for activation of these axons. 3. The inhibitory responses were not abolished by strychnine administered by micro-electrophoresis to preganglionic neurones, but were blocked by the intravenous administration of strychnine. 4. The firing of preganglionic neurones elicited by micro-electrophoretic administration of an excitant amino acid (DL-homocysteic acid) was not depressed by stimulation of the ventral roots. 5. It is concluded that the inhibition of the sacral outflow to the bladder by stimulation of sacral ventral roots is related to antidromic activation of vesical preganglionic axons. Collaterals of these axons must excite inhibitory interneurones which in turn depress transmission at a site on the micturition reflex pathway prior to the preganglionic neurones. PMID:950603

A study on difference and importance of sacral slope and pelvic sacral angle that affect lumbar curvature.

PubMed

Choi, Seyoung; Lee, Minsun; Kwon, Byongan

2014-01-01

Individual pelvic sacral angle was measured, compared and analyzed for the 6 male and female adults who were diagnosed with lumbar spinal stenosis, foraminal stenosis and mild spondylolisthesis in accordance with spinal parameters, pelvic parameters and occlusion state of sacroiliac joint presented by the author of this thesis based on the fact that the degree of lumbar excessive lordosis that was one of the causes for lumbar pain was determined by sacral slope. The measured values were compared with the standard values of the average normal range from 20 s to 40 s of normal Koreans stated in the study on the change in lumbar lordosis angle, lumbosacral angle and sacral slope in accordance with the age by Oh et al. [5] and sacral slope and pelvic sacral slope of each individual of the subjects for measurement were compared. Comparing the difference between the two tilt angles possessed by an individual is a comparison to determine how much the sacroiliac joint connecting pelvis and sacral vertebrae compensated and corrected the sacral vertebrae slope by pelvic tilt under the condition of synarthrodial joint.Under the condition that the location conforming to the line in which the sagittal line of gravity connects with pelvic ASIS and pubic pubic tuberele is the neutral location of pelvic tilt, sacral slope being greater than pelvic sacral slope means pelvic anterior tilting, whereas sacral slope being smaller than pelvic sacral slope means pelvic posterior tilting. On that account, male B, female A and female C had a pelvic posterior tilting of 16 degrees, 1 degree and 5 degrees respectively, whereas male A, male C and female B had a pelvic anterior tilting of 3 degrees, 9 degrees and 4 degrees respectively. In addition, the 6 patients the values of lumbar lordosis angle, lumbosacral angle and sacral slope that were almost twice as much as the normal standard values of Koreans. It is believed that this is because the pelvic sacral slope maintaining an angle that is slightly greater than the normal range by being located in the lowest end of spine considering that the compensation for pelvic tilt, in other words, pelvic limb is not much causes an excess of lumbar lordosis angle. The meaning of this study based on these results is to prove that PSA is one of the important factors that fundamentally determine lumbar curvature. And this is because it is definitely required to have a study on the guideline for appropriate posture and life habit to the maintenance and management of ideal PSA before the end of growth phase and also the exercise therapy and adjustment for the control of PSA.

The presence of a negative sacral slope in patients with ankylosing spondylitis with severe thoracolumbar kyphosis.

PubMed

Qian, Bang-Ping; Jiang, Jun; Qiu, Yong; Wang, Bin; Yu, Yang; Zhu, Ze-Zhang

2014-11-19

Pelvic retroversion is one of the mechanisms for regulating sagittal balance in patients with a kyphotic deformity. This retroversion is limited by hip extension, which prevents the pelvis from becoming excessively retroverted, achieving a sacral slope of <0°. However, a negative sacral slope can be found in some patients with ankylosing spondylitis with thoracolumbar kyphosis. The purpose of this study was to analyze this finding. We performed a retrospective review of 106 consecutive Chinese Han patients with ankylosing spondylitis with thoracolumbar kyphosis treated at our center from October 2005 to October 2012. Forty-one patients in whom the upper third of the femur was clearly visualized on lateral radiographs were analyzed. Seventeen had a sacral slope of <0° (group A) and twenty-four had a sacral slope of ≥0° (group B). Eight sagittal parameters were measured and compared between the two groups. Correlations among sacral slope, the femoral obliquity angle, and the other sagittal parameters were analyzed. Mean global kyphosis, lumbar lordosis, pelvic tilt, the sagittal vertical axis, and the femoral obliquity angle were significantly larger in group A than in group B, whereas mean pelvic incidence and sacral slope were significantly smaller in group A (p < 0.05 for all). Global kyphosis, lumbar lordosis, pelvic tilt, and the sagittal vertical axis were significantly negatively associated with sacral slope but positively associated with the femoral obliquity angle, whereas pelvic incidence was significantly positively associated with sacral slope but negatively associated with the femoral obliquity angle (p < 0.05 for all). The femoral obliquity angle was significantly negatively associated with sacral slope (p < 0.05). Negative sacral slope does exist in Chinese Han patients with ankylosing spondylitis with thoracolumbar kyphosis. This appears to be caused by severe kyphosis, an initially small sacral slope, and pronounced tilting of the femoral shaft as a result of knee flexion, resulting in the pelvis becoming further retroverted. Copyright © 2014 by The Journal of Bone and Joint Surgery, Incorporated.

Structural Joint with Multi-Axis Load Carrying Capability

NASA Technical Reports Server (NTRS)

Wu, K. Chauncey (Inventor); Martin, Robert A. (Inventor); Stewart, Brian K. (Inventor)

2017-01-01

A structural joint is formed of a mandrel having a plurality of bumps and dimples formed thereon which is fitted into a sleeve. The bumps and dimples form a non-circular geometry at all points along the length of the mandrel. The bumps are defined by surfaces which have 1st and 2nd derivatives which are continuous.

The influence of rail surface irregularities on contact forces and local stresses

NASA Astrophysics Data System (ADS)

Andersson, Robin; Torstensson, Peter T.; Kabo, Elena; Larsson, Fredrik

2015-01-01

The effect of initial rail surface irregularities on promoting further surface degradation is investigated. The study concerns rolling contact fatigue formation, in particular in the form of the so-called squats. The impact of surface irregularities in the form of dimples is quantified by peak magnitudes of dynamic contact stresses and contact forces. To this end simulations of two-dimensional (later extended to three-dimensional) vertical dynamic vehicle-track interaction are employed. The most influencing parameters are identified. It is shown that even very shallow dimples might have a large impact on local contact stresses. Peak magnitudes of contact forces and stresses due to the influence of rail dimples are shown to exceed those due to rail corrugation.

Sacral Peak Pressure in Healthy Volunteers and Patients With Spinal Cord Injury: With and Without Liquid-Based Pad.

PubMed

Duetzmann, Stephan; Forsey, Lynn M; Senft, Christian; Seifert, Volker; Ratliff, John; Park, Jon

2015-01-01

The prevalence of sacral pressure ulcers in patients with spinal cord injuries is high. The sacral area is vulnerable to compressive pressure because of immobility and because the sacrum and posterior superior iliac prominence lie closely under the skin with no muscle layer in between. The aim of this study was to assess peak sacral pressure before and after use of PURAP, a liquid-based pad that covers only the sacral area and can be applied on any bed surface. Healthy volunteers (n = 12) and patients with spinal cord injuries (n = 10) took part; the patients had undergone spine surgery within 7 days before data collection. Participants were in bed, pretest pressure maps were generated, PURAP was placed for 15 minutes, and then posttest pressure maps were generated. Peak pressure was obtained every second and averaged over the entire period. Patients rated whether their comfort had improved when PURAP was in use. For healthy volunteers, mean pretest peak sacral pressure was 74.7 (SD = 16.2) mmHg; the posttest mean was 49.1 (SD = 7.5) mmHg (p < .001, Wilcoxon signed-rank test). For patients with spinal cord injuries, mean pretest peak sacral pressure was 105.7 (SD = 22.4) mmHg; the posttest mean was 81.4 (SD = 18.3) mmHg (p < .001, Wilcoxon signed-rank test). The pad reduced the peak sacral pressure in the patient group by 23% (range = 11%-42%) and in the volunteers by 32% (range = 19%-46%). Overall, 70% of the patients reported increased comfort with PURAP. Peak sacral pressure was reduced when PURAP was used. It covers only the sacral area but could help many patients with spinal cord injury because the prevalence of sacral pressure ulcers is high in this group. PURAP may be economically advantageous in countries and hospitals with limited financial resources needed for more expensive mattresses and cushions.

Neural tube defects in Waardenburg syndrome: A case report and review of the literature.

PubMed

Hart, Joseph; Miriyala, Kalpana

2017-09-01

Waardenburg syndrome type 1 (WS1) is an autosomal dominant genetic condition characterized by sensorineural deafness and pigment abnormalities, and is caused by variants in the PAX3 homeodomain. PAX3 variants have been associated with severe neural tube defects in mice and humans, but the frequency and clinical manifestations of this symptom remain largely unexplored in humans. Consequently, the role of PAX3 in human neural tube formation remains a study of interest, for clinical as well as research purposes. Though the association between spina bifida and WS1 is now well-documented, no study has attempted to characterize the range of spina bifida phenotypes seen in WS. Spina bifida encompasses several diagnoses with a wide scope of clinical severity, ranging from spina bifida occulta to myelomeningocele. We present a patient with Waardenburg syndrome type 1 caused by a novel missense variant in PAX3, presenting with myelomeningocele, Arnold-Chiari malformation, and hydrocephalus at birth. Additionally, we review 32 total cases of neural tube defects associated with WS. Including this report, there have been 15 published cases of myelomeningocele, 10 cases of unspecified spina bifida, 3 cases of sacral dimples, 0 cases of meningocele, and 4 cases of miscellaneous other neural tube defects. Though the true frequency of each phenotype cannot be determined from this collection of cases, these results demonstrate that Waardenburg syndrome type 1 carries a notable risk of severe neural tube defects, which has implications in prenatal and genetic counseling. © 2017 Wiley Periodicals, Inc.

Landmarks for Sacral Debridement in Sacral Pressure Sores.

PubMed

Choo, Joshua H; Wilhelmi, Bradon J

2016-03-01

Most cases of sacral osteomyelitis arising in the setting of sacral pressure ulcers require minimal cortical debridement. When faced with advanced bony involvement, the surgeon is often unclear about how much can safely be resected. Unfamiliarity with sacral anatomy can lead to concerns of inadvertent entry into the dural space and compromise of future flap options. A cadaveric study (n = 6), in which a wide posterior dissection of the sacrum, was performed. Relationships of the dural sac to bony landmarks of the posterior pelvis were noted. The termination of the dural sac was found in our study to occur at the junction of S2/S3 vertebral bodies, which was located at a mean distance of 0.38 ± 0.16 cm distal to the inferior-most extent of the posterior superior iliac spine (PSIS). The mean thickness of the posterior table of sacrum at this level was 1.7 cm at the midline and 0.5 cm at the sacral foramina. The PSIS is a reliable landmark for localizing the S2/S3 junction and the termination of the dural sac. Sacral debridement medial to the sacral foramina above the level of PSIS must be conservative whenever possible. If aggressive debridement is necessary above this level, the surgeon must be alert to the possibility of dural involvement.

Assessment of sacrococcygeal pressure ulcers using diffuse correlation spectroscopy

NASA Astrophysics Data System (ADS)

Diaz, David; Lafontant, Alec; Neidrauer, Michael; Weingarten, Michael S.; DiMaria-Ghalili, Rose Ann; Fried, Guy W.; Rece, Julianne; Lewin, Peter A.; Zubkov, Leonid

2016-03-01

Microcirculation is essential for proper supply of oxygen and nutritive substances to the biological tissue and the removal of waste products of metabolism. The determination of microcirculatory blood flow (mBF) is therefore of substantial interest to clinicians for assessing tissue health; particularly in pressure ulceration and suspected deep tissue injury. The goal of this pilot clinical study was to assess deep-tissue pressure ulceration by non-invasively measuring mBF using Diffuse Correlation Spectroscopy (DCS). DCS provides information about the flow of red blood cells in the capillary network by measuring the temporal autocorrelation function of scattering light intensity. A novel optical probe was developed in order to obtain measurements under the load of the subject's body as pressure is applied (ischemia) and then released (reperfusion) on sacrococcygeal tissue in a hospital bed. Prior to loading measurements, baseline readings of the sacral region were obtained by measuring the subjects in a side-lying position. DCS measurements from the sacral region of twenty healthy volunteers have been compared to those of two patients who initially had similar non-blanchable redness. The temporal autocorrelation function of scattering light intensity of the patient whose redness later disappeared was similar to that of the average healthy subject. The second patient, whose redness developed into an advanced pressure ulcer two weeks later, had a substantial decrease in blood flow while under the loading position compared to healthy subjects. Preliminary results suggest the developed system may potentially predict whether non-blanchable redness will manifest itself as advanced ulceration or dissipate over time.

Optimization of Heat Exchangers with Dimpled Surfaces to Improve the Performance in Thermoelectric Generators Using a Kriging Model

NASA Astrophysics Data System (ADS)

Li, Shuai; Wang, Yiping; Wang, Tao; Yang, Xue; Deng, Yadong; Su, Chuqi

2017-05-01

Thermoelectric generators (TEGs) have become a topic of interest for vehicle exhaust energy recovery. Electrical power generation is deeply influenced by temperature differences, temperature uniformity and topological structures of TEGs. When the dimpled surfaces are adopted in heat exchangers, the heat transfer rates can be augmented with a minimal pressure drop. However, the temperature distribution shows a large gradient along the flow direction which has adverse effects on the power generation. In the current study, the heat exchanger performance was studied in a computational fluid dynamics (CFD) model. The dimple depth, dimple print diameter, and channel height were chosen as design variables. The objective function was defined as a combination of average temperature, temperature uniformity and pressure loss. The optimal Latin hypercube method was used to determine the experiment points as a method of design of the experiment in order to analyze the sensitivity of the design variables. A Kriging surrogate model was built and verified according to the database resulting from the CFD simulation. A multi-island genetic algorithm was used to optimize the structure in the heat exchanger based on the surrogate model. The results showed that the average temperature of the heat exchanger was most sensitive to the dimple depth. The pressure loss and temperature uniformity were most sensitive to the parameter of channel rear height, h 2. With an optimal design of channel structure, the temperature uniformity can be greatly improved compared with the initial exchanger, and the additional pressure loss also increased.

The effect of microstructure and strength on the fracture toughness of an 18 Ni, 300 grade maraging steel

NASA Technical Reports Server (NTRS)

Psioda, J. A.; Low, J. R., Jr.

1977-01-01

Fractography and metallographic sectioning were used to investigate the influence of microstructure and strength on the fracture toughness (KIc) and fracture mechanism of an 18 Ni, 300 grade maraging steel. Increased yield strength from 1442 to 2070 MN/m squared through precipitation hardening results in a KIc loss from 143 to 55 MN/m superscript 3/2. Ti (C,N) Ti2S, and TiC inclusions in sizes from 1 to 8, 1 to 15, and 0.1 to 2 microns respectively serve as sites for void nucleation and lead to fracture by the dimpled rupture process in all strength levels considered. TiC nucleated dimples occupy more than half the fracture in all conditions. Void nucleation rate and resultant number of dimples per unit area of fracture increase with increasing yield strength. Average dimple size decreases with increasing strength and/or overaging which follows from the decreasing amount of stable void growth measured by sectioning tensile specimens. Void growth is assisted by crack branching along a path of TiC inclusions. Coalescence occurs in the highest strength materials by a combination of TiC void nucleation and premature separation at strengthening precipitates.

Numerical investigation of the effect of sphere dimples on the drag crisis and the Magnus effect

NASA Astrophysics Data System (ADS)

Li, Jing; Tsubokura, Makoto; Tsunoda, Masaya

2015-11-01

The present study investigates the flow over a golf ball and a smooth sphere around the critical Reynolds numbers under both stationary and self-spinning conditions by conducting Large-eddy simulations (LES) based on high resolution unstructured grids. For the stationary cases, the present calculation results validate the promotion of the drag crisis at a relatively lower Reynolds number due to the golf ball dimples. It also shows that the golf ball dimples have a limited effect on the time-dependent lateral force development in the subcritical regime, whereas the dimples are beneficial in suppressing the lateral force oscillations in the supercritical regimes. With spin parameter Γ = 0.1, the drag coefficients for the spinning smooth sphere increase slightly in all Reynolds number regimes when compared to the stationary cases, whereas for the spinning golf ball, the drag force decreases in the critical regime and increases in the supercritical regime. For both spinning models, the inverse Magnus effect was reproduced in the critical regime, whereas in the supercritical regime the ordinary Magnus force was generated. Relatively weaker lift forces were also observed in the cases of the spinning golf balls when compared to the spinning smooth spheres.

Numerical and experimental investigation of enhancement of heat transfer in dimpled rib heat exchanger tube

NASA Astrophysics Data System (ADS)

Kumar, Anil; Maithani, Rajesh; Suri, Amar Raj Singh

2017-12-01

In this study, numerical and experimental investigation has been carried out for a range of system and operating parameters in order to analyse the effect of dimpled rib on heat and fluid flow behaviours in heat exchanger tube. Tube has, stream wise spacing ( x/ d d ) range of 15-35, span wise spacing ( y/ d d ) range of 15-35, ratio of dimpled depth to print diameter ( e/ d d ) of 1.0 and Reynolds number ( Re n ) ranges from 4000 to 28,000. Simulations were carried out to obtain heat and fluid flow behaviour of smooth and rough tube, using commercial CFD software, ANSYS 16.0 (Fluent). Renormalization k - ɛ model was employed to assess the influence of dimpled on turbulent flow and velocity field. Simulation results show that, the enhancement of 3.18 times in heat transfer and 2.87 times enhancement in thermal hydraulic performance as a function of stream wise direction ( x/ d d ) of 15 and span wise direction ( y/ d d ) of 15 respectively. Comparison between numerical and experimental simulation results showed that good agreement as the data fell within ±10% error band.

The influence of micro-scale dimples and nano-sized grains on the fretting characteristics generated by laser pulses.

PubMed

Amanov, Auezhan; Watabe, Tsukasa; Sasaki, Shinya

2013-12-01

The tribological characteristics of micro-scale dimpled Cu-based alloy specimen generated using a laser surface texturing (LST) were assessed and compared with that of the untextured specimen. The objective of this study is to improve the tribological characteristics of internal combustion engine (ICE) bearings and bushings made of Cu-based alloy by generating micro-scale dimples using an LST. Fretting wear tests were performed by sliding a hardened SAE52100 steel ball against the untextured and LSTed specimens at a normal load of 5 N under oil-lubricated conditions. The friction force and relative movement between the specimens were measured simultaneously during the fretting tests. The test results showed that the LSTed specimens showed a reduction in friction coefficient and an enhancement in fretting wear resistance compared to that of the untextured specimen. The friction coefficient and fretting wear volume increased with increasing frequency for both untextured and LSTed specimens. The improved tribological properties of the LSTed specimen may be attributed to the micro-scale dimples, refined grain size and high lattice strain. In addition, a model for the nanocrystallization mechanism of the LSTed specimen was proposed.

A numerical investigation of the impact of surface topology on laminar boundary layers

NASA Astrophysics Data System (ADS)

Beratlis, Nikolaos; Squires, Kyle; Balaras, Elias

2015-11-01

Surface topology, such as dimples or trip wires, has been utilized in the past for passive separation control over bluff bodies. The majority of the work, however, has focused on the indirect effects on the drag and lift forces, while the details of the impact on the boundary layer evolution are not well understood. Here we report a series of DNS of flow over a single row of spherical and hexagonal dimples, as well as, circular grooves. The Reynolds number and the thickness of the incoming laminar boundary layer is carefully controlled. In all cases transition to turbulence downstream of the elements comes with reorientation of the spanwise vorticity into hairpin like vortices. Although qualitatively the transition mechanism amongst different dimples and grooves is similar, important quantitative differences exist: two-dimensional geometries such as the groove, are more stable than three-dimensional geometries. In addition, it was found that the cavity geometry controls the initial thickness of the boundary layer and practically results in a shift of the virtual origin of the turbulent boundary layer. Important differences in the momentum transport downstream of the dimples exist, but in all cases the boundary layer evolves in a self-similar manner.

Prophylactic Sacral Dressing for Pressure Ulcer Prevention in High-Risk Patients.

PubMed

Byrne, Jaime; Nichols, Patricia; Sroczynski, Marzena; Stelmaski, Laurie; Stetzer, Molly; Line, Cynthia; Carlin, Kristen

2016-05-01

Patients in intensive care units are likely to have limited mobility owing to hemodynamic instability and activity orders for bed rest. Bed rest is indicated because of the severity of the disease process, which often involves intubation, sedation, paralysis, surgical procedures, poor nutrition, low flow states, and poor circulation. These patients are predisposed to the development and/or the progression of pressure ulcers not only because of their underlying diseases, but also because of limited mobility and deconditioned states of health. To assess whether treating high-risk patients with a prophylactic sacral dressing decreases the incidence of unit-acquired sacral pressure ulcers. An evidence-based tool for identifying patients at high risk for pressure ulcers was used in 3 intensive care units at an urban tertiary care hospital and academic medical center. Those patients deemed at high risk had a prophylactic sacral dressing applied. Incidence rates were collected and compared for the 7 months preceding use of the dressings and for 7 months during the trial period when the dressing was used. After the sacral dressing began being used, the number of unit-acquired sacral pressure ulcers decreased by 3.4 to 7.6 per 1000 patient days depending on the unit. A prophylactic sacral dressing may help prevent unit-acquired sacral pressure ulcers. Implementation of an involved care team with heightened awareness and increased education along with a prophylactic sacral dressing in patients deemed high risk for skin breakdown are all essential for success. ©2016 American Association of Critical-Care Nurses.

Sacral Variability in Tailless Species: Homo sapiens and Ochotona princeps.

PubMed

Tague, Robert G

2017-05-01

Homo sapiens is variable in number of sacral vertebrae, and this variability can lead to obstetrical complication. This study uses the comparative method to test the hypothesis that sacral variability in H. sapiens is associated with absence of a tail. Three species of lagomorphs are studied: Ochotona princeps (N = 271), which is tailless, and Lepus californicus (N = 212) and Sylvilagus audubonii (N = 206), which have tails. Results show that O. princeps has (1) higher diversity index for number of sacral vertebrae (0.49) compared to L. californicus (0.25) and S. audubonii (0.26) and (2) significantly higher percentage of individuals with the species-specific nonmodal number of sacral vertebrae (43.9%) compared to L. californicus (14.2%) and S. audubonii (15.5%). Comparison of H. sapiens (N = 1,030; individuals of age 20-39 years) with O. princeps shows similarities between the species in diversity index (also 0.49 in H. sapiens) and percentage of individuals with nonmodal number of sacral vertebrae (37.3% in H. sapiens). Homeotic transformation best explains the results. H. sapiens and O. princeps show propensity for caudal shift at the sacral-caudal border (i.e., homeotic transformation of the first caudal vertebra to a sacral vertebra). Caudal and cranial shift among presacral vertebrae increases or decreases this propensity, respectively. Increase in number of sacral vertebrae in H. sapiens by homeotic transformation reduces pelvic outlet capacity and can be obstetrically hazardous. Anat Rec, 300:798-809, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Critical dimensions of trans-sacral corridors assessed by 3D CT models: Relevance for implant positioning in fractures of the sacrum.

PubMed

Wagner, Daniel; Kamer, Lukas; Sawaguchi, Takeshi; Geoff Richards, R; Noser, Hansrudi; Uesugi, Masafumi; Ossendorf, Christian; Rommens, Pol M

2017-11-01

Trans-sacral implants can be used alternatively to sacro-iliac screws in the treatment of osteoporosis-associated fragility fractures of the pelvis and the sacrum. We investigated trans-sacral corridor dimensions, the number of individuals amenable to trans-sacral fixation, as well as the osseous boundaries and shape of the S1 corridor. 3D models were reconstructed from pelvic CT scans from 92 Europeans and 64 Japanese. A corridor of <12 mm was considered critical for trans-sacral implant positioning, and <8 mm as impossible. A statistical model of trans-sacral corridor S1 was computed. The limiting cranio-caudal diameter was 11.6 mm (±5.4) for S1 and 14 mm (±2.4) for S2. Trans-sacral implant positioning was critical in 52% of cases for S1, and in 21% for S2. The S1 corridor was impossible in 26%, with no impossible corridor in S2. Antero-superiorly, the S1 corridor was limited not only by the sacrum but in 40% by the iliac fossa. The statistical model demonstrated a consistent oval shape of the trans-section of corridor S1. Considering the variable in size and shape of trans-sacral corridors in S1, a thorough anatomical knowledge and preoperative planning are mandatory using trans-sacral implants. In critical cases, S2 is a veritable alternative. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2577-2584, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Malignant fibrous histiocytoma developing in irradiated sacral chordoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halpern, J.; Kopolovic, J.; Catane, R.

1984-06-15

Malignant fibrous histiocytoma (MFH), arising at the site of a sacral chordoma 8 years after massive radiotherapy, is described. Initially, the patient received 7000 rad to the sacral area and, on recurrence, 5 years later, an additional 4000 rad. Two years later, a sacral mass was noted again. Biopsy then revealed MFH; chest x-ray showed multiple lung metastases. A combination chemotherapy, consisting of cyclophosphamide, vincristine, adriamycin (doxorubicin), and DTIC, resulted in a 6 month partial response. Subsequently, the patient died because of progressive metastatic disease. At autopsy, 8 years after diagnosis, both the sacral lesion and the lung metastases provedmore » to be MFH, and no residual chordoma was found.« less

The predictive value of the sacral base pressure test in detecting specific types of sacroiliac dysfunction

PubMed Central

Mitchell, Travis D.; Urli, Kristina E.; Breitenbach, Jacques; Yelverton, Chris

2007-01-01

Abstract Objective This study aimed to evaluate the validity of the sacral base pressure test in diagnosing sacroiliac joint dysfunction. It also determined the predictive powers of the test in determining which type of sacroiliac joint dysfunction was present. Methods This was a double-blind experimental study with 62 participants. The results from the sacral base pressure test were compared against a cluster of previously validated tests of sacroiliac joint dysfunction to determine its validity and predictive powers. The external rotation of the feet, occurring during the sacral base pressure test, was measured using a digital inclinometer. Results There was no statistically significant difference in the results of the sacral base pressure test between the types of sacroiliac joint dysfunction. In terms of the results of validity, the sacral base pressure test was useful in identifying positive values of sacroiliac joint dysfunction. It was fairly helpful in correctly diagnosing patients with negative test results; however, it had only a “slight” agreement with the diagnosis for κ interpretation. Conclusions In this study, the sacral base pressure test was not a valid test for determining the presence of sacroiliac joint dysfunction or the type of dysfunction present. Further research comparing the agreement of the sacral base pressure test or other sacroiliac joint dysfunction tests with a criterion standard of diagnosis is necessary. PMID:19674694

Restoration of bladder function in spastic neuropathic bladder using sacral deafferentation and different techniques of neurostimulation.

PubMed

Schumacher, S; Bross, S; Scheepe, J R; Alken, P; Jünemann, K P

1999-01-01

Conventional sacral anterior root stimulation (SARS) results in simultaneous activation of both the detrusor muscle and the external urethral sphincter. We evaluated the possibilities of different neurostimulation techniques to overcome stimulation induced detrusor-sphincter-dyssynergia and to achieve a physiological voiding. The literature was reviewed on different techniques of sacral anterior root stimulation of the bladder and the significance of posterior rhizotomy in patients with supraconal spinal cord injury suffering from the loss of voluntary bladder control, detrusor hyperreflexia and sphincter spasm. The achievement of selective detrusor activation would improve current sacral neurostimulation of the bladder, including the principle of "poststimulus voiding". This is possible with the application of selective neurostimulation in techniques of anodal block, high frequency block, depolarizing prepulses and cold block. Nowadays, sacral deafferentation is a standard therapy in combination with neurostimulation of the bladder because in conclusion advantages of complete rhizotomy predominate. The combination of sacral anterior root stimulation and sacral deafferentation is a successful procedure for restoration of bladder function in patients with supraconal spinal cord injury. Anodal block technique and cryotechnique are excellent methods for selective bladder activation to avoid detrusor-sphincter-dyssynergia and thus improve stimulation induced voiding.

Paraspinal Transposition Flap for Reconstruction of Sacral Soft Tissue Defects: A Series of 53 Cases from a Single Institute

PubMed Central

Chattopadhyay, Debarati; Agarwal, Akhilesh Kumar; Guha, Goutam; Bhattacharya, Nirjhar; Chumbale, Pawan K; Gupta, Souradip; Murmu, Marang Buru

2014-01-01

Study Design Case series. Purpose To describe paraspinal transposition flap for coverage of sacral soft tissue defects. Overview of Literature Soft tissue defects in the sacral region pose a major challenge to the reconstructive surgeon. Goals of sacral wound reconstruction are to provide a durable skin and soft tissue cover adequate for even large sacral defects; minimize recurrence; and minimize donor site morbidity. Various musculocutaneous and fasciocutanous flaps have been described in the literature. Methods The flap was applied in 53 patients with sacral soft tissue defects of diverse etiology. Defects ranged in size from small (6 cm×5 cm) to extensive (21 cm×10 cm). The median age of the patients was 58 years (range, 16-78 years). Results There was no flap necrosis. Primary closure of donor sites was possible in all the cases. The median follow up of the patients was 33 months (range, 4-84 months). The aesthetic outcomes were acceptable. There has been no recurrence of pressure sores. Conclusions The authors conclude that paraspinal transposition flap is suitable for reconstruction of large sacral soft tissue defects with minimum morbidity and excellent long term results. PMID:24967044

Descriptive Cadaveric Study Comparing the Accuracy of Ultrasound Versus Fluoroscopic Guidance for First Sacral Transforaminal Injections: A Comparison Study.

PubMed

Thompson, Bradley F; Pingree, Matthew J; Qu, Wenchun; Murthy, Naveen S; Lachman, Nirusha; Hurdle, Mark Friedrich

2018-04-01

Ultrasound is rarely used for guiding lumbosacral epidural steroid injections due to its technical limitations. For example, sonographic imaging lacks the ability to confirm epidural spread and identify vascular uptake. The perceived risk that these limitations pose to human subjects has precluded any large scale clinical trials to date. To compare the accuracy of ultrasound versus fluoroscopic guidance for first sacral transforaminal epidural injections. Cadaveric comparative study using dichotomous outcomes. A fluoroscopy suite and anatomic laboratory at an academic medical center. Four unembalmed adult human cadavers with no history of spinal surgery. Eight sites were injected twice by one interventionalist, using fluoroscopic and ultrasound guidance. In the fluoroscopy arm, contrast spread was assessed using computed tomography. In the ultrasound arm, latex spread was assessed using gross anatomic dissection. Any visible evidence of epidural spread constituted a positive result. Comparison of the success of obtaining epidural contrast flow was the primary outcome measure. Secondary outcome measures included average duration, rate of intravascular uptake, and quantity of intravascular uptake. All injections performed in both the ultrasound arm and the fluoroscopy arm had positive epidural spread. The average duration was 3.03 minutes with fluoroscopy and 4.76 minutes with ultrasound. The rate of intravascular uptake was 37.5% with fluoroscopy and 50% with ultrasound. Within the ultrasound arm, greater intravascular spread and duration variability were recorded. Although ultrasonography can provide reliable image guidance for cannulating the first sacral foramen in cadavers, it would have limited clinical utility due to its inability to visualize relevant neurovascular structures deep to the osseus roof and exclude intravascular uptake. IV. Copyright © 2018 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Developmental identity versus typology: Lucy has only four sacral segments.

PubMed

Machnicki, Allison L; Lovejoy, C Owen; Reno, Philip L

2016-08-01

Both interspecific and intraspecific variation in vertebral counts reflect the action of patterning control mechanisms such as Hox. The preserved A.L. 288-1 ("Lucy") sacrum contains five fused elements. However, the transverse processes of the most caudal element do not contact those of the segment immediately craniad to it, leaving incomplete sacral foramina on both sides. This conforms to the traditional definition of four-segmented sacra, which are very rare in humans and African apes. It was recently suggested that fossilization damage precludes interpretation of this specimen and that additional sacral-like features of its last segment (e.g., the extent of the sacral hiatus) suggest a general Australopithecus pattern of five sacral vertebrae. We provide updated descriptions of the original Lucy sacrum. We evaluate sacral/coccygeal variation in a large sample of extant hominoids and place it within the context of developmental variation in the mammalian vertebral column. We report that fossilization damage did not shorten the transverse processes of the fifth segment of Lucy's sacrum. In addition, we find that the extent of the sacral hiatus is too variable in apes and hominids to provide meaningful information on segment identity. Most importantly, a combination of sacral and coccygeal features is to be expected in vertebrae at regional boundaries. The sacral/caudal boundary appears to be displaced cranially in early hominids relative to extant African apes and humans, a condition consistent with the likely ancestral condition for Miocene hominoids. While not definitive in itself, a four-segmented sacrum accords well with the "long-back" model for the Pan/Homo last common ancestor. Am J Phys Anthropol 160:729-739, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Periodic buckling of constrained cylindrical elastic shells

NASA Astrophysics Data System (ADS)

Marthelot, Joel; Brun, Pierre-Thomas; Lopez Jimenez, Francisco; Reis, Pedro M.

We revisit the classic problem of buckling of a thin cylindrical elastic shell loaded either by pneumatic depressurization or axial compression. The control of the resulting dimpled pattern is achieved by using a concentric inner rigid mandrel that constrains and stabilizes the post-buckling response. Under axial compression, a regular lattice of diamond-like dimples appears sequentially on the surface of the shell to form a robust spatially extended periodic pattern. Under pressure loading, a periodic array of ridges facets the surface of the elastic cylindrical shell. The sharpness of these ridges can be readily varied and controlled through a single scalar parameter, the applied pressure. A combination of experiments, simulations and scaling analyses is used to rationalize the combined role of geometry and mechanics in the nucleation and evolution of the diamond-like dimples and ridges networks.

The Macroanatomy of the Sacral Plexus and Its Nerves in Eurasian Eagle Owls (Bubo bubo).

PubMed

Akbulut, Y; Demiraslan, Y; Aslan, K; Coban, A

2016-10-01

This study was carried out to reveal the formation of the sacral plexus in the Eurasian Eagle Owls (Bubo bubo) and the nerves originating from this plexus. Five EEOs, three of them were male and two were female, were provided from Wildlife Rescue and Rehabilitation Center of Kafkas University and used as materials. Following the euthanizing of the animals, abdominal cavity was opened. The nerves of plexus sacrales were dissected and photographed. It was detected that the sacral plexus was formed by the ventral ramus of five synsacral nerves. Moreover, it was determined that the roots of the sacral plexus formed three trunks: the truncus cranialis, the truncus medius and the truncus caudalis in fossa renalis. The availability of the n. ischiofemoralis and the availability of n. parafibularis were detected in the EEOs. Five branches were specified as having segregated from the sacral plexus: the n. cutaneus femoralis caudalis, the mutual root of n. fibularis with n. tibialis (n. ischiadicus), the rami musculares, the n. coxalis caudalis and the ramus muscularis. It was observed that the sacral plexus was linked to the lumbar plexus by the n. furcalis, to the pudendus plexus via the n. bigeminus. Consequently, the anatomic structure of the EEO's sacral plexus, the participating synsacral nerves to plexus and the innervation areas of these nerves were revealed. © 2015 Blackwell Verlag GmbH.

A Twice Electrochemical-Etching Method to Fabricate Superhydrophobic-Superhydrophilic Patterns for Biomimetic Fog Harvest.

PubMed

Yang, Xiaolong; Song, Jinlong; Liu, Junkai; Liu, Xin; Jin, Zhuji

2017-08-18

Superhydrophobic-superhydrophilic patterned surfaces have attracted more and more attention due to their great potential applications in the fog harvest process. In this work, we developed a simple and universal electrochemical-etching method to fabricate the superhydrophobic-superhydrophilic patterned surface on metal superhydrophobic substrates. The anti-electrochemical corrosion property of superhydrophobic substrates and the dependence of electrochemical etching potential on the wettability of the fabricated dimples were investigated on Al samples. Results showed that high etching potential was beneficial for efficiently producing a uniform superhydrophilic dimple. Fabrication of long-term superhydrophilic dimples on the Al superhydrophobic substrate was achieved by combining the masked electrochemical etching and boiling-water immersion methods. A long-term wedge-shaped superhydrophilic dimple array was fabricated on a superhydrophobic surface. The fog harvest test showed that the surface with a wedge-shaped pattern array had high water collection efficiency. Condensing water on the pattern was easy to converge and depart due to the internal Laplace pressure gradient of the liquid and the contact angle hysteresis contrast on the surface. The Furmidge equation was applied to explain the droplet departing mechanism and to control the departing volume. The fabrication technique and research of the fog harvest process may guide the design of new water collection devices.

Interpedicular Approach in Percutaneous Sacroplasty for Treatment of Sacral Vertebral Body Pathologic Fractures

DOE Office of Scientific and Technical Information (OSTI.GOV)

F Latin-Small-Letter-Dotless-I rat, Ahmet Kemal, E-mail: ahmetfirat2@hotmail.com; Guemues, Burcak, E-mail: bgumus@yahoo.com; Kaya, Emin, E-mail: ekaya@inonu.edu.tr

2011-02-15

For this technique, bone needle is introduced into the S1 vertebral body through the interpedicular route by penetrating the central spinal canal at the level of S3-4 and passing through the vertebral body of S2-3 parallel to the anterior border of sacrum. With the interpedicular approach, two sacral vertebral bodies can be injected in one session and lower sacral body injection also is available. interpedicular technique is a safe, practical, and effective technique for the treatment of sacral vertebral body pathologic fractures.

Sacral Stress Fracture Mimicking Lumbar Radiculopathy in a Mounted Police Officer: Case Report and Literature Review.

PubMed

Bednar, Drew A; Almansoori, Khaled

2015-10-01

Study Design Case report and review of the literature. Objective To present a unique case of L5 radiculopathy caused by a sacral stress fracture without neurologic compression. Methods We present our case and its clinical evolution and review the available literature on similar pathologies. Results Relief of the unusual mechanical loading causing sacral stress fracture led to rapid resolution of radiculopathy. Conclusion L5 radiculopathy can be caused by a sacral stress fracture and can be relieved by simple mechanical treatment of the fracture.

Prevalence of sacral dysmorphia in a prospective trauma population: Implications for a "safe" surgical corridor for sacro-iliac screw placement

PubMed Central

2011-01-01

Background Percutaneous sacro-iliac (SI) screw fixation represents a widely used technique in the management of unstable posterior pelvic ring injuries and sacral fractures. The misplacement of SI-screws under fluoroscopic guidance represents a critical complication for these patients. This study was designed to determine the prevalence of sacral dysmorphia and the radiographic anatomy of surgical S1 and S2 corridors in a representative trauma population. Methods Prospective observational cohort study on a consecutive series of 344 skeletally mature trauma patients of both genders enrolled between January 1, 2007, to September 30, 2007, at a single academic level 1 trauma center. Inclusion criteria included a pelvic CT scan as part of the initial diagnostic trauma work-up. The prevalence of sacral dysmorphia was determined by plain radiographic pelvic films and CT scan analysis. The anatomy of sacral corridors was analyzed on 3 mm reconstruction sections derived from multislice CT scan, in the axial, coronal, and sagittal plane. "Safe" potential surgical corridors at S1 and S2 were calculated based on these measurements. Results Radiographic evidence of sacral dysmorphia was detected in 49 patients (14.5%). The prevalence of sacral dysmorphia was not significantly different between male and female patients (12.2% vs. 19.2%; P = 0.069). In contrast, significant gender-related differences were detected with regard to radiographic analysis of surgical corridors for SI-screw placement, with female trauma patients (n = 99) having significantly narrower corridors at S1 and S2 in all evaluated planes (axial, coronal, sagittal), compared to male counterparts (n = 245; P < 0.01). In addition, the mean S2 body height was higher in dysmorphic compared to normal sacra, albeit without statistical significance (P = 0.06), implying S2 as a safe surgical corridor of choice in patients with sacral dysmorphia. Conclusions These findings emphasize a high prevalence of sacral dysmorphia in a representative trauma population and imply a higher risk of SI-screw misplacement in female patients. Preoperative planning for percutaneous SI-screw fixation for unstable pelvic and sacral fractures must include a detailed CT scan analysis to determine the safety of surgical corridors. PMID:21569232

Prevalence of sacral dysmorphia in a prospective trauma population: Implications for a "safe" surgical corridor for sacro-iliac screw placement.

PubMed

Hasenboehler, Erik A; Stahel, Philip F; Williams, Allison; Smith, Wade R; Newman, Justin T; Symonds, David L; Morgan, Steven J

2011-05-10

Percutaneous sacro-iliac (SI) screw fixation represents a widely used technique in the management of unstable posterior pelvic ring injuries and sacral fractures. The misplacement of SI-screws under fluoroscopic guidance represents a critical complication for these patients. This study was designed to determine the prevalence of sacral dysmorphia and the radiographic anatomy of surgical S1 and S2 corridors in a representative trauma population. Prospective observational cohort study on a consecutive series of 344 skeletally mature trauma patients of both genders enrolled between January 1, 2007, to September 30, 2007, at a single academic level 1 trauma center. Inclusion criteria included a pelvic CT scan as part of the initial diagnostic trauma work-up. The prevalence of sacral dysmorphia was determined by plain radiographic pelvic films and CT scan analysis. The anatomy of sacral corridors was analyzed on 3 mm reconstruction sections derived from multislice CT scan, in the axial, coronal, and sagittal plane. "Safe" potential surgical corridors at S1 and S2 were calculated based on these measurements. Radiographic evidence of sacral dysmorphia was detected in 49 patients (14.5%). The prevalence of sacral dysmorphia was not significantly different between male and female patients (12.2% vs. 19.2%; P = 0.069). In contrast, significant gender-related differences were detected with regard to radiographic analysis of surgical corridors for SI-screw placement, with female trauma patients (n = 99) having significantly narrower corridors at S1 and S2 in all evaluated planes (axial, coronal, sagittal), compared to male counterparts (n = 245; P < 0.01). In addition, the mean S2 body height was higher in dysmorphic compared to normal sacra, albeit without statistical significance (P = 0.06), implying S2 as a safe surgical corridor of choice in patients with sacral dysmorphia. These findings emphasize a high prevalence of sacral dysmorphia in a representative trauma population and imply a higher risk of SI-screw misplacement in female patients. Preoperative planning for percutaneous SI-screw fixation for unstable pelvic and sacral fractures must include a detailed CT scan analysis to determine the safety of surgical corridors.

The Relationship Between Osteoarthritis of the Lumbar Facet Joints and Lumbosacropelvic Morphology.

PubMed

Sahin, Mehmet Sukru; Ergün, Adviye; Aslan, Akın

2015-10-01

Cross-sectional study. To investigate the relation between lumbosacropelvic morphology and the presence and degree of facet joint degeneration. Osteoarthritis of the facet joints is one of the most common degenerative changes in the spine. It is considered to be formed secondary to repetitive stress or trauma and spinal deformity with secondary overload. The cause(s) of facet joints osteoarthritis, however, have not been clearly identified. Abdominal computed tomography (CT) images of 723 patients which were taken between the years 2010 and 2014 were evaluated retrospectively. Patients with prior lumbar spinal surgery, serious congenital anomalies on CT, incomplete or complete lumbosacral transition, severe scoliosis, were excluded from the study. To eliminate the age- and sex-related differences in spinopelvic morphology, a study group was formed of the remaining subjects by including patients from a specific age group (30-35 yr) and same sex (females). For each patient the presence and grade of facet joint degeneration was investigated. In addition, pelvic incidence (PI), sacral slope and the angles of L1-L5 lumbar lordosis, sacral table, L5 vertebra posterior, and sacral kyphosis were measured for each patient. Sacral slope, sacral kyphosis, and L1-L5 lumbar lordosis angle were significantly higher in patients with osteoarthritic compared with normal subjects (P = 0.015, P = 0.018, P = 0.016). L5 vertebra posterior and sacral table angle were found to be significantly lower in patients with osteoarthritic than in normal subjects (P = 0.019, P = 0.007). The degree of facet joint degeneration was noticed to increase parallel to the decrease in the sacral table angle and L5 vertebra posterior angle, and to the increase in the L1-L5 lumbar lordosis, PI, and sacral slope. A close relation exists between the presence and degree of degeneration in the facet joint and lumbosacral pelvic morphology. Prevalence and degree of the degeneration in facet joint increases as the angle of sacral slope, L1-L5 lumbar lordosis, and PI increases or the angle of sacral table and L5 vertebra posterior decreases. 4.

Parasacral Perforator Flaps for Reconstruction of Sacral Pressure Sores.

PubMed

Lin, Chin-Ta; Chen, Shih-Yi; Chen, Shyi-Gen; Tzeng, Yuan-Sheng; Chang, Shun-Cheng

2015-07-01

Despite advances in reconstruction techniques, pressure sores continue to present a challenge to the plastic surgeon. The parasacral perforator flap is a reliable flap that preserves the entire contralateral side as a future donor site. On the ipsilateral side, the gluteal muscle itself is preserved and all flaps based on the inferior gluteal artery are still possible. We present our experience of using parasacral perforator flaps in reconstructing sacral defects. Between August 2004 and January 2013, 19 patients with sacral defects were included in this study. All the patients had undergone surgical reconstruction of sacral defects with a parasacral perforator flap. The patients' sex, age, cause of sacral defect, flap size, flap type, numbers of perforators used, rotation angle, postoperative complications, and hospital stay were recorded. There were 19 parasacral perforator flaps in this series. All flaps survived uneventfully except for 1 parasacral perforator flap, which failed because of methicillin-resistant Staphylococcus aureus infection. The overall flap survival rate was 95% (18/19). The mean follow-up period was 17.3 months (range, 2-24 months). The average length of hospital stay was 20.7 days (range, 9-48 days). No flap surgery-related mortality was found. Also, there was no recurrence of sacral pressure sores or infected pilonidal cysts during the follow-up period. Perforator-based flaps have become popular in modern reconstructive surgery because of low donor-site morbidity and good preservation of muscle. Parasacral perforator flaps are durable and reliable in reconstructing sacral defects. We recommend the parasacral perforator flap as a good choice for reconstructing sacral defects.

New Postcranial Material of the Early Caseid Casea broilii Williston, 1910 (Synapsida: Caseidae) with a Review of the Evolution of the Sacrum in Paleozoic Non-Mammalian Synapsids

PubMed Central

LeBlanc, Aaron R. H.; Reisz, Robert R.

2014-01-01

Here we use the description of a new specimen of the small caseid synapsid Casea broilii that preserves the sacral, pelvic and hind limb regions in great detail and in three dimensions, as a unique opportunity to reevaluate the early stages in the evolution of the sacrum in the lineage that led to mammals. We place this new material in the context of sacral evolution in early caseid synapsids and conclude that the transition from two to three sacral vertebrae occurred in small-bodied species, suggesting that it was not an adaptation to heavy weight bearing. Furthermore, we compare descriptions of sacral anatomy among known early synapsids, including caseids, ophiacodontids, edaphosaurids, varanopids, and sphenacodontians and review sacral evolution in early synapsids. Based on the descriptions of new species of caseids, edaphosaurids, and varanopids over the past several decades, it is clear that a sacrum consisting of three vertebrae evolved independently at least four times in synapsids during the Late Carboniferous and Early Permian. Furthermore, similarities in the morphologies of the sacral vertebrae and ribs of these early synapsids lead us to conclude that an anterior caudal vertebra had been incorporated into the sacral series convergently in these groups. Given the repeated acquisition of a three-vertebra sacrum in early synapsids and no apparent link to body size, we argue that this sacral anatomy was related to more efficient terrestrial locomotion than to increased weight bearing. PMID:25545624

Dimpled ball grid array process development for space flight applications

NASA Technical Reports Server (NTRS)

Barr, S. L.; Mehta, A.

2000-01-01

A 472 dimpled ball grid array (D-BGA) package has not been used in past space flight environments, therefore it was necessary to develop a process that would yield robust and reliable solder joints. The process developing assembly, inspection and rework techniques, were verified by conducting environmental tests. Since the 472 D-BGA packages passed the above environmental tests within the specifications, the process was successfully developed for space flight electronics.

Micro and sub-micron surface structuring of AZ31 by laser re-melting and dimpling

NASA Astrophysics Data System (ADS)

Furlan, Valentina; Demir, Ali Gökhan; Previtali, Barbara

2015-12-01

In this work, the use of ns-pulsed fibre laser for surface structuring of AZ31 Mg alloy is investigated. Surface re-melting was employed to change surface morphology, especially in terms of surface roughness. Dimpling by percussion microdrilling was investigated to control the hole geometry.. With surface remelting mono-directional and homogeneous surfaces were obtained with Fl<500 J/cm2. Above 500 J/cm2 particle generation was observed, which induced sub-micron structure growth with nano-fibrous features. Moreover, surface roughness could be controlled below the initial value and much higher. With dimpling, transformation from gentle to strong ablation was observed at F0=10.3 J/cm2. XRD analysis was employed to link oxide growth to the surface morphology. Tensile tests were carried out to assess the damage on the mechanical properties after surface structuring.

Evaluation of Partial Cut-out of Sacroiliac Screws From the Sacral Ala Slope via Pelvic Inlet and Outlet View.

PubMed

Zhang, Jingwei; Hamilton, Ryan; Li, Ming; Ebraheim, Nabil A; He, Xianfeng; Liu, Jiayong; Zhu, Limei

2015-12-01

An anatomic and radiographic study of placement of sacroiliac screws. The aim of this study was to quantitatively assess the risk of partial cut-out of sacroiliac screws from the sacral ala slope via inlet and outlet view. The partial cut-out of sacroiliac screws from the superior surface of sacral ala can jeopardize the L5 nerve root, which is difficult to identify on the pelvic inlet and outlet views. Computed tomography images of 60 patients without pelvic ring deformity or injury were used to measure the width (on inlet view) and height (on outlet view) of the sacral ala. The angle of the sacral ala slope was measured on lateral view. According to the measured parameters, the theoretical safe trajectories of screw placement were calculated using inverse trigonometric functions. Under fluoroscopic guidance, a sacroiliac screw was placed close to the midline on both inlet and outlet views, including posterosuperior, posteroinferior, anterosuperior, and anteroinferior regions to the midline. The incidence of screw partial cut-out from the superior surface of sacral ala was identified. The measured widths and heights of the sacral alas were 28.1 ± 2.8 and 29.8 ± 3.1 mm, respectively. The average angle between the superior aspect of the S1 vertebral body and the superior aspect of the sacral ala was 37.2 ± 2.5 degrees. The rate of partial cut-out of the screws from the superior surface of sacral ala slope was 12.5% (5/40) in posterosuperior, 0% (0/40) in posteroinferior, 70% (28/40) in anterosuperior, and 20% (8/40) in anteroinferior. To avoid the risk of partial cut-out from sacroiliac screw placement, more precise description should be added to the conventional description: the sacroiliac screws should be placed at the inferior half portion on outlet view and at the posterior half portion on inlet view. 4.

A comparative, descriptive study of systemic factors and survival in elderly patients with sacral pressure ulcers.

PubMed

Jaul, Efraim; Menczel, Jacob

2015-03-01

Sacral pressure ulcers (PUs) are a serious complication in frail elderly patients. Thin tissue in the sacral area, low body mass index, and anatomical location contribute to the development of sacral PUs. A comparative, descriptive study was conducted to identify patient systemic factors associated with sacral PUs and to compare survival time in patients with and without PU. All consecutive patients with PUs (n = 77) and without sacral PUs (n = 53) admitted to the skilled nursing department of a geriatric hospital in Jerusalem, Israel between July 1, 2008 and December 31, 2011 were eligible to participate. Charts of previously admitted patients were abstracted and patients were prospectively followed until discharge, death, or the end of the study. Patient demographics, comorbidities, nutritional status, physical and cognitive function (measured using the Reisberg's Functional Assessment Staging Tool [FAST], Stages of Dementia of Alzheimer Scale, and the Glasgow Coma Scale), PU status, number of courses of antibiotic treatment during admission, length of hospitalization, and mortality were compared between patients admitted with and without a sacral PU using descriptive and univariate statistics. Logistic regression models were used to estimate the odds ratio (OR) and 95% confidence intervals (CI) for sacral PU versus without PU by study covariate. The association between sacral PU and survival time was assessed using Kaplan-Meier models. Patients with a sacral PU were significantly older (average age 81.60 ±10.78 versus 77.06±11.19 years old, P = 0.02) and had a higher prevalence of dementia (70% versus 30%, P = 0.007), Parkinson's disease (92.3% versus 7.7%, P = 0.03), and anemia (67.7% versus 32.3%, P = 0.06) than patients admitted without a PU. Patients with a sacral PU also had a lower body mass index (23.1 versus 25.4, P = 0.04), and lower hemoglobin (10.54 versus 11.11, P = 0.03), albumin (26.2 versus 29.7, P = 0.002), and total protein levels (61.3 versus 65.7, P = 0.04). In addition, antibiotic treatment was significantly higher in the patients with PU (50.6% versus 28.3%, P = 0.01). Patients with a sacral PU also had significantly lower physical and cognitive functioning scores and their median survival time was 70 days compared to 401 days in the non-PU group (P <0.001). These findings are generally consistent with the literature regarding risk factors for PU development and confirm the need for preventive measures. In addition, clinicians need to address the overall goal of patient care and patient quality of life when considering PU management interventions in this patient population.

"Lucy" (A.L. 288-1) had five sacral vertebrae.

PubMed

Russo, Gabrielle A; Williams, Scott A

2015-02-01

A "long-backed" scenario of hominin vertebral evolution posits that early hominins possessed six lumbar vertebrae coupled with a high frequency of four sacral vertebrae (7:12-13:6:4), a configuration acquired from a hominin-panin last common ancestor (PLCA) having a vertebral formula of 7:13:6-7:4. One founding line of evidence for this hypothesis is the recent assertion that the "Lucy" sacrum (A.L. 288-1an, Australopithecus afarensis) consists of four sacral vertebrae and a partially-fused first coccygeal vertebra (Co1), rather than five sacral vertebrae as in modern humans. This study reassesses the number of sacral vertebrae in Lucy by reexamining the distal end of A.L.288-1an in the context of a comparative sample of modern human sacra and Co1 vertebrae, and the sacrum of A. sediba (MH2). Results demonstrate that, similar to S5 in modern humans and A. sediba, the last vertebra in A.L. 288-1an exhibits inferiorly-projecting (right side) cornua and a kidney-shaped inferior body articular surface. This morphology is inconsistent with that of fused or isolated Co1 vertebrae in humans, which either lack cornua or possess only superiorly-projecting cornua, and have more circularly-shaped inferior body articular surfaces. The level at which the hiatus' apex is located is also more compatible with typical five-element modern human sacra and A. sediba than if only four sacral vertebrae are present. Our observations suggest that A.L. 288-1 possessed five sacral vertebrae as in modern humans; thus, sacral number in "Lucy" does not indicate a directional change in vertebral count that can provide information on the PLCA ancestral condition. © 2015 Wiley Periodicals, Inc.

Fractures of the Sacrum After Chemoradiation for Rectal Carcinoma: Incidence, Risk Factors, and Radiographic Evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Han Jo; Boland, Patrick J.; Meredith, Dennis S.

Purpose: Sacral insufficiency fractures after adjuvant radiation for rectal carcinoma can present similarly to recurrent disease. As a complication associated with pelvic radiation, it is important to be aware of the incidence and risk factors associated with sacral fractures in the clinical assessment of these patients. Methods and Materials: Between 1998 and 2007, a total of 582 patients with locally advanced rectal carcinoma received adjuvant chemoradiation and surgical excision. Of these, 492 patients had imaging studies available for review. Hospital records and imaging studies from all 492 patients were retrospectively evaluated to identify risk factors associated with developing a sacralmore » insufficiency fracture. Results: With a median follow-up time of 3.5 years, the incidence of sacral fractures was 7.1% (35/492). The 4-year sacral fracture free rate was 0.91. Univariate analysis showed that increasing age ({>=}60 vs. <60 years), female sex, and history of osteoporosis were significantly associated with shorter time to sacral fracture (P=.01, P=.004, P=.001, respectively). There was no significant difference in the time to sacral fracture for patients based on stage, radiotherapy dose, or chemotherapy regimen. Multivariate analysis showed increasing age ({>=}60 vs. <60 years, hazard ratio [HR] = 2.50, 95% confidence interval [CI] = 1.22-5.13, P=.01), female sex (HR = 2.64, CI = 1.29-5.38, P=.008), and history of osteoporosis (HR = 3.23, CI = 1.23-8.50, P=.02) were independent risk factors associated with sacral fracture. Conclusions: Sacral insufficiency fractures after pelvic radiation for rectal carcinoma occur more commonly than previously described. Independent risk factors associated with fracture were osteoporosis, female sex, and age greater than 60 years.« less

Chordomas of the Skull Base, Mobile Spine, and Sacrum: An Epidemiologic Investigation of Presentation, Treatment, and Survival.

PubMed

Zuckerman, Scott L; Bilsky, Mark H; Laufer, Ilya

2018-05-01

Chordomas are rare primary bone tumors that arise from the axial skeleton. Our objective was to analyze trends in radiation and surgery over time and determine location-based survival predictors for chordomas of the skull base, mobile spine, and sacrum. A retrospective cohort study of the SEER (Surveillance Epidemiology and End Results) database from 1973 to 2013 was conducted. All patients had histologically confirmed chordomas. The principal outcome measure was overall survival (OS). The cohort included 1616 patients: skull base (664), mobile spine (444), and sacrum (508). Skull base tumors presented earliest in life (47.4 years) and sacral tumors presented latest (62.7 years). Rates of radiation remained stable for skull base and mobile spine tumors but declined for sacral tumors (P = 0.006). Rates of surgical resection remained stable for skull base and sacral tumors but declined for mobile spine tumors (P = 0.046). Skull base chordomas had the longest median survival (162 months) compared with mobile spine (94 months) and sacral tumors (87 months). Being married was independently associated with improved OS for skull base tumors (hazard ratio, 0.73; 95% confidence interval, 0.53-0.99; P = 0.044). Surgical resection was independently associated with improved OS for sacral chordomas (hazard ratio, 0.48; 95% confidence interval, 0.34-0.69; P < 0.001). Surgical resection for mobile spine chordomas and radiation for sacral chordomas decreased over time. Patients with skull base tumors survived longer than did patients with mobile spine and sacral chordomas, and surgical resection was associated with improved survival in sacral chordomas only. Understanding the behavior of these tumors can help cranial and spinal surgeons improve treatment in this patient population. Copyright © 2018 Elsevier Inc. All rights reserved.

Vibration dampener for dampening vibration of a tubular member

DOEpatents

Obermeyer, Franklin D.; Middlebrooks, Willis B.; DeMario, Edmund E.

1994-01-01

Vibration dampener for dampening vibration of a tubular member, such as an instrumentation tube of the type found in nuclear reactor pressure vessels. The instrumentation tube is received in an outer tubular member, such as a guide thimble tube. The vibration dampener comprises an annular sleeve which is attachable to the inside surface of the guide thimble tube and which is sized to surround the instrumentation tube. Dimples are attached to the interior wall of the sleeve for radially supporting the instrumentation tube. The wall of the sleeve has a flexible spring member, which is formed from the wall, disposed opposite the dimples for biasing the instrumentation tube into abutment with the dimples. Flow-induced vibration of the instrumentation tube will cause it to move out of contact with the dimples and further engage the spring member, which will flex a predetermined amount and exert a reactive force against the instrumentation tube to restrain its movement. The amount by which the spring member will flex is less than the unrestrained amplitude of vibration of the instrumentation tube. The reactive force exerted against the instrumentation tube will be sufficient to return it to its original axial position within the thimble tube. In this manner, vibration of the instrumentation tube is dampened so that in-core physics measurements are accurate and so that the instrumentation tube will not wear against the inside surface of the guide thimble tube.

Sacral neuromodulation and cardiac pacemakers.

PubMed

Roth, Ted M

2010-08-01

Potential for cross-talk between cardiac pacemakers and sacral neuromodulation remains speculative. We present a case series of patients with cardiac pacemakers who underwent staged Interstim (Medtronic, Minneapolis, MN) implantation and patients who had pulse generator implantation who later required cardiac pacemakers. No cross-talk was demonstrated in either group. Sacral neuromodulation appears to be safe in the setting of cardiac pacemakers without cardioversion/defibrillation technology.

The osteology of Camarasaurus lewisi (Jensen, 1988)

USGS Publications Warehouse

Mcintosh, J.S.; Miller, W.E.; Stadtman, K.L.; Gillette, D.D.

1996-01-01

Preparation of an approximately two-thirds complete, well-preserved Camarasaurus skeleton has recently been finished. Its detailed osteological description presented here provides a number of interesting characters, some not previously reported for the genus. This specimen (BYU 9047) was earlier named Cathetosaurus lewisi, n. gen. et sp., based on seven characters cited by Jensen (1988). Of these characters, four appear to be age related (this skeleton represents a very old individual) and not of taxonomic significance. Nevertheless, they are useful in advancing our understanding of the ligamentation associated with the sacral and posterior dorsal regions, not only of Camarasaurus but of the sauropods in general. These characters also contribute to a greater knowledge of the ontogenetic development and fusion of the sacral elements. Camarasaurus lewisi (Jensen, 1988) is a valid species whose diagnostic characters include (1) a deep but narrow cleft in the neural spines of presacral vertebrae, which most significantly persists to the sacrum rather than ending in the mid-dorsal region, as in all other species of Camarasaurus; (2) a forward rotation of the ilium with respect to the long axis of the sacrum, a hitherto unreported major character of the genus Camarasaurus; and (3) a steep angle that the posterior chevron articulating facets make with the horizontal plane.

Incarceration of the Gravid Uterus.

PubMed

Shnaekel, Kelsey L; Wendel, Michael P; Rabie, Nader Z; Magann, Everett F

2016-10-01

The aim of this review was to describe the risk factors, clinical and radiographic criteria, and management of this rare complication of pregnancy. A PubMed, Web of Science, and CINAHL search was undertaken with no limitations on the number of years searched. There were 60 articles identified, with 53 articles being the basis of this review. Multiple risk factors have been suggested in the literature including retroverted uterus in the first trimester, deep sacral concavity with an overlying sacral promontory, endometriosis, previous abdominal or pelvic surgery, pelvic or uterine adhesions, ovarian cysts, leiomyomas, multifetal gestation, uterine anomalies, uterine prolapse, and uterine incarceration in a prior pregnancy. The diagnosis is difficult to make owing to the nonspecific presenting symptoms. The diagnosis is clinical and confirmed by imaging. Magnetic resonance imaging is superior to ultrasound to accurately diagnose and elucidate the distorted maternal anatomy. Treatment is dictated by gestational age at diagnosis based on risks and benefits. The recommended route of delivery is cesarean delivery when uterine polarity cannot be corrected. Incarceration of the gravid uterus is a rare but serious complication of pregnancy. The diagnosis is clinical and confirmed with imaging, with magnetic resonance imaging being superior to delineate the distorted maternal anatomy. Reduction of the incarcerated uterus should be attempted to restore polarity and avoid unnecessary cesarean delivery.

Electrical management of neurogenic lower urinary tract disorders.

PubMed

Joussain, C; Denys, P

2015-09-01

Management of lower urinary tract dysfunction (LUTD) in neurological diseases remains a priority because it leads to many complications such as incontinence, renal failure and decreased quality of life. A pharmacological approach remains the first-line treatment for patients with neurogenic LUTD, but electrical stimulation is a well-validated and recommended second-line treatment. However, clinicians must be aware of the indications, advantages and side effects of the therapy. This report provides an update on the 2 main electrical stimulation therapies for neurogenic LUTD - inducing direct bladder contraction with the Brindley procedure and modulating LUT physiology (sacral neuromodulation, tibial posterior nerve stimulation or pudendal nerve stimulation). We also describe the indications of these therapies for neurogenic LUTD, following international guidelines, as illustrated by their efficacy in patients with neurologic disorders. Electrical stimulation could be proposed for neurogenic LUTD as second-line treatment after failure of oral pharmacologic approaches. Nevertheless, further investigations are needed for a better understanding of the mechanisms of action of these techniques and to confirm their efficacy. Other electrical investigations, such as deep-brain stimulation and repetitive transcranial magnetic stimulation, or improved sacral anterior root stimulation, which could be associated with non-invasive and highly specific deafferentation of posterior roots, may open new fields in the management of neurogenic LUTD. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Presacral abscess as a rare complication of sacral nerve stimulator implantation.

PubMed

Gumber, A; Ayyar, S; Varia, H; Pettit, S

2017-03-01

A 50-year-old man with intractable anal pain attributed to proctalgia fugax underwent insertion of a sacral nerve stimulator via the right S3 vertebral foramen for pain control with good symptomatic relief. Thirteen months later, he presented with signs of sepsis. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a large presacral abscess. MRI demonstrated increased enhancement along the pathway of the stimulator electrode, indicating that the abscess was caused by infection introduced at the time of sacral nerve stimulator placement. The patient was treated with broad spectrum antibiotics, and the sacral nerve stimulator and electrode were removed. Attempts were made to drain the abscess transrectally using minimally invasive techniques but these were unsuccessful and CT guided transperineal drainage was then performed. Despite this, the presacral abscess progressed, developing enlarging gas locules and extending to the pelvic brim to involve the aortic bifurcation, causing hydronephrosis and radiological signs of impending sacral osteomyelitis. MRI showed communication between the rectum and abscess resulting from transrectal drainage. In view of the progressive presacral sepsis, a laparotomy was performed with drainage of the abscess, closure of the upper rectum and formation of a defunctioning end sigmoid colostomy. Following this, the presacral infection resolved. Presacral abscess formation secondary to an infected sacral nerve stimulator electrode has not been reported previously. Our experience suggests that in a similar situation, the optimal management is to perform laparotomy with drainage of the presacral abscess together with simultaneous removal of the sacral nerve stimulator and electrode.

Presacral abscess as a rare complication of sacral nerve stimulator implantation

PubMed Central

Gumber, A; Ayyar, S; Varia, H

2017-01-01

A 50-year-old man with intractable anal pain attributed to proctalgia fugax underwent insertion of a sacral nerve stimulator via the right S3 vertebral foramen for pain control with good symptomatic relief. Thirteen months later, he presented with signs of sepsis. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a large presacral abscess. MRI demonstrated increased enhancement along the pathway of the stimulator electrode, indicating that the abscess was caused by infection introduced at the time of sacral nerve stimulator placement. The patient was treated with broad spectrum antibiotics, and the sacral nerve stimulator and electrode were removed. Attempts were made to drain the abscess transrectally using minimally invasive techniques but these were unsuccessful and CT guided transperineal drainage was then performed. Despite this, the presacral abscess progressed, developing enlarging gas locules and extending to the pelvic brim to involve the aortic bifurcation, causing hydronephrosis and radiological signs of impending sacral osteomyelitis. MRI showed communication between the rectum and abscess resulting from transrectal drainage. In view of the progressive presacral sepsis, a laparotomy was performed with drainage of the abscess, closure of the upper rectum and formation of a defunctioning end sigmoid colostomy. Following this, the presacral infection resolved. Presacral abscess formation secondary to an infected sacral nerve stimulator electrode has not been reported previously. Our experience suggests that in a similar situation, the optimal management is to perform laparotomy with drainage of the presacral abscess together with simultaneous removal of the sacral nerve stimulator and electrode. PMID:28071947

Introduction of laparoscopic sacral colpopexy to a fellowship training program.

PubMed

Kantartzis, Kelly; Sutkin, Gary; Winger, Dan; Wang, Li; Shepherd, Jonathan

2013-11-01

Minimally invasive sacral colpopexy has increased over the past decade, with many senior physicians adopting this new skill set. However, skill acquisition at an academic institution in the presence of postgraduate learners is not well described. This manuscript outlines the introduction of laparoscopic sacral colpopexy to an academic urogynecology service that was not performing minimally invasive sacral colpopexies, and it also defines a surgical learning curve. The first 180 laparoscopic sacral colpopexies done by four attending urogynecologists from January 2009 to December 2011 were retrospectively analyzed. The primary outcome was operative time. Secondary outcomes included conversion to laparotomy, estimated blood loss, and intra- and postoperative complications. Linear regression was used to analyze trends in operative times. Fisher's exact test compared surgical complications and counts of categorical variables. Mean total operative time was 250 ± 52 min (range 146-452) with hysterectomy and 222 ± 45 (range 146-353) for sacral colpopexy alone. When compared with the first ten cases performed by each surgeon, operative times in subsequent groups decreased significantly, with a 6-16.3% reduction in overall times. There was no significant difference in the rate of overall complications regardless of the number of prior procedures performed (p = 0.262). Introduction of laparoscopic sacral colpopexy in a training program is safe and efficient. Reduction in operative time is similar to published learning curves in teaching and nonteaching settings. Introducing this technique does not add additional surgical risk as these skills are acquired.

Proximal sacral deformity: a common element in lytic isthmic spondylolisthesis at L5 and in degenerative spondylolisthesis at L4-L5 segment. Two apparently very different etiopathogenic entities.

PubMed

Gallego-Goyanes, A; Barahona-Lorenzo, D; Díez-Ulloa, M A

A radiographic study was carried out to investigate the relationship between proximal sacral sagittal anatomy (either kyphosis or lordosis) and either isthmic or degenerative spondylolisthesis. In addition, we studied whether there is a relationship between proximal sacral kyphosis and the degree of such listhesis in the case of L5 isthmic spondylolisthesis. Lateral standing x-rays were used from 173 patients, ninety of whom had degenerative spondylolisthesis L4-L5, and eighty-three an isthmic spondylolisthesis of L5 (67 low-grade and 16 high-grade) and compared with a control group of 100 patients adjusted by age and gender, without any type of spondylolisthesis. Listhesis was graded using Meyerding's classification and the proximal sacral kyphosis angle (CSP) was measured between S1 and S2 posterior walls, according to Harrison's method. In our series, there was a proximal sacral kyphosis in both types of spondylolisthesis, greater in the lytic type. By contrast, the control group had a proximal sacral lordosis. The differences were statistically significant. Therefore, we concluded that there was a proximal sacral kyphosis in patients with both degenerative and isthmic lytic spondylolisthesis, but with our results, we were not able to ascertain whether it is a cause or a consequence of this listhesis. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

Sacral nerve stimulation can be an effective treatment for low anterior resection syndrome.

PubMed

Eftaiha, S M; Balachandran, B; Marecik, S J; Mellgren, A; Nordenstam, J; Melich, G; Prasad, L M; Park, J J

2017-10-01

Sacral nerve stimulation has become a preferred method for the treatment of faecal incontinence in patients who fail conservative (non-operative) therapy. In previous small studies, sacral nerve stimulation has demonstrated improvement of faecal incontinence and quality of life in a majority of patients with low anterior resection syndrome. We evaluated the efficacy of sacral nerve stimulation in the treatment of low anterior resection syndrome using a recently developed and validated low anterior resection syndrome instrument to quantify symptoms. A retrospective review of consecutive patients undergoing sacral nerve stimulation for the treatment of low anterior resection syndrome was performed. Procedures took place in the Division of Colon and Rectal Surgery at two academic tertiary medical centres. Pre- and post-treatment Cleveland Clinic Incontinence Scores and Low Anterior Resection Syndrome scores were assessed. Twelve patients (50% men) suffering from low anterior resection syndrome with a mean age of 67.8 (±10.8) years underwent sacral nerve test stimulation. Ten patients (83%) proceeded to permanent implantation. Median time from anterior resection to stimulator implant was 16 (range 5-108) months. At a median follow-up of 19.5 (range 4-42) months, there were significant improvements in Cleveland Clinic Incontinence Scores and Low Anterior Resection Syndrome scores (P < 0.001). Sacral nerve stimulation improved symptoms in patients suffering from low anterior resection syndrome and may therefore be a viable treatment option. Colorectal Disease © 2017 The Association of Coloproctology of Great Britain and Ireland.

Evaluation of the diagnostic accuracy of four-view radiography and conventional computed tomography analysing sacral and pelvic fractures in dogs.

PubMed

Stieger-Vanegas, S M; Senthirajah, S K J; Nemanic, S; Baltzer, W; Warnock, J; Bobe, G

2015-01-01

The purpose of our study was (1) to determine whether four-view radiography of the pelvis is as reliable and accurate as computed tomography (CT) in diagnosing sacral and pelvic fractures, in addition to coxofemoral and sacroiliac joint subluxation or luxation, and (2) to evaluate the effect of the amount of training in reading diagnostic imaging studies on the accuracy of diagnosing sacral and pelvic fractures in dogs. Sacral and pelvic fractures were created in 11 canine cadavers using a lateral impactor. In all cadavers, frog-legged ventro-dorsal, lateral, right and left ventro-45°-medial to dorsolateral oblique frog leg ("rollover 45-degree view") radiographs and a CT of the pelvis were obtained. Two radiologists, two surgeons and two veterinary students classified fractures using a confidence scale and noted the duration of evaluation for each imaging modality and case. The imaging results were compared to gross dissection. All evaluators required significantly more time to analyse CT images compared to radiographic images. Sacral and pelvic fractures, specifically those of the sacral body, ischiatic table, and the pubic bone, were more accurately diagnosed using CT compared to radiography. Fractures of the acetabulum and iliac body were diagnosed with similar accuracy (at least 86%) using either modality. Computed tomography is a better method for detecting canine sacral and some pelvic fractures compared to radiography. Computed tomography provided an accuracy of close to 100% in persons trained in evaluating CT images.

Quantitative evaluation of the lumbosacral sagittal alignment in degenerative lumbar spinal stenosis

PubMed Central

Makirov, Serik K.; Jahaf, Mohammed T.; Nikulina, Anastasia A.

2015-01-01

Goal of the study This study intends to develop a method of quantitative sagittal balance parameters assessment, based on a geometrical model of lumbar spine and sacrum. Methods One hundred eight patients were divided into 2 groups. In the experimental group have been included 59 patients with lumbar spinal stenosis on L1-5 level. Forty-nine healthy volunteers without history of any lumbar spine pathlogy were included in the control group. All patients have been examined with supine MRI. Lumbar lordosis has been adopted as circular arc and described either anatomical (lumbar lordosis angle), or geometrical (chord length, circle segment height, the central angle, circle radius) parameters. Moreover, 2 sacral parameters have been assessed for all patients: sacral slope and sacral deviation angle. Both parameters characterize sacrum disposition in horizontal and vertical axis respectively. Results Significant correlation was observed between anatomical and geometrical lumbo-sacral parameters. Significant differences between stenosis group and control group were observed in the value of the “central angle” and “sacral deviation” parameters. We propose additional parameters: lumbar coefficient, as ratio of the lordosis angle to the segmental angle (Kl); sacral coefficient, as ratio of the sacral tilt (ST) to the sacral deviation (SD) angle (Ks); and assessment modulus of the mathematical difference between sacral and lumbar coefficients has been used for determining lumbosacral balance (LSB). Statistically significant differences between main and control group have been obtained for all described coefficients (p = 0.006, p = 0.0001, p = 0.0001, accordingly). Median of LSB value of was 0.18 and 0.34 for stenosis and control groups, accordingly. Conclusion Based on these results we believe that that spinal stenosis is associated with an acquired deformity that is measureable by the described parameters. It's possible that spinal stenosis occurs in patients with an LSB of 0.2 or less, so this value can be predictable for its development. It may suggest that spinal stenosis is more likely to occur in patients with the spinal curvature of this type because of abnormal distribution of the spine loads. This fact may have prognostic significance for develop vertebral column disease and evaluation of treatment results. PMID:26767160

Friction and wear on laser textured Ti6Al4V surface subjected to laser shock peening with contacting foil

NASA Astrophysics Data System (ADS)

Dai, F. Z.; Geng, J.; Tan, W. S.; Ren, X. D.; Lu, J. Z.; Huang, Shu

2018-07-01

The Ti6Al4V micro-dimple surfaces fabricated by a masked laser surface texturing (MLST) technique within water were subjected to soft contact laser shock peening (SCLSP) and hard contact laser shock peening (HCLSP). The effects of these two LSP methods on topography, micro-hardness and residual stress distribution were studied. The friction and wear performance under dry friction and oil lubrication were also studied. The enclosure of micro cracks in the micro-dimple bottom was observed when treated by SCLSP and HCLSP. The dry friction and wear test showed that the MLST+HCLSP surfaces had the best wear resistance performance. In the oil lubricated friction test, the occurrence of the hydrodynamic lubrication effect occurred on the micro-dimple surfaces. The MLST+HCLSP exhibited the best friction and wear resistance performance. These were due to the micro-hardness increase, the producing of compressive residual stress and the surface roughness reduction of as treated surfaces.

Effects of laser shock peening with contacting foil on micro laser texturing surface of Ti6Al4V

NASA Astrophysics Data System (ADS)

Dai, Fengze; Zhang, Zidong; Ren, Xudong; Lu, Jinzhong; Huang, Shu

2018-02-01

Ti6Al4V samples with micro-dimple arrays were subjected to laser shock peening in contact with foil (HCLSP). The surface roughness, micro-hardness, the residual stress distribution and the surface morphology of the micro-dimple arrays were studied to evaluate the effects of HCLSP. Moreover, the surface topography of the foils in contact was also analyzed. The gap existence between the foil and the to-be treated surface led the mechanism of HCLSP to be different compared to regular laser shock peening. The surface roughness reduction, the work-hardening effects, the compressive residual stress and the micro crack enclosure were achieved. A simplified ball-hitting-surface model was utilized to analyze the HCLSP impact. The model could well explain the experimental results. When treated by the HCLSP with H62 foil at the laser power density of 4.24 GW/cm2, the Ti6Al4V samples with micro-dimple arrays exhibit well surface topography and mechanical performance.

An elastic dimpling instability with Kosterlitz-Thouless character and a precursor role in creasing

NASA Astrophysics Data System (ADS)

Engstrom, Tyler; Paulsen, Joseph; Schwarz, Jennifer

Creasing instability, also known as sulcification, occurs in a variety of quasi-2d elastic systems subject to compressive plane strain, and has been proposed as a mechanism of brain folding. While the dynamics of pre-existing creases can be understood in terms of crack propagation, a detailed critical phenomena picture of the instability is lacking. We show that surface dimpling is an equilibrium phase transition, and can be described in a language of quasi-particle excitations conceptualized as ``ghost fibers'' within the shear lag model. Tension-compression pairs (dipoles) of ghost fibers are energetically favorable at low strains, and the pairs unbind at a critical compressive plane strain, analogously to vortices in the Kosterlitz-Thouless transition. This dimpling transition bears strong resemblance to the creasing instability. We argue that zero-length creases are ghost fibers, which are a special case of ``ghost slabs''. Critical strain of a ghost slab increases linearly with its length, and is independent of both shear modulus and system thickness.

Broadband focusing ultrasonic transducers based on dimpled LiNbO3 plate with inversion layer.

PubMed

Chen, Jin; Dai, Ji-Yan; Zhang, Chao; Zhang, Zhitian; Feng, Guanping

2012-12-01

A high-frequency broadband focusing transducer based on dimpled LiNbO(3) inversion layer plate has been fabricated and characterized. A spherical surface with a curvature radius of 6 mm is formed on the half-thickness LiNbO(3) inversion layer plate of Y36° cut orientation. The domain structure in the cross section is observed after a hydrofluoric acid etching process. For transducer fabrication, conductive epoxy is used as the backing material and polymer is deposited on the front face as the matching layer. The center frequency, bandwidth, and insertion loss of the focused transducer are measured to be 72 MHz, 136%, and -32 dB, respectively. The focused transducer has been successfully used for rabbit eyeball imaging and a better imaging capability compared with the planar transducer has been demonstrated. These promising results prove that the dimpled LiNbO(3) inversion layer plate has great potential for fabrication of high-frequency broadband focusing ultrasonic transducers.

Sacral root neuromodulation in the treatment of various voiding and storage problems.

PubMed

Shaker, H; Hassouna, M M

1999-01-01

This paper reviews the use of sacral neuromodulation as a treatment modality for patients with bladder dysfunction. The dual functions of the urinary bladder are to act as a reservoir and to evacuate under voluntary control. Bladder dysfunction is a descriptive term describing the loss or the impairment of one or both of these functions. In the first part of the manuscript we describe the different components of sacral neuromodulation: the screening test known as percutaneous nerve evaluation (PNE), which involves screening patients who could potentially benefit from the therapy. Those who show a satisfactory response will have a permanent neuroprosthesis implanted. The technical aspects of both components of neuromodulation are described in detail, as well as the technical difficulties encountered. In the second part we present our long-term results in patients with sacral neuromodulation. Sacral neuromodulation is a safe and efficient therapeutic modality that helps patients with refractory voiding dysfunction restore their bladder function.

Pelvic trauma with displaced sacral fractures: functional outcome at one year.

PubMed

Tötterman, Anna; Glott, Thomas; Søberg, Helene Lundgaard; Madsen, Jan Erik; Røise, Olav

2007-06-01

A prospective single-cohort study of 31 patients surgically treated for pelvic injuries with displaced sacral fractures. To describe the medium term functional outcome in unstable sacral fractures. Displaced sacral fractures pose a special challenge in orthopedic surgery due to the high rate of associated injuries. Little information is available on the medium-term functional outcome of patients with injuries which include unstable sacral fractures. We examined 31 patients with displaced sacral fractures having 10 mm or more displacement, 1 year (mean, 1.4 years; range, 1.0-2.5 years) after injury. Data from a previous study were supplemented with functional outcome measures (work status, independence in ADL, and SF-36). An association between outcome and tested variables was sought. Fifteen months after injury, 65% of the patients had regained their independence in functions pertaining to daily activities; 33% had returned to work. All dimensions of perceived health were affected. Polytrauma and impairments relative to voiding and sexual function had a detrimental effect on outcome. Fracture characteristics were not predictive of poor outcome. Although the majority of patients achieved independent living, medium-term follow-up indicated significant residual disability. The complex nature of these fractures and the associated injuries should be considered in the rehabilitation of these patients.

Anterior sacral meningocele with presacral cysts: report of a case.

PubMed

Krivokapić, Zoran; Grubor, Nikica; Micev, Marjan; Colović, Radoje

2004-11-01

Anterior sacral meningocele is a rare anomaly most frequently presenting as a presacral mass. Since the first description in 1837, approximately 150 cases have been reported. The case presented is a 37-year-old female in whom an asymptomatic presacral mass was discovered during her first delivery. Because normal delivery was impossible, a cesarean section was performed. A year later, in a regional hospital a "cystic presacral tumor" was treated with biopsy and drainage. Four years later, she developed constipation caused by perineal compression for which she was admitted to our department in which two anterior presacral cysts were excised. The recovery was complicated with meningitis, which was successfully treated with antibiotics. Whenever a presacral mass is found, anterior sacral meningocele has to be a diagnostic consideration. The symptoms are usually related to the compression on rectum, bladder, and sacral nervous plexus. Rectal examination and radiography of the pelvis with the sacral bone showing the "scimitar sign" are the main diagnostic methods. Myelography, computed tomography, and magnetic resonance imaging are the best methods for identifying the precise anatomy of sacral meningocele and for proper planning of the operation. Transvaginal or transrectal aspiration and drainage are not advised, because they may result in a lethal outcome caused by sepsis.

Finding sacral: Developmental evolution of the axial skeleton of odontocetes (Cetacea).

PubMed

Buchholtz, Emily A; Gee, Jessica K

2017-07-01

Axial morphology was dramatically transformed during the transition from terrestrial to aquatic environments by archaeocete cetaceans, and again during the subsequent odontocete radiation. Here, we reconstruct the sequence of developmental events that underlie these phenotypic transitions. Archaeocete innovations include the loss of primaxial/abaxial interaction at the sacral/pelvic articulation and the modular dissociation of the fluke from the remainder of the tail. Odontocetes subsequently integrated lumbar, sacral, and anterior caudal vertebrae into a single torso module, and underwent multiple series-specific changes in vertebral count. The conservation of regional proportions despite regional fluctuations in count strongly argues that rates of somitogenesis can vary along the column and that segmentation was dissociated from regionalization during odontocete evolution. Conserved regional proportions also allow the prediction of the location and count of sacral homologs within the torso module. These predictions are tested with the analysis of comparative pudendal nerve root location and geometric morphometrics. We conclude that the proportion of the column represented by the sacral series has been conserved, and that its vertebrae have changed in count and relative centrum length in parallel with other torso vertebrae. Although the sacral series of odontocetes is de-differentiated, it is not de-regionalized. © 2017 Wiley Periodicals, Inc.

Intrapartum sacral stress fracture due to pregnancy-related osteoporosis: a case report.

PubMed

Oztürk, Gülcan; Külcü, Duygu Geler; Aydoğ, Ece

2013-01-01

Low back pain (LBP) and hip pain frequently occur during pregnancy and postpartum period. Although pelvic and mechanic lesions of the soft tissues are most responsible for the etiology, sacral fracture is also one of the rare causes. A 32-year-old primigravid patient presented with LBP and right hip pain which started 3 days after vaginal delivery. Although direct radiographic examination was normal, magnetic resonance imaging of the sacrum revealed sacral stress fracture. Lumbar spine and femoral bone mineral density showed osteoporosis as a risk factor. There were no other risk factors such as trauma, excessive weight gain, and strenuous physical activity. It is considered that the patient had sacral fatigue and insufficiency fracture in intrapartum period. The patient's symptoms subsided in 3 months after physical therapy and rest. In conclusion, sacral fractures during pregnancy and postpartum period, especially resulting from childbirth, are very rare. To date, there are two cases in the literature. In cases who even do not have risk factors related to vaginal delivery such as high birth weight infant and the use of forceps, exc., sacral fracture should be considered in the differential diagnosis of LBP and hip pain started soon after child birth. Pregnancy-related osteoporosis may lead to fracture during vaginal delivery.

Application of cylindrical, triangular and hemispherical dimples in the film cooling technology

NASA Astrophysics Data System (ADS)

Khalatov, A. A.; Panchenko, N. A.; Severin, S. D.

2017-11-01

The results of film cooling numerical simulation over a flat plate with coolant supply through a single span-wise array of inclined (α = 30°) holes arranged inside cylindrical, triangular, and hemispherical dimples are represented in the paper. Such configurations are of a great practical interest for application in advanced blade cooling systems of high-performance gas turbines. The schemes with coolant supply into triangular and hemispherical dimples were first proposed and patented by the IET of the NAS of Ukraine. For numerical simulation the ANSYS CFX 14 commercial code was used. Numerical simulation were carried out in a wide range of the blowing ratio parameter varied from 0.5 to 2.0. For low blowing ratio parameter (m = 0.5) the laterally averaged film cooling efficiency is actually the same for all investigated schemes over the main film cooling area. In this area, the most simple in terms of the film cooling production technology configuration can be used. At the medium and high blowing ratios (m = 1.0 or higher) all investigated film cooling schemes allow to increase the laterally averaged film cooling efficiency in comparison with the traditional cooling scheme with single row of incline holes. In this case the configuration with coolant supply into triangular dimples of the «crater» type demonstrates the best film cooling efficiency due to significant reduction in the intensity and scale of the “kidney” vortex beyond configuration, as well as due to decrease in the coolant blowing non-uniformity factor.

Slow Strain Rate Testing for Hydrogen Embrittlement Susceptibility of Alloy 718 in Substitute Ocean Water

NASA Astrophysics Data System (ADS)

LaCoursiere, M. P.; Aidun, D. K.; Morrison, D. J.

2017-05-01

The hydrogen embrittlement susceptibility of near-peak-aged UNS N07718 (Alloy 718) was evaluated by performing slow strain rate tests at room temperature in air and substitute ocean water. Tests in substitute ocean water were accomplished in an environmental cell that enabled in situ cathodic charging under an applied potential of -1.1 V versus SCE. Some specimens were cathodically precharged for 4 or 16 weeks at the same potential in a 3.5 wt.% NaCl-distilled water solution at 50 °C. Unprecharged specimens tested in substitute ocean water exhibited only moderate embrittlement with plastic strain to failure decreasing by about 20% compared to unprecharged specimens tested in air. However, precharged specimens exhibited significant embrittlement with plastic strain to failure decreasing by about 70%. Test environment (air or substitute ocean water with in situ charging) and precharge time (4 or 16 weeks) had little effect on the results of the precharged specimens. Fracture surfaces of precharged specimens were typical of hydrogen embrittlement and consisted of an outer brittle ring related to the region in which hydrogen infused during precharging, a finely dimpled transition zone probably related to the region where hydrogen was drawn in by dislocation transport, and a central highly dimpled ductile region. Fracture surfaces of unprecharged specimens tested in substitute ocean water consisted of a finely dimpled outer ring and heavily dimpled central region typical of ductile fracture.

Fabrication and characterization of DLC coated microdimples on hip prosthesis heads.

PubMed

Choudhury, Dipankar; Ay Ching, Hee; Mamat, Azuddin Bin; Cizek, Jan; Abu Osman, Noor Azuan; Vrbka, Martin; Hartl, Martin; Krupka, Ivan

2015-07-01

Diamond like carbon (DLC) is applied as a thin film onto substrates to obtain desired surface properties such as increased hardness and corrosion resistance, and decreased friction and wear rate. Microdimple is an advanced surface modification technique enhancing the tribological performance. In this study, DLC coated microdimples were fabricated on hip prosthesis heads and their mechanical, material and surface properties were characterized. An Electro discharge machining (EDM) oriented microdrilling was utilized to fabricate a defined microdimple array (diameter of 300 µm, depth of 70 µm, and pitch of 900 µm) on stainless steel (SS) hip prosthesis heads. The dimpled surfaces were then coated by hydrogenated amorphous carbon (a-C:H) and tetrahedral amorphous carbon (Ta-C) layers by using a magnetron sputtering technology. A preliminary tribology test was conducted on these fabricated surfaces against a ceramic ball in simulated hip joint conditions. It was found that the fabricated dimples were perpendicular to the spherical surfaces and no cutting-tools wear debris was detected inside the individual dimples. The a-C:H and Ta-C coatings increased the hardness at both the dimple edges and the nondimpled region. The tribology test showed a significant reduction in friction coefficient for coated surfaces regardless of microdimple arrays: the lowest friction coefficient was found for the a-C:H samples (µ = 0.084), followed by Ta-C (µ = 0.119), as compared to the SS surface (µ = 0.248). © 2014 Wiley Periodicals, Inc.

Vibration dampener for dampening vibration of a tubular member

DOEpatents

Obermeyer, F.D.; Middlebrooks, W.B.; DeMario, E.E.

1994-10-18

Vibration dampener for dampening vibration of a tubular member, such as an instrumentation tube of the type found in nuclear reactor pressure vessels is disclosed. The instrumentation tube is received in an outer tubular member, such as a guide thimble tube. The vibration dampener comprises an annular sleeve which is attachable to the inside surface of the guide thimble tube and which is sized to surround the instrumentation tube. Dimples are attached to the interior wall of the sleeve for radially supporting the instrumentation tube. The wall of the sleeve has a flexible spring member, which is formed from the wall, disposed opposite the dimples for biasing the instrumentation tube into abutment with the dimples. Flow-induced vibration of the instrumentation tube will cause it to move out of contact with the dimples and further engage the spring member, which will flex a predetermined amount and exert a reactive force against the instrumentation tube to restrain its movement. The amount by which the spring member will flex is less than the unrestrained amplitude of vibration of the instrumentation tube. The reactive force exerted against the instrumentation tube will be sufficient to return it to its original axial position within the thimble tube. In this manner, vibration of the instrumentation tube is dampened so that in-core physics measurements are accurate and so that the instrumentation tube will not wear against the inside surface of the guide thimble tube. 14 figs.

Wrinkling crystallography on spherical surfaces

PubMed Central

Brojan, Miha; Terwagne, Denis; Lagrange, Romain; Reis, Pedro M.

2015-01-01

We present the results of an experimental investigation on the crystallography of the dimpled patterns obtained through wrinkling of a curved elastic system. Our macroscopic samples comprise a thin hemispherical shell bound to an equally curved compliant substrate. Under compression, a crystalline pattern of dimples self-organizes on the surface of the shell. Stresses are relaxed by both out-of-surface buckling and the emergence of defects in the quasi-hexagonal pattern. Three-dimensional scanning is used to digitize the topography. Regarding the dimples as point-like packing units produces spherical Voronoi tessellations with cells that are polydisperse and distorted, away from their regular shapes. We analyze the structure of crystalline defects, as a function of system size. Disclinations are observed and, above a threshold value, dislocations proliferate rapidly with system size. Our samples exhibit striking similarities with other curved crystals of charged particles and colloids. Differences are also found and attributed to the far-from-equilibrium nature of our patterns due to the random and initially frozen material imperfections which act as nucleation points, the presence of a physical boundary which represents an additional source of stress, and the inability of dimples to rearrange during crystallization. Even if we do not have access to the exact form of the interdimple interaction, our experiments suggest a broader generality of previous results of curved crystallography and their robustness on the details of the interaction potential. Furthermore, our findings open the door to future studies on curved crystals far from equilibrium. PMID:25535355

Evaluation of the rostral projection of the sacral lamina as a component of degenerative lumbosacral stenosis in German shepherd dogs.

PubMed

Saunders, Harvey; Worth, Andrew J; Bridges, Janis P; Hartman, Angela

2018-05-20

To determine the association between a greater rostral projection of the sacral lamina and clinical signs of cauda equina syndrome (CES) in German shepherd dogs (GSD) with presumptive degenerative lumbosacral disease (DLSS). Retrospective cohort study. One hundred forty-three GSD (125 police dogs and 18 pet dogs) presenting for either CES or prebreeding evaluation. Fifty-five were classified as affected by CES and diagnosed with DLSS, and 88 were classified as unaffected on the basis of clinical and imaging findings. The position of the rostral edge of the sacral lamina was measured from radiographs and/or computed tomography (CT) scans. This position was compared between affected and unaffected dogs. In dogs that underwent both radiography and CT scanning, the agreement between sacral lamina localization using each imaging modality was determined. Owners/handlers were contacted to determine whether dogs subsequently developed clinical signs compatible with CES at a mean of 29 months (unaffected). The sacral lamina did not extend as far rostrally in affected dogs, compared to unaffected dogs (P = .04). Among the 88 dogs unaffected by CES at initial evaluation, 2 developed clinical signs consistent with CES at follow-up. Rostral projection of the sacral lamina, previously proposed as a potential risk factor in dogs with CES due to lumbosacral degeneration, was not associated with a diagnosis of DLSS in this study; the opposite was true. Rostral projection of the sacral lamina may not be a predisposing factor in the development of CES due to DLSS in GSD. © 2018 The American College of Veterinary Surgeons.

Comparative sacral morphology and the reconstructed tail lengths of five extinct primates: Proconsul heseloni, Epipliopithecus vindobonensis, Archaeolemur edwardsi, Megaladapis grandidieri, and Palaeopropithecus kelyus.

PubMed

Russo, Gabrielle A

2016-01-01

This study evaluated the relationship between the morphology of the sacrum-the sole bony link between the tail or coccyx and the rest of the body-and tail length (including presence/absence) and function using a comparative sample of extant mammals spanning six orders (Primates, Carnivora, Rodentia, Diprotodontia, Pilosa, Scandentia; N = 472). Phylogenetically-informed regression methods were used to assess how tail length varied with respect to 11 external and internal (i.e., trabecular) bony sacral variables with known or suspected biomechanical significance across all mammals, only primates, and only non-primates. Sacral variables were also evaluated for primates assigned to tail categories ('tailless,' 'nonprehensile short-tailed,' 'nonprehensile long-tailed,' and 'prehensile-tailed'). Compared to primates with reduced tail lengths, primates with longer tails generally exhibited sacra having larger caudal neural openings than cranial neural openings, and last sacral vertebrae with more mediolaterally-expanded caudal articular surfaces than cranial articular surfaces, more laterally-expanded transverse processes, more dorsally-projecting spinous processes, and larger caudal articular surface areas. Observations were corroborated by the comparative sample, which showed that shorter-tailed (e.g., Lynx rufus [bobcat]) and longer-tailed (e.g., Acinonyx jubatus [cheetah]) non-primate mammals morphologically converge with shorter-tailed (e.g., Macaca nemestrina) and longer-tailed (e.g., Macaca fascicularis) primates, respectively. 'Prehensile-tailed' primates exhibited last sacral vertebrae with more laterally-expanded transverse processes and greater caudal articular surface areas than 'nonprehensile long-tailed' primates. Internal sacral variables performed poorly compared to external sacral variables in analyses of extant primates, and were thus deemed less useful for making inferences concerning tail length and function in extinct primates. The tails lengths of five extinct primates were reconstructed from the external sacral variables: Archaeolemur edwardsi had a 'nonprehensile long tail,' Megaladapis grandidieri, Palaeopropithecus kelyus, and Epipliopithecus vindobonensis probably had 'nonprehensile short tails,' and Proconsul heseloni was 'tailless.' Copyright © 2015 Elsevier Ltd. All rights reserved.

Sacroplasty for symptomatic sacral hemangioma: a novel treatment approach. A case report.

PubMed

Agarwal, V; Sreedher, G; Weiss, K R; Hughes, M A

2013-06-01

Painful vertebral body hemangiomas have been successfully treated with vertebroplasty and kyphoplasty. Sacral hemangiomas are uncommon and as such painful sacral hemangiomas are rare entities. We report what we believe is only the second successful treatment of a painful sacral hemangioma with CT-guided sacroplasty. A 56-year-old woman with a history of right-sided total hip arthroplasty and lipoma excision presented to her orthopedic surgeon with persistent right-sided low back pain which radiated into her buttock and right groin and hindered her ability to walk and perform her activities of daily living. MRIs of the thoracic spine, lumbar spine and pelvis showed numerous lesions with imaging characteristics consistent with multiple hemangiomas including a 2.2×2.1 cm lesion involving the right sacrum adjacent to the right S1 neural foramen. Conservative measures including rest, physical therapy, oral analgesics and right-sided sacroiliac joint steroid injection did not provide significant relief. Given her lack of improvement and the fact that her pain localized to the right sacrum, the patient underwent CT-guided sacroplasty for treatment of a painful right sacral hemangioma. Under CT fluoroscopic guidance, a 10 gauge introducer needle was advanced through the soft tissues of the back to the margin of the lesion. Biopsy was then performed and after appropriate preparation, cement was then introduced through the needle using a separate cement filler cannula. Appropriate filling of the right sacral hemangioma was visualized using intermittent CT fluoroscopy. After injection of approximately 2.5 cc of cement, it was felt that there was near complete filling of the right sacral hemangioma. With satisfactory achievement of cement filling, the procedure was terminated. Pathology from biopsy taken at the time of the procedure was consistent with hemangioma. Image-guided sacroplasty with well-defined endpoints is an effective, minimally invasive and safe procedure. Patients with painful sacral hemangiomas can be treated with this technique with no significant complications.

Sacroplasty for Symptomatic Sacral Hemangioma: A Novel Treatment Approach

PubMed Central

Agarwal, V.; Sreedher, G.; Weiss, K.R.; Hughes, M.A.

2013-01-01

Summary Painful vertebral body hemangiomas have been successfully treated with vertebroplasty and kyphoplasty. Sacral hemangiomas are uncommon and as such painful sacral hemangiomas are rare entities. We report what we believe is only the second successful treatment of a painful sacral hemangioma with CT-guided sacroplasty. A 56-year-old woman with a history of right-sided total hip arthroplasty and lipoma excision presented to her orthopedic surgeon with persistent right-sided low back pain which radiated into her buttock and right groin and hindered her ability to walk and perform her activities of daily living. MRIs of the thoracic spine, lumbar spine and pelvis showed numerous lesions with imaging characteristics consistent with multiple hemangiomas including a 2.2×2.1 cm lesion involving the right sacrum adjacent to the right S1 neural foramen. Conservative measures including rest, physical therapy, oral analgesics and right-sided sacroiliac joint steroid injection did not provide significant relief. Given her lack of improvement and the fact that her pain localized to the right sacrum, the patient underwent CT-guided sacroplasty for treatment of a painful right sacral hemangioma. Under CT fluoroscopic guidance, a 10 gauge introducer needle was advanced through the soft tissues of the back to the margin of the lesion. Biopsy was then performed and after appropriate preparation, cement was then introduced through the needle using a separate cement filler cannula. Appropriate filling of the right sacral hemangioma was visualized using intermittent CT fluoroscopy. After injection of approximately 2.5 cc of cement, it was felt that there was near complete filling of the right sacral hemangioma. With satisfactory achievement of cement filling, the procedure was terminated. Pathology from biopsy taken at the time of the procedure was consistent with hemangioma. Image-guided sacroplasty with well-defined endpoints is an effective, minimally invasive and safe procedure. Patients with painful sacral hemangiomas can be treated with this technique with no significant complications. PMID:23693051

[Four cases of urinary dysfunction associated with sacral herpes zoster].

PubMed

Matsuo, Tomohiro; Oba, Kojiro; Miyata, Yasuyoshi; Igawa, Tsukasa; Sakai, Hideki

2014-02-01

Herpes zoster is caused by the infection of Varicella-Zoster virus. The anatomical distribution of herpes zoster in the sacral area is only 6. 9%1). Moreover, the onset rate of herpes zoster with urinary dysfunction is 0.6%1). The lesion sites of herpes zoster which cause urinary dysfunction are almost lumber and sacral areas. We describe four cases of sacral herpes zoster with urinary dysfunction in this report. All patients were elderly people (66-84 years old), and all patients were administered anti-virus drugs and alpha 1-adrenergic receptor blockers. Because of urinary retention, three patients have performed clean intermittent self-catheterization (CIC) for several weeks. As the lesions of herpes zoster healed, each patient recovered from urinary dysfunction.

[Sacral nerve stimulation in fecal incontinence].

PubMed

Rasmussen, Ole Ø; Christiansen, John

2002-08-12

Sacral nerve stimulation for the treatment of faecal incontinence has gained increasing use in Europe over the last two years. Experience with the first patients treated in Denmark is described here. Fourteen patients with severe faecal incontinence were given sacral nerve stimulation. The first treatment was temporary, and if this was successful they had a device for permanent stimulation implanted. The result of the test stimulation was good in ten of the 14 patients and a permanent system was implanted. After a median of 4.5 months' stimulation, nine of the ten patients continued to respond to respond well. Sacral nerve stimulation in the treatment of faecal incontinence shows promising results. Compared to other more advanced forms of treatment, this method is minimally invasive.

Soliton-sound interactions in quasi-one-dimensional Bose-Einstein condensates.

PubMed

Parker, N G; Proukakis, N P; Leadbeater, M; Adams, C S

2003-06-06

Longitudinal confinement of dark solitons in quasi-one-dimensional Bose-Einstein condensates leads to sound emission and reabsorption. We perform quantitative studies of the dynamics of a soliton oscillating in a tight dimple trap, embedded in a weaker harmonic trap. The dimple depth provides a sensitive handle to control the soliton-sound interaction. In the limit of no reabsorption, the power radiated is found to be proportional to the soliton acceleration squared. An experiment is proposed to detect sound emission as a change in amplitude and frequency of soliton oscillations.

Method for thinning specimen

DOEpatents

Follstaedt, David M.; Moran, Michael P.

2005-03-15

A method for thinning (such as in grinding and polishing) a material surface using an instrument means for moving an article with a discontinuous surface with an abrasive material dispersed between the material surface and the discontinuous surface where the discontinuous surface of the moving article provides an efficient means for maintaining contact of the abrasive with the material surface. When used to dimple specimens for microscopy analysis, a wheel with a surface that has been modified to produce a uniform or random discontinuous surface significantly improves the speed of the dimpling process without loss of quality of finish.

Influence of the shielding effect on the formation of a micro-texture on the cermet with nanosecond pulsed laser ablation.

PubMed

Yuan, Jiandong; Liang, Liang; Jiang, Lelun; Liu, Xin

2018-04-01

The degree of laser pulse overlapping in a laser scanning path has a significant impact on the ablation regime in the laser machining of a micro-texture. In this Letter, a nanosecond pulsed laser is used to prepare the micro-scaled groove on WC-8Co cermet under different scanning speeds. It is observed that as the scanning speed increases, the ablated trace morphology in the first scanning pass transits from a succession of intermittent deep dimples to the consecutive overlapped shallow pits. The test result also indicates that ablated trace morphology with respect to the low scanning speed stems from a plume shielding effect. Moreover, the ablation regime considering the shielding effect in micro-groove formation process is clarified. The critical scanning speed that can circumvent the shielding effect is also summarized with respect to different laser powers.

Global Curvature Buckling and Snapping of Spherical Shells.

NASA Astrophysics Data System (ADS)

Pezzulla, Matteo; Stoop, Norbert; Steranka, Mark; Bade, Abdikhalaq; Trejo, Miguel; Holmes, Douglas

A spherical shell under external pressure will eventually buckle locally through the development of a dimple. However, when a free spherical shell is subject to variations in natural curvature, it will either buckle globally or snap towards a buckled configuration. We study the similarities and differences between pressure and curvature instabilities in spherical shells. We show how the critical buckling natural curvature is largely independent of the thinness and half-angle of the shell, while the critical snapping natural curvature grows linearly with the half-angle. As a result, we demonstrate how a critical half-angle, depending only on the thinness of the shell, sets the threshold between two different kinds of snapping: as a rule of thumb, shallow shells snap into everted shells, while deep shells snap into buckled shells. As the developed models are purely geometrical, the results are applicable to a large variety of stimuli and scales. NSF CAREER CMMI-1454153.

Preliminary results of sacral transcutaneous electrical nerve stimulation for fecal incontinence.

PubMed

Leung, Edmund; Francombe, James

2013-03-01

Fecal incontinence is a common debilitating condition. The aim of this study is to investigate the feasibility of sacral transcutaneous electrical nerve stimulation as an alternative treatment modality for fecal incontinence. All consecutive patients who presented with fecal incontinence to the senior author's clinic were prospectively recruited between June 2009 and September 2010. The severity of their fecal incontinence was assessed by the Wexner and Vaizey scores and anal physiology. Any improvement following a period of sacral transcutaneous electrical nerve stimulation treatment was determined by repeating the scores. In addition, patient satisfaction with the procedure was assessed by using a patient impression score. Twenty female patients with a median age of 57.5 years (range, 30-86) were evaluated. The median follow-up was 10 months (range, 5-12 months). Two patients did not record a change in their Vaizey score. The overall mean Wexner score was 7.9 ± 4.2 before in comparison with 4.0 ± 3.1 after sacral transcutaneous electrical nerve stimulation treatment (p < 0.0001, CI = 2.2-5.7, SE = 0.832). The overall mean Vaizey score was 12.7 ± 5.7 before in comparison with 5.8 ± 5.6 after sacral transcutaneous electrical nerve stimulation treatment (p < 0.0001, CI = 4.5-9.4, SE = 1.162). The pretreatment patient impression score was set at a mean of 1 ± 0 in comparison with 2.8 ± 1.1 after sacral transcutaneous electrical nerve stimulation treatment (p < 0.0001, CI = 1.2-2.3, SE = 0.25). The preliminary results suggest sacral transcutaneous electrical nerve stimulation is a promising noninvasive alternative to existing modalities in the treatment of idiopathic fecal incontinence.

Prevalence of simple and complex sacral perineural Tarlov cysts in a French cohort of adults and children.

PubMed

Kuhn, Félix P; Hammoud, Sonia; Lefèvre-Colau, Marie-Martine; Poiraudeau, Serge; Feydy, Antoine

2017-02-01

To determine the prevalence of simple and complex sacral perineural Tarlov cysts (TCs) in a cohort of children and adults. Retrospective observational epidemiological study assessing 1100 consecutive sacral magnetic resonance (MR) studies, including 100 children and adolescents. All patients underwent 1.5T MR imaging with T1 and T2 weighted image acquisitions in sagittal and axial planes. All perineural cysts affecting the sacral nerve roots S1-S4 were quantitatively and qualitatively assessed. Two hundred and sixty-three sacral TCs were found in 132 adult patients (13.2%), with a female predominance (68%). None was found in children. The prevalence of TCs increased with age. The average number of cysts per patient was 2.0±1.2 with a maximum of 6 cysts in a single patient. Most of the cysts (87.5%) showed a homogenous central fluid collection and a parietal course of the nerve fibers. Complex patterns were present in 33 cysts (12.5%) within which 28 cysts showed endocystic crossing of nerve fibers and 5 cysts contained internal septations. Seventy cysts (26.6%) eroded the adjacent bone and 13 cysts (4.9%) extended to the pelvis. The prevalence of sacral TCs in our cohort corresponded to 13%, with a female predominance. Interestingly no TCs were found in children or adolescents (<18 years). In relation to the non-negligible percentage of complex cysts with internal septations, or endocystic crossing of nerve fibers, pre-interventional characterization of sacral TCs might help to choose an appropriate procedure in the treatment of rare symptomatic variants. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Safe Zone Quantification of the Third Sacral Segment in Normal and Dysmorphic Sacra.

PubMed

Hwang, John S; Reilly, Mark C; Shaath, Mohammad K; Changoor, Stuart; Eastman, Jonathan; Routt, Milton Lee Chip; Sirkin, Michael S; Adams, Mark R

2018-04-01

To quantify the osseous anatomy of the dysmorphic third sacral segment and assess its ability to accommodate internal fixation. Retrospective chart review of a trauma database. University Level 1 Trauma Center. Fifty-nine patients over the age of 18 with computed tomography scans of the pelvis separated into 2 groups: a group with normal pelvic anatomy and a group with sacral dysmorphism. The sacral osseous area was measured on computed tomography scans in the axial, coronal, and sagittal planes in normal and dysmorphic pelves. These measurements were used to determine the possibility of accommodating a transiliac transsacral screw in the third sacral segment. In the normal group, the S3 coronal transverse width averaged 7.71 mm and the S3 axial transverse width averaged 7.12 mm. The mean S3 cross-sectional area of the normal group was 55.8 mm. The dysmorphic group was found to have a mean S3 coronal transverse width of 9.49 mm, an average S3 axial transverse width of 9.14 mm, and an S3 cross-sectional area of 77.9 mm. The third sacral segment of dysmorphic sacra has a larger osseous pathway available to safely accommodate a transiliac transsacral screw when compared with normal sacra. The S3 segment of dysmorphic sacra can serve as an additional site for screw placement when treating unstable posterior pelvic ring fractures.

Dual-dermal-barrier fashion flaps for the treatment of sacral pressure sores.

PubMed

Hsiao, Yen-Chang; Chuang, Shiow-Shuh

2015-02-01

The sacral region is one of the most vulnerable sites for the development of pressure sores. Even when surgical reconstruction is performed, there is a high chance of recurrence. Therefore, the concept of dual-dermal-barrier fashion flaps for sacral pressure sore reconstruction was proposed. From September 2007 to June 2010, nine patients with grade IV sacral pressures were enrolled. Four patients received bilateral myocutaneous V-Y flaps, four patients received bilateral fasciocutaneous V-Y flaps, and one patient received bilateral rotation-advanced flaps for sacral pressure reconstruction. The flaps were designed based on the perforators of the superior gluteal artery in one patient's reconstructive procedure. All flaps' designs were based on dual-dermal-barrier fashion. The mean follow-up time was 16 months (range = 12-25). No recurrence was noted. Only one patient had a complication of mild dehiscence at the middle suture line, occurring 2 weeks after the reconstructive surgery. The dual-dermal fashion flaps are easily duplicated and versatile. The study has shown minimal morbidity and a reasonable outcome.

Dynamic processes in Be star atmospheres. I - 'Dimple' formation in the He I lambda 6678 line of lambda Eridani

NASA Technical Reports Server (NTRS)

Smith, Myron A.; Polidan, Ronald S.

1993-01-01

Several examples of weakenings of the C IV and N V resonance lines are found to coincide with the appearance of lambda 6678 dimples. The absence of variations in other UV lines and in the UV continuum at the same time or nearly the same time argues against dimples being caused by thermal variations from the underlying star. It is instead suggested that the resonance line weakenings are caused by non-LTE effects associated with the condensation of high density structures at some elevation over the star. A simple model of an opaque, essentially stationary slab which backscatters lambda 6678 line radiation into a surrounding 'penumbral' region is presented. Lambda 6678 photons are scattered a second time in this region back into the observer's line of sight and in the process acquire the local projected Doppler shift from rotation. Slabs would probably produce too little emission to be easily detected in the H alpha profile. Their detection in strong He I lines seems the best strategy among early Be stars.

Controlling the Adhesion of Superhydrophobic Surfaces Using Electrolyte Jet Machining Techniques

PubMed Central

Yang, Xiaolong; Liu, Xin; Lu, Yao; Zhou, Shining; Gao, Mingqian; Song, Jinlong; Xu, Wenji

2016-01-01

Patterns with controllable adhesion on superhydrophobic areas have various biomedical and chemical applications. Electrolyte jet machining technique (EJM), an electrochemical machining method, was firstly exploited in constructing dimples with various profiles on the superhydrophobic Al alloy surface using different processing parameters. Sliding angles of water droplets on those dimples firstly increased and then stabilized at a certain value with the increase of the processing time or the applied voltages of the EJM, indicating that surfaces with different adhesion force could be obtained by regulating the processing parameters. The contact angle hysteresis and the adhesion force that restricts the droplet from sliding off were investigated through experiments. The results show that the adhesion force could be well described using the classical Furmidge equation. On account of this controllable adhesion force, water droplets could either be firmly pinned to the surface, forming various patterns or slide off at designed tilting angles at specified positions on a superhydrophobic surface. Such dimples on superhydrophopbic surfaces can be applied in water harvesting, biochemical analysis and lab-on-chip devices. PMID:27046771

A Prospective Randomized Clinical Trial of a Novel, Noninvasive Perfusion Enhancement System for the Prevention of Hospital-Acquired Sacral Pressure Injuries.

PubMed

Bharucha, Jitendra B; Seaman, Linda; Powers, Michele; Kelly, Erica; Seaman, Rodney; Forcier, Lea; McGinnis, Janice; Nodiff, Isabel; Pawlak, Brooke; Snyder, Samantha; Nodiff, Susan; Patel, Rohan; Squitieri, Rafael; Wang, Lansheng

2018-06-08

The purpose of this study was to determine the effectiveness of a novel, noninvasive perfusion enhancement system versus beds with integrated alternating pressure capabilities for the prevention of hospital-acquired sacral region (sacral, coccygeal, and ischium) pressure injuries in a high-risk, acute care patient population. A prospective randomized trial of high-risk inpatients without preexisting sacral region pressure injuries was conducted. The sample comprised 431 randomly enrolled adult patients in a 300-bed tertiary care community teaching hospital. Subjects were randomly allocated to one of 2 groups: control and experimental. Both groups received "standard-of-care" pressure injury prevention measures per hospital policy, and both were placed on alternating pressure beds during their hospital stays. In addition, patients in the experimental group used a noninvasive perfusion enhancement system placed on top of their alternating pressure beds and recovery chairs throughout their hospital stay. Fischer's exact probability test was used to compare group differences, and odds ratio (OR) were calculated for comparing pressure injury rates in the experimental and control groups. Three hundred ninety-nine patients completed the trial; 186 patients were allocated to the experimental group and 213 patients to the control group. Eleven patients in the control group versus 2 in the experimental group developed hospital-acquired sacral region pressure injuries (51.6% vs 1.07%; P = .024). Control patients were 5.04 times more likely to develop hospital-acquired sacral region pressure injuries (OR = 0.1996; 95% CI, 0.0437-0.9125). Patients using a noninvasive perfusion enhancement system developed significantly fewer hospital-acquired sacral pressure injuries than those using an alternating pressure bed without the perfusion enhancement system. These findings suggest that a perfusion enhancement system enhances the success of use of pressure redistributing beds for prevention of hospital-acquired sacral pressure injuries.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

Evaluation of the Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity (POSSUM) scoring system in elderly patients with pressure sores undergoing fasciocutaneous flap-reconstruction.

PubMed

Mizumoto, Kazuo; Morita, Eishin

2009-01-01

The aim of the present study was to predict operative morbidity in elderly patients with deep pressure sores by using the Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity (POSSUM) scoring system. Fifteen patients over 70 years old were retrospectively reviewed who had undergone gluteus maximus fasciocutaneous flap-reconstruction for pressure sores of the sacral region from 1 April 2005 to 31 March 2007. Complications were seen in six cases (40%) after operation. Four were wound infection, one was chest infection and another was septicemia. The subjects were divided into two groups by the presence (complicated group) or absence (non-complicated group) of postoperative complications. Each item of physiological scores, physiological score (PS), operative severity score (OS) and predicted morbidity rate (R) were calculated and compared between two groups. As a result, hemoglobin (P = 0.0276), PS (P = 0.0023) and R (P = 0.0078) differed significantly between the two groups. It is noteworthy that the PS were over 25 in all of the complicated group, but in only one of nine in the non-complicated group (P = 0.0014). Our study suggests that, for pressure sores in the sacral region in elderly patients, gluteus maximus fasciocutaneous flap-reconstruction can be employed in patients whose PS are under 24 in the POSSUM scoring system.

A large giant cell tumor of the sacrum. Advantage of an abdomino-sacral approach.

PubMed

Alla, Abubakr H; Mahadi, Seif I; Elhassan, Ahmed M; Ahmed, Mohamed E

2005-01-01

We report a case of giant cell tumor of the sacrum, presenting with sacral pain, swelling, and change of bowel habits. Rectal examination revealed a huge retrorectal mass fixed to the sacrum but not to the wall of the rectum. Abdominal ultrasonography, computed tomography CT scan, and magnetic resonance imaging MRI showed a huge pelvic mass invading the sacrum. Exploration via posterior sacral approach was not successful due to both, extensive bleeding and difficult accessibility. Re-exploration was carried out 2 days later with the patient in lithotomy position. Using abdomino-sacral approach the mass together with part of the sacrum and the whole coccyx were excised. Histopathology reported giant cell tumor of the sacrum with no evidence of mitosis. The patient was symptomless 12 months after surgery and on follow up.

A 40-year-old woman with cauda equina syndrome caused by rectothecal fistula arising from an anterior sacral meningocele.

PubMed

Bergeron, Eric; Roux, Alain; Demers, Jacques; Vanier, Laurent E; Moore, Lynne

2010-11-01

We present a rare case of a rectothecal fistula arising from an anterior sacral meningocele in a patient with Currarino syndrome. The patient was a 40-year-old woman presenting with cauda equina syndrome and ascending meningitis. The meningocele was removed using an anterior abdominal approach. A sigmoid resection was performed with rectal on-table antegrade lavage followed by closure of the rectal fistula, closure of the rectal stump, and proximal colostomy. Closure of the sacral deficit was carried out by suturing a strip of well-vascularized omentum and fibrin glue. We discuss the characteristics, management, and evolution of this unusual case. Prompt surgical management using an anterior approach, resection of the sac, closure of the sacral deficit, and fecal diversion resulted in a satisfactory outcome.

Method of securing filter elements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Erik P.; Haslam, Jeffery L.; Mitchell, Mark A.

2016-10-04

A filter securing system including a filter unit body housing; at least one tubular filter element positioned in the filter unit body housing, the tubular filter element having a closed top and an open bottom; a dimple in either the filter unit body housing or the top of the tubular filter element; and a socket in either the filter unit body housing or the top of the tubular filter element that receives the dimple in either the filter unit body housing or the top of the tubular filter element to secure the tubular filter element to the filter unit bodymore » housing.« less

Comparison of open reduction versus minimally invasive surgical approaches on screw position in canine sacroiliac lag-screw fixation.

PubMed

Déjardin, Loïc M; Marturello, Danielle M; Guiot, Laurent P; Guillou, Reunan P; DeCamp, Charles E

2016-07-19

To compare accuracy and consistency of sacral screw placement in canine pelves treated for sacroiliac luxation with open reduction and internal fixation (ORIF) or minimally invasive osteosynthesis (MIO) techniques. Unilateral sacroiliac luxations created experimentally in canine cadavers were stabilized with an iliosacral lag screw applied via ORIF or MIO techniques (n = 10/group). Dorsoventral and craniocaudal screw angles were measured using computed tomography multiplanar reconstructions in transverse and dorsal planes, respectively. Ratios between pilot hole length and sacral width (PL/SW-R) were obtained. Data between groups were compared statistically (p <0.05). Mean screw angles (±SD) were greater in ORIF specimens in both transverse (p <0.001) and dorsal planes (p <0.004). Mean PL/SW-R was smaller (p <0.001) in the ORIF group, yet was greater than 60%. While pilot holes exited the first sacral end-plate in three of 10 ORIF specimens, the spinal canal was not violated in either group. This study demonstrates that MIO fixation of canine sacroiliac luxations provides more accurate and consistent sacral screw placement than ORIF. With proper techniques, iatrogenic neurological damage can be avoided with both techniques. The PL /SW-R, which relates to safe screw fixation, also demonstrates that screw penetration of at least 60% of the sacral width is achievable regardless of surgical approach. These findings, along with the limited dissection needed for accurate sacral screw placement, suggest that MIO of sacroiliac luxations is a valid alternative to ORIF.

What questionnaires to use when measuring quality of life in sacral tumor patients: the updated sacral tumor survey.

PubMed

van Wulfften Palthe, Olivier D R; Janssen, Stein J; Wunder, Jay S; Ferguson, Peter C; Wei, Guo; Rose, Peter S; Yaszemski, Micheal J; Sim, Franklin H; Boland, Patrick J; Healey, John H; Hornicek, Francis J; Schwab, Joseph H

2017-05-01

Patient-reported outcomes are becoming increasingly important when investigating results of patient and disease management. In sacral tumor, the symptoms of patients can vary substantially; therefore, no single questionnaire can adequately account for the full spectrum of symptoms and disability. The purpose of this study is to analyze redundancy within the current sacral tumor survey and make a recommendation for an updated version based on the results and patient and expert opinions. A survey study from a tertiary care orthopedic oncology referral center was used. The patient sample included 70 patients with sacral tumors (78% chordoma). The following 10 questionnaires included in the current sacral tumor survey were evaluated: the Patient-Reported Outcomes Measurement Information System (PROMIS) Global Item short form, PROMIS Pain Intensity short form, PROMIS Pain Interference short form, PROMIS Neuro-QOL v1.0 Lower Extremity Function short form, PROMIS v1.0 Anxiety short form, the PROMIS v1.0 Depression short form, the International Continence Society Male short form, the Modified Obstruction-Defecation Syndrome questionnaire, the PROMIS Sexual Function Profile v1.0, and the Stoma Quality of Life tool. We performed an exploratory factor analysis to calculate the possible underlying latent traits. Spearman rank correlation coefficients were used to measure to what extent the questionnaires converged. We hypothesized the existence of six domains based on current literature: mental health, physical health, pain, gastrointestinal symptoms, sexual function, and urinary incontinence. To assess content validity, we surveyed 32 patients, 9 orthopedic oncologists, 1 medical oncologist, 1 radiation oncologist, and 1 orthopedic oncology nurse practitioner with experience in treating sacral tumor patients on the relevance of the domains. Reliability as measured by Cronbach alpha ranged from 0.65 to 0.96. Coverage measured by floor and ceiling effects ranged from 0% to 52% and from 0% to 30%, respectively. Explanatory factor analysis identified three traits to which the questionnaires that were expected to measure a similar construct correlated the most: mental health, physical function, and pain. Content validity index demonstrated low disagreement among patients (range: 0.10-0.18) and high agreement among physicians (range: 0.91-1.0) on the relevance of the proposed domains. Social health was identified by 50% of the commenting patients as an important yet missing domain. The current sacral tumor survey is incomplete and time-consuming, and not all surveys are appropriate for the sacral tumor population. Our recommended survey contains less than half the questions and includes the newly recognized social health domain. Copyright © 2016 Elsevier Inc. All rights reserved.

A novel three-dimensional printed guiding device for electrode implantation of sacral neuromodulation.

PubMed

Cui, Z; Wang, Z; Ye, G; Zhang, C; Wu, G; Lv, J

2018-01-01

The aim was to test the feasibility of a novel three-dimensional (3D) printed guiding device for electrode implantation of sacral neuromodulation (SNM). A 3D printed guiding device for electrode implantation was customized to patients' anatomy of the sacral region. Liquid photopolymer was selected as the printing material. The details of the device designation and prototype building are described. The guiding device was used in two patients who underwent SNM for intractable constipation. Details of the procedure and the outcomes are given. With the help of the device, the test needle for stimulation was placed in the target sacral foramen successfully at the first attempt of puncture in both patients. The time to implant a tined SNM electrode was less than 20 min and no complications were observed. At the end of the screening phase, symptoms of constipation were relieved by more than 50% in both patients and permanent stimulation was established. The customized 3D printed guiding device for implantation of SNM is a promising instrument that facilitates a precise and quick implantation of the electrode into the target sacral foramen. Colorectal Disease © 2017 The Association of Coloproctology of Great Britain and Ireland.

Sacral neuromodulation for women with Fowler's syndrome.

PubMed

Swinn, M J; Kitchen, N D; Goodwin, R J; Fowler, C J

2000-10-01

Neuromodulation of the sacral nerves has been found to be an effective therapy for a variety of lower urinary tract dysfunctions. The reported success rate for the period of trial stimulation (peripheral nerve evaluation test) prior to permanent implantation of a sacral nerve stimulator is variable, but generally reported to be in the region of 30-50%. We present here the results of the peripheral nerve evaluation test in 38 patients with urinary retention. 34 of the 38 had been found to have an abnormality of their striated urethral sphincter on electromyography using a concentric needle electrode, i.e., they had the disorder which was described by Fowler and coworkers in 1988. The overall success rate in this group was 68%. We believe that our relatively high success rate is due to sacral neuromodulation working via a mechanism which involves the urethral sphincter, an abnormality which had been demonstrated in 89% of these patients. Twelve of the patients subsequently underwent permanent implantation of a sacral nerve stimulator, and all of them have experienced a return of voiding. However, in 2 patients, there is a persisting need for self-catheterization. There is, however, a high reoperation rate.

Surface localization of sacral foramina for neuromodulation of bladder function. An anatomical study.

PubMed

Hasan, S T; Shanahan, D A; Pridie, A K; Neal, D E

1996-01-01

A method is described for percutaneous localization of the sacral foramina, for neuromodulation of bladder function. We carried out an anatomical study of 5 male and 5 female human cadaver pelves. Using the described surface markings, needles were placed percutaneously into all sacral foramina from nine different angles. Paths of needle entry were studied by subsequent dissection. We observed that although it was possible to enter any sacral foramen at a wide range of insertion angles, the incidence of nerve root/vascular penetration increased with increasing angle of needle entry. Also, the incidence of nerve root penetration was higher with the medial approach compared with lateral entry. The insertion of a needle into the S1 foramen was associated with a higher incidence of nerve root penetration and presents a potential for arterial haemorrhage. On the other hand the smaller S3 and S4 nerve roots were surrounded by venous plexuses, presenting a potential source of venous haemorrhage during procedures. Our study suggests a new method for identifying the surface markings of sacral foramina and it describes the paths of inserted needles into the respective foramina. In addition, it has highlighted some potential risk factors secondary to needle insertion.

Regular dorsal dimples and damaged mites of Varroa destructor in some Iranian honey bees (Apis mellifera).

PubMed

Ardestani, Masoud M; Ebadi, Rahim; Tahmasbi, Gholamhossein

2011-07-01

The frequency of damaged Varroa destructor Anderson and Trueman (Mesostigmata: Varroidae) found on the bottom board of hives of the honey bee, Apis mellifera L. (Hymenoptera: Apidae) has been used as an indicator of the degree of tolerance or resistance of honey bee colonies against mites. However, it is not clear that this measure is adequate. These injuries should be separated from regular dorsal dimples that have a developmental origin. To investigate damage to Varroa mites and regular dorsal dimples, 32 honey bee (A. mellifera) colonies were selected from four Iranian provinces: Isfahan, Markazi, Qazvin, and Tehran. These colonies were part of the National Honey bee Breeding Program that resulted in province-specific races. In April, Varroa mites were collected from heavily infested colonies and used to infest the 32 experimental colonies. In August, 20 of these colonies were selected (five colonies from each province). Adult bees from these colonies were placed in cages and after introducing mites, damaged mites were collected from each cage every day. The average percentage of injured mites ranged from 0.6 to 3.0% in four provinces. The results did not show any statistical differences between the colonies within provinces for injuries to mites, but there were some differences among province-specific lines. Two kinds of injuries to the mites were observed: injuries to legs and pedipalps, and injuries to other parts of the body. There were also some regular dorsal dimples on dorsal idiosoma of the mites that were placed in categories separate from mites damaged by bees. This type of classification helps identifying damage to mites and comparing them with developmental origin symptoms, and may provide criteria for selecting bees tolerant or resistant to this mite.

[Unusually large stromal tumor of the rectum causing obstruction].

PubMed

Hornok, L; Lestár, B; Nagy, P; Ritter, L; László, S; Kiss, J

2000-06-01

A male, 74 years old patient with perineal, sacral pain and with defecation disorders attended the outpatient clinic of HIETE. The origine of the complains was a retrorectal, fist like, rectum narrowing tumor. The tumor was covered by normal mucosa from rectal side. Preoperative examinations--endoscopy, CT, MRI transrectal US--detected a tumor with size 7 x 6 x 5 cm, growing from the muscular wall of the rectum, with no connection with the surrounding tissues. Deep biopsy revealed malignant mesenchymal tumor. After preoperative irradiation abdominoperineal rectum amputation was performed. The recovery was uneventful. The definitive hystological examination proved a gastrointestinal stromal tumor (GIST). This type of tumor rarely occurs in the large intestine or in the rectum, that why the publishing can be interesting.

Exclusion of the Sonic Hedgehog gene as responsible for Currarino syndrome and anorectal malformations with sacral hypodevelopment.

PubMed

Seri, M; Martucciello, G; Paleari, L; Bolino, A; Priolo, M; Salemi, G; Forabosco, P; Caroli, F; Cusano, R; Tocco, T; Lerone, M; Cama, A; Torre, M; Guys, J M; Romeo, G; Jasonni, V

1999-01-01

Anorectal malformations (ARMs) are common congenital anomalies that account for 1:4 digestive malformations. ARM patients show different degrees of sacral hypodevelopment while the hemisacrum is characteristic of the Currarino syndrome (CS). Cases of CS present an association of ARM, hemisacrum and presacral mass. A gene responsible for CS has recently been mapped in 7q36. Among the genes localized in this critical region, sonic hedgehog (SHH) was thought to represent a candidate gene for CS as well as for ARM with different levels of sacral hypodevelopment according to its role in the differentiation of midline mesoderm. By linkage analysis we confirmed the critical region in one large family with recurrence of CS. In addition, the screening of SHH in 7 CS and in 15 sporadic ARM patients with sacral hypodevelopment allowed us to exclude its role in the pathogenesis of these disorders.

The superior gluteal artery perforator flap for reconstruction of sacral sores

PubMed Central

Chen, Weijian; Jiang, Bo; Zhao, Jiaju; Wang, Peiji

2016-01-01

This report describes our experiences using the superior gluteal artery perforator (SGAP) flaps for reconstruction of 2 sacral sore cases. A 47-year-old female patient and a 38-year-old man with sacral sores were treated in our unit. The size of the defects were approximately 5×6 cm2 and 8×9 cm2, the defects were repaired by SGAP flaps. The size of designed was SGAP flaps varied from 7×20 to 9×16 cm2. All flaps survived and healed primary, the texture, functions, and appearance of flaps were satisfactory, and also without region dysfunction of donor and recipient sites. The SGAP flap, which has reliable blood supply, preserves the gluteus maximus muscle and could be transferred simply and safely, is an ideal and reusable method to reconstruct sacral sores with low rate of postoperative recurrence and satisfactory appearance. PMID:27652367

Retention of urine and sacral paraesthesia in anogenital herpes simplex infection.

PubMed

Edis, R H

1981-01-01

Two definite and 2 probable cases of anogenital herpes simplex and sacral radiculitis are described. Symptoms were typical and consisted of paraesthesia and neuralgic pain in the perineum and legs, urinary retention and constipation occurring within several days to a week after an anogenital herpetic eruption. However, at presentation only 1 case had an obvious history of anogenital herpes simplex. Neurological signs were not striking and consisted of a reduced appreciation of light touch and pin prick over the sacral dermatomes and in 2 cases reduced anal sphincter tone. CSF examination in 3 patients showed a lymphocytosis. Bladder catheterisation was required for up to 2 weeks in 2 patients. The paraesthesia persisted for weeks to months. It should be more widely recognised that anogenital herpes simplex, with sacral radiculitis, is probably the commonest cause of acute retention of urine in young sexually active people.

Acute urinary retention due to benign inflammatory nervous diseases.

PubMed

Sakakibara, Ryuji; Yamanishi, Tomonori; Uchiyama, Tomoyuki; Hattori, Takamichi

2006-08-01

Both neurologists and urologists might encounter patients with acute urinary retention due to benign inflammatory nervous diseases. Based on the mechanism of urinary retention, these disorders can be divided into two subgroups: disorders of the peripheral nervous system (e.g., sacral herpes) or the central nervous system (e.g., meningitis-retention syndrome [MRS]). Laboratory abnormalities include increased herpes virus titers in sacral herpes, and increased myelin basic protein in the cerebrospinal fluid (CSF) in some cases with MRS. Urodynamic abnormality in both conditions is detrusor areflexia; the putative mechanism of it is direct involvement of the pelvic nerves in sacral herpes; and acute spinal shock in MRS. There are few cases with CSF abnormality alone. Although these cases have a benign course, management of the acute urinary retention is necessary to avoid bladder injury due to overdistension. Clinical features of sacral herpes or MRS differ markedly from those of the original "Elsberg syndrome" cases.

Cost of dressings for prevention of sacral pressure ulcers.

PubMed

Inoue, Kelly Cristina; Matsuda, Laura Misue

2016-01-01

to identify costs of dressings to prevent sacral pressure ulcers in an adult intensive care unit in Paraná, Brazil. secondary analysis study with 25 patients admitted between October 2013 and March 2014, using transparent polyurethane film (n=15) or hydrocolloid dressing (n=10) on the sacral region. The cost of each intervention was based on the unit amount used in each type of dressing, and its purchase price (transparent film = R$15.80, hydrocolloid dressing = R$68.00). the mean cost/patient was R$23.17 for use of transparent film and R$190.40 for use of hydrocolloid dressing. The main reason for changing the dressing was detachment. the transparent film was the most economically advantageous alternative to prevent sacral pressure ulcers in critical care patients. However, additional studies should be carried out including assessment of the effectiveness of both dressings.

Management of Sacral Tumors Requiring Spino-Pelvic Reconstruction with Different Histopathologic Diagnosis: Evaluation with Four Cases

PubMed Central

Togral, Guray; Hasturk, Askin Esen; Kekec, Fevzi; Parpucu, Murat; Gungor, Safak

2015-01-01

In this retrospective study, surgical results of four patients with sacral tumors having disparate pathologic diagnoses, who were treated with partial or total sacrectomy and lumbopelvic stabilization were abstracted. Two patients were treated with partial sacral resection and two patients were treated with total sacrectomy and spinopelvic fixation. Fixation methods included spinopelvic fixation with rods and screws in two cases, reconstruction plate in one case, and fresh frozen allografts in two cases. Fibular allografts used for reconstruction accelerated bony union and enhanced the stability in two cases. Addition of polymethyl methacrylate in the cavity in the case of a giant cell tumor had a positive stabilizing effect on fixation. As a result, we can conclude that mechanical instability after sacral resection can be stabilized securely with lumbopelvic fixation and polymethyl methacrylate application or addition of fresh frozen allografts between the rods can augment the stability of the reconstruction. PMID:26713133

Incidentally diagnosed giant invasive sacral schwannoma

PubMed Central

Togral, Guray; Arikan, Murat; Hasturk, Askin E.; Gungor, Safak

2014-01-01

Schwannomas are benign encapsulated tumors of Schwan cells that grow slowly along the peripheral myelin nerve fibers. Sacral spinal schwannomas are very rare, and the incidence of sacral schwannoma ranges from 1-5% of all spinal schwannomas, and only around 50 cases are reported in the literature. There are 3 defined types of sacral schwannomas. These are retroperitoneal or presacral, intra osseous, and spinal schwannomas. Patients commonly present with complaints of pain and paresthesia due to the spinal schwannoma extending to extra spinal tissues. Direct x-ray, CT, MRI, and scintigraphy are used for preoperative diagnosis and treatment planning. Local recurrence and transformation to malignancy is very rare. For this reason, the frequently preferred treatments are subtotal removal of the mass or simple enucleation. In our article, we discuss the clinical features and the surgical treatment we performed without the need for stabilization in an incidentally determined giant invasive schwannoma case. PMID:24983285

Management of Sacral Tumors Requiring Spino-Pelvic Reconstruction with Different Histopathologic Diagnosis: Evaluation with Four Cases.

PubMed

Arıkan, Murat; Togral, Guray; Hasturk, Askin Esen; Kekec, Fevzi; Parpucu, Murat; Gungor, Safak

2015-12-01

In this retrospective study, surgical results of four patients with sacral tumors having disparate pathologic diagnoses, who were treated with partial or total sacrectomy and lumbopelvic stabilization were abstracted. Two patients were treated with partial sacral resection and two patients were treated with total sacrectomy and spinopelvic fixation. Fixation methods included spinopelvic fixation with rods and screws in two cases, reconstruction plate in one case, and fresh frozen allografts in two cases. Fibular allografts used for reconstruction accelerated bony union and enhanced the stability in two cases. Addition of polymethyl methacrylate in the cavity in the case of a giant cell tumor had a positive stabilizing effect on fixation. As a result, we can conclude that mechanical instability after sacral resection can be stabilized securely with lumbopelvic fixation and polymethyl methacrylate application or addition of fresh frozen allografts between the rods can augment the stability of the reconstruction.

Vascular entrapment of the sciatic plexus causing catamenial sciatica and urinary symptoms.

PubMed

Lemos, Nucelio; Marques, Renato Moretti; Kamergorodsky, Gil; Ploger, Christine; Schor, Eduardo; Girão, Manoel J B C

2016-02-01

Pelvic congestion syndrome is a well-known cause of cyclic pelvic pain (Ganeshan et al., Cardiovasc Intervent Radiol 30(6):1105-11, 2007). What is much less well known is that dilated or malformed branches of the internal or external iliac vessels can entrap the nerves of the sacral plexus against the pelvic sidewalls, producing symptoms that are not commonly seen in gynecological practice, such as sciatica, or refractory urinary and anorectal dysfunction (Possover et al., Fertil Steril 95(2):756-8. 2011). The objective of this video is to explain and describe the symptoms suggestive of vascular entrapment of the sacral plexus, as well as the technique for the laparoscopic decompression of these nerves. Two anecdotal cases of intrapelvic vascular entrapment are used to review the anatomy of the lumbosacral plexus and demonstrate the laparoscopic surgical technique for decompression at two different sites, one on the sciatic nerve and one on the sacral nerve roots. After surgery, the patient with the sciatic entrapment showed full recovery of the sciatica and partial recovery of the myofascial pain. The patient with sacral nerve root entrapment showed full recovery with resolution of symptoms. The symptoms suggestive of intrapelvic nerve entrapment are: perineal pain or pain irradiating to the lower limbs in the absence of a spinal disorder, and lower urinary tract symptoms in the absence of prolapse of a bladder lesion. In the presence of such symptoms, the radiologist should provide specific MRI sequences of the intrapelvic portion of the sacral plexus and a team and equipment to expose and decompress the sacral nerves should be prepared.

Critical Anatomy Relative to the Sacral Suture: A Postoperative Imaging Study After Robotic Sacrocolpopexy.

PubMed

Crisp, Catrina C; Herfel, Charles V; Pauls, Rachel N; Westermann, Lauren B; Kleeman, Steven D

2016-01-01

This study aimed to characterize pertinent anatomy relative to the sacral suture placed at time of robotic sacrocolpopexy using postoperative computed tomography and magnetic resonance imaging. A vascular clip was placed at the base of the sacral suture at the time of robotic sacrocolpopexy. Six weeks postoperatively, subjects returned for a computed tomography scan and magnetic resonance imaging. Ten subjects completed the study. The middle sacral artery and vein coursed midline or to the left of midline in all the subjects. The left common iliac vein was an average of 26 mm from the sacral suture. To the right of the suture, the right common iliac artery was 18 mm away. Following the right common iliac artery to its bifurcation, the right internal iliac was on average 10 mm from the suture. The bifurcations of the inferior vena cava and the aorta were 33 mm and 54 mm further cephalad, respectively.The right ureter, on average, was 18 mm from the suture. The thickness of the anterior longitudinal ligament was 2 mm.The mean angle of descent of the sacrum was 70 degrees. Lastly, we found that 70% of the time, a vertebral body was directly below the suture; the disc was noted in 30%. We describe critical anatomy surrounding the sacral suture placed during robotic sacrocolpopexy. Proximity of both vascular and urologic structures within 10 to 18 mm, as well as anterior ligament thickness of only 2 mm highlights the importance of adequate exposure, careful dissection, and surgeon expertise.

Long-term efficacy and safety of sacral nerve stimulation for fecal incontinence.

PubMed

Mellgren, Anders; Wexner, Steven D; Coller, John A; Devroede, Ghislain; Lerew, Darin R; Madoff, Robert D; Hull, Tracy

2011-09-01

Sacral nerve stimulation is effective in the treatment of urinary incontinence and is currently under Food and Drug Administration review in the United States for fecal incontinence. Previous reports have focused primarily on short-term results of sacral nerve stimulation for fecal incontinence. The present study reports the long-term effectiveness and safety of sacral nerve stimulation for fecal incontinence in a large prospective multicenter study. Patients with fecal incontinent episodes more than twice per week were offered participation in this multicentered prospective trial. Patients showing ≥ 50% improvement during test stimulation were offered chronic implantation of the InterStim Therapy system (Medtronic; Minneapolis, MN). The aims of the current report were to provide 3-year follow-up data on patients from that study who underwent sacral nerve stimulation and were monitored under the rigors of an Food and Drug Administration-approved investigational protocol. One hundred thirty-three patients underwent test stimulation with a 90% success rate, of whom 120 (110 females) with a mean age of 60.5 years and a mean duration of fecal incontinence of 7 years received chronic implantation. Mean length of follow-up was 3.1 (range, 0.2-6.1) years, with 83 patients completing all or part of the 3-year follow-up assessment. At 3 years follow-up, 86% of patients (P < .0001) reported ≥ 50% reduction in the number of incontinent episodes per week compared with baseline and the number of incontinent episodes per week decreased from a mean of 9.4 at baseline to 1.7. Perfect continence was achieved in 40% of subjects. The therapy also improved the fecal incontinence severity index. Sacral nerve stimulation had a positive impact on the quality of life, as evidenced by significant improvements in all 4 scales of the Fecal Incontinence Quality of Life instrument at 12, 24, and 36 months of follow-up. The most common device- or therapy-related adverse events through the mean 36 months of follow-up included implant site pain (28%), paresthesia (15%), change in the sensation of stimulation (12%), and infection (10%). There were no reported unanticipated adverse device effects associated with sacral nerve stimulation therapy. Sacral nerve stimulation using InterStim Therapy is a safe and effective treatment for patients with fecal incontinence. These data support long-term safety and effectiveness to 36 months.

Comparative analysis of film cooling efficiency at coolant supply into a single array of triangular dimples

NASA Astrophysics Data System (ADS)

Khalatov, A. A.; Petliak, O. O.; Severin, S. D.; Panchenko, N. A.

2018-03-01

The purpose of this work is a comparative study of the physical structure and film cooling efficiency of the single array of inclined holes, placed in triangular dimples and in a trench. The software package ANSYS CFX 17.0 was used along with RANS SST turbulence model. Calculations were made in a wide range of the blowing ratio ranging from 0.5 to 2.0. Results of modeling have shown high efficiency of triangular film cooling configuration. At m ≥ 1.5, the triangular configuration is comparable with the trench configuration in terms of the film cooling efficiency.

Jammed elastic shells - a 3D experimental soft frictionless granular system

NASA Astrophysics Data System (ADS)

Jose, Jissy; Blab, Gerhard A.; van Blaaderen, Alfons; Imhof, Arnout

2015-03-01

We present a new experimental system of monodisperse, soft, frictionless, fluorescent labelled elastic shells for the characterization of structure, universal scaling laws and force networks in 3D jammed matter. The interesting fact about these elastic shells is that they can reversibly deform and therefore serve as sensors of local stress in jammed matter. Similar to other soft particles, like emulsion droplets and bubbles in foam, the shells can be packed to volume fractions close to unity, which allows us to characterize the contact force distribution and universal scaling laws as a function of volume fraction, and to compare them with theoretical predictions and numerical simulations. However, our shells, unlike other soft particles, deform rather differently at large stresses. They deform without conserving their inner volume, by forming dimples at contact regions. At each contact one of the shells buckled with a dimple and the other remained spherical, closely resembling overlapping spheres. We conducted 3D quantitative analysis using confocal microscopy and image analysis routines specially developed for these particles. In addition, we analysed the randomness of the process of dimpling, which was found to be volume fraction dependent.

Transient thermal analysis of a titanium multiwall thermal protection system

NASA Technical Reports Server (NTRS)

Blosser, M. L.

1982-01-01

The application of the SPAR thermal analyzer to the thermal analysis of a thermal protection system concept is discussed. The titanium multiwall thermal protection system concept consists of alternate flat and dimpled sheets which are joined together at the crests of the dimples and formed into 30 cm by 30 cm (12 in. by 12 in.) tiles. The tiles are mechanically attached to the structure. The complex tile geometry complicates thermal analysis. Three modes of heat transfer were considered: conduction through the gas inside the tile, conduction through the metal, and radiation between the various layers. The voids between the dimpled and flat sheets were designed to be small enough so that natural convection is insignificant (e.g., Grashof number 1000). A two step approach was used in the thermal analysis of the multiwall thermal protection system. First, an effective normal (through-the-thickness) thermal conductivity was obtained from a steady state analysis using a detailed SPAR finite element model of a small symmetric section of the multiwall tile. This effective conductivity was then used in simple one dimensional finite element models for preliminary analysis of several transient heat transfer problems.

Improving friction performance of cast iron by laser shock peening

NASA Astrophysics Data System (ADS)

Feng, Xu; Zhou, Jianzhong; Huang, Shu; Sheng, Jie; Mei, Yufen; Zhou, Hongda

2015-05-01

According to different purpose, some high or low friction coefficient of the material surface is required. In this study, micro-dent texture was fabricated on cast iron specimens by a set of laser shock peening (LSP) experiments under different laser energy, with different patterns of micro dimples in terms of the depth over diameter. The mechanism of LSP was discussed and surface morphology of the micro dimples were investigated by utilizing a Keyence KS-1100 3D optical surface profilometer. The tests under the conditions of dry and lubricating sliding friction were accomplished on the UMT-2 apparatus. The performance of treated samples during friction and wear tests were characterized and analyzed. Based on theoretical analysis and experimental study, friction performance of textured and untextured samples were studied and compared. Morphological characteristics were observed by scanning electron microscope (SEM) and compared after friction tests under dry condition. The results showed that friction coefficient of textured samples were obvious changed than smooth samples. It can be seen that LSP is an effective way to improve the friction performance of cast iron by fabricating high quality micro dimples on its surface, no matter what kind of engineering application mentioned in this paper.

Long range magnetic ordering of ultracold fermions in an optical lattice

NASA Astrophysics Data System (ADS)

Duarte, P. M.; Hart, R. A.; Yang, T.-L.; Hulet, R. G.

2013-05-01

We present progress towards the observation of long range antiferromagnetic (AFM) ordering of fermionic 6Li atoms in an optical lattice. We prepare a two spin state mixture of 106 atoms at T /TF = 0 . 1 by evaporatively cooling in an optical dipole trap. The sample is then transferred to a dimple trap formed by three retroreflected laser beams at 1064 nm that propagate in orthogonal directions. The polarization of the retroreflected light is controlled using liquid crystal retarders, which allow us to adiabatically transform the dimple trap into a 3D lattice. Overlapped with each of the three dimple/lattice beams is a beam at 532 nm, which can cancel the harmonic confinement and flatten the band structure in the lattice. This setup offers the possibility of implementing proposed schemes which enlarge the size of the AFM phase in the trap. As a probe for AFM we use Bragg scattering of light. We have observed Bragg scattering off of the (100) lattice planes, and using an off-angle probe we can see the diffuse scattering from the sample which serves as background for the small signals expected before the onset of AFM ordering. Supported by NSF, ONR, DARPA, and the Welch Foundation.

Sacral neuromodulation in the treatment of the unstable bladder.

PubMed

Bosch, J L

1998-07-01

Sacral neuromodulation as a treatment for urge incontinence in patients with an unstable bladder is the subject of ongoing clinical studies. Although approximately 75% of the patients treated with a permanent sacral foramen electrode implant have experienced significant improvements, it is now also clear that there is an initial failure rate of about 25%. Recent studies have pointed out the importance of improved patient selection on the basis of sex differences, urodynamic parameters and psychological factors. Also, newer forms of test stimulation and permanent electrode implantation are being explored in an effort to improve on the present results.

Rectal ulcer in a patient with VZV sacral meningoradiculitis (Elsberg syndrome).

PubMed

Matsumoto, Hideyuki; Shimizu, Takahiro; Tokushige, Shin-ichi; Mizuno, Hideo; Igeta, Yukifusa; Hashida, Hideji

2012-01-01

This report describes the case of a 55-year-old woman with varicella-zoster virus (VZV) sacral meningoradiculitis (Elsberg syndrome) who presented with herpes zoster in the left S2 dermatome area, urinary retention, and constipation. Lumbar magnetic resonance imaging showed the left sacral nerve root swelling with enhancement. Thereafter, she suddenly showed massive hematochezia and hemorrhagic shock because of a rectal ulcer. To elucidate the relation between Elsberg syndrome and rectal ulcer, accumulation of similar cases is necessary. To avoid severe complications, attention must be devoted to the possibility of rectal bleeding in the early stage of Elsberg syndrome.

Use of Sacral Nerve Stimulation for the Treatment of Overlapping Constipation and Fecal Incontinence

PubMed Central

Sreepati, Gouri; James-Stevenson, Toyia

2017-01-01

Patient: Female, 51 Final Diagnosis: Fecal incontinence Symptoms: Constipation • fecal incontinence Medication: — Clinical Procedure: Sacral nerve stimulator Specialty: Gastroenterology and Hepatology Objective: Rare co-existance of disease or pathology Background: Fecal incontinence and constipation are common gastrointestinal complaints, but rarely occur concurrently. Management of these seemingly paradoxical processes is challenging, as treatment of one symptom may exacerbate the other. Case Report: A 51-year-old female with lifelong neurogenic bladder secondary to spina bifida occulta presented with progressive symptoms of daily urge fecal incontinence as well as hard bowel movements associated with straining and a sensation of incomplete evacuation requiring manual disimpaction. Pelvic floor testing showed poor ability to squeeze the anal sphincter, which indicated sphincter weakness as a major contributor to her fecal incontinence symptoms. Additionally, on defecography she was unable to widen her posterior anorectal angle or relax the anal sphincter during defecation consistent with dyssynergic defecation. A sacral nerve stimulator was placed for management of her fecal incontinence. Interestingly, her constipation also dramatically improved with sacral neuromodulation. Conclusions: This unique case highlights the emerging role of sacral nerve stimulation in the treatment of complex pelvic floor dysfunction with improvement in symptoms beyond fecal incontinence in a patient with dyssynergic-type constipation. PMID:28265107

Sacral electrical neuromodulation as an alternative treatment option for lower urinary tract dysfunction.

PubMed

Grünewald, Volker; Höfner, Klaus; Thon, Walter F.; Kuczyk, Markus A.; Jonas, Udo

1999-01-01

Temporary electrical stimulation using anal or vaginal electrodes and an external pulse generator has been a treatment modality for urinary urge incontinence for nearly three decades. In 1981 Tanagho and Schmidt introduced chronic electrical stimulation of the sacral spinal nerves using a permanently implanted sacral foramen electrode and a battery powered pulse generator for treatment of different kinds of lower urinary tract dysfunction, refractory to conservative treatment. At our department chronic unilateral electrical stimulation of the S3 sacral spinal nerve has been used for treatment of vesi-courethral dysfunction in 43 patients with a mean postoperative follow up of 43,6 months. Lasting symptomatic improvement by more than 50 % could be achieved in 13 of 18 patients with motor urge incontinence (72,2 %) and in 18 of the 21 patients with urinary retention (85,7 %). Implants offer a sustained therapeutic effect to treatment responders, which is not achieved by temporary neuromodulation. Chronic neuromodulation should be predominantly considered in patients with urinary retention. Furthermore in patients with motor urge incontinence, refusing temporary techniques or in those requiring too much effort to achieve a sustained clinical effect. Despite high initial costs chronic sacral neuromodulation is an economically reasonable treatment option in the long run, when comparing it to the more invasive remaining therapeutic alternatives.

[Sacral gigantocellular tumor treated with total sacrectomy and spinal-pelvic fixation].

PubMed

Savić, Milenko

2011-09-01

Total sacrectomy with spinal-pelvic fixation is considered to be a successful approach to the radical surgical treatment of extensive sacral tumors, however, technically very demanding, thus only rarely reported in the literature. We presented a patient with sacral gigantocellular tumor managed successfully using this method but with certain standard operative techniques improvements. A 30-year old patient with a pronounced painful syndrome and sphincter disorders was confirmed to have sacral gigantocellular tumor affecting a greater part of the sacrum. Tumor resection was performed in the first act out off retroperitoneal organs (colon and blood vessels), sacroiliac joints were open by the ventral side, the L5 discus removed, the S2-S5 roots cut off. In the second act, performed three weeks later, sacrectomy was completed by the reconstruction of pelvic ring and spinal-pelvic fixation. Then, the standard technique was modified to provide additional spinal fixation. The results of the operation (duration, blood loss, postoperative deficit) were quite comparable with, and in some aspects even better than the results published in the literature. Total sacrectomy with spinal-pelvic fixation can be a therapy of choice in patients with extensive sacral tumors requaring, however, the multidisciplinary approach and a considerable experience with instrumental spinal stabilization.

Sacral neuromodulation for lower urinary tract dysfunction.

PubMed

Van Kerrebroeck, Philip E V; Marcelissen, Tom A T

2012-08-01

To review the technique, indications, results and working mechanisms of sacral neuromodulation (SNM) for lower urinary tract dysfunction. The available literature on SNM for lower urinary tract dysfunction was searched. Based on the information available in the literature and also based on personal experience, the urological indications, technique, mechanisms of action and results of SNM are presented and discussed. SNM for lower urinary tract dysfunction involves stimulation of the 3rd sacral nerve with an electrode implanted in the sacral foramen and connected to a pulse generator. The technique is accepted by the FDA since 1997. Currently, SNM for lower urinary tract dysfunction has been successfully used in about 26,000 patients with various forms of lower urinary tract dysfunction, including urgency, frequency and urgency incontinence as well as non-obstructive urinary retention. The actual procedure of SNM consists of a minimal invasive technique and is effective in about 70% of the patients who have been implanted with a permanent system. Also, in pelvic pain, interesting results have been described. SNM modulates the micturition reflexes at different levels in the central nervous system. Sacral neuromodulation is a safe and effective therapy for various forms of lower urinary tract dysfunction, including urgency, frequency and urgency incontinence as well as non-obstructive urinary retention. It should be the first choice after failure of maximal conservative therapy.

What Questionnaires To Use When Measuring Quality Of Life In Sacral Tumor Patients? The Updated Sacral Tumor Survey

PubMed Central

van Wulfften Palthe, Olivier D.R.; Janssen, Stein J.; Wunder, Jay S.; Ferguson, Peter C.; Wei, Guo; Rose, Peter. S.; Yaszemski, Micheal J.; Sim, Franklin H.; Boland, Patrick J.; Healey, John H.; Hornicek, Francis J.; Schwab, Joseph H.

2017-01-01

Background context Patient reported outcomes are becoming increasingly important when investigating results of patient and disease management. In sacral tumor patients symptoms can vary substantially, therefore no single questionnaire can adequately account for the full spectrum of symptoms and disability. Purpose The purpose of this study is to analyze redundancy within the current sacral tumor survey and make a recommendation for an updated version based on the results and patient and expert opinions. Study design/setting A survey study from a tertiary care orthopaedic oncology referral center was used for this study. Patient sample The patient sample included 70 patients with sacral tumors (78% chordoma). Outcome measures The following ten questionnaires included in the current sacral tumor survey were evaluated: the Patient Reported Outcomes Measurement Information System (PROMIS) Global Item short form, PROMIS Pain Intensity short form, PROMIS Pain Interference short form, PROMIS Neuro-QOL v1.0 Lower Extremity Function short form, PROMIS v1.0 Anxiety short form, the PROMIS v1.0 Depression short form, the International Continence Society (ICS) Male short form, the Modified Obstruction-Defecation Syndrome (MODS) questionnaire, the PROMIS Sexual Function Profile v1.0, and The Stoma Quality Of Life tool. Methods We performed an exploratory factor analysis to calculate possible underlying latent traits. Spearman rank correlation coefficients were used to measure to what extent the questionnaires converged. We hypothesized the existence of six domains based on current literature: mental health, physical health, pain, gastrointestinal symptoms, sexual function, and urinary incontinence. To assess content validity, we surveyed 32 patients, nine orthopaedic oncologists, one medical oncologist, one radiation oncologist, and an orthopaedic oncology nurse practitioner with experience in treating sacral tumor patients on the relevance of the domains. Results Reliability as measured by Cronbach alpha ranged from 0.65 to 0.96. Coverage measured by floor and ceiling effects ranged from 0 to 52% and from 0 to 30%, respectively. Explanatory factor analysis identified three traits to which the questionnaires that were expected to measure a similar construct correlated the most; mental health, physical function, and pain. Content validity index demonstrated low disagreement among patients (range: 0.10 to 0.18) and high agreement among physicians (range: 0.91 to 1.0) on the relevance of the proposed domains. Social health was identified by 50% of the commenting patients as an important yet missing domain. Conclusions The current sacral tumor survey is incomplete, time consuming, and not all surveys are appropriate for the sacral tumor population. Our recommended survey contains less than half the questions and includes the newly recognized domain social health. PMID:27856381

Effectiveness and Value of Prophylactic 5-Layer Foam Sacral Dressings to Prevent Hospital-Acquired Pressure Injuries in Acute Care Hospitals: An Observational Cohort Study.

PubMed

Padula, William V

The purpose of this study was to examine the effectiveness and value of prophylactic 5-layer foam sacral dressings to prevent hospital-acquired pressure injury rates in acute care settings. Retrospective observational cohort. We reviewed records of adult patients 18 years or older who were hospitalized at least 5 days across 38 acute care hospitals of the University Health System Consortium (UHC) and had a pressure injury as identified by Patient Safety Indicator #3 (PSI-03). All facilities are located in the United States. We collected longitudinal data pertaining to prophylactic 5-layer foam sacral dressings purchased by hospital-quarter for 38 academic medical centers between 2010 and 2015. Longitudinal data on acute care, hospital-level patient outcomes (eg, admissions and PSI-03 and pressure injury rate) were queried through the UHC clinical database/resource manager from the Johns Hopkins Medicine portal. Data on volumes of dressings purchased per UHC hospital were merged with UHC data. Mixed-effects negative binomial regression was used to test the longitudinal association of prophylactic foam sacral dressings on pressure injury rates, adjusted for hospital case-mix and Medicare payments rules. Significant pressure injury rate reductions in US acute care hospitals between 2010 and 2015 were associated with the adoption of prophylactic 5-layer foam sacral dressings within a prevention protocol (-1.0 cases/quarter; P = .002) and changes to Medicare payment rules in 2014 (-1.13 cases/quarter; P = .035). Prophylactic 5-layer foam sacral dressings are an effective component of a pressure injury prevention protocol. Hospitals adopting these technologies should expect good value for use of these products.

Effectiveness and Value of Prophylactic 5-Layer Foam Sacral Dressings to Prevent Hospital-Acquired Pressure Injuries in Acute Care Hospitals

PubMed Central

2017-01-01

PURPOSE: The purpose of this study was to examine the effectiveness and value of prophylactic 5-layer foam sacral dressings to prevent hospital-acquired pressure injury rates in acute care settings. DESIGN: Retrospective observational cohort. SAMPLE AND SETTING: We reviewed records of adult patients 18 years or older who were hospitalized at least 5 days across 38 acute care hospitals of the University Health System Consortium (UHC) and had a pressure injury as identified by Patient Safety Indicator #3 (PSI-03). All facilities are located in the United States. METHODS: We collected longitudinal data pertaining to prophylactic 5-layer foam sacral dressings purchased by hospital-quarter for 38 academic medical centers between 2010 and 2015. Longitudinal data on acute care, hospital-level patient outcomes (eg, admissions and PSI-03 and pressure injury rate) were queried through the UHC clinical database/resource manager from the Johns Hopkins Medicine portal. Data on volumes of dressings purchased per UHC hospital were merged with UHC data. Mixed-effects negative binomial regression was used to test the longitudinal association of prophylactic foam sacral dressings on pressure injury rates, adjusted for hospital case-mix and Medicare payments rules. RESULTS: Significant pressure injury rate reductions in US acute care hospitals between 2010 and 2015 were associated with the adoption of prophylactic 5-layer foam sacral dressings within a prevention protocol (−1.0 cases/quarter; P = .002) and changes to Medicare payment rules in 2014 (−1.13 cases/quarter; P = .035). CONCLUSIONS: Prophylactic 5-layer foam sacral dressings are an effective component of a pressure injury prevention protocol. Hospitals adopting these technologies should expect good value for use of these products. PMID:28816929

Close correlation of herpes zoster-induced voiding dysfunction with severity of zoster-related pain: A single faculty retrospective study.

PubMed

Fujii, Mizue; Takahashi, Ichiro; Honma, Masaru; Ishida-Yamamoto, Akemi

2015-11-01

Herpes zoster (HZ), a common vesiculo-erythematous skin disease associated with reactivation of varicella zoster virus in the cranial nerve, dorsal root, and autonomic ganglia, is accompanied by several related symptoms represented by postherpetic neuralgia. Among them, involvement of vesicorectal dysfunction is relatively rare. The vesicorectal symptom can usually be recovered in transient course, but is quite important in terms of impaired quality of life. Male individuals affected with HZ and skin lesions on sacral dermatome have been reported as independent risk factors of zoster-related voiding dysfunction. In this study, urinary symptoms were focused upon and six patients with zoster-related voiding dysfunction at a single faculty of dermatology in Japan from 2009 to 2014 were retrospectively analyzed. All patients showed HZ lesions on the sacral area and the urinary symptom recovered in approximately 2 months (14 days to 7 months). The term of treatment for zoster-associated urinary dysfunction was positively correlated with that for zoster-related pain without significance (r = 0.661, P = 0.153). Average treatment term for pain relief of sacral HZ accompanied by voiding dysfunction (91.3 ± 76.44 days) was significantly longer than that of sacral HZ without urinary symptom (18.9 ± 20.42 days) (P = 0.032). These results suggested that zoster-related voiding dysfunction would mainly be involved in sacral HZ and closely associated with severity of zoster-related pain. Dermatologists should be aware that severe zoster-related pain accompanied by sacral HZ, which is related to prolonged treatment of pain relief, can be a predictive factor of voiding dysfunction. © 2015 Japanese Dermatological Association.

Relative Importance of Hip and Sacral Pain Among Long-Term Gynecological Cancer Survivors Treated With Pelvic Radiotherapy and Their Relationships to Mean Absorbed Doses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waldenstroem, Ann-Charlotte, E-mail: ann-charlotte.waldenstrom@oncology.gu.se; Department of Oncology, Sahlgrenska University Hospital, Gothenburg; Olsson, Caroline

Purpose: To investigate the relative importance of patient-reported hip and sacral pain after pelvic radiotherapy (RT) for gynecological cancer and its relationship to the absorbed doses in these organs. Methods and Materials: We used data from a population-based study that included 650 long-term gynecological cancer survivors treated with pelvic RT in the Gothenburg and Stockholm areas in Sweden with a median follow-up of 6 years (range, 2-15) and 344 population controls. Symptoms were assessed through a study-specific postal questionnaire. We also analyzed the hip and sacral dose-volume histogram data for 358 of the survivors. Results: Of the survivors, one inmore » three reported having or having had hip pain after completing RT. Daily pain when walking was four times as common among the survivors compared to controls. Symptoms increased in frequency with a mean absorbed dose >37.5 Gy. Also, two in five survivors reported pain in the sacrum. Sacral pain also affected their walking ability and tended to increase with a mean absorbed dose >42.5 Gy. Conclusions: Long-term survivors of gynecological cancer treated with pelvic RT experience hip and sacral pain when walking. The mean absorbed dose was significantly related to hip pain and was borderline significantly related to sacral pain. Keeping the total mean absorbed hip dose below 37.5 Gy during treatment might lower the occurrence of long-lasting pain. In relation to the controls, the survivors had a lower occurrence of pain and pain-related symptoms from the hips and sacrum compared with what has previously been reported for the pubic bone.« less

Evaluation of the Diagnostic Accuracy of Conventional 2-Dimensional and 3-Dimensional Computed Tomography for Assessing Canine Sacral and Pelvic Fractures by Radiologists, Orthopedic Surgeons, and Veterinary Medical Students.

PubMed

Stieger-Vanegas, Susanne M; Senthirajah, Sri Kumar Jamie; Nemanic, Sarah; Baltzer, Wendy; Warnock, Jennifer; Hollars, Katelyn; Lee, Scott S; Bobe, Gerd

2015-08-01

To determine, using 3 groups of evaluators of varying experience reading orthopedic CT studies, if 3-dimensional computed tomography (3D-CT) provides a more accurate and time efficient method for diagnosis of canine sacral and pelvic fractures, and displacements of the sacroiliac and coxofemoral joints compared with 2-dimensional computed tomography (2D-CT). Retrospective clinical and prospective study. Dogs (n = 23): 12 dogs with traumatic pelvic fractures, 11 canine cadavers with pelvic trauma induced by a lateral impactor. All dogs had a 2D-CT exam of the pelvis and subsequent 3D-CT reconstructions from the 2D-CT images. Both 2D-CT and 3D-CT studies were anonymized and randomly presented to 2 veterinary radiologists, 2 veterinary orthopedic surgeons, and 2 veterinary medical students. Evaluators classified fractures using a confidence scale and recorded the duration of evaluation for each modality and case. 3D-CT was a more time-efficient technique for evaluation of traumatic sacral and pelvic injuries compared with 2D-CT in all evaluator groups irrespective of experience level reading orthopedic CT studies. However, for radiologists and surgeons, 2D-CT was the more accurate technique for evaluating sacral and pelvic fractures. 3D-CT improves sacral and pelvic fracture diagnosis when added to 2D-CT; however, 3D-CT has a reduced accuracy for evaluation of sacral and pelvic fractures if used without concurrent evaluation of 2D-CT images. © Copyright 2014 by The American College of Veterinary Surgeons.

Sacral stress fracture after lumbar and lumbosacral fusion. How to manage it? A proposition based on three cases and literature review.

PubMed

Scemama, C; D'astorg, H; Guigui, P

2016-04-01

Sacral fracture after lumbosacral instrumentation could be a source of prolonged pain and a late autonomy recovery in old patients. Diagnosis remains difficult and usually delayed. No clear consensus for efficient treatment of this complication has been defined. Aim of this study was to determine how to manage them. Three patients who sustained sacral fracture after instrumented lumbosacral fusion performed for degenerative disease of the spine are discussed. History, physical examinations' findings and radiographic features are presented. Pertinent literature was analyzed. All patients complained of unspecific low back and buttock pain a few weeks after index surgery. Diagnosis was done on CT-scan. We always choose revision surgery with good functional results. Sacral stress fracture has to be reminded behind unspecific buttock or low back pain. CT-scan seems to be the best radiological test to do the diagnosis. Surgical treatment is recommended when lumbar lordosis and pelvic incidence mismatched. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Effect of surgical approach on physical activity and pain control after sacral colpopexy.

PubMed

Collins, Sarah A; Tulikangas, Paul K; O'Sullivan, David M

2012-05-01

We sought to compare recovery of activity and pain control after robotic (ROB) vs abdominal (ABD) sacral colpopexy. Women undergoing ROB and ABD sacral colpopexy wore accelerometers for 7 days preoperatively and the first 10 days postoperatively. They completed postoperative pain diaries and Short Form-36 questionnaires before and after surgery. At 5 days postoperatively, none of the 14 subjects in the ABD group and 4 of 28 (14.3%) in the ROB group achieved 50% total baseline activity counts (P = .283). At 10 days, 5 of 14 (35.7%) in the ABD group and 8 of 26 (30.8%) in the ROB group (P = .972) achieved 50%. Postoperative pain was similar in both groups. Short Form-36 vitality scores were lower (P = .017) after surgery in the ABD group, but not in the ROB group. Women undergoing ROB vs ABD sacral colpopexy do not recover physical activity faster, and pain control is not improved. Copyright © 2012 Mosby, Inc. All rights reserved.

CyberKnife frameless single-fraction stereotactic radiosurgery for tumors of the sacrum.

PubMed

Gerszten, Peter C; Ozhasoglu, Cihat; Burton, Steven A; Welch, William C; Vogel, William J; Atkins, Barbara A; Kalnicki, Shalom

2003-08-15

The role of stereotactic radiosurgery for the treatment of intracranial lesions is well established. The experience with radiosurgery for the treatment of spinal and sacral lesions is more limited. Sacral lesions should be amenable to radiosurgical treatment similar to that used for their intracranial counterparts. The authors evaluated a single- fraction radiosurgical technique performed using the CyberKnife Real-Time Image-Guided Radiosurgery System for the treatment of the sacral lesion. The CyberKnife is a frameless radiosurgery system based on the coupling of an orthogonal pair of x-ray cameras to a dynamically manipulated robot-mounted linear accelerator possessing six degrees of freedom, which guides the therapy beam to the intended target without the need for frame-based fixation. All sacral lesions were located and tracked for radiation delivery relative to fiducial bone markers placed percutaneously. Eighteen patients were treated with single-fraction radiosurgery. Tumor histology included one benign and 17 malignant tumors. Dose plans were calculated based on computerized tomography scans acquired using 1.25-mm slices. Planning treatment volume was defined as the radiographically documented tumor volume with no margin. Tumor dose was maintained at 12 to 20 Gy to the 80% isodose line (mean 15 Gy). Tumor volume ranged from 23.6 to 187.4 ml (mean 90 ml). The volume of the cauda equina receiving greater than 8 Gy ranged from 0 to 1 ml (mean 0.1 ml). All patients underwent the procedure in an outpatient setting. No acute radiation toxicity or new neurological deficits occurred during the mean follow-up period of 6 months. Pain improved in all 13 patients who were symptomatic prior to treatment. No tumor progression has been documented on follow-up imaging. Stereotactic radiosurgery was found to be feasible, safe, and effective for the treatment of both benign and malignant sacral lesions. The major potential benefits of radiosurgical ablation of sacral lesions are relatively short treatment time in an outpatient setting and minimal or no side effects. This new technique offers a new and important therapeutic modality for the primary treatment of a variety of sacral tumors or for lesions not amenable to open surgical techniques.

SU-E-J-125: A Novel IMRT Planning Technique to Spare Sacral Bone Marrow in Pelvic Cancer Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGuire, S; Bhatia, S; Sun, W

Purpose: Develop an IMRT planning technique that can preferentially spare sacral bone marrow for pelvic cancer patients. Methods: Six pelvic cancer patients (two each with anal, cervical, and rectal cancer) were enrolled in an IRB approved protocol to obtain FLT PET images at simulation, during, and post chemoradiation therapy. Initially, conventional IMRT plans were created to maintain target coverage and reduce dose to OARs such as bladder, bowel, rectum, and femoral heads. Simulation FLT PET images were used to create IMRT plans to spare bone marrow identified as regions with SUV of 2 or greater (IMRT-BMS) within the pelvic bonesmore » from top of L3 to 5mm below the greater trochanter without compromising PTV coverage or OAR sparing when compared to the initial IMRT plan. IMRT-BMS plans used 8–10 beam angles that surrounded the subject. These plans were used for treatment. Retrospectively, the same simulation FLT PET images were used to create IMRT plans that spared bone marrow located in the sacral pelvic bone region (IMRT-FAN) also without compromising PTV coverage or OAR sparing. IMRT-FAN plans used 16 beam angles every 12° anteriorly from 90° – 270°. Optimization objectives for the sacral bone marrow avoidance region were weighted to reduce ≥V10. Results: IMRT-FAN reduced dose to the sacral bone marrow for all six subjects. The average V5, V10, V20, and V30 differences from the IMRT-BMS plan were −2.2 ± 1.7%, −11.4 ± 3.6%, −17.6 ± 5.1%, and −19.1 ± 8.1% respectively. Average PTV coverage change was 0.5% ± 0.8% from the conventional IMRT plan. Conclusion: An IMRT planning technique that uses beams from the anterior and lateral directions reduced the volume of sacral bone marrow that receives ≤10Gy while maintaining PTV coverage and OAR sparing. Additionally, the volume of sacral bone marrow that received 20 or 30 Gy was also reduced.« less

Feasibility of 3.0T pelvic MR imaging in the evaluation of endometriosis.

PubMed

Manganaro, L; Fierro, F; Tomei, A; Irimia, D; Lodise, P; Sergi, M E; Vinci, V; Sollazzo, P; Porpora, M G; Delfini, R; Vittori, G; Marini, M

2012-06-01

Endometriosis represents an important clinical problem in women of reproductive age with high impact on quality of life, work productivity and health care management. The aim of this study is to define the role of 3T magnetom system MRI in the evaluation of endometriosis. Forty-six women, with transvaginal (TV) ultrasound examination positive for endometriosis, with pelvic pain, or infertile underwent an MR 3.0T examination with the following protocol: T2 weighted FRFSE HR sequences, T2 weighted FRFSE HR CUBE 3D sequences, T1 w FSE sequences, LAVA-flex sequences. Pelvic anatomy, macroscopic endometriosis implants, deep endometriosis implants, fallopian tube involvement, adhesions presence, fluid effusion in Douglas pouch, uterus and kidney pathologies or anomalies associated and sacral nervous routes were considered by two radiologists in consensus. Laparoscopy was considered the gold standard. MRI imaging diagnosed deep endometriosis in 22/46 patients, endometriomas not associated to deep implants in 9/46 patients, 15/46 patients resulted negative for endometriosis, 11 of 22 patients with deep endometriosis reported ovarian endometriosis cyst. We obtained high percentages of sensibility (96.97%), specificity (100.00%), VPP (100.00%), VPN (92.86%). Pelvic MRI performed with 3T system guarantees high spatial and contrast resolution, providing accurate information about endometriosis implants, with a good pre-surgery mapping of the lesions involving both bowels and bladder surface and recto-uterine ligaments. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Application of local indentations for film cooling of gas turbine blade leading edge

NASA Astrophysics Data System (ADS)

Petelchyts, V. Yu.; Khalatov, A. A.; Pysmennyi, D. N.; Dashevskyy, Yu. Ya.

2016-09-01

The paper presents results of computer simulation of the film cooling on the turbine blade leading edge model where the air coolant is supplied through radial holes and row of cylindrical inclined holes placed inside hemispherical dimples or trench. The blowing factor was varied from 0.5 to 2.0. The model size and key initial parameters for simulation were taken as for a real blade of a high-pressure high-performance gas turbine. Simulation was performed using commercial software code ANSYS CFX. The simulation results were compared with reference variant (no dimples or trench) both for the leading edge area and for the flat plate downstream of the leading edge.

Rotating concave eddy current probe

DOEpatents

Roach, Dennis P [Albuquerque, NM; Walkington, Phil [Albuquerque, NM; Rackow, Kirk A [Albuquerque, NM; Hohman, Ed [Albuquerque, NM

2008-04-01

A rotating concave eddy current probe for detecting fatigue cracks hidden from view underneath the head of a raised head fastener, such as a buttonhead-type rivet, used to join together structural skins, such as aluminum aircraft skins. The probe has a recessed concave dimple in its bottom surface that closely conforms to the shape of the raised head. The concave dimple holds the probe in good alignment on top of the rivet while the probe is rotated around the rivet's centerline. One or more magnetic coils are rigidly embedded within the probe's cylindrical body, which is made of a non-conducting material. This design overcomes the inspection impediment associated with widely varying conductivity in fastened joints.

Comparison of fasciocutaneous V-Y and rotational flaps for defect coverage of sacral pressure sores: a critical single-centre appraisal.

PubMed

Djedovic, Gabriel; Metzler, Julia; Morandi, Evi M; Wachter, Tanja; Kühn, Shafreena; Pierer, Gerhard; Rieger, Ulrich M

2017-12-01

Pressure sore rates remain high in both nursing homes as well as in hospitals. Numerous surgical options are available for defect coverage in the sacral region. However, objective data is scarce as to whether a specific flap design is superior to another. Here, we aim to compare two fasciocutaneous flap designs for sacral defect coverage: the gluteal rotation flap and the gluteal V-Y flap. All primary sacral pressure sores of grades III-IV that were being covered with gluteal fasciocutaneous rotational or V-Y flaps between January 2008 and December 2014 at our institution were analysed. A total of 41 patients received a total of 52 flaps. Of these, 18 patients received 20 gluteal rotational flaps, and 23 patients received 32 V-Y flaps. Both groups were comparable with regards to demographics, comorbidities and complications. Significantly more V-Y flaps were needed to cover smaller defects. Mean length of hospital stay was significantly prolonged when surgical revision had to be carried out. Both flap designs have proven safe and reliable for defect coverage after sacral pressure sores. Gluteal rotational flaps appear to be more useful for larger defects. Both flap designs facilitate their reuse in case of pressure sore recurrence. Complication rates appear to be comparable in both designs and to the current literature. © 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Effect of Different Chromium Additions on the Microstructure and Mechanical Properties of Multipass Weld Joint of Duplex Stainless Steel

NASA Astrophysics Data System (ADS)

Kang, Dong Hoon; Lee, Hae Woo

2012-12-01

The correlation between the mechanical properties and ferrite volume fraction (approximately 40, 50, and 60 Ferrite Number [FN]) in duplex stainless steel weld metals were investigated by changing the Cr content in filler wires with a flux-cored arc-welding (FCAW) process. The interpass temperature was thoroughly maintained under a maximum of 423 K (150 °C), and the heat input was also sustained at a level under 15 KJ/cm in order to minimize defects. The microstructure examination demonstrated that the δ-ferrite volume fraction in the deposited metals increased as the Cr/Ni equivalent ratio increased, and consequently, chromium nitride (Cr2N) precipitation was prone to occur in the ferrite domains due to low solubility of nitrogen in this phase. Thus, more dislocations are pinned by the precipitates, thereby lowering the mobility of the dislocations. Not only can this lead to the strength improvement, but also it can accentuate embrittlement of the weld metal at subzero temperature. Additionally, the solid-solution strengthening by an increase of Cr and Mo content in austenite phase depending on the reduction of austenite proportion also made an impact on the increase of the tensile and yield strength. On the other hand, the impact test (at 293 K, 223 K, and 173 K [20 °C, -50 °C, and -100 °C]) showed that the specimen containing about 40 to 50 FN had the best result. The absorbed energy of about 40 to 50 J sufficiently satisfied the requirements for industrial applications at 223 K (-50 °C), while the ductile-to-brittle transition behavior exhibited in weldment containing 60 FN. As the test temperature decreased under 223 K (-50 °C), a narrow and deep dimple was transformed into a wide and shallow dimple, and a significant portion of the fracture surface was occupied by a flat cleavage facet with river patterns.

[Effect of iliolumbar fixation in patients with Tile C pelvic injury and analysis of relative factors].

PubMed

Ge, Zhenxin; Wang, Ben; Zhang, Dongzheng; Liu, Zhaojie; Zhang, Yinguang; Jia, Jian

2012-11-01

To explore the relative prognostic factors of Tile C pelvic injury after iliolumbar fixation. Between March 2007 and March 2010, 60 patients with Tile C pelvic injuries were surgically treated with iliolumbar fixation, including 39 males and 21 females with an average age of 37 years (range, 17-66 years). Of them, 27 cases were classified as Tile C1, 20 as Tile C2, and 13 as Tile C3. The preoperative injury severity score (ISS) was 12-66 (mean, 29.4). The time from injury to surgery was 2-25 days (mean, 8.1 days). Iliolumbar fixation was performed in all patients. Unconditional logistic analysis was used to analyze the relationship between the age, sex, body mass index (BMI), operation opportunity, the preoperative combined injury, classification of fracture, the postoperative complication, reduction outcome, sacral nerve injury, and the time of physical exercise and the prognosis. All 60 patients were followed up 12-56 months (mean, 27.3 months). Infection of incisions occurred in 12 cases and were cured after dressing change; healing of incision by first intention was obtained in the other patients. Delay sacral nerve injury was found in 15 patients, 6 patients underwent nerve decompression, and 9 underwent conservative treatment. Ten patients had nail protrusion of Schanz screws at the posterior superior illac spine, and 3 patients had pain, which was relieved after removal of the internal fixator. One patient had bone-grafting nonunion of sacroiliac joint, which was improved by pressured bone graft. Five patients had the beam breakage without significant effect. Six patients had deep vein thrombosis, among them 4 underwent filter and 2 underwent nonsurgical treatment. The healing time of fracture was 3-6 months (mean, 3.9 months). According to the Matta function score, the results were excellent in 31 cases, good in 24 cases, fair in 3 cases, and poor in 2 cases with an excellent and good rate of 91.7% at last follow-up. Majeed score was 58-100 (mean, 86), 28 were rated as excellent, 12 as good, 16 as fair, and 4 as poor with an excellent and good rate of 66.7%. The logistic analysis showed that the age, sex, BMI, and postoperative complications were not prognostic factors; early operation (within 10 days), early function exercises (within 7 days), the better reduction quality, and the less sacral nerve injury were in favor of prognosis; and the worse preoperative combined injury and pelvic injury were, the worse the prognosis was. Operation opportunity, the preoperative combined injury, reduction outcome, sacral nerve injury, and the time of physical exercise are all significantly prognostic factors of Tile C pelvic injuries.

Correlation analysis of symmetry breaking in the surface nanostructure ordering: case study of the ventral scale of the snake Morelia viridis

NASA Astrophysics Data System (ADS)

Kovalev, A.; Filippov, A.; Gorb, S. N.

2016-03-01

In contrast to the majority of inorganic or artificial materials, there is no ideal long-range ordering of structures on the surface in biological systems. Local symmetry of the ordering on biological surfaces is also often broken. In the present paper, the particular symmetry violation was analyzed for dimple-like nano-pattern on the belly scales of the skin of the pythonid snake Morelia viridis using correlation analysis and statistics of the distances between individual nanostructures. The results of the analysis performed on M. viridis were compared with a well-studied nano-nipple pattern on the eye of the sphingid moth Manduca sexta, used as a reference. The analysis revealed non-random, but very specific symmetry violation. In the case of the moth eye, the nano-nipple arrangement forms a set of domains, while in the case of the snake skin, the nano-dimples arrangement resembles an ordering of particles (molecules) in amorphous (glass) state. The function of the nano-dimples arrangement may be to provide both friction and strength isotropy of the skin. A simple model is suggested, which provides the results almost perfectly coinciding with the experimental ones. Possible mechanisms of the appearance of the above nano-formations are discussed.

Femtosecond laser full and partial texturing of steel surfaces to reduce friction in lubricated contact

NASA Astrophysics Data System (ADS)

Ancona, Antonio; Carbone, Giuseppe; De Filippis, Michele; Volpe, Annalisa; Lugarà, Pietro Mario

2014-12-01

Minimizing mechanical losses and friction in vehicle engines would have a great impact on reducing fuel consumption and exhaust emissions, to the benefit of environmental protection. With this scope, laser surface texturing (LST) with femtosecond pulses is an emerging technology, which consists of creating, by laser ablation, an array of high-density microdimples on the surface of a mechanical device. The microtexture decreases the effective contact area and, in case of lubricated contact, acts as oil reservoir and trap for wear debris, leading to an overall friction reduction. Depending on the lubrication regime and on the texture geometry, several mechanisms may concur to modify friction such as the local reduction of the shear stress, the generation of a hydrodynamic lift between the surfaces or the formation of eddy-like flows at the bottom of the dimple cavities. All these effects have been investigated by fabricating and characterizing several LST surfaces by femtosecond laser ablation with different features: partial/full texture, circular/elliptical dimples, variable diameters, and depths but equivalent areal density. More than 85% of friction reduction has been obtained from the circular dimple geometry, but the elliptical texture allows adjusting the friction coefficient by changing its orientation with respect to the sliding direction.

Fretting wear behaviors of a dual-cooled nuclear fuel rod under a simulated rod vibration

NASA Astrophysics Data System (ADS)

Lee, Young-Ho; Kim, Hyung-Kyu; Kang, Heung-Seok; Yoon, Kyung-Ho; Kim, Jae-Yong; Lee, Kang-Hee

2012-06-01

Recently, a dual-cooled fuel (i.e., annular fuel) that is compatible with current operating PWR plants has been proposed in order to realize both a considerable amount of power uprating and an increase of safety margins. As the design concept should be compatible with current operating PWR plants, however, it shows a narrow gap between the fuel rods when compared with current solid nuclear fuel arrays and needs to modify the spacer grid shapes and their positions. In this study, fretting wear tests have been performed to evaluate the wear resistance of a dual-cooled fuel by using a proposed spring and dimple of spacer grids that have a cantilever type and hemispherical shape, respectively. As a result, the wear volume of the spring specimen gradually increases as the contact condition is changed from a certain gap, just contact to positive force. However, in the dimple specimen, just contact condition shows a large wear volume. In addition, a circular rod motion at upper region of contact surface is gradually increased and its diametric size depends on the wear depth increase. Based on the test results, the fretting wear resistance of the proposed spring and dimple is analyzed by comparing the wear measurement results and rod motion in detail.

The effect of dimple error on the horizontal launch angle and side spin of the golf ball during putting.

PubMed

Richardson, Ashley K; Mitchell, Andrew C S; Hughes, Gerwyn

2017-02-01

This study aimed to examine the effect of the impact point on the golf ball on the horizontal launch angle and side spin during putting with a mechanical putting arm and human participants. Putts of 3.2 m were completed with a mechanical putting arm (four putter-ball combinations, total of 160 trials) and human participants (two putter-ball combinations, total of 337 trials). The centre of the dimple pattern (centroid) was located and the following variables were measured: distance and angle of the impact point from the centroid and surface area of the impact zone. Multiple regression analysis was conducted to identify whether impact variables had significant associations with ball roll variables, horizontal launch angle and side spin. Significant associations were identified between impact variables and horizontal launch angle with the mechanical putting arm but this was not replicated with human participants. The variability caused by "dimple error" was minimal with the mechanical putting arm and not evident with human participants. Differences between the mechanical putting arm and human participants may be due to the way impulse is imparted on the ball. Therefore it is concluded that variability of impact point on the golf ball has a minimal effect on putting performance.

Development of a High-Strength Ultrafine-Grained Ferritic Steel Nanocomposite

NASA Astrophysics Data System (ADS)

Rahmanifard, Roohollah; Farhangi, Hasan; Novinrooz, Abdul Javad; Moniri, Samira

2013-02-01

This article describes the microstructural and mechanical properties of 12YWT oxide-dispersion-strengthened (ODS)-ferritic steel nanocomposite. According to the annealing results obtained from X-ray diffraction line profile analysis on mechanically alloyed powders milled for 80 hours, the hot extrusion at 1123 K (850 °C) resulted in a nearly equiaxed ultrafine structure with an ultimate tensile strength of 1470 MPa, yield strength of 1390 MPa, and total elongation of 13 pct at room temperature comparable with high-strength 14YWT ODS steel. Maximum total elongation was found at 973 K (600 °C) where fractography of the tensile specimen showed a fully ductile dimple feature compared with the splitting cracks and very fine dimpled structure observed at room temperature. The presence of very small particles on the wall of dimples at 1073 K (800 °C) with nearly chemical composition of the matrix alloy was attributed to the activation of the boundaries decohesion mechanism as a result of diffusion of solute atoms. The results of Charpy impact test also indicated significant improvement of transition temperature with respect to predecessor 12YWT because of the decreased grain size and more homogeneity of grain size distribution. Hence, this alloy represented a good compromise between the strength and Charpy impact properties.

Acute urinary retention attributable to sacral herpes zoster.

PubMed

Acheson, J; Mudd, D

2004-11-01

Acute urinary retention in women is uncommon. A 63 year old woman presented with suprapubic pain, a palpable bladder, and multiple grouped vesicles on the right buttock. Catheterisation showed a residual of 2000 ml. A case is reported of acute urinary retention secondary to herpes zoster infection of the sacral nerves (S2-4).

Surgical anesthesia with a combination of T12 paravertebral block and lumbar plexus, sacral plexus block for hip replacement in ankylosing spondylitis: CARE-compliant 4 case reports.

PubMed

Ke, Xijian; Li, Ji; Liu, Yong; Wu, Xi; Mei, Wei

2017-06-26

Anesthesia management for patients with severe ankylosing spondylitis scheduled for total hip arthroplasty is challenging due to a potential difficult airway and difficult neuraxial block. We report 4 cases with ankylosing spondylitis successfully managed with a combination of lumbar plexus, sacral plexus and T12 paravertebral block. Four patients were scheduled for total hip arthroplasty. All of them were diagnosed as severe ankylosing spondylitis with rigidity and immobilization of cervical and lumbar spine and hip joints. A combination of T12 paravertebral block, lumbar plexus and sacral plexus block was successfully used for the surgery without any additional intravenous anesthetic or local anesthetics infiltration to the incision, and none of the patients complained of discomfort during the operations. The combination of T12 paravertebral block, lumbar plexus and sacral plexus block, which may block all nerves innervating the articular capsule, surrounding muscles and the skin involved in total hip arthroplasty, might be a promising alternative for total hip arthroplasty in ankylosing spondylitis.

Congenital talipes equinovarus and congenital vertical talus secondary to sacral agenesis.

PubMed

Bray, Jonathan James Hyett; Crosswell, Sebastien; Brown, Rick

2017-05-05

Sacral agenesis is a rare congenital defect which is associated with foot deformities such as congenital talipes equinovarus (CTEV) and less commonly congenital vertical talus (CVT). We report a 3-year-old Caucasian girl who was born with right CTEV and left CVT secondary to sacral agenesis. Her right foot was managed with a Ponseti casting method at 2 weeks, followed by an Achilles tenotomy at 4 months. The left foot was initially managed with a nocturnal dorsi-flexion splint. Both feet remained resistant and received open foot surgery at 10 months producing plantigrade feet with neutral hindfeet. At 19 months, she failed to achieve developmental milestones and examinations revealed abnormal lower limb reflexes. A full body MRI was performed which identified the sacral agenesis. We advocate early MRI of the spine to screen for spinal defects when presented with resistant foot deformities, especially when bilateral. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Long-term results of sacral neuromodulation for women with urinary retention.

PubMed

Dasgupta, Ranan; Wiseman, Oliver J; Kitchen, Neil; Fowler, Clare J

2004-08-01

OBJECTIVE ; To review the long-term results of sacral nerve stimulation in the treatment of women with Fowler's syndrome, over a 6-year period at one tertiary referral centre. Between 1996 and 2002, 26 women with urinary retention were treated by implanting a sacral nerve stimulator. Their case records were reviewed for follow-up, complications and revision procedures, and the most recent uroflowmetry results. There were 20 patients (77%) still voiding spontaneously at the time of review (with two having deactivated their stimulator because of pregnancy). Fourteen patients (54%) required revision surgery, and the most common complications included loss of efficacy, implant-related discomfort and leg pain. The mean postvoid residual volume was 75 mL and mean maximum flow rate 20.8 mL/s. In young women with retention, for whom there is still no alternative to lifelong self-catheterization, sacral neuromodulation is effective for up to 5 years after implantation. However, there was a significant complication rate, in line with other reports, which may be improved by new technical developments.

Characterization of herpes simplex virus type 2 latency-associated transcription in human sacral ganglia and in cell culture.

PubMed

Croen, K D; Ostrove, J M; Dragovic, L; Straus, S E

1991-01-01

The ability of herpes simplex virus type 2 (HSV-2) to establish latency in and reactivate from sacral dorsal root sensory ganglia is the basis for recurrent genital herpes. The expression of HSV-2 genes in latently infected human sacral ganglia was investigated by in situ hybridization. Hybridizations with a probe from the long repeat region of HSV-2 revealed strong nuclear signals overlying neurons in sacral ganglia from five of nine individuals. The RNA detected overlaps with the transcript for infected cell protein O but in the opposite, or "anti-sense," orientation. These observations mimic those made previously with HSV-1 in human trigeminal ganglia and confirm the recent findings during latency in HSV-2-infected mice and guinea pigs. Northern hybridization of RNA from infected Vero cells showed that an HSV-2 latency-associated transcript was similar in size to the larger (1.85 kb) latency transcript of HSV-1. Thus, HSV-1 and HSV-2 latency in human sensory ganglia are similar, if not identical, in terms of their cellular localization and pattern of transcription.

Sacral root neuromodulation in idiopathic nonobstructive chronic urinary retention.

PubMed

Shaker, H S; Hassouna, M

1998-05-01

Sacral root neuromodulation is becoming a superior alternative to the standard treatment of idiopathic nonobstructive urinary retention. We report results in 20 successive patients who underwent sacral foramen implantation to restore bladder function. After an initial, thorough baseline assessment 20 patients 19.43 to 55.66 years old with idiopathic nonobstructive urinary retention underwent percutaneous nerve evaluation. Response was assessed by a detailed voiding diary. Responders underwent implantation with an S3 foramen implant, and were followed 1, 3 and 6 months postoperatively, and every 6 months thereafter. Sacral root neuromodulation restored voiding capability in these patients. Bladders were emptied with minimal post-void residual urine, which decreased from 78.3 to 5.5 to 10.2% of the total voided volume from baseline to postoperative followup. These results were reflected in uroflowmetry and pressure-flow studies, which were almost normal after implantation. Furthermore, the urinary tract infection rate decreased significantly and associated pelvic pain improved substantially. The Beck depression inventory and SF-36 quality of life questionnaire indicated some improvement but reached significance in only 1 item. In addition, cystometrography showed no significant difference after 6 months of implantation compared with baseline values. Complications were minimal and within expectations. Sacral root neuromodulation is an appealing, successful modality for nonobstructive urinary retention. Only patients who have a good response to percutaneous nerve evaluation are candidates for implantation. The high efficacy in patients who undergo implantation, relative simplicity of the procedure and low complication rate make this a treatment breakthrough in this difficult group.

Determination of lumbosacral transitional vertebrae in kidney urinary bladder x-ray films in the Saudi population

PubMed Central

Khashoggi, Khalid G.; Hafiz, Rawan M.; Bock, Yasmin M.; Kaki, Abdullah M.

2017-01-01

Objectives: To investigated the rate of occurrence of lumbosacral transitional vertebrae (LSTV), spinal variant, in kidney urinary bladder (KUB) plain radiographs in a Saudi population. Methods: Between January 2012 to January 2015, KUB plain films obtained from patients at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, were reviewed, and the presence or absence of LSTV was documented and classified as incomplete or complete. Patients who had evidence of spinal surgery that would obscure the view were excluded. Results: A total of 2078 patients underwent KUB examinations during the study period; LSTV anomalies were detected in 158 of these. Sacralization was present in 153 (96.8%) of this cohort, while lumbarization was present in 5 (3.2%). A total of 136 (86.1%) of the sacralized segments were of the incomplete type, whereas 17 (10.7%) were complete. Of the lumbarized vertebrae, 3 (1.8%) were incomplete, and 2 (1.2%) were complete. The most frequent type in men was type Ib (28.5%) for sacralized segments, and type IIb for lumbarized segments (0.6%). In women, type Ia was the most common form of sacralized segments (11.3%) and type IIb was the most common form of lumbarized segments (2.8%). Conclusion: The prevalence of LSTV in Saudi patients is 7.6%, with a higher incidence of sacralization than lumbarization. Further studies with larger sample sizes and longer follow-up time are needed to demonstrate the clinical significance thereof. PMID:28762430

Subarachnoid and basal cistern navigation through the sacral hiatus with guide wire assistance.

PubMed

Layer, Lauren; Riascos, Roy; Firouzbakht, Farhood; Amole, Adewumi; Von Ritschl, Rudiger; Dipatre, Pier; Cuellar, Hugo

2011-07-01

Intraspinal navigation with catheters and fiberscopes has shown feasible results for diagnosis and treatment of intraspinal and intracranial lesions. The most common approach, lumbar puncture, has allowed access to the spinal cord, however, coming with the difficulties of fiberscope damage and decreased torque for guidance. Our objective in this study is to allow an alternate access, the sacral hiatus, with guide wire assistance into the subarachnoid and intracranial structures, while easing the angle of entry and increasing torque. We advanced catheters with guide wire and fluoroscopy assistance into the sacral hiatus of three cadavers. After entry, the thecal sac was punctured and the catheter with guide wire was advanced rostrally until positioned in the basal cisterns of the brain. We confirmed catheter placement with contrast injection, autopsy, and dissection. In our study, the sacral hiatus was easily accessed, but resistance was found when attempting to puncture the thecal sac. The advancement of the catheter with guide wire assistance glided easily rostrally until some mild resistance was discovered at entry into the foramen magnum. With redirection, all catheters passed with ease into the basal cisterns. Positioning was confirmed with contrast injection with fluoroscopy evidence, autopsy, and dissection. There was no macroscopic or microscopic evidence of damage to the spinal roots, spinal cord, or cranial nerves. The sacral hiatus with guide wire assistance is an accessible conduit for uncomplicated entry into the subarachnoid and basal cistern space without damaging surrounding structures.

Long-term durability of sacral nerve stimulation therapy for chronic fecal incontinence.

PubMed

Hull, Tracy; Giese, Chad; Wexner, Steven D; Mellgren, Anders; Devroede, Ghislain; Madoff, Robert D; Stromberg, Katherine; Coller, John A

2013-02-01

Limited data have been published regarding the long-term results of sacral nerve stimulation, or sacral neuromodulation, for severe fecal incontinence. The aim was to assess the outcome of sacral nerve stimulation with the use of precise tools and data collection, focusing on the long-term durability of the therapy. Five-year data were analyzed. Patients entered in a multicenter, prospective study for fecal incontinence were followed at 3, 6, and 12 months and annually after device implantation. Patients with chronic fecal incontinence in whom conservative treatments had failed or who were not candidates for more conservative treatments were selected. Patients with ≥ 50% improvement over baseline in fecal incontinence episodes per week during a 14-day test stimulation period received sacral nerve stimulation therapy. Patients were assessed with a 14-day bowel diary and Fecal Incontinence Quality of Life and Fecal Incontinence Severity Index questionnaires. Therapeutic success was defined as ≥ 50% improvement over baseline in fecal incontinence episodes per week. All adverse events were collected. A total of 120 patients (110 women; mean age, 60.5 years) underwent implantation. Seventy-six of these patients (63%) were followed a minimum of 5 years (maximum, longer than 8 years) and are the basis for this report. Fecal incontinence episodes per week decreased from a mean of 9.1 at baseline to 1.7 at 5 years, with 89% (n = 64/72) having ≥ 50% improvement (p < 0.0001) and 36% (n = 26/72) having complete continence. Fecal Incontinence Quality of Life scores also significantly improved for all 4 scales between baseline and 5 years (n = 70; p < 0.0001). Twenty-seven of the 76 (35.5%) patients required a device revision, replacement, or explant. The therapeutic effect and improved quality of life for fecal incontinence is maintained 5 years after sacral nerve stimulation implantation and beyond. Device revision, replacement, or explant rate was acceptable, but future efforts should be aimed at improvement.

Mechanical seal with textured sidewall

DOEpatents

Khonsari, Michael M.; Xiao, Nian

2017-02-14

The present invention discloses a mating ring, a primary ring, and associated mechanical seal having superior heat transfer and wear characteristics. According to an exemplary embodiment of the present invention, one or more dimples are formed onto the cylindrical outer surface of a mating ring sidewall and/or a primary ring sidewall. A stationary mating ring for a mechanical seal assembly is disclosed. Such a mating ring comprises an annular body having a central axis and a sealing face, wherein a plurality of dimples are formed into the outer circumferential surface of the annular body such that the exposed circumferential surface area of the annular body is increased. The texture added to the sidewall of the mating ring yields superior heat transfer and wear characteristics.

Fracture surface analysis of a quenched (α+β)-metastable titanium alloy

NASA Astrophysics Data System (ADS)

Illarionov, A. G.; Stepanov, S. I.; Demakov, S. L.

2017-12-01

Fracture surface analysis is conducted by means of SEM for VT16 titanium alloy specimens solution-treated at temperatures ranging from 700 to 875 °C, water-quenched and subjected to tensile testing. A cup and cone shape failure and dimple microstructure of the fracture surface indicates the ductile behavior of the alloy. Dimple dimensions correlated with the β-grain size of the alloy in quenched condition. The fracture area (namely, the size; the cup and cone shape) depends on the volume fraction of the primary α-phase in the quenched sample. However, the fracture surface changes considerably when the strain-induced β-αʺ-transformation takes place during tensile testing, resulting in the increase of alloy ductility.

A Novel Collaborative Protocol for Successful Management of Penile Pain Mediated by Radiculitis of Sacral Spinal Nerve Roots From Tarlov Cysts.

PubMed

Goldstein, Irwin; Komisaruk, Barry R; Rubin, Rachel S; Goldstein, Sue W; Elliott, Stacy; Kissee, Jennifer; Kim, Choll W

2017-09-01

Since 14 years of age, the patient had experienced extreme penile pain within seconds of initial sexual arousal through masturbation. Penile pain was so severe that he rarely proceeded to orgasm or ejaculation. After 7 years of undergoing multiple unsuccessful treatments, he was concerned for his long-term mental health and for his future ability to have relationships. To describe a novel collaboration among specialists in sexual medicine, neurophysiology, and spine surgery that led to successful management. Collaborating health care providers conferred with the referring physician, patient, and parents and included a review of all medical records. Elimination of postpubertal intense penile pain during sexual arousal. The patient presented to our sexual medicine facility at 21 years of age. The sexual medicine physician identifying the sexual health complaint noted a pelvic magnetic resonance imaging report of an incidental sacral Tarlov cyst. A subsequent sacral magnetic resonance image showed four sacral Tarlov cysts, with the largest measuring 18 mm. Neuro-genital testing result were abnormal. The neurophysiologist hypothesized the patient's pain at erection was produced by Tarlov cyst-induced neuropathic irritation of sensory fibers that course within the pelvic nerve. The spine surgeon directed a diagnostic injection of bupivacaine to the sacral nerve roots and subsequently morphine to the conus medullaris of the spinal cord. The bupivacaine produced general penile numbness; the morphine selectively decreased penile pain symptoms during sexual arousal without blocking penile skin sensation. The collaboration among specialties led to the conclusion that the Tarlov cysts were pathophysiologically mediating the penile pain symptoms during arousal. Long-term follow-up after surgical repair showed complete symptom elimination at 18 months after treatment. This case provides evidence that (i) Tarlov cysts can cause sacral spinal nerve root radiculitis through sensory pelvic nerve and (ii) there are management benefits from collaboration among sexual medicine, neurophysiology, and spine surgery subspecialties. Goldstein I, Komisaruk BR, Rubin RS, et al. A Novel Collaborative Protocol for Successful Management of Penile Pain Mediated by Radiculitis of Sacral Spinal Nerve Roots From Tarlov Cysts. Sex Med 2017;5:e203-e211. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Nanostructuring of thin Au films deposited on ordered Ti templates for applications in SERS

NASA Astrophysics Data System (ADS)

Grochowska, Katarzyna; Siuzdak, Katarzyna; Macewicz, Łukasz; Skiba, Franciszek; Szkoda, Mariusz; Karczewski, Jakub; Burczyk, Łukasz; Śliwiński, Gerard

2017-10-01

In this work the results on thermal nanostructuring of the Au films on Ti templates as well as morphology and optical properties of the obtained structures are reported. The bimetal nanostructures are fabricated in a multi-step process. First, the titania nanotubes are produced on the surface of Ti foil by anodization in an ethylene glycol-water solution containing fluoride ions. This is followed by chemical etching in oxalic acid and results in a highly ordered dimpled surface. Subsequently, thin gold films (5-20 nm) are deposited onto prepared Ti substrates by magnetron sputtering. The as-prepared layers are then dewetted by the UV nanosecond laser pulses or alternatively in the furnace (temperature < 500 °C). The SEM inspection reveals formation of honeycomb nanostructures (cavity diameter: ∼100 nm) covered with Au nanoparticles (NPs). It is observed that both the laser annealing and continuous thermal treatment in furnace can lead to the creation of NPs inside every Ti dimple and result in uniform coating of the whole area of structured templates. The size and localization of NPs obtained via both dewetting processes as well as their shape can be tuned by the annealing time and the laser processing parameters and also by initial thickness of Au layer and presence of the dimples themselves in the substrate. Results confirm that the prepared material can be used as substrate for SERS (Surface Enhanced Raman Spectroscopy).

Finite element simulation of gap opening between cladding tube and spacer grid in a fuel rod assembly using crystallographic models of irradiation growth and creep

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patra, Anirban; Tomé, Carlos N.

A physically-based crystal plasticity framework for modeling irradiation growth and creep is interfaced with the finite element code ABAQUS in order to study the contact forces and the gap evolution between the spacer grid and the cladding tube as a function of irradiation in a representative section of a fuel rod assembly. Deformation mechanisms governing the gap opening are identified and correlated to the texture-dependent material response. Thus, in the absence of coolant flow-induced vibrations, these simulations predict the contribution of irradiation growth and creep to the gap opening between the cladding tube and the springs and dimples on themore » spacer grid. The simulated contact forces on the springs and dimples are compared to available experimental and modeling data. Various combinations of external loads are applied on the springs and dimples to simulate fuel rods in the interior and at the periphery of the fuel rod assembly. Furthermore, we found that loading conditions representative (to a first order approximation) of fuel rods at the periphery show higher gap opening. This is in agreement with in-reactor data, where rod leakages due to the synergistic effects of gap opening and coolant flow-induced vibrations were generally found to occur at the periphery of the fuel rod assembly.« less

Finite element simulation of gap opening between cladding tube and spacer grid in a fuel rod assembly using crystallographic models of irradiation growth and creep

DOE PAGES

Patra, Anirban; Tomé, Carlos N.

2017-03-06

A physically-based crystal plasticity framework for modeling irradiation growth and creep is interfaced with the finite element code ABAQUS in order to study the contact forces and the gap evolution between the spacer grid and the cladding tube as a function of irradiation in a representative section of a fuel rod assembly. Deformation mechanisms governing the gap opening are identified and correlated to the texture-dependent material response. Thus, in the absence of coolant flow-induced vibrations, these simulations predict the contribution of irradiation growth and creep to the gap opening between the cladding tube and the springs and dimples on themore » spacer grid. The simulated contact forces on the springs and dimples are compared to available experimental and modeling data. Various combinations of external loads are applied on the springs and dimples to simulate fuel rods in the interior and at the periphery of the fuel rod assembly. Furthermore, we found that loading conditions representative (to a first order approximation) of fuel rods at the periphery show higher gap opening. This is in agreement with in-reactor data, where rod leakages due to the synergistic effects of gap opening and coolant flow-induced vibrations were generally found to occur at the periphery of the fuel rod assembly.« less

Giant anterior sacral meningocele presenting as bacterial meningitis in a previously healthy adult.

PubMed

Miletic, D; Poljak, I; Eskinja, N; Valkovic, P; Sestan, B; Troselj-Vukic, B

2008-02-01

Meningocele may be asymptomatic and incidentally discovered. Presenting as a retrorectal mass, sacral meningocele may produce urinary, rectal, and menstrual pain. Anterior sacral meningocele may be the cause of tethered cord syndrome. This article presents a case of a previously healthy 39-year-old man with large meningeal herniation that occupied the entire pelvis who developed symptoms of bacterial meningitis. A 39-year-old man was admitted with fever, chills, headache and photophobia. Escherichia coli was isolated from cerebrospinal fluid culture. Moderate improvement regarding meningeal symptoms was noted due to intravenous antibiotic therapy, but intense pain in the lower back associated with constipation, fecal and urinary incontinence, and saddle anesthesia developed. Abdominal ultrasound was negative. Plain radiographs and computed tomography demonstrated sacral bone defect and retrorectal expansive mass. MRI confirmed anterior sacral meningocele with cord tethering. After posterior laminectomy and dural opening, communication between meningocele and intrathecal compartment was obliterated. Computed tomography-guided percutaneous drainage through the ischiorectal fossa was performed to treat residual presacral cyst. Delayed diagnosis in our patient was related to misleading signs of bacterial meningitis without symptoms of intrapelvic expansion until the second week of illness. In our patient, surgical treatment was unavoidable due to resistive meningitis, acute back pain, and symptoms of space-occupying pelvic lesion. Neurosurgical approach was successful in treatment of meningitis and neurological disorders. Computed tomography-guided evacuation of the residual retrorectal cyst was less invasive than laparotomy, resulting in normalization of defecation and miction despite incomplete evacuation. Further follow-up studies may provide insight into the most effective treatment of such conditions.

Comparison of gluteal perforator flaps and gluteal fasciocutaneous rotation flaps for reconstruction of sacral pressure sores.

PubMed

Chen, Yen-Chou; Huang, Eng-Yen; Lin, Pao-Yuan

2014-03-01

The gluteus maximus myocutaneous flap was considered the workhorse that reconstructed sacral pressure sores, but was gradually replaced by fasciocutaneous flap because of several disadvantages. With the advent of the perforator flap technique, gluteal perforator (GP) flap has gained popularity nowadays. The aim of this study was to compare the complications and outcomes between GP flaps and gluteal fasciocutaneous rotation (FR) flaps in the treatment of sacral pressure sores. Between April 2007 and June 2012, 63 patients underwent sacral pressure sore reconstructions, with a GP flap used in 31 cases and an FR flap used in 32 cases. Data collected on the patients included patient age, gender, co-morbidity for being bedridden and follow-up time. Surgical details collected included the defect size, operative time and estimated blood loss. Complications recorded included re-operation, dehiscence, flap necrosis, wound infection, sinus formation, donor-site morbidity and recurrence. The complications and clinical outcomes were compared between these two groups. We found that there was no significant difference in patient demographics, surgical complications and recurrence between these two groups. In gluteal FR flap group, all recurrent cases (five) were treated by reuse of previous flaps. Both methods are comparable, good and safe in treating sacral pressure sores. Gluteal FR flap can be performed without microsurgical dissection, and re-rotation is feasible in recurrent cases. The authors suggest using gluteal FR flaps in patients with a high risk of sore recurrence. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Sacral neuromodulation for the treatment of neurogenic lower urinary tract dysfunction caused by multiple sclerosis: a single-centre prospective series.

PubMed

Engeler, Daniel S; Meyer, Daniel; Abt, Dominik; Müller, Stefanie; Schmid, Hans-Peter

2015-10-23

Sacral neuromodulation is well established in the treatment of refractory, non-neurogenic lower urinary tract dysfunction, but its efficacy and safety in patients with lower urinary tract dysfunction of neurological origin is unclear. Only few case series have been reported for multiple sclerosis. We prospectively evaluated the efficacy and safety of sacral neuromodulation in patients with multiple sclerosis. Seventeen patients (13 women, 4 men) treated with sacral neuromodulation for refractory neurogenic lower urinary tract dysfunction caused by multiple sclerosis were prospectively enrolled (2007-2011). Patients had to have stable disease and confirmed neurogenic lower urinary tract dysfunction. Voiding variables, adverse events, and subjective satisfaction were assessed. Sixteen (94 %) patients had a positive test phase with a >70 % improvement. After implantation of the pulse generator (InterStim II), the improvement in voiding variables persisted. At 3 years, the median voided volume had improved significantly from 125 (range 0 to 350) to 265 ml (range 200 to 350) (p < 0.001), the post void residual from 170 (range 0 to 730) to 25 ml (range 0 to 300) (p = 0.01), micturition frequency from 12 (range 6 to 20) to 7 (range 4 to 12) (p = 0.003), and number of incontinence episodes from 3 (range 0 to 10) to 0 (range 0 to 1) (p = 0.006). The median subjective degree of satisfaction was 80 %. Only two patients developed lack of benefit. No major complications occurred. Chronic sacral neuromodulation promises to be an effective and safe treatment of refractory neurogenic lower urinary tract dysfunction in selected patients with multiple sclerosis.

Adhesive arachnoiditis after percutaneous fibrin glue treatment of a sacral meningeal cyst.

PubMed

Hayashi, Kazunori; Nagano, Junji; Hattori, Satoshi

2014-06-01

The authors present the case of a 64-year-old woman who was referred for severe sacral pain. She reported that her pain had been longstanding, and had greatly increased after percutaneous fibrin glue placement therapy for a sacral meningeal cyst 2 months earlier at a different hospital. An MRI scan obtained immediately after fibrin glue placement at that hospital suggested that fibrin glue had migrated superiorly into the subarachnoid space from the sacral cyst to the level of L-4. On admission to the authors' institution, physical examination demonstrated no abnormal findings except for perianal hypesthesia. An MRI study obtained at admission demonstrated a cystic lesion in the peridural space from the level of S-2 to S-4. Inhomogeneous intensity was identified in this region on T2-weighted images. Because the cauda equina and nerve roots appeared to be compressed by the lesion, total cyst excision was performed. The cyst cavity was filled with fluid that resembled CSF, plus gelatinous material. Histopathological examination revealed that the cyst wall was composed of hyaline connective tissue with some calcification. No nervous tissue or ganglion cells were found in the tissue. The gelatinous material was acellular, and appeared to be degenerated fibrin glue. Sacral pain persisted to some extent after surgery. The authors presumed that migrated fibrin glue caused the development of adhesive arachnoiditis. The risk of adhesive arachnoiditis should be considered when this therapy is planned. Communication between a cyst and the subarachnoid space should be confirmed to be sufficiently narrow to prevent the migration of injected fibrin glue.

Perineal colostomy prolapse: a novel application of mesh sacral pexy.

PubMed

Landen, S; Ursaru, D; Delugeau, V; Landen, C

2018-01-01

Full thickness colonic prolapse following pseudocontinent perineal colostomy has not been previously reported. Possible contributing factors include a large skin aperture at the site of the perineal stoma, the absence of anal sphincters and mesorectal attachments and the presence of a perineal hernia. A novel application of sacral pexy combined with perineal hernia repair using two prosthetic meshes is described.

[Current status of neurostimulation and neuromodulation for vesicourethral dysfunction].

PubMed

González-Chamorro, F; Verdú Tartajo, F; Hernández Fernández, C

1997-01-01

To describe the current indications, techniques and results of sacral root stimulation in patients with spinal cord lesions as a treatment for patients with high pressure bladders and/or urinary incontinence despite conservative management, as well as sacral root neuromodulation with permanent stimulators for complex bladder dysfunction: vesical instability, sensory urgency, chronic pelvic pain and chronic voiding dysfunction. The literature is reviewed, both techniques are described and the results of the most significant series are discussed, with special reference to the first groups that utilized these techniques. There is ample experience in the application of sacral root electrical stimulation. The reported results are comparable with those achieved by other treatments, such as augmentation cystoplasty. Neurostimulation and neuromodulation techniques are simple, the complications are minimal and they do not prelude the use of other therapies.

Refractory urgency urinary incontinence treatment in women: impact of age on outcomes and complications.

PubMed

Komesu, Yuko M; Amundsen, Cindy L; Richter, Holly E; Erickson, Stephen W; Ackenbom, Mary F; Andy, Uduak U; Sung, Vivian W; Albo, Michael; Gregory, W Thomas; Paraiso, Marie Fidela; Wallace, Dennis

2018-01-01

Women with refractory urgency urinary incontinence (ie, unresponsive to behavioral and pharmacological interventions) are treated with onabotulinumtoxinA or sacral neuromodulation. The objective of the study was to compare treatment efficacy and adverse events in women <65 and ≥65 years old treated with onabotulinumtoxinA or sacral neuromodulation. This study was a planned secondary analysis of a multicenter, randomized trial that enrolled community-dwelling women with refractory urgency urinary incontinence to onabotulinumtoxinA or sacral neuromodulation treatments. The primary outcome was a change in mean daily urgency urinary incontinence episodes on a bladder diary over 6 months. Secondary outcomes included ≥75% urgency urinary incontinence episode reduction, change in symptom severity/quality of life, treatment satisfaction, and treatment-related adverse events. Both age groups experienced improvement in mean urgency urinary incontinence episodes per day following each treatment. There was no evidence that mean daily urgency urinary incontinence episode reduction differed between age groups for onabotulinumtoxinA (adjusted coefficient, -0.127, 95% confidence interval, -1.233 to 0.979; P = .821) or sacral neuromodulation (adjusted coefficient, -0.698, 95% confidence interval, -1.832 to 0.437; P = .227). Among those treated with onabotulinumtoxinA, women <65 years had 3.3-fold greater odds of ≥75% resolution than women ≥65 years (95% confidence interval, 1.56 -7.02). Women <65 years had a greater reduction in Overactive Bladder Questionnaire Short Form symptom bother scores compared with women ≥65 years by 7.49 points (95% confidence interval, -3.23 to -11.74), regardless of treatment group. There was no difference between quality of life improvement by age. Women ≥65 years had more urinary tract infections following onabotulinumtoxinA and sacral neuromodulation (odds ratio, 1.9, 95% confidence interval, 1.2-3.3). There was no evidence of age differences in sacral neuromodulation revision/removal or catheterization following onabotulinumtoxinA treatment. Younger women experienced greater absolute continence, symptom improvement, and fewer urinary tract infections; both older and younger women had beneficial urgency urinary incontinence episode reduction, similar rates of other treatment adverse events, and improved quality of life. Copyright © 2017 Elsevier Inc. All rights reserved.

[X-ray characteristics of sacroiliac joint disorders and its clinical significance].

PubMed

Shi, Ning-Ning; Shen, Guo-Quan; He, Shui-Yong; Guo, Ru-bao

2013-02-01

To study the X-ray characteristics of sacroiliac joint disorders and its clinical significance,so as to provide clinical diagnosis basis for Tuina treatment of sacroiliac joint disorder. From July 2009 to March 2011,104 patients with sacroiliac joint disorder were reviewed,including 64 males and 40 females,ranging in age from 18 to 81 years, with an average of (45.39 +/- 1.30) years. The duration of the disease ranged from 1 to 144 months,with an average of (12.64 +/- 2.19) months. One hundred and four pelvic plain films and 97 lumbar spine lateral films of the patients with sacroiliac joint disorder were taken. On the lateral X-ray of lumbar,the sacral horizontal angles (lumbosacral angle) were measured; and on the X-ray of pelvis,the vertical distance of two side iliac crest (iliac crest difference), the distance from lateral border to medial margin of two hips (hip width),the clip angle between sacral spin connection and vertical axis were measured,and then the data were analyzed. The mean difference of iliac crest was (10.34+/-0.73) mm; the mean width difference of hip'was (6.73+/-1.01) mm; and the mean difference of the iliac crest was larger than that of mean difference of hip (P<0.01). The occurrence rate of inequal width of hip was higher(P<0.01). The mean abnormal lumbosacral angle was (7.29 +/- 1.86) degrees,and the mean angle of sacral crest tilting to left or right was (3.18 +/- 0.47) degrees; the mean abnormal lumbosacral angle was larger than that of angle of sacral crest tilting to left or right (P<0.01), and the occurrence rate of sacral crest tilting to left or right was higher

An animal model for the neuromodulation of neurogenic bladder dysfunction.

PubMed

Zvara, P; Sahi, S; Hassouna, M M

1998-08-01

To develop an animal model to examine the pathophysiology by which S3 sacral root electrostimulation alters the micturition reflex in patients with bladder hyper-reflexia. Chronic sacral nerve root electrostimulation was applied to spinally transected rats; 21 animals were divided into four groups. The spinal cord was completely transected at the T10-11 level and stainless-steel electrodes implanted into the sacral foramen in 17 animals; these animals were subsequently divided into two groups (1 and 2). Six rats in group 1 underwent sacral root elctrostimulation for 2 h/day and five in group 2 for 6 h/day, for 21 days. The sham group (group 3, six rats) received no stimulation and four rats were used as healthy controls (group 4). Voiding frequency was recorded and each animal was evaluated cystometrically at the end of the stimulation period. The results were compared with the sham and control groups. Spinal cord transection resulted in bladder areflexia and complete urinary retention; 7-9 days after the injury, the bladder recovered its activity. Twenty-one days after transection all animals had evidence of uninhibited bladder contractions. The mean (SD) hourly frequency of urination was 0.66 (0.18) in healthy controls, 0.83 (0.21) in group 1, 0.87 (0.34) in group 2 and 1.1 (0.31) in group 3. There was a significant decrease in eh cystometric signs of bladder hyper-reflexia in groups 1 and 2 when compared with group 3. This work reports and initial study showing that chronic electrostimulation of sacral nerve roots can reduce the signs of bladder hyper-reflexia in the spinally injured rat. To our knowledge, this is the first report describing the rat as an animal model to determine the effects of chronic electrostimulation on the micturition reflex.

Surgical management of U-shaped sacral fractures: a systematic review of current treatment strategies.

PubMed

König, M A; Jehan, S; Boszczyk, A A; Boszczyk, B M

2012-05-01

U-shaped sacral fractures usually result from axial loading of the spine with simultaneous sacral pivoting due to a horizontal fracture which leads to a highly unstable spino-pelvic dissociation. Due to the rarity of these fractures, there is lack of an agreed treatment strategy. A thorough literature search was carried out to identify current treatment concepts. The studies were analysed for mechanism of injury, diagnostic imaging, associated injuries, type of surgery, follow-up times, complications, neurological, clinical and radiological outcome. Sixty-three cases were found in 12 articles. No Class I, II or III evidence was found in the literature. The most common mechanism of injury was a fall or jump from height. Pre-operative neurological deficit was noted in 50 (94.3%) out of 53 cases (not available in 10 patients). The most used surgical options were spino-pelvic fixation with or without decompression and ilio-sacral screws. Post-operative complications occurred in 24 (38.1%) patients. Average follow-up time was 18.6 months (range 2-34 months). Full neurological recovery was noted in 20 cases, partial recovery in 14 and 9 patients had no neurological recovery (5 patients were lost in follow-up). Fracture healing was mentioned in 7 articles with only 1 case of fracture reduction loss. From the current available data, an evidence based treatment strategy regarding outcome, neurological recovery or fracture healing could not be identified. Limited access and minimal-invasive surgery focussing on sacral reduction and restoration seems to offer comparable results to large spino-pelvic constructs with fewer complications and should be considered as the method of choice. If the fracture is highly unstable and displaced, spino-pelvic fixation might offer better stability.

Sacral Nerve Stimulation for Pediatric Lower Urinary Tract Dysfunction: Development of a Standardized Pathway with Objective Urodynamic Outcomes.

PubMed

Schober, Megan S; Sulkowski, Jason P; Lu, Peter L; Minneci, Peter C; Deans, Katherine J; Teich, Steven; Alpert, Seth A

2015-12-01

We propose that sacral nerve stimulation is a valid adjunctive therapy for refractory pediatric lower urinary tract dysfunction, and that prospective collection of preoperative and postoperative validated questionnaires and urodynamic data in a standardized fashion is beneficial in characterizing patient response. Patients were candidates for sacral nerve stimulation if they had refractory voiding dysfunction and standard treatments had failed. Preoperative evaluation included urodynamic studies, spinal magnetic resonance imaging, and validated bladder and bowel related questionnaires. Children were stratified into 2 groups, ie overactive bladder with or without incontinence (group 1) and detrusor underactivity/urinary retention requiring clean intermittent catheterization (group 2). A staged procedure was used with initial test lead placement, followed by permanent device insertion 2 weeks later if patients demonstrated symptom improvement with test lead. Postoperatively children were followed with questionnaires and at least 1 urodynamic study. A total of 26 children underwent sacral nerve stimulation. Mean patient age was 10.8 years and median followup was 1.2 years. There were 23 patients in group 1 and 4 in group 2 (1 patient was included in both groups). In group 1 voiding dysfunction scores improved significantly, and urodynamic studies revealed a significant decrease in mean number of uninhibited contractions and maximum detrusor pressure during the filling phase. In group 2 there was significant improvement in mean post-void residual. Sacral nerve stimulation is a treatment option that may produce significant improvement in objective and subjective measures of bladder function in children with refractory lower urinary tract dysfunction. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Method of manufacturing lightweight thermo-barrier material

NASA Technical Reports Server (NTRS)

Blair, Winford (Inventor)

1987-01-01

A method of manufacturing thermal barrier structures comprising at least three dimpled cores separated by flat plate material with the outer surface of the flat plate material joined together by diffusion bonding.

Quantitative scintigraphy of sacroiliac joints: effects of age, gender, and laterality

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vyas, K.; Eklem, M.; Seto, H.

The effects of age, gender, and laterality on sacroiliac/sacral ratios obtained during quantitative joint imaging were assessed in 97 nonarthritic control subjects. For the entire group, the right sacroiliac-to-sacral mean ratio of 1.27 in 54 males was significantly higher than the right mean ratio of 1.18 in 53 females. In both genders the right joint ratio tended to be higher than the left in all age groups. The difference in mean ratio between the two joints was wider for males than for females. The age did not afect the joint ratio in either gender. It is concluded that the rangemore » of normal sacroiliac-to-sacral ratios are different for males and females and should be taken into account during a quantitative sacroiliac joint imaging examination.« less

Rare location of spondylitis tuberculosis;atlanto-axial, sacral and cervico-thoracic junction

NASA Astrophysics Data System (ADS)

Victorio; Nasution, M. D.; Ibrahim, S.; Dharmajaya, R.

2018-03-01

Three cases of rare location spondylitis tuberculosis are reported, each in atlantoaxial, cervico-thoracic junction,and sacral. The complaints were aweakness of motoric strength and local back pain. Patients’thoracal x-ray was normal, there was no complaint of acough, PCR forTB was early diagnostic and positive in all three cases, HIV negative, intraoperative tissue samplings were sent for histopathology examination and the results showed thespecific inflammatory process. Lesions were evaluated with computer tomography and/or MRI imaging.Preoperative TB regimens therapy were given for 2 weeks and continued for nine months. The surgical procedurewas done in all cases with excellent improvement of symptoms and motoric strength. In our institution,25 cases of total TB spondylitis were performed in 2 years, only 1 case eachwas found in atlanto-axial, cervico-thoracic and sacral.

Diffuse Large Cell Lymphoma Presenting as a Sacral Mass and Lupus Anticoagulant

PubMed Central

Ediriwickrema, Lilangi S.; Zaheer, Wajih

2011-01-01

A 67-year-old gentleman presented to Yale-New Haven Hospital (YNHH) for assessment of a supratherapeutic INR and sacral lesion. Hematologic workup revealed elevated ESR, PT, INR, PTT, and CRP, mixing studies that failed to correct, and a positive Russell Viper Venom Test (RVVT), which confirmed the presence of lupus anticoagulant (LA), a subtype of antiphospholipid syndrome (APA). Pathology of the patient’s sacral lesion revealed diffuse large B-cell lymphoma. This case provides insight into the association between APA and lymphoid neoplasm. The patient’s unique presentation is in marked contrast to other reports of APA and lymphoid malignancy, which are typically associated with elevated PTT, normal PT, minimal extranodal disease, and potential thrombotic complications. Further, treatment with Rituximab-CHOP chemotherapy led to excellent clinical response with tumor remission and normalization of PT and PTT. PMID:22180680

Diffuse large cell lymphoma presenting as a sacral mass and lupus anticoagulant.

PubMed

Ediriwickrema, Lilangi S; Zaheer, Wajih

2011-12-01

A 67-year-old gentleman presented to Yale-New Haven Hospital (YNHH) for assessment of a supratherapeutic INR and sacral lesion. Hematologic workup revealed elevated ESR, PT, INR, PTT, and CRP, mixing studies that failed to correct, and a positive Russell Viper Venom Test (RVVT), which confirmed the presence of lupus anticoagulant (LA), a subtype of antiphospholipid syndrome (APA). Pathology of the patient's sacral lesion revealed diffuse large B-cell lymphoma. This case provides insight into the association between APA and lymphoid neoplasm. The patient's unique presentation is in marked contrast to other reports of APA and lymphoid malignancy, which are typically associated with elevated PTT, normal PT, minimal extranodal disease, and potential thrombotic complications. Further, treatment with Rituximab-CHOP chemotherapy led to excellent clinical response with tumor remission and normalization of PT and PTT.

Sacral myeloradiculitis complicating genital herpes in a HIV-infected patient.

PubMed

Corral, I; Quereda, C; Navas, E; Pérez-Elias, M J; Jover, F; Moreno, S

2005-02-01

Myeloradiculitis is a rare neurological complication of herpes simplex type 2 (HSV-2) infection, frequently associated with a fatal outcome. Among patients with HIV infection, HSV-2 myeloradiculitis has occasionally been reported, always associated with advanced immunosuppression and AIDS. We report a patient with HIV infection but no history of previous opportunistic infections, who developed sacral myeloradiculitis immediately after an episode of genital herpes. Magnetic resonance imaging with gadolinium showed necrotizing myelitis in the conus medullaris and enhancement of sacral roots. CD4 lymphocyte count was 530/mm3. Other possible causes of myeloradiculitis in HIV-infected patients were appropriately excluded. Acyclovir therapy resulted in partial clinical improvement. This report shows that myeloradiculitis as a complication of genital herpes may occur in the early stages of HIV infection and may have a favourable outcome with antiviral treatment.

Trans-sacral resection of a solitary fibrous tumor in the pelvis: report of a case.

PubMed

Katsuno, Hidetoshi; Maeda, Koutarou; Hanai, Tsunekazu; Sato, Harunobu; Masumori, Koji; Koide, Yoshikazu; Matsuoka, Hiroshi; Noro, Tomohito; Takakuwa, Yasunari; Hanaoka, Ryouta

2011-11-01

Solitary fibrous tumors (SFTs) develop most commonly in the pleura, although they have occasionally been reported to arise in the pelvic cavity. We report a case of an SFT presenting as a painless nodule in the pelvis of a 56-year-old woman. Histologically, the tumor was composed of spindle-shaped cells arranged without pattern, with short and narrow fascicles and interspersed bundles of thick collagen, and numerous blood vessels with a focally hemangiopericytoma-like appearance. Immunohistochemically, the tumor cells strongly expressed vimentin, CD34, and bcl-2. The tumor was excised via a trans-sacral approach, without preoperative transcatheter embolization, and the patient remains well more than 2 years after her operation. To our knowledge, this is the first case of an SFT in the pelvis, which was excised completely via a trans-sacral approach.

Virtual Vesta

NASA Image and Video Library

2011-03-10

This image shows NASAS Dawn scientists best guess to date of what the surface of the protoplanet Vesta might look like; it incorporates the best data on dimples and bulges from ground-based telescopes and NASA Hubble Space Telescope.

Surgery for pilonidal cyst

MedlinePlus

Pilonidal abscess; Pilonidal dimple; Pilonidal disease; Pilonidal cyst; Pilonidal sinus ... An infected pilonidal cyst or abscess requires surgical drainage. It will not heal with antibiotic medicines. If you continue to have infections, the pilonidal cyst can be ...

Tensile Deformation Temperature Impact on Microstructure and Mechanical Properties of AISI 316LN Austenitic Stainless Steel

NASA Astrophysics Data System (ADS)

Xiong, Yi; He, Tiantian; Lu, Yan; Ren, Fengzhang; Volinsky, Alex A.; Cao, Wei

2018-03-01

Uniaxial tensile tests were conducted on AISI 316LN austenitic stainless steel from - 40 to 300 °C at a rate of 0.5 mm/min. Microstructure and mechanical properties of the deformed steel were investigated by optical, scanning and transmission electron microscopies, x-ray diffraction, and microhardness testing. The yield strength, ultimate tensile strength, elongation, and microhardness increase with the decrease in the test temperature. The tensile fracture morphology has the dimple rupture feature after low-temperature deformations and turns to a mixture of transgranular fracture and dimple fracture after high-temperature ones. The dominating deformation microstructure evolves from dislocation tangle/slip bands to large deformation twins/slip bands with temperature decrease. The deformation-induced martensite transformation can only be realized at low temperature, and its quantity increases with the decrease in the temperature.

Pubectomy and stereotactic radiotherapy for the treatment of a non-resectable sacral osteosarcoma causing pelvic canal obstruction in a dog

PubMed Central

Randall, Victoria D.; Boston, Sarah E.; Gardner, Heather L.; Griffin, Lynn; Oblak, Michelle L.; Kubicek, Lyndsay

2016-01-01

A pubectomy was carried out to relieve obstruction of the pelvic canal in a 6-year-old dog diagnosed with sacral osteosarcoma. Two days after surgery, the dog was ambulatory with normal urination and defecation. Pubectomy is a viable option to relieve clinical signs in patients with pelvic canal obstruction due to a non-resectable tumor. PMID:27587885

Rectal sphincter pressure monitoring device.

PubMed

Hellbusch, L C; Nihsen, B J

1989-05-01

A silicone, dual cuffed catheter designed for the control of nasal hemorrhage was used for rectal sphincter pressure monitoring. Patients with lipomyelomeningocele and tethered spinal cord were monitored during their operative procedures to aid in distinguishing sacral nerve roots from other tissues. Stimulation of sacral nerve roots was done with a disposable nerve stimulator. The use of a catheter with two balloons helps to keep the outer balloon placed against the rectal sphincter.

Neck Injury in Advanced Military Aircraft Environments

DTIC Science & Technology

1990-02-01

injury alibhis the Fast 2 nortbs In atstlitied by type of oihcrafr. This table demonstrates a statistirally significant trend in frequency (P- S5 aud...it appears that ransitional vertebrae aic relatively coarnon and equally distributed bhtweon the thoracico-lumbal (9.0%) and the lumbo- sacral area...unilateral contact of asymmetrical lumbar sacralization which increases torque forces with consequent strain on the spine and risk of disc herniation above

Transcutaneous sacral neurostimulation for irritative voiding dysfunction.

PubMed

Walsh, I K; Johnston, R S; Keane, P F

1999-01-01

Patients with irritative voiding dysfunction are often unresponsive to standard clinical treatment. We evaluated the response of such individuals to transcutaneous electrical stimulation of the third sacral nerve. 32 patients with refractory irritative voiding dysfunction (31 female and 1 male; mean age 47 years) were recruited to the study. Ambulatory transcutaneous electrical neurostimulation was applied bilaterally to the third sacral dermatomes for 1 week. Symptoms of frequency, nocturia, urgency, and bladder pain were scored by each patient throughout and up to 6 months following treatment. The mean daytime frequency was reduced from 11.3 to 7.96 (p = 0.01). Nocturia episodes were reduced from a mean of 2.6 to 1.8 (p = 0.01). Urgency and bladder pain mean symptom scores were reduced from 5.97 to 4.89 and from 1.48 to 0.64, respectively. After stopping therapy, symptoms returned to pretreatment levels within 2 weeks in 40% of the patients and within 6 months in 100%. Three patients who continued with neurostimulation remained satisfied with this treatment modality at 6 months. Transcutaneous third sacral nerve stimulation may be an effective and noninvasive ambulatory technique for the treatment of patients with refractory irritative voiding dysfunction. Following an initial response, patients may successfully apply this treatment themselves to ensure long-term relief.

Accessing 3D Location of Standing Pelvis: Relative Position of Sacral Plateau and Acetabular Cavities versus Pelvis

PubMed Central

Berthonnaud, E.; Hilmi, R.; Dimnet, J.

2012-01-01

The goal of this paper is to access to pelvis position and morphology in standing posture and to determine the relative locations of their articular surfaces. This is obtained from coupling biplanar radiography and bone modeling. The technique involves different successive steps. Punctual landmarks are first reconstructed, in space, from their projected images, identified on two orthogonal standing X-rays. Geometric models, of global pelvis and articular surfaces, are determined from punctual landmarks. The global pelvis is represented as a triangle of summits: the two femoral head centers and the sacral plateau center. The two acetabular cavities are modeled as hemispheres. The anterior sacral plateau edge is represented by an hemi-ellipsis. The modeled articular surfaces are projected on each X-ray. Their optimal location is obtained when the projected contours of their models best fit real outlines identified from landmark images. Linear and angular parameters characterizing the position of global pelvis and articular surfaces are calculated from the corresponding sets of axis. Relative positions of sacral plateau, and acetabular cavities, are then calculated. Two hundred standing pelvis, of subjects and scoliotic patients, have been studied. Examples are presented. They focus upon pelvis orientations, relative positions of articular surfaces, and pelvis asymmetries. PMID:22567279

Effect of Carbon Ion Radiotherapy for Sacral Chordoma: Results of Phase I-II and Phase II Clinical Trials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Imai, Reiko, E-mail: r_imai@nirs.go.j; Kamada, Tadashi; Tsuji, Hiroshi

2010-08-01

Purpose: To summarize the results of treatment for sacral chordoma in Phase I-II and Phase II carbon ion radiotherapy trials for bone and soft-tissue sarcomas. Patients and Methods: We performed a retrospective analysis of 38 patients with medically unresectable sacral chordomas treated with the Heavy Ion Medical Accelerator in Chiba, Japan between 1996 and 2003. Of the 38 patients, 30 had not received previous treatment and 8 had locally recurrent tumor after previous resection. The applied carbon ion dose was 52.8-73.6 Gray equivalents (median, 70.4) in a total of 16 fixed fractions within 4 weeks. Results: The median patient agemore » was 66 years. The cranial tumor extension was S2 or greater in 31 patients. The median clinical target volume was 523 cm{sup 3}. The median follow-up period was 80 months. The 5-year overall survival rate was 86%, and the 5-year local control rate was 89%. After treatment, 27 of 30 patients with primary tumor remained ambulatory with or without supportive devices. Two patients experienced severe skin or soft-tissue complications requiring skin grafts. Conclusion: Carbon ion radiotherapy appears effective and safe in the treatment of patients with sacral chordoma and offers a promising alternative to surgery.« less

Treatment of aneurysmal bone cysts of the pelvis and sacrum.

PubMed

Papagelopoulos, P J; Choudhury, S N; Frassica, F J; Bond, J R; Unni, K K; Sim, F H

2001-11-01

Aneurysmal bone cysts are benign, non-neoplastic, highly vascular bone lesions. The purpose of this study was to describe the prevalence, the clinical presentation, and the recurrence rate of aneurysmal bone cysts of the pelvis and sacrum and to examine the diagnostic and therapeutic options and prognosis for patients with this condition. Forty consecutive patients with an aneurysmal bone cyst of the pelvis and/or sacrum were treated from 1921 to 1996. Their medical records and radiographic and imaging studies were reviewed, and histological sections from the cysts were examined. Seventeen lesions were iliosacral, sixteen were acetabular, and seven were ischiopubic. Seven involved the hip joint, and two involved the sacroiliac joint. All twelve sacral lesions extended to more than one sacral segment and were associated with neurological signs and symptoms. Destructive acetabular lesions were associated with pathological fracture in five patients and with medial migration of the femoral head, hip subluxation, and hip dislocation in one patient each. The mean duration of follow-up was thirteen years (range, three to fifty-three years). Thirty-five patients who were initially treated for a primary lesion had surgical treatment (twenty-one had excision-curettage and fourteen had intralesional excision); two patients also had adjuvant radiation therapy. Of the thirty-five patients, five (14%) had a local recurrence noted less than eighteen months after the operation. Of five patients initially treated for a recurrent lesion, one had a local recurrence. At the latest follow-up examination, all forty patients were disease-free and twenty-eight (70%) were asymptomatic. There were two deep infections. Aneurysmal bone cysts of the pelvis and sacrum are usually aggressive lesions associated with substantial bone destruction, pathological fractures, and local recurrence. Current management recommendations include preoperative selective arterial embolization, excision-curettage, and bone-grafting.

Model of Vesta

NASA Image and Video Library

2011-03-10

This image incorporates the best data on dimples and bulges of the protoplanet Vesta from ground-based telescopes and NASA Hubble Space Telescope. This model of Vesta uses scientists best guess to date of what the surface might look like.

Comparison of gluteal fasciocutaneous rotational flaps and myocutaneous flaps for the treatment of sacral sores

PubMed Central

Ip, F. K.

2005-01-01

To compare the outcomes of gluteal fasciocutaneous rotational flaps and myocutaneous flaps in the treatment of sacral sores, together with a review of surgical complications in two matched cohorts. Thirty-eight patients (18 gluteal fasciocutaneous rotational flaps and 20 myocutaneous flaps) were reviewed retrospectively at a mean follow-up of 58 weeks. The rate of healing of the sore, the sore healing time, and the incidence of surgical complications, together with rate of recurrence, were obtained by chart review. Treatment groups were matched by patient characteristics, operative time and blood loss. The rate of healing of the sore, sore healing time and complication rate were comparable in the two groups but the rate of recurrence was lower to a statistically significant extent in myocutaneous flap patients. The authors suggest that both methods are comparable, good and safe in treating sacral sores; myocutaneous flaps are more durable. PMID:16333656

[Sacral nerve stimulation in the treatment of the lower urinary tract function disorders].

PubMed

Miotła, Paweł; Kulik-Rechberger, Beata; Skorupski, Paweł; Rechberger, Tomasz

2011-11-01

Functional disorders of the female lower urinary tract like urge incontinence, idiopathic urinary retention and symptoms of urgency-frequency occasionally do not respond properly to classical behavioral and pharmacological therapy Therefore, additional alternative therapies are needed to alleviate these bothersome symptoms. Sacral neuromodulation (SNS) utilize mild electrical pulses which activate or suppress neural reflexes responsible for voiding by stimulating the sacral nerves that innervate the bladder, external urethral sphincter and pelvic floor muscles. The exact mechanism of SNS action is not yet fully understood but it is assumed that it influences the neuroaxis at different levels of the central nervous system and restores the balance between inhibitory and activatory control over the voiding reflex. There is numerous evidence on the success of SNS not only in the treatment of refractory urge incontinence in adult and children but also in idiopathic urinary retention and symptoms of urgency-frequency

Intravascular flow detection during transforaminal epidural injections: a prospective assessment.

PubMed

El Abd, Omar Hamman; Amadera, Joao Eduardo Daud; Pimentel, Daniel Camargo; Pimentel, Thais Spacov Camargo

2014-01-01

Transforaminal epidural steroid injections (TFESI) are a mainstay in the treatment of spine pain. Though this commonly performed procedure is generally felt to be safe, devastating complications following inadvertent intra-arterial injections of particulate steroid have been reported. The use of digital subtraction angiography (DSA) has been suggested as a means of detecting intra-arterial needle placements prior to medication injection. To examine the efficacy of DSA in detecting intra-arterial needle placements during TFESI. Prospective cohort study evaluating the impact of DSA on detecting intra-arterial needle placements during TFESI. We enrolled 150 consecutive patients presenting to a university-affiliated spine center with discogenic and/or radicular symptoms affecting the cervical, lumbar, and sacral regions. For each injection, prior to imaging with DSA, traditional methods for vascular penetration detection were employed, including the identification of blood in the needle hub (flash), negative aspiration of blood prior to injection, and live fluoroscopic injection of contrast. Once these tests were performed and negative for signs of intra-arterial needle placement, DSA imaging was utilized prior to medication administration for identification of vascular flow. A total number of 222 TFESI were performed, 41 injections at the cervical levels (18.47%), 113 at the lumbar levels (50.9%), and 68 at the sacral levels (30.36%). Flash was observed in 13 injections performed (5.85% of the total number of injections): one (0.45%) in the cervical, 2 (0.9%) in the lumbar, and 10 (4.5%) in the sacral levels. In 11 TFESI blood aspiration was obtained (4.95% of all injections): 3 (1.3%) in cervical, 4 (1.8%) in lumbar, and 4 (1.8%) in sacral injections. Live fluoroscopy during contrast injection detected 46 (20.72%) intravascular flow patterns: 7 (3.1%) cervical, 17 (7.6%) lumbar, and 22 (9.9%) sacral. DSA identified an additional 5 intravascular injections after all previous steps had resulted in negative vascular penetration signs, which accounted for 2.25% of all injections. This is a prospective, single-center study with a relatively small number of patients and no control group. DSA detected additional 5.26% intravascular needle placements following traditional methods. Our findings also support other studies that conclude TFESI are generally a safe procedure. We recommend that special attention should be paid to the sacral injections as vascular penetration was statistically higher than at other levels.

Comparison and correlation of pelvic parameters between low-grade and high-grade spondylolisthesis.

PubMed

Min, Woo-Kie; Lee, Chang-Hwa

2014-05-01

This study was retrospectively conducted on 51 patients with L5-S1 spondylolisthesis. This study was conducted to compare a total of 11 pelvic parameters, such as the level of displacement by Meyerding method, lumbar lordosis, sacral inclination, lumbosacral angle, slip angle, S2 inclination, pelvic incidence (PI), L5 inclination, L5 slope, pelvic tilt (PT), and sacral slope (SS) between low-grade and high-grade spondylolisthesis, and to investigate a correlation of the level of displacement by Meyerding method with other pelvic parameters. Pelvic parameters were measured using preoperational erect lateral spinal simple radiographs. The patients were divided into 39 patients with low-grade spondylolisthesis and 12 patients with high-grade spondylolisthesis before analysis. In all patients of both groups, 11 radiographic measurements including the level of displacement by Meyerding method, lumbar lordosis, sacral inclination, lumbosacral angle, slip angle, S2 inclination, PI, L5 inclination, L5 slope, PT, and SS were performed. T test and Pearson correlation analysis were conducted to compare and analyze each measurement. As for the comparison between the 2 groups, a statistically great significance in the level of displacement by Meyerding method, lumbosacral angle, slip angle, L5 incidence, PI, and L5 slope (P≤0.001) was shown. Meanwhile, a statistical significance in the sacral inclination and PT (P<0.05) was also shown. However, no statistical significance in the S2 incidence and SS was shown. A correlation of the level of displacement by Meyerding method with each parameter was analyzed in the both the groups. A high correlation was observed in the lumbar lordosis, lumbosacral angle, slip angle, L5 incidence, and L5 slope (Pearson correlation coefficient, P=0.01), as well as the sacral inclination, PI, and PT (Pearson correlation coefficient, P=0.05). Meanwhile, no correlation was shown in the S2 incidence and SS. A significant difference in the lumbosacral angle, slip angle, L5 incidence, PI, L5 slope, sacral inclination, and PT was shown between the patients with high-grade spondylolisthesis and patients with low-grade spondylolisthesis. Among the aforementioned measurements, the PI showed a significant difference between the 2 groups and also had a significant correlation with the dislocation level in all the patients.

Establishing the Learning Curve of Robotic Sacral Colpopexy in a Start-up Robotics Program.

PubMed

Sharma, Shefali; Calixte, Rose; Finamore, Peter S

2016-01-01

To determine the learning curve of the following segments of a robotic sacral colpopexy: preoperative setup, operative time, postoperative transition, and room turnover. A retrospective cohort study to determine the number of cases needed to reach points of efficiency in the various segments of a robotic sacral colpopexy (Canadian Task Force II-2). A university-affiliated community hospital. Women who underwent robotic sacral colpopexy at our institution from 2009 to 2013 comprise the study population. Patient characteristics and operative reports were extracted from a patient database that has been maintained since the inception of the robotics program at Winthrop University Hospital and electronic medical records. Based on additional procedures performed, 4 groups of patients were created (A-D). Learning curves for each of the segment times of interest were created using penalized basis spline (B-spline) regression. Operative time was further analyzed using an inverse curve and sequential grouping. A total of 176 patients were eligible. Nonparametric tests detected no difference in procedure times between the 4 groups (A-D) of patients. The preoperative and postoperative points of efficiency were 108 and 118 cases, respectively. The operative points of proficiency and efficiency were 25 and 36 cases, respectively. Operative time was further analyzed using an inverse curve that revealed that after 11 cases the surgeon had reached 90% of the learning plateau. Sequential grouping revealed no significant improvement in operative time after 60 cases. Turnover time could not be assessed because of incomplete data. There is a difference in the operative time learning curve for robotic sacral colpopexy depending on the statistical analysis used. The learning curve of the operative segment showed an improvement in operative time between 25 and 36 cases when using B-spline regression. When the data for operative time was fit to an inverse curve, a learning rate of 11 cases was appreciated. Using sequential grouping to describe the data, no improvement in operative time was seen after 60 cases. Ultimately, we believe that efficiency in operative time is attained after 30 to 60 cases when performing robotic sacral colpopexy. The learning curve for preoperative setup and postoperative transition, which is reflective of anesthesia and nursing staff, was approximately 110 cases. Copyright © 2016 AAGL. Published by Elsevier Inc. All rights reserved.

Stress intensity factors for part-elliptical cracks emanating from dimpled rivet holes

NASA Astrophysics Data System (ADS)

Wang, Ailun; She, Chongmin; Lin, Gang; Zhou, You; Guo, Wanlin

2014-11-01

Detailed investigations on the stress intensity factors (SIFs) for corner cracks emanated from interference fitted dimpled rivet holes are conducted using three-dimensional finite element method. The influences of the crack length a, elliptical shape factor t, far-end stress S and interference magnitude δ on the stress intensity factors are systematically studied. The SIFs for corner cracks emanated from open holes are also investigated for comparisons. An empirical formula of the normalized SIF is proposed by use of the least square method for convenience of the engineering application, which is a function of the crack length a, elliptical shape factor t, far-end stress S, interference magnitude δ and the normalized elliptical centrifugal angle φn. Based on the empirical formula, a crack growth simulation for a rivet filled hole is conducted, which shows a good agreement with the test data.

Influence of Soft Drinks with Low pH on Different Ni-Ti Orthodontic Archwire Surface Patterns

NASA Astrophysics Data System (ADS)

Abalos, C.; Paul, A.; Mendoza, A.; Solano, E.; Palazon, C.; Gil, F. J.

2013-03-01

The aim of this study was to determine the influence of soft drinks on the surface of Ni-Ti archwires and their corrosion behavior. Archwires with different patterns (smooth, scratch, dimple, and crack) were selected and characterized by scanning electron microscopy and laser confocal microscopy. Immersion tests were performed in artificial saliva (pH 6.7) with a soft drink with a pH of 2.5 for 28 days. The results showed an increase in the surface defects and/or roughness of the dimple, crack and scratch patterns with the immersion times, and a decrease in corrosion resistance. A relationship between the surface pattern and the extent of the corrosion in Ni-Ti archwires with soft drinks at low pH has been demonstrated. Pattern should be taken into account in future studies, and manufacturing processes that produce surface defects (especially cracks) should be avoided.

Surface dimpling on rotating work piece using rotation cutting tool

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhapkar, Rohit Arun; Larsen, Eric Richard

A combined method of machining and applying a surface texture to a work piece and a tool assembly that is capable of machining and applying a surface texture to a work piece are disclosed. The disclosed method includes machining portions of an outer or inner surface of a work piece. The method also includes rotating the work piece in front of a rotating cutting tool and engaging the outer surface of the work piece with the rotating cutting tool to cut dimples in the outer surface of the work piece. The disclosed tool assembly includes a rotating cutting tool coupledmore » to an end of a rotational machining device, such as a lathe. The same tool assembly can be used to both machine the work piece and apply a surface texture to the work piece without unloading the work piece from the tool assembly.« less

Medtronic, Inc.; premarket approval of the Interstim Sacral Nerve Stimulation (SNS) System--FDA. Notice.

PubMed

1998-01-29

The Food and Drug Administration (FDA) is announcing its approval of the application by Medtronic, Inc., Minneapolis, MN, for premarket approval, under the Federal Food, Drug, and Cosmetic Act (the act), of the Interstim Sacral Nerve Stimulation (SNS) System. After reviewing the recommendation of the Gastroenterology and Urology Devices Panel, FDA's Center for Devices and Radiological Health (CDRH) notified the applicant, by letter of September 29, 1997, of the approval of the application.

Ligament-induced sacral fractures of the pelvis are possible.

PubMed

Steinke, Hanno; Hammer, Niels; Lingslebe, Uwe; Höch, Andreas; Klink, Thomas; Böhme, Jörg

2014-07-01

Pelvic ring stability is maintained passively by both the osseous and the ligamentous apparatus. Therapeutic approaches focus mainly on fracture patterns, so ligaments are often neglected. When they rupture along with the bone after pelvic ring fractures, disrupting stability, ligaments need to be considered during reconstruction and rehabilitation. Our aim was to determine the influence of ligaments on open-book injury using two experimental models with body donors. Mechanisms of bone avulsion related to open-book injury were investigated. Open-book injuries were induced in human pelves and subsequently investigated by anatomical dissection and endoscopy. The findings were compared to CT and MRI scans of open-book injuries. Relevant structures were further analyzed using plastinated cross-sections of the posterior pelvic ring. A fragment of the distal sacrum was observed, related to open-book injury. Two ligaments were found to be responsible for this avulsion phenomenon: the caudal portion of the anterior sacroiliac ligament and another ligament running along the ventral surface of the third sacral vertebra. The sacral fragment remained attached to the coxal bone by this second ligament after open-book injury. These results were validated using plastination and the structures were identified. Pelvic ligaments are probably involved in sacral avulsion caused by lateral traction. Therefore, ligaments should to be taken into account in diagnosis of open-book injury and subsequent therapy. Copyright © 2014 Wiley Periodicals, Inc.

Triangular osteosynthesis of vertically unstable sacrum fractures: a new concept allowing early weight-bearing.

PubMed

Schildhauer, T A; Josten, Ch; Muhr, G

2006-01-01

Presentation of a new triangular osteosynthesis technique that permits early weight-bearing in vertically unstable sacral fractures. : Retrospective evaluation of a consecutive series. Level I trauma center. Thirty-four patients, twenty-eight of whom were poly-traumatized, all with vertically unstable sacral fractures. This group included eight women and twenty-six men, with a mean age of thirty-five years. Average time between trauma and definite operation was thirteen days (range 0 to 28 days). All patients underwent triangular osteosynthesis using a combination of a vertical vertebro-pelvic distraction osteosynthesis (pedicle screw system) and a transverse fixation of the sacrum fracture with either iliosacral screws or trans-sacral plating. Immediate postoperative weight-bearing was permitted postoperatively. Nineteen patients were treated with early progressive weight-bearing and advanced to full weight-bearing, on average, after twenty-three days (range 8 to 70 days). Three of the thirty-four patients (9 percent) experienced loosening of hardware, including two patients (6 percent) who required secondary intervention because of loss of the original reduction. Further complications included one pulmonary embolism (3 percent), one iatrogenic nerve lesion (3 percent), one wound necrosis (3 percent), and two local infections (6 percent). Triangular osteosynthesis is a demanding procedure that can be performed on vertically unstable sacral fractures to allow early progressive weight-bearing with an acceptable complication rate.

[Distribution of herpes simplex virus type 1 and 2 genomes in the human spinal ganglia].

PubMed

Obara, Y

1994-09-01

Herpes simplex virus (HSV) is well known for its propensity to cause recurrent oral or genital mucosal infections in humans. HSV-1 is involved primarily in oral lesions, whereas HSV-2 is more frequently involved in genital lesions. Based on this, it is thought that HSV-1 may produce latent infections in trigeminal ganglia, and HSV-2 in the sacral ganglia. However the distribution pattern of latent HSV-1 and HSV-2 infections in spinal ganglia remains unknown. Using the polymerase chain reaction we detected latent herpes HSV-1 and HSV-2 in human spinal ganglia obtained from autopsy material. A pair of primers which were specific for a part of the HSV-1 and HSV-2 DNA polymerase domain were employed. HSV-1 and HSV-2 DNAs were detected in 11 of 40 (28%) and 15 of 40 (38%) cervical ganglia, respectively, 52 of 103 (50%) and 47 of 103 (46%) thoracic ganglia, 16 of 53 (30%) and 17 of 53 (32%) lumbar ganglia, and 3 of 20 (15%) and 3 of 20 (15%) sacral ganglia. These findings suggest that latent HSV-1 and HSV-2 infections have a widespread distribution from the cervical ganglia to sacral ganglia. Importantly this study demonstrated latent HSV-1 infection of both the lumbar and sacral ganglia for the first time.

When do anterior external or internal fixators provide additional stability in an unstable (Tile C) pelvic fracture? A biomechanical study.

PubMed

Mcdonald, E; Theologis, A A; Horst, P; Kandemir, U; Pekmezci, M

2015-12-01

This study aimed at evaluating the additional stability that is provided by anterior external and internal fixators in an unstable pelvic fracture model (OTA 61-C). An unstable pelvic fracture (OTA 61-C) was created in 27 synthetic pelves by making a 5-mm gap through the sacral foramina (posterior injury) and an ipsilateral pubic rami fracture (anterior injury). The posterior injury was fixed with either a single iliosacral (IS) screw, a single trans-iliac, trans-sacral (TS) screw, or two iliosacral screws (S1S2). Two anterior fixation techniques were utilized: external fixation (Ex-Fix) and supra-acetabular external fixation and internal fixation (In-Fix); supra-acetabular pedicle screws connected with a single subcutaneous spinal rod. The specimens were tested using a nondestructive single-leg stance model. Peak-to-peak (P2P) displacement and rotation and conditioning displacement (CD) were calculated. The Ex-Fix group failed in 83.3 % of specimens with concomitant single-level posterior fixation (Total: 15/18-7 of 9 IS fixation, 8 of 9 TS fixation), and 0 % (0/9) of specimens with concomitant two-level (S1S2) posterior fixation. All specimens with the In-Fix survived testing except for two specimens treated with In-Fix combined with IS fixation. Trans-sacral fixation had higher pubic rotation and greater sacral and pubic displacement than S1S2 (p < 0.05). Rotation of the pubis and sacrum was not different between In-Fix constructs combined with single-level IS and TS fixation. In this model of an unstable pelvic fracture (OTA 61-C), anterior fixation with an In-Fix was biomechanically superior to an anterior Ex-Fix in the setting of single-level posterior fixation. There was no biomechanical difference between the In-Fix and Ex-Fix when each was combined with two levels of posterior sacral fixation.

A multi-level rapid prototyping drill guide template reduces the perforation risk of pedicle screw placement in the lumbar and sacral spine.

PubMed

Merc, Matjaz; Drstvensek, Igor; Vogrin, Matjaz; Brajlih, Tomaz; Recnik, Gregor

2013-07-01

The method of free-hand pedicle screw placement is generally safe although it carries potential risks. For this reason, several highly accurate computer-assisted systems were developed and are currently on the market. However, these devices have certain disadvantages. We have developed a method of pedicle screw placement in the lumbar and sacral region using a multi-level drill guide template, created with the rapid prototyping technology and have validated it in a clinical study. The aim of the study was to manufacture and evaluate the accuracy of a multi-level drill guide template for lumbar and first sacral pedicle screw placement and to compare it with the free-hand technique under fluoroscopy supervision. In 2011 and 2012, a randomized clinical trial was performed on 20 patients. 54 screws were implanted in the trial group using templates and 54 in the control group using the fluoroscopy-supervised free-hand technique. Furthermore, applicability for the first sacral level was tested. Preoperative CT-scans were taken and templates were designed using the selective laser sintering method. Postoperative evaluation and statistical analysis of pedicle violation, displacement, screw length and deviation were performed for both groups. The incidence of cortex perforation was significantly reduced in the template group; likewise, the deviation and displacement level of screws in the sagittal plane. In both groups there was no significantly important difference in deviation and displacement level in the transversal plane as not in pedicle screw length. The results for the first sacral level resembled the main investigated group. The method significantly lowers the incidence of cortex perforation and is therefore potentially applicable in clinical practice, especially in some selected cases. The applied method, however, carries a potential for errors during manufacturing and practical usage and therefore still requires further improvements.

Exhausted implanted pulse generator in sacral nerve stimulation for faecal incontinence: What next in daily practice for patients?

PubMed

Duchalais, Emilie; Meurette, Guillaume; Perrot, Bastien; Wyart, Vincent; Kubis, Caroline; Lehur, Paul-Antoine

2016-02-01

The efficacy of sacral nerve stimulation in faecal incontinence relies on an implanted pulse generator known to have a limited lifespan. The long-term use of sacral nerve stimulation raises concerns about the true lifespan of generators. The aim of the study was to assess the lifespan of sacral nerve stimulation implanted pulse generators in daily practice, and the outcome of exhausted generator replacement, in faecal incontinent patients. Faecal incontinent patients with pulse generators (Medtronic Interstim™ or InterstimII™) implanted in a single centre from 2001 to 2014 were prospectively followed up. Generator lifespan was measured according to the Kaplan-Meier method. Patients with a generator explanted/turned off before exhaustion were excluded. Morbidity of exhausted generator replacement and the outcome (Cleveland Clinic Florida Faecal Incontinence (CCF-FI) and Faecal Incontinence Quality of Life (FIQL) scores) were recorded. Of 135 patients with an implanted pulse generator, 112 (InterstimII 66) were included. Mean follow-up was 4.9 ± 2.8 years. The generator reached exhaustion in 29 (26%) cases. Overall median lifespan of an implanted pulse generator was approximately 9 years (95% CI 8-9.2). Interstim and InterstimII 25th percentile lifespan was 7.2 (CI 6.4-8.3) and 5 (CI 4-not reached) years, respectively. After exhaustion, generators were replaced, left in place or explanted in 23, 2 and 4 patients, respectively. Generator replacement was virtually uneventful. CCF-FI/FIQL scores remained unchanged after generator replacement (CCF-FI 8 ± 2 vs 7 ± 3; FIQL 3 ± 0.6 vs 3 ± 0.5; p = ns). In this study, the implanted pulse generator observed median lifespan was 9 years. After exhaustion, generators were safely and efficiently replaced. The study also gives insight into long-term needs and costs of sacral nerve stimulation (SNS) therapy.

The effect of low force chiropractic adjustments on body surface electromagnetic field.

PubMed

Zhang, John; Snyder, Brian J; Vernor, Lori

2004-03-01

The purpose of this study was to investigate the body surface electromagnetic field (EMF) changes using a sensitive magnetometer before and after a specific Toftness chiropractic adjustment in asymptomatic human subjects. Forty-four subjects were randomly assigned into control (20 subjects) and experimental groups (24 subjects) in a pre and post-test design. The Triaxial Fluxgate Magnetometer FGM-5DTAA (Walker Scientific, Worcester, Massachusetts) with five digit display and resolution of 1 nanotesla (nT) was used for EMF detection. The EMF in the research room and on the adjustment table was monitored and recorded. The subjects' body surface (cervical, thoracic, lumbar and sacral areas) EMF was determined in the prone position before and after the chiropractic adjustment. A low force Toftness chiropractic adjustment was applied to the cervical, thoracic, lumbar and sacral areas as determined by the practitioner. The EMF in the research room was recorded as 41611 nT at the Z axis (earth field), 13761 nT at the X axis and 7438 nT at the Y axis. The EMF on the adjusting table changed minimally during the 15 minute observation period. The EMF on the subjects' body surface decreased at 4 spinal locations after chiropractic adjustment. The EMF (mean +/- SD in nT) decreased significantly at the cervical region from 42449 +/- 907 to 41643 +/- 1165 (p < 0.01) and at the sacral regions from 43206 +/- 760 to 42713 +/- 552 (p < 0.01). The EMF at the lumbar and thoracic regions decreased but did not reach a statistically significant level. No significant changes of the body surface EMF were found in the control group. A low force Toftness chiropractic adjustment in the cervical and sacral areas resulted in a significant reduction of the cervical and sacral surface EMF. No significant body surface EMF changes were observed in the lumbar and thoracic regions. The mechanisms of the EMF reduction after chiropractic adjustment are not known.

The effect of low force chiropractic adjustments on body surface electromagnetic field

PubMed Central

Zhang, John; Snyder, Brian J; Vernor, Lori

2004-01-01

Objective The purpose of this study was to investigate the body surface electromagnetic field (EMF) changes using a sensitive magnetometer before and after a specific Toftness chiropractic adjustment in asymptomatic human subjects. Method Forty-four subjects were randomly assigned into control (20 subjects) and experimental groups (24 subjects) in a pre and post-test design. The Triaxial Fluxgate Magnetometer FGM-5DTAA (Walker Scientific, Worcester, Massachusetts) with five digit display and resolution of 1 nanotesla (nT) was used for EMF detection. The EMF in the research room and on the adjustment table was monitored and recorded. The subjects’ body surface (cervical, thoracic, lumbar and sacral areas) EMF was determined in the prone position before and after the chiropractic adjustment. A low force Toftness chiropractic adjustment was applied to the cervical, thoracic, lumbar and sacral areas as determined by the practitioner. Results The EMF in the research room was recorded as 41611 nT at the Z axis (earth field), 13761 nT at the X axis and 7438 nT at the Y axis. The EMF on the adjusting table changed minimally during the 15 minute observation period. The EMF on the subjects’ body surface decreased at 4 spinal locations after chiropractic adjustment. The EMF (mean ± SD in nT) decreased significantly at the cervical region from 42449 ± 907 to 41643 ± 1165 (p < 0.01) and at the sacral regions from 43206 ± 760 to 42713 ± 552 (p < 0.01). The EMF at the lumbar and thoracic regions decreased but did not reach a statistically significant level. No significant changes of the body surface EMF were found in the control group. Conclusion A low force Toftness chiropractic adjustment in the cervical and sacral areas resulted in a significant reduction of the cervical and sacral surface EMF. No significant body surface EMF changes were observed in the lumbar and thoracic regions. The mechanisms of the EMF reduction after chiropractic adjustment are not known. PMID:17549217

Pelvic X-ray misses out on detecting sacral fractures in the elderly - Importance of CT imaging in blunt pelvic trauma.

PubMed

Schicho, Andreas; Schmidt, Stefan A; Seeber, Kevin; Olivier, Alain; Richter, Peter H; Gebhard, Florian

2016-03-01

Patients aged 75 years and older with blunt pelvic trauma are frequently seen in the ER. The standard diagnostic tool in these patients is the plain a.p.-radiograph of the pelvis. Especially lesions of the posterior pelvic ring are often missed due to e.g. bowel gas projection and enteric overlay. With a retrospective study covering these patients over a 3 year period in our level I trauma centre, we were able to evaluate the rate of missed injuries in the a.p.-radiograph whenever a corresponding CT scan was performed. Age, gender, and accompanying fractures of the pelvic ring were recorded. The intrinsic test characteristics and the performance in the population were calculated according to standard formulas. Thus, 233 consecutive patients with blunt pelvic trauma with both conventional radiographic examination and computed tomography (CT) were included. Thereof, 56 (23%) showed a sacral fracture in the CT scan. Of 233 pelvic X-ray-images taken, 227 showed no sacral fracture. 51 (21.7%) of these were false negative, yielding a sensitivity of just 10.5%. Average age of patients with sacral fractures was 85.1±6.1 years, with 88% being female. Sacral fractures were often accompanied by lesions of the anterior pelvic ring with pubic bone fractures in 75% of sacrum fracture cases. Second most concomitant fractures are found at the acetabulum (23.3%). Plain radiographic imaging is especially likely to miss out fractures of the posterior pelvic ring, which nowadays can be of therapeutic consequence. Besides the physicians experience in the ED, profound knowledge of insensitivity of plain radiographs in finding posterior pelvic ring lesions is crucial for a reliable diagnostic routine. Since the high mortality caused by prolonged immobilisation due to pelvic ring injuries, all fractures should be identified. We therefore provide a diagnostic algorithm for blunt pelvic trauma in the elderly. Copyright © 2016 Elsevier Ltd. All rights reserved.

Safety and effectiveness of percutaneous sacroplasty: a single-centre experience in 58 consecutive patients with tumours or osteoporotic insufficient fractures treated under fluoroscopic guidance.

PubMed

Pereira, Licia Pacheco; Clarençon, Frédéric; Cormier, Evelyne; Rose, Michèle; Jean, Beatrix; Le Jean, Lise; Chiras, Jacques

2013-10-01

To report our experience in percutaneous sacroplasty (PSP) for tumours and insufficiency fractures of the sacrum. Single-centre retrospective analysis of 58 consecutive patients who underwent 67 PSPs for intractable pain from sacral tumours (84.5 %) or from osteoporotic fractures (15.5 %). The following data were assessed: visual analogue scale (VAS) before and after the procedure for global pain; short-term (1-month) clinical follow-up using a four-grade patient satisfaction scale (worse, unchanged, mild improvement and significant improvement); modification in analgesics consumption; referred short-term walking mobility. Minor and major complications were systematically assessed. The mean VAS score was 5.3 ± 2.0 in pre-procedure and 1.7 ± 1.8 in post-procedure. At 1-month follow-up, 34/58 (58.5 %) patients experienced a mild improvement; 15/58 (26 %) presented a significant improvement while 4/58 (7 %) and 5/58 (8.5 %) patients had unchanged or worse pain, respectively. Decreased analgesic consumption was observed in 34 % (20/58) of the patients. Eighty percent of patients with walking limitation experienced improvement, 16 % remained unchanged and 4 % were worse. We noted minor complications in 2/58 patients (3.4 %) and major complications in 2/58 patients (3.4 %). Percutaneous sacroplasty for metastatic and osteoporotic fractures is a safe and effective technique in terms of pain relief and functional outcome. • Percutaneous sacroplasty provides pain relief and functional improvement for insufficiency sacral fractures. • Percutaneous sacroplasty provides pain relief and function improvement for sacral tumours. • The major complication rate is acceptable (3.4 %), and is higher in sacral tumours. • Posterior wall/cortical sacral bone disruption is not statistically associated with more complications. • However, osteolytic tumours seem to be associated with higher risk of complications.

[PELVIS/SACRAL syndrome with livedoid haemangioma and amniotic band].

PubMed

Bourrat, E; Lemarchand-Venencie, F; Jacquemont, M-L; El Ghoneimi, A; Wassef, M; Leger, J; Morel, P

2008-12-01

PELVIS or SACRAL syndrome denotes the association of local haemangioma and malformation in the pelvic region. In this paper, we report a case noteworthy on account of the initially livedoid appearance of the haemangioma as well as associated amniotic banding of an upper limb. A newborn male infant underwent left colostomy on the day of birth due to anal imperforation and anomalies of the external genital organs with sexual ambiguity. Examination of the skin and appendages revealed poorly delineated hypopigmentation in the sacrolumbar region and a fibrous groove around the right arm characteristic of amniotic band syndrome. Sacrolumbar and pelvic MRI scans revealed deviation towards the left of the last three sacral vertebrae with no medullary anomalies. Retrograde cystography showed a recto-uretral fistula. Progression of the infant's condition was marked by the appearance during the first month of a flat, violaceous, angiomatous, livedoid lesion in the middle of the buttocks and the perineum and a linear lesion on the rear aspect of the right lower limb. The skin biopsy of this lesion revealed a single capillary lobule at the dermal-hypodermal junction of non-specific appearance but with marked Glut1 expression by endothelial cells highly evocative of infantile haemangioma. Segmented haemangiomas are commonly associated with extracutaneous abnormalities. By analogy with PHACE syndrome, defined as association of segmented facial haemangioma with cerebral, ocular and cardio-aortic abnormalities, PELVIS/SACRAL syndrome denotes the association of segmented haemangioma of the loins (sacrolumbar region, buttocks or perineum=napkin haemangioma) with spinal dysraphia affecting the sacrolumbar spine, the terminal medullary cone, the genitourinary organs and the anal region to different degrees. Diagnosis of haemangioma associated with PELVIS/SACRAL syndrome may be delayed or complicated due to the macular, telangiectasic or livedoid appearance commonly seen. To our knowledge, there have been no reports to date of an association of amniotic banding with haemangioma or perineal dysraphia.

The surgical management of sacral chordomas.

PubMed

Schwab, Joseph H; Healey, John H; Rose, Peter; Casas-Ganem, Jorge; Boland, Patrick J

2009-11-15

Retrospective case series. The purpose of this study was to evaluate factors that contribute to improved local control and survival. In addition, we sought to define the expected morbidity associated with treatment. Sacral chordomas are rare tumors presumed to arise from notochordal cells. Local recurrence presents a major problem in the management of these tumors and it has been correlated with survival. Resection of sacral tumors is associated with significant morbidity. Forty-two patients underwent resection for sacral chordoma between 1990 and 2005. Twelve patients had their initial surgery elsewhere. There were 12 female and 30 male patients. The proximal extent of the sacrectomy was at least S2 in 32 patients. Median survival was 84 months, and 5-year disease-free (DFS) and disease-specific survival (DSF) were 56% and 77%, respectively. Local recurrence (LR) and metastasis occurred in 17 (40%) and 13 (31%) patients, respectively. Local recurrence (P=0.0001), metastasis (P=0.0001), prior resection (P=0.046), and higher grade (P=0.05) were associated with a worse DSF. Prior resections (P=0.0001) and intralesional resections (P=0.01) were associated with a higher rate of LR. Intralesional resections were associated with a lower DSF (P=0.0001). Wide contaminated margins treated with cryosurgery and/or radiation were not associated with a higher LR rate. Rectus abdominus flaps were associated with decreased wound complications (P=0.01). Thirty-one (74%) patients reported that they self catheterize; and 16 (38%) patients required bowel training, while an additional twelve (29%) patients had a colostomy. Twenty-eight (67%) patients reported sexual dysfunction. Two (5%) patients died due to sepsis. Intralesional resection should be avoided as it is associated with a higher LR rate and worse survival. Rectus abdominus flaps ought to be considered as they lower the wound complication rate. Sacral resection is associated with significant morbidity.

Influence of lumbar lordosis restoration on thoracic curve and sagittal position in lumbar degenerative kyphosis patients.

PubMed

Jang, Jee-Soo; Lee, Sang-Ho; Min, Jun-Hong; Maeng, Dae Hyeon

2009-02-01

A retrospective study. To determine postsurgical correlations between thoracic and lumbar sagittal curves in lumbar degenerative kyphosis (LDK) and to determine predictability of spontaneous correction of thoracic curve and sacral angle after surgical restoration of lumbar lordosis and fusion. To our knowledge, there are only a limited number of articles about the relationship between thoracic and lumbar curve in sagittal thoracic compensated LDK. Retrospective review of 53 consecutive patients treated with combined anterior and posterior spinal arthrodesis. We included patients with sagittal thoracic compensated LDK caused by sagittal imbalance in this study. Total lumbar lordosis, thoracic kyphosis, sacral slope, and C7 plumb line were measured on the pre- and postoperative whole spine lateral views. Postoperative changes in thoracic kyphosis, sacral slope, and C7 plumb line according to the surgical lumbar lordosis restoration were measured and evaluated. The mean preoperative sagittal imbalance by plumb line was 78.3 mm (+/-76.5); this improved to 13.6 mm (+/-25) after surgery (P < 0.0001). Mean lumbar lordosis was 9.4 degrees (+/-19.2) before surgery and increased to 38.4 degrees (+/-13.1) at follow-up (P < 0.0001). Mean thoracic kyphosis was 1.1 degrees (+/-12.7) before surgery and increased to 17.6 degrees (+/-12.2) at follow-up (P < 0.0001). Significant preoperative correlations existed between kyphosis and lordosis (r = 0.772, P < 0.0001) and between lordosis and sacral slope (r = 0.785, P < 0.0001). Postoperative lumbar lordosis is correlated to thoracic kyphosis increase (r = 0.620, P < 0.0001). Postoperative lumbar lordosis is correlated to sacral slope increase (r = 0.722, P < 0.0001). Reciprocal relationship exists between lumbar lordosis and thoracic kyphosis in sagittal thoracic compensated LDK. Surgical restoration of lumbar lordosis for LDK brings about high level of statistical correlation to thoracic kyphosis improvement. At the same time, the reciprocal relationship is maintained.

Urodynamic results, clinical efficacy, and complication rates of sacral intradural deafferentation and sacral anterior root stimulation in patients with neurogenic lower urinary tract dysfunction resulting from complete spinal cord injury.

PubMed

Krasmik, D; Krebs, Jörg; van Ophoven, Arndt; Pannek, Jürgen

2014-11-01

To investigate the outcome and complications of sacral deafferentation (SDAF) and sacral anterior root stimulation (SARS) in patients with neurogenic lower urinary tract dysfunction (NLUTD) resulting from complete spinal cord injury (SCI). Retrospective chart analysis of 137 patients who underwent SDAF/SARS at a single institution. Patients were categorized as being at risk of renal damage when the maximum detrusor pressure was >40 cmH2 O or detrusor compliance was <20 ml/cmH2 O. After a mean follow-up time of 14.8 ± 5.3 years, SDAF/SARS treatment significantly (P < 0.001) reduced the number of patients suffering from elevated detrusor pressure from 65 to 2, and from low detrusor compliance from 62 to 13, respectively. Mean bladder capacity significantly (P < 0.001) improved from 272.4 ± 143.0 to 475.0 ± 82.7 ml. The mean number of symptomatic UTI also decreased significantly (P < 0.001) from 6.2 ± 4.5 to 2.5 ± 2.6 per year. The number of patients suffering from incontinence had significantly (P < 0.001) decreased from 70 to 44. At the last follow-up visit, 107 (78.1%) patients were still using the stimulator. A total of 84 complications requiring surgical revision were observed. Defects of the stimulator cables or the receiver plate were the most common events (n = 38). The retrospective design pertains to the limitations of the study. Sacral deafferentation and SARS are an effective treatment option for refractory NLUTD in patients with complete SCI, despite a substantial long-term complication rate. © 2014 Wiley Periodicals, Inc.

How is sagittal balance acquired during bipedal gait acquisition? Comparison of neonatal and adult pelves in three dimensions. Evolutionary implications.

PubMed

Tardieu, Christine; Bonneau, Noémie; Hecquet, Jérôme; Boulay, Christophe; Marty, Catherine; Legaye, Jean; Duval-Beaupère, Geneviève

2013-08-01

We compare adult and intact neonatal pelves, using a pelvic sagittal variable, the angle of sacral incidence, which presents significant correlations with vertebral curvature in adults and plays an important role in sagittal balance of the trunk on the lower limbs. Since the lumbar curvature develops in the child in association with gait acquisition, we expect a change in this angle during growth which could contribute to the acquisition of sagittal balance. To understand the mechanisms underlying the sagittal balance in the evolution of human bipedalism, we also measure the angle of incidence of hominid fossils. Fourty-seven landmarks were digitized on 50 adult and 19 intact neonatal pelves. We used a three-dimensional model of the pelvis (DE-VISU program) which calculates the angle of sacral incidence and related functional variables. Cross-sectional data from newborns and adults show that the angle of sacral incidence increases and becomes negatively correlated with the sacro-acetabular distance. During ontogeny the sacrum becomes curved, tends to sink down between the iliac blades as a wedge and moves backward in the sagittal plane relative to the acetabula, thus contributing to the backwards displacement of the center of gravity of the trunk. A chain of correlations links the degree of the sacral slope and of the angle of incidence, which is tightly linked with the lumbar lordosis. We sketch a model showing the coordinated changes occurring in the pelvis and vertebral column during the acquisition of bipedalism in infancy. In the australopithecine pelves, Sts 14 and AL 288-1, and in the Homo erectus Gona pelvis the angle of sacral incidence reaches the mean values of humans. Discussing the incomplete pelves of Ardipithecus ramidus, Australopithecus sediba and the Nariokotome Boy, we suggest how the functional linkage between pelvis and spine, observed in humans, could have emerged during hominid evolution. Copyright © 2013 Elsevier Ltd. All rights reserved.

Urinary retention, erectile dysfunction and meningitis due to sacral herpes zoster: a case report and review of the literature.

PubMed

Erol, B; Avci, A; Eken, C; Ozgok, Y

2009-01-01

Zona zoster infection is often associated with painful erythematous vesicular eruptions of the skin or mucous membranes. Varicella zoster virus which stays latent in the sensorial root ganglia causes zona zoster infection. The most recognized feature of zona zoster is the dermatomal distribution of vesicular rashes. In the present case report, we state an unusual presentation of sacral zona zoster with urinary retention, erectile dysfunction and meningitis. Copyright 2009 S. Karger AG, Basel.

OnabotulinumtoxinA vs Sacral Neuromodulation on Refractory Urgency Urinary Incontinence in Women: A Randomized Clinical Trial.

PubMed

Amundsen, Cindy L; Richter, Holly E; Menefee, Shawn A; Komesu, Yuko M; Arya, Lily A; Gregory, W Thomas; Myers, Deborah L; Zyczynski, Halina M; Vasavada, Sandip; Nolen, Tracy L; Wallace, Dennis; Meikle, Susan F

2016-10-04

Women with refractory urgency urinary incontinence are treated with sacral neuromodulation and onabotulinumtoxinA with limited comparative information. To assess whether onabotulinumtoxinA is superior to sacral neuromodulation in controlling refractory episodes of urgency urinary incontinence. Multicenter open-label randomized trial (February 2012-January 2015) at 9 US medical centers involving 381 women with refractory urgency urinary incontinence. Cystoscopic intradetrusor injection of 200 U of onabotulinumtoxinA (n = 192) or sacral neuromodulation (n = 189). Primary outcome, change from baseline mean number of daily urgency urinary incontinence episodes over 6 months, was measured with monthly 3-day diaries. Secondary outcomes included change from baseline in urinary symptom scores in the Overactive Bladder Questionnaire Short Form (SF); range, 0-100, higher scores indicating worse symptoms; Overactive Bladder Satisfaction questionnaire; range, 0-100; includes 5 subscales, higher scores indicating better satisfaction; and adverse events. Of the 364 women (mean [SD] age, 63.0 [11.6] years) in the intention-to-treat population, 190 women in the onabotulinumtoxinA group had a greater reduction in 6-month mean number of episodes of urgency incontinence per day than did the 174 in the sacral neuromodulation group (-3.9 vs -3.3 episodes per day; mean difference, 0.63; 95% CI, 0.13 to 1.14; P = .01). Participants treated with onabotulinumtoxinA showed greater improvement in the Overactive Bladder Questionnaire SF for symptom bother (-46.7 vs -38.6; mean difference, 8.1; 95% CI, 3.0 to 13.3; P = .002); treatment satisfaction (67.7 vs 59.8; mean difference, 7.8; 95% CI, 1.6 to 14.1; P = .01) and treatment endorsement (78.1 vs 67.6; mean difference; 10.4, 95% CI, 4.3 to 16.5; P < .001) than treatment with sacral neuromodulation. There were no differences in convenience (67.6 vs 70.2; mean difference, -2.5; 95% CI, -8.1 to 3.0; P = .36), adverse effects (88.4 vs 85.1; mean difference, 3.3; 95% CI, -1.9 to 8.5; P = .22), and treatment preference (92.% vs 89%; risk difference, -3%; 95% CI, -16% to 10%; P = .49). Urinary tract infections were more frequent in the onabotulinumtoxinA group (35% vs 11%; risk difference, -23%; 95% CI, -33% to -13%; P < .001). The need for self-catheterization was 8% and 2% at 1 and 6 months in the onabotulinumtoxinA group. Neuromodulation device revisions and removals occurred in 3%. Among women with refractory urgency urinary incontinence, treatment with onabotulinumtoxinA compared with sacral neuromodulation resulted in a small daily improvement in episodes that although statistically significant is of uncertain clinical importance. In addition, it resulted in a higher risk of urinary tract infections and need for transient self-catheterizations.

Simulated Vesta from the South Pole

NASA Image and Video Library

2011-03-10

This image shows the scientists best guess to date of what the surface of the protoplanet Vesta might look like from the south pole and incorporates the best data on dimples and bulges Vesta from ground-based telescopes and NASA Hubble Space Telescope.

Reconstruction of upper lip muscle system by anatomy, magnetic resonance imaging, and serial histological sections.

PubMed

Bo, Chen; Ningbei, Yin

2014-01-01

Surgeons need references to undertake cleft lip repairs. We aimed to establish a three-dimensional model of upper lip muscles. We examined specimens from 2 adult cadaver heads and 8 adult cadaver lips, obtaining serial sections in the axial, sagittal, and coronal planes. Sections were stained to observe the philtrum, Cupid bow, vermilion, and nostril sill. Reconstruction was done with three-dimensional software (eg, 3D-DOCTOR, MicroMR). Parallel circular muscle fibers existed between modioli. The orbicularis oris deep layer contained fan muscle fibers inclining inward. Some ended at the anterior nasal crest. Others migrated to the depressor septum, crossed the midline, and migrated to the nasalis muscle. At the nostril floor, the depressor septum muscle bundle and ipsilateral orbicularis oris overlapped the nasalis muscle and the contralateral orbicularis oris. This construction shaped the nostril sill. The levator labii superioris alaeque nasi, levator labii superioris, and zygomaticus minor crossed the nasolabial groove and migrated to the superficial orbicularis oris, entering the outer edge of the nasal alar to the upper lip near the vermilion border and philtrum ridge, shaping Cupid bow. Contralateral deep orbicularis oris muscle fibers crossed the philtrum dimple to the lateral philtrum ridge (axial plane). Superficial reticular muscle fibers of the levator labii superioris, zygomaticus minor, zygomaticus major, and orbicularis oris inserted into the medial philtrum ridge (coronal plane). They intersected to form the philtrum ridge. A three-dimensional upper lip muscular system model was established that can be referenced for cleft lip repair and lip operations.

Neurostimulation for bladder evacuation: is sacral root stimulation a substitute for microstimulation?

PubMed

Probst, M; Piechota, H J; Hohenfellner, M; Gleason, C A; Tanagho, E A

1997-04-01

To determine by anatomical and functional studies whether stimulation of sacral rootlets might permit selective stimulation of autonomic fibres, thus avoiding the detrusor/sphincter dyssynergia characteristic of current techniques of neurostimulation for bladder evacuation. In 10 male mongrel dogs, the S2 root was isolated and its constituent rootlets followed from their origin in the spinal cord to the point of exit from the dura. The entire root and the individual rootlets were then stimulated, including intra- and extra-dural stimulation and at proximal, mid and distal levels. Neuroanatomical and histological findings showed that rootlets of ventral S2 maintain their identity throughout their intradural course; some carry predominantly autonomic fibres, some predominantly somatic and some a mixture of the two. It appears surgically feasible to identify, isolate and sever the predominantly somatic rootlets intradurally, sparing the predominantly autonomic rootlets for inclusion in extradural electrode placement around the entire sacral root, thus eliminating sphincteric interference with detrusor contraction for voiding at low pressure.

Formation of the sacrum requires down-regulation of sonic hedgehog signaling in the sacral intervertebral discs.

PubMed

Bonavita, Raffaella; Vincent, Kathleen; Pinelli, Robert; Dahia, Chitra Lekha

2018-05-21

In humans, the sacrum forms an important component of the pelvic arch, and it transfers the weight of the body to the lower limbs. The sacrum is formed by collapse of the intervertebral discs (IVDs) between the five sacral vertebrae during childhood, and their fusion to form a single bone. We show that collapse of the sacral discs in the mouse is associated with the down-regulation of sonic hedgehog (SHH) signaling in the nucleus pulposus (NP) of the disc, and many aspects of this phenotype can be reversed by experimental postnatal activation of HH signaling. We have previously shown that SHH signaling is essential for the normal postnatal growth and differentiation of intervertebral discs elsewhere in the spine, and that loss of SHH signaling leads to pathological disc degeneration, a very common disorder of aging. Thus, loss of SHH is pathological in one region of the spine but part of normal development in another. © 2018. Published by The Company of Biologists Ltd.

The sacral autonomic outflow is parasympathetic: Langley got it right.

PubMed

Horn, John P

2018-04-01

A recent developmental study of gene expression by Espinosa-Medina, Brunet and colleagues sparked controversy by asserting a revised nomenclature for divisions of the autonomic motor system. Should we re-classify the sacral autonomic outflow as sympathetic, as now suggested, or does it rightly belong to the parasympathetic system, as defined by Langley nearly 100 years ago? Arguments for rejecting Espinosa-Medina, Brunet et al.'s scheme subsequently appeared in e-letters and brief reviews. A more recent commentary in this journal by Brunet and colleagues responded to these criticisms by labeling Langley's scheme as a historical myth perpetuated by ignorance. In reaction to this heated exchange, I now examine both sides to the controversy, together with purported errors by the pioneers in the field. I then explain, once more, why the sacral outflow should remain known as parasympathetic, and outline suggestions for future experimentation to advance the understanding of cellular identity in the autonomic motor system.

Reduction and temporary stabilization of Tile C pelvic ring injuries using a posteriorly based external fixation system.

PubMed

Martin, Murphy P; Rojas, David; Mauffrey, Cyril

2018-07-01

Tile C pelvic ring injuries are challenging to manage even in the most experienced hands. The majority of such injuries can be managed using percutaneous reduction techniques, and the posterior ring can be stabilized using percutaneous transiliac-transsacral screw fixation. However, a subgroup of patients present with inadequate bony corridors, significant sacral zone 2 comminution or significant lateral/vertical displacement of the hemipelvis through a complete sacral fracture. Percutaneous strategies in such circumstances can be dangerous. Those patients may benefit from prone positioning and open reduction of the sacral fracture with fixation through tension band plating or lumbo-pelvic fixation. Soft tissue handling is critical, and direct reduction techniques around the sacrum can be difficult due to the complex anatomy and the fragile nature of the sacrum making clamp placement and tightening a challenge. In this paper, we propose a mini-invasive technique of indirect reduction and temporary stabilization, which is soft tissue friendly and permits maintenance of reduction during definitive fixation surgical.

MAdCAM-1 expressing sacral lymph node in the lymphotoxin beta-deficient mouse provides a site for immune generation following vaginal herpes simplex virus-2 infection.

PubMed

Soderberg, Kelly A; Linehan, Melissa M; Ruddle, Nancy H; Iwasaki, Akiko

2004-08-01

The members of the lymphotoxin (LT) family of molecules play a critical role in lymphoid organogenesis. Whereas LT alpha-deficient mice lack all lymph nodes and Peyer's patches, mice deficient in LT beta retain mesenteric lymph nodes and cervical lymph nodes, suggesting that an LT beta-independent pathway exists for the generation of mucosal lymph nodes. In this study, we describe the presence of a lymph node in LT beta-deficient mice responsible for draining the genital mucosa. In the majority of LT beta-deficient mice, a lymph node was found near the iliac artery, slightly misplaced from the site of the sacral lymph node in wild-type mice. The sacral lymph node of the LT beta-deficient mice, as well as that of the wild-type mice, expressed the mucosal addressin cell adhesion molecule-1 similar to the mesenteric lymph node. Following intravaginal infection with HSV type 2, activated dendritic cells capable of stimulating a Th1 response were found in this sacral lymph node. Furthermore, normal HSV-2-specific IgG responses were generated in the LT beta-deficient mice following intravaginal HSV-2 infection even in the absence of the spleen. Therefore, an LT beta-independent pathway exists for the development of a lymph node associated with the genital mucosa, and such a lymph node serves to generate potent immune responses against viral challenge.

Formation of curvature singularities on the interface between dielectric liquids in a strong vertical electric field.

PubMed

Kochurin, Evgeny A; Zubarev, Nikolay M; Zubareva, Olga V

2013-08-01

The nonlinear dynamics of the interface between two deep dielectric fluids in the presence of a vertical electric field is studied. We consider the limit of a strong external electric field where electrostatic forces dominate over gravitational and capillary forces. The nonlinear integrodifferential equations for the interface motion are derived under the assumption of small interfacial slopes. It is shown in the framework of these equations that, in the generic case, the instability development leads to the formation of root singularities at the interface in a finite time. The interfacial curvature becomes infinite at singular points, while the slope angles remain relatively small. The curvature is negative in the vicinity of singularities if the ratio of the permittivities of the fluids exceeds the inverse ratio of their densities, and it is positive in the opposite case (we consider that the lower fluid is heavier than the upper one). In the intermediate case, the interface evolution equations describe the formation and sharpening of dimples at the interface. The results obtained are applicable for the description of the instability of the interface between two magnetic fluids in a vertical magnetic field.

A method for the formation of Pt metal nanoparticle arrays using nanosecond pulsed laser dewetting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Owusu-Ansah, Ebenezer; Horwood, Corie A.; Birss, Viola I.

2015-05-18

Nanosecond pulsed laser dewetting of Pt thin films, deposited on a dimpled Ta (DT) surface, has been studied here in order to form ordered Pt nanoparticle (NP) arrays. The DT substrate was fabricated via a simple electrochemical anodization process in a highly concentrated H{sub 2}SO{sub 4} and HF solution. Pt thin films (3–5 nm) were sputter coated on DT and then dewetted under vacuum to generate NPs using a 355 nm laser radiation (6–9 ns, 10 Hz). The threshold laser fluence to fully dewet a 3.5 nm thick Pt film was determined to be 300 mJ/cm{sup 2}. Our experiments have shown that shorter irradiation timesmore » (≤60 s) produce smaller nanoparticles with more uniform sizes, while longer times (>60 s) give large nanoparticles with wider size distributions. The optimum laser irradiation time of 1 s (10 pulses) has led to the formation of highly ordered Pt nanoparticle arrays with an average nanoparticle size of 26 ± 3 nm with no substrate deformation. At the optimum condition of 1 s and 500 mJ/cm{sup 2}, as many as 85% of the dewetted NPs were found neatly in the well-defined dimples. This work has demonstrated that pulsed laser dewetting of Pt thin films on a pre-patterned dimpled substrate is an efficient and powerful technique to produce highly ordered Pt nanoparticle arrays. This method can thus be used to produce arrays of other high-melting-point metal nanoparticles for a range of applications, including electrocatalysis, functionalized nanomaterials, and analytical purposes.« less

In vivo evaluation of needle force and friction stress during insertion at varying insertion speed into the brain.

PubMed

Casanova, Fernando; Carney, Paul R; Sarntinoranont, Malisa

2014-11-30

Convection enhanced delivery (CED) infuses drugs directly into brain tissue. Needle insertion is required and results in tissue damage which can promote flowback along the needle track and improper targeting. The goal of this study was to evaluate friction stress (calculated from needle insertion force) as a measure of tissue contact and damage during needle insertion for varying insertion speeds. Forces and surface dimpling during needle insertion were measured in rat brain in vivo. Needle retraction forces were used to calculate friction stresses. These measures were compared to track damage from a previous study. Differences between brain tissues and soft hydrogels were evaluated for varying insertion speeds: 0.2, 2, and 10mm/s. In brain tissue, average insertion force and surface dimpling increased with increasing insertion speed. Average friction stress along the needle-tissue interface decreased with insertion speed (from 0.58 ± 0.27 to 0.16 ± 0.08 kPa). Friction stress varied between brain regions: cortex (0.227 ± 0.27 kPa), external capsule (0.222 ± 0.19 kPa), and CPu (0.383 ± 0.30 kPa). Hydrogels exhibited opposite trends for dimpling and friction stress with insertion speed. Previously, increasing needle damage with insertion speed has been measured with histological methods. Friction stress appears to decrease with increasing tissue damage and decreasing tissue contact, providing the potential for in vivo and real time evaluation along the needle track. Force derived friction stress decreased with increasing insertion speed and was smaller within white matter regions. Hydrogels exhibited opposite trends to brain tissue. Copyright © 2014 Elsevier B.V. All rights reserved.

Nasofrontal dermoid sinus cyst: report of two cases.

PubMed

Zerris, Vasilios A; Annino, Don; Heilman, Carl B

2002-09-01

Nasofrontal dermoid sinus cysts are rare. The embryological origin, presentation, treatment, and genetic associations of two cases of these cysts are discussed. Emphasis is placed on physical findings and the importance of addressing both the intracranial and extracranial components. The first patient, a 33-year-old woman, sought care for chemical meningitis. As a child, she was differentiated from her identical twin sister by a dimple on the tip of her nose. The second patient, a 34-year-old man, sought care for new-onset seizures. Since birth, he had a dimple on the tip of his nose. As a child, he had undergone resection of a nasal cyst. Imaging studies in both patients indicated a midline anterior cranial base mass within the falx and a defect in the crista galli. Both patients underwent biorbitofrontal nasal craniotomy. A bifrontal craniotomy was performed first, then removal of the orbitonasal ridge. The dermoid and involved falx were resected. The sinus tract was followed through the crista galli and resected up to the osteocartilaginous junction in the nose. The remainder of the tract was resected via a small incision through the nares. The dura was closed primarily by mobilizing the dura along the sides of the crista galli. After surgery, both patients still possessed their sense of smell. Nasofrontal dermoid sinus cysts have a unique embryological origin. A midline basal frontal dermoid associated with a dimple on the nasal surface with or without protruding hair and sebaceous discharge is the pathognomonic presentation. It is important to address both the intracranial and extracranial component surgically. Although concomitant anomalies and familial clustering have been described, most cases are spontaneous occurrences.

The position of the anal dimple in newborns and infants with anorectal malformations and its correlation with the normal anal position.

PubMed

Patel, Jigar N; Kumar, Amit; Yadav, Partap Singh; Chadha, Rajiv; Datta, Vikram; Roy Choudhury, Subhasis

2017-11-16

The anal position index (API) defines the normal anal position as the ratio of fourchette-anal distance to fourchette-coccyx distance for females and the scrotum-anal distance to scrotum-coccyx distance for males. In this study, measurement of the API in newborns and infants with anorectal malformations (ARM), using the center of the midline anal dimple (AD) to represent the center of the proposed neoanus, was performed to assess whether or not the AD was located in a significantly abnormal position as correlated with the normal anal position. The cases comprised 65 consecutive newborn and infants with ARM, divided into 2 age-based groups (Group A: 1st day to 1month; Group B: 1-12months), without sacral or significant perineal abnormalities. Controls included an equal number of age and gender matched patients admitted for other conditions. The characteristics of the AD ('well developed' or 'moderately developed') as well as those of the midline perineal raphé in males and the perineal groove in females were also recorded. Combining both age groups, the mean API±SD was 0.41±0.012 in male cases and 0.53±0.07 in male controls (p value 0.003). The corresponding values for female cases and controls were 0.31±0.09 and 0.36±0.07 respectively (p = 0.040). In male newborns, the API in cases was significantly lower than the API in controls (p<0.001). Combining both males and female newborns, the differences between the API in cases and controls was also statistically significant (p<0.001). In older boys as well as in girls from both age groups, apart from cases of persistent cloaca, the API was lower in cases than in controls, especially in boys, although the difference was not statistically significant. On comparing the API in individual male ARM with that in male controls, cases of rectobulbar urethral fistula (RBUF) and rectovesical fistula had a statistically significant lower API (p<0.001). In the 4 cases of persistent cloaca, the mean API (0.40±0.1) was higher than the mean API in female controls and the AD was well developed with a well-delineated, narrow perineal groove. The majority (53/65; 81.53%) of patients had a 'well developed' AD. Twelve patients (18.47%) had a 'moderately developed' AD including 10 females and 2 males. There were 15 patients with a depressed AD (anal fossette); of these 12 (80%) were females. All boys had a well delineated perineal raphé in contrast to 10 girls (29.4% of total female ARM) who had a poorly delineated midline perineal groove. During definitive surgery for ARM, if the AD is taken as the site of the proposed neoanus, the neoanal position is likely to be anterior to the normal anal position in both males and females and especially so in males. Overall, girls with ARM appear to be more likely to have a relatively poorly developed and/ or depressed AD and a poorly delineated perineal groove. Clinical Research. Level III. Copyright © 2017 Elsevier Inc. All rights reserved.

A case of Capnocytophaga canimorsus sacral abscess in an immunocompetent patient.

PubMed

Joswig, H; Gers, B; Dollenmaier, G; Heilbronner, R; Strahm, C

2015-04-01

We report a unique case of sacral Capnocytophaga canimorsus abscess successfully treated with surgery and antibiotics. Close contact to a dog was assumed to be the most likely source of infection. Established risk factors for invasive C. canimorsus infection such as splenectomy, alcoholism or overt immunosuppression could not be identified. The role of cigarette smoking, portal of entry and the possible relevance of altered skin microbiota as well as the diagnostic value of polymerase chain reaction are discussed in the light of the scarce literature of spinal C. canimorsus infections.

Robot-assisted radiofrequency ablation of a sacral S1-S2 aggressive hemangioma.

PubMed

Kaoudi, A; Capel, C; Chenin, L; Peltier, J; Lefranc, M

2018-05-16

Aggressive vertebral hemangiomas are rare tumors of the spine. The treatment management strategy usually consists of vertebroplasty, radiation therapy or in rare cases of surgical strategy. We present a case of a bulging sacral S1-S2 hemangioma in the spinal canal that could not be managed in the usual manner. Here, we demonstrate the usefulness of radiofrequency ablation technique as an alternative treatment as well as robotic assistance for optimal placement of the ablation probe within the lesion. Copyright © 2018. Published by Elsevier Inc.

Comparative study of two negative CAR resists: EN-024M and NEB 31

NASA Astrophysics Data System (ADS)

Baik, Ki-Ho; Dean, Robert; Lem, Homer Y.; Osborne, Stephen P.; Mueller, Mark A.; Cole, Damon M.

2004-08-01

In this paper, two negative-tone chemically amplified resists (CAR) are evaluated. The methodology and results are compared and discussed. The resists include EN-024M from TOK, and NEB 31 from Sumitomo. Both resists show high contrast, good dry etch selectivity, and high environmental stability. EN-024M showed good coating uniformity while NEB31 showed a coating uniformity problem. This was a round "dimple" approximately one centimeter in diameter of different thickness and density at the center of the plate. We addressed the "dimple" coating problem as described in the paper. Optimum PAB and PEB temperatures and nominal to maximum doses for isolated features were determined by running a matrix of PAB and PEB temperatures along with a dose series. We evaluated the process and compared the lithographic performance in terms of dose sensitivity, dose and bake latitude, resolution, resist profile, OPC (Optical Proximity Correction) pattern fidelity, CD uniformity, environmental stability, Line Edge Roughness (LER) and etching bias and resistance.

The Role of Hydrogen-Enhanced Strain-Induced Lattice Defects on Hydrogen Embrittlement Susceptibility of X80 Pipeline Steel

NASA Astrophysics Data System (ADS)

Hattori, M.; Suzuki, H.; Seko, Y.; Takai, K.

2017-08-01

Studies to date have not completely determined the factors influencing hydrogen embrittlement of ferrite/bainite X80 pipeline steel. Hydrogen embrittlement susceptibility was evaluated based on fracture strain in tensile testing. We conducted a thermal desorption analysis to measure the amount of tracer hydrogen corresponding to that of lattice defects. Hydrogen embrittlement susceptibility and the amount of tracer hydrogen significantly increased with decreasing crosshead speed. Additionally, a significant increase in the formation of hydrogen-enhanced strain-induced lattice defects was observed immediately before the final fracture. In contrast to hydrogen-free specimens, the fracture surface of the hydrogen-charged specimens exhibited shallower dimples without nuclei, such as secondary phase particles. These findings indicate that the presence of hydrogen enhanced the formation of lattice defects, particularly just prior to the occurrence of final fracture. This in turn enhanced the formation of shallower dimples, thereby potentially causing premature fracture of X80 pipeline steel at lower crosshead speeds.

Effect of irradiation-induced plastic flow localization on ductile crack resistance behavior of a 9%Cr tempered martensitic steel

NASA Astrophysics Data System (ADS)

Chaouadi, R.

2008-01-01

This paper examines the effect of irradiation-induced plastic flow localization on the crack resistance behavior. Tensile and crack resistance measurements were performed on Eurofer-97 that was irradiated at 300 °C to neutron doses ranging between 0.3 and 2.1 dpa. A severe degradation of crack resistance behavior is experimentally established at quasi-static loading, in contradiction with the Charpy impact data and the dynamic crack resistance measurements. This degradation is attributed to the dislocation channel deformation phenomenon. At quasi-static loading rate, scanning electron microscopy observations of the fracture surfaces revealed a significant change of fracture topography, mainly from equiaxed dimples (mode I) to shear dimples (mode I + II). With increasing loading rate, the high peak stresses that develop inside the process zone activate much more dislocation sources resulting in a higher density of cross cutting dislocation channels and therefore an almost unaffected crack resistance. These explanations provide a rational to all experimental observations.

Path-programmable water droplet manipulations on an adhesion controlled superhydrophobic surface

PubMed Central

Seo, Jungmok; Lee, Seoung-Ki; Lee, Jaehong; Seung Lee, Jung; Kwon, Hyukho; Cho, Seung-Woo; Ahn, Jong-Hyun; Lee, Taeyoon

2015-01-01

Here, we developed a novel and facile method to control the local water adhesion force of a thin and stretchable superhydrophobic polydimethylsiloxane (PDMS) substrate with micro-pillar arrays that allows the individual manipulation of droplet motions including moving, merging and mixing. When a vacuum pressure was applied below the PDMS substrate, a local dimple structure was formed and the water adhesion force of structure was significantly changed owing to the dynamically varied pillar density. With the help of the lowered water adhesion force and the slope angle of the formed dimple structure, the motion of individual water droplets could be precisely controlled, which facilitated the creation of a droplet-based microfluidic platform capable of a programmable manipulation of droplets. We showed that the platform could be used in newer and emerging microfluidic operations such as surface-enhanced Raman spectroscopy with extremely high sensing capability (10−15 M) and in vitro small interfering RNA transfection with enhanced transfection efficiency of ~80%. PMID:26202206

Elements of Dynamics of a One-Dimensional Trapped Bose-Einstein Condensate Excited by a Time-Dependent Dimple: A Lagrangian Variational Approach

NASA Astrophysics Data System (ADS)

Sakhel, Asaad R.; Sakhel, Roger R.

2018-02-01

We examine the dynamics of a one-dimensional harmonically trapped Bose-Einstein condensate (BEC), induced by the addition of a dimple trap whose depth oscillates with time. For this purpose, the Lagrangian variational method (LVM) is applied to provide the required analytical equations. The goal is to provide an analytical explanation for the quasiperiodic oscillations of the BEC size at resonance, that is additional to the one given by Adhikari (J Phys B At Mol Opt Phys 36:1109, 2003). It is shown that LVM is able to reproduce instabilities in the dynamics along the same lines outlined by Lellouch et al. (Phys Rev X 7:021015, 2017). Moreover, it is found that at resonance the energy dynamics display ordered oscillations, whereas at off-resonance they tend to be chaotic. Further, by using the Poincare-Lindstedt method to solve the LVM equation of motion, the resulting solution is able to reproduce the quasiperiodic oscillations of the BEC.

Sacral nerve root neuromodulation: an effective treatment for refractory urge incontinence.

PubMed

Shaker, H S; Hassouna, M

1998-05-01

Sacral foramina implants have been recognized recently as a method for treatment of refractory urinary urge incontinence. We study the outcome of the procedure with in-depth analysis of the results of 18 implanted cases. Patients with urinary urge incontinence were subjected to percutaneous nerve evaluation of the S3 roots as a temporary screening test to determine response to neuromodulation. Satisfactory responders were implanted with permanent sacral root neuroprosthesis. The study design included comprehensive voiding diaries for 4 consecutive days twice as a baseline, 1 with percutaneous nerve evaluation screening, 1 after the percutaneous nerve evaluation, 1 at the 1, 3 and 6 post-implantation visits, and every 6 months thereafter. Uroflowmetry and quality of life questionnaires were performed at the same intervals. Urodynamic study was done as a baseline and 6 months after implantation of the neuroprosthesis. All 18 patients (16 women and 2 men) with refractory urge incontinence received a sacral foramina neuroprosthesis after demonstrating a good response to the percutaneous nerve evaluation. Average patient age at presentation was 42.3+/-3.3 years (range 22 to 67) and duration of urinary symptoms was 6.6+/-1.3 years (range 1.2 to 18.8). Average followup was 18.8 months (range 3 to 83). Neuromodulation in these patients showed a marked reduction in leakage episodes from 6.49 to 1.98 times per 24 hours and in the leakage severity score. Eight patients became completely dry and 4 had average leakage episodes of 1 or less daily. Patients showed as well a decrease in urinary frequency with an increase in functional bladder capacity. Associated pelvic pain improved substantially. Cystometrograms demonstrated increased volume at first sensation by 50% and increased cystometric capacity by 15% with the disappearance of uninhibited contractions in 1 of the 4 patients who presented with it preoperatively. There was also noticeable improvement in the quality of life. Complication rate was low and none was life threatening. Sacral root neuromodulation is an appealing modality for treatment of urge incontinence refractory to conventional pharmacotherapy. The relative simplicity of the technique, promising results and low complication rate make this therapy a likely alternative.

Sacral Bone Mass Distribution Assessed by Averaged Three-Dimensional CT Models: Implications for Pathogenesis and Treatment of Fragility Fractures of the Sacrum.

PubMed

Wagner, Daniel; Kamer, Lukas; Sawaguchi, Takeshi; Richards, R Geoff; Noser, Hansrudi; Rommens, Pol M

2016-04-06

Fragility fractures of the sacrum are increasing in prevalence due to osteoporosis and epidemiological changes and are challenging in their treatment. They exhibit specific fracture patterns with unilateral or bilateral fractures lateral to the sacral foramina, and sometimes an additional transverse fracture leads to spinopelvic dissociation. The goal of this study was to assess sacral bone mass distribution and corresponding changes with decreased general bone mass. Clinical computed tomography (CT) scans of intact pelves in ninety-one individuals (mean age and standard deviation, 61.5 ± 11.3 years) were used to generate three-dimensional (3D) models of the sacrum averaging bone mass in Hounsfield units (HU). Individuals with decreased general bone mass were identified by measuring bone mass in L5 (group 1 with <100 HU; in contrast to group 2 with ≥100 HU). In group 1, a large zone of negative Hounsfield units was located in the paraforaminal lateral region from S1 to S3. Along the trans-sacral corridors, a Hounsfield unit peak was observed laterally, corresponding to cortical bone of the auricular surface. The lowest Hounsfield unit values were found in the paraforaminal lateral region in the sacral ala. An intermediate level of bone mass was observed in the area of the vertebral bodies, which also demonstrated the largest difference between groups 1 and 2. Overall, the Hounsfield units were lower at S2 than S1. The models of averaged bone mass in the sacrum revealed a distinct 3D distribution pattern. The negative values in the paraforaminal lateral region may explain the specific fracture patterns in fragility fractures of the sacrum involving the lateral areas of the sacrum. Transverse fractures located between S1 and S2 leading to spinopelvic dissociation may occur because of decreased bone mass in S2. The largest difference between the studied groups was found in the vertebral bodies and might support the use of transsacral or cement-augmented implants. Copyright © 2016 by The Journal of Bone and Joint Surgery, Incorporated.

[CRITERION-RELATED VALIDITY OF SIT-AND-REACH TEST AS A MEASURE OF HAMSTRING EXTENSIBILITY IN OLDER WOMEN].

PubMed

López-Miñarro, Pedro Ángel; Vaquero-Cristóbal, Raquel; Muyor, José María; Espejo-Antúnez, Luis

2015-07-01

lumbo-sacral posture and the sit-andreach score have been proposed as measures of hamstring extensibility. However, the validity is influenced by sample characteristics. to determine the validity of lumbo-horizontal angle and score in the sit-and-reach test as measures of hamstring extensibility in older women. a hundred and twenty older women performed the straight leg raise test with both leg, and the sit-and-reach test (SR) in a random order. For the sitand- reach test, the score and the lumbo-sacral posture in bending (lumbo-horizontal angle, L-Hfx) were measured. the mean values of straight leg raise in left and right leg were 81.70 ± 13.83º and 82.10 ± 14.36º, respectively. The mean value of EPR of both legs was 81.90 ± 12.70º. The mean values of SR score and L-Hfx were -1.54 ± 8.09 cm and 91.08º ± 9.32º, respectively. The correlation values between the mean straight leg raise test with respect to lumbo-sacral posture and SR score were moderate (L-Hfx: r = -0.72, p < 0.01; SR: r = 0.70, p < 0.01). Both variables independently explained about 50% of the variance (L-Hfx: R2 = 0.52, p < 0,001; SR: R2 = 0.49, p < 0,001). the validity of lumbo-sacral posture in bending as measure of hamstring muscle extensibility on older women is moderate, with similar values than SR score. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Does cortical bone thickness in the last sacral vertebra differ among tail types in primates?

PubMed

Nishimura, Abigail C; Russo, Gabrielle A

2017-04-01

The external morphology of the sacrum is demonstrably informative regarding tail type (i.e., tail presence/absence, length, and prehensility) in living and extinct primates. However, little research has focused on the relationship between tail type and internal sacral morphology, a potentially important source of functional information when fossil sacra are incomplete. Here, we determine if cortical bone cross-sectional thickness of the last sacral vertebral body differs among tail types in extant primates and can be used to reconstruct tail types in extinct primates. Cortical bone cross-sectional thickness in the last sacral vertebral body was measured from high-resolution CT scans belonging to 20 extant primate species (N = 72) assigned to tail type categories ("tailless," "nonprehensile short-tailed," "nonprehensile long-tailed," and "prehensile-tailed"). The extant dataset was then used to reconstruct the tail types for four extinct primate species. Tailless primates had significantly thinner cortical bone than tail-bearing primates. Nonprehensile short-tailed primates had significantly thinner cortical bone than nonprehensile long-tailed primates. Cortical bone cross-sectional thickness did not distinguish between prehensile-tailed and nonprehensile long-tailed taxa. Results are strongly influenced by phylogeny. Corroborating previous studies, Epipliopithecus vindobonensis was reconstructed as tailless, Archaeolemur edwardsi as long-tailed, Megaladapis grandidieri as nonprehensile short-tailed, and Palaeopropithecus kelyus as nonprehensile short-tailed or tailless. Results indicate that, in the context of phylogenetic clade, measures of cortical bone cross-sectional thickness can be used to allocate extinct primate species to tail type categories. © 2017 Wiley Periodicals, Inc.

Multielectrode array recordings of bladder and perineal primary afferent activity from the sacral dorsal root ganglia

NASA Astrophysics Data System (ADS)

Bruns, Tim M.; Gaunt, Robert A.; Weber, Douglas J.

2011-10-01

The development of bladder and bowel neuroprostheses may benefit from the use of sensory feedback. We evaluated the use of high-density penetrating microelectrode arrays in sacral dorsal root ganglia (DRG) for recording bladder and perineal afferent activity. Arrays were inserted in S1 and S2 DRG in three anesthetized cats. Neural signals were recorded while the bladder volume was modulated and mechanical stimuli were applied to the perineal region. In two experiments, 48 units were observed that tracked bladder pressure with their firing rates (79% from S2). At least 50 additional units in each of the three experiments (274 total; 60% from S2) had a significant change in their firing rates during one or more perineal stimulation trials. This study shows the feasibility of obtaining bladder-state information and other feedback signals from the pelvic region with a sacral DRG electrode interface located in a single level. This natural source of feedback would be valuable for providing closed-loop control of bladder or other pelvic neuroprostheses.

[Meningoradiculitis caused by herpes simplex virus type 2].

PubMed

Bollen, A E; Venema, A W; Veldkamp, K E

2007-10-27

A 24-year-old immune-competent woman was admitted to hospital with a three-day history of fever and headache. On examination bilateral facial nerve palsy, lumbosacral radicular pain, reduced sacral sensibility and urinary retention were found. Open perianal lesions were suspect for genital herpes. The symptoms were compatible with a meningoradiculitis including a sacral polyradiculitis. On testing, cerebrospinal fluid was found to be abnormal with a lymphocytic cell reaction. Polymerase chain reaction (PCR) of cerebrospinal fluid and of the perianal lesions was positive for herpes simplex virus type 2 (HSV-2). An MRI scan showed colouration of part of the cauda equina. The patient was treated by intravenous injections of acyclovir 10 mg/kg t.i.d. for 21 days, after which she completely recovered. HSV-2 infection of the nervous system can cause lymphocytic, and sometimes recurrent meningitis as well as sacral polyradiculitis. It may also occur without any symptomatic genital herpes infection. A positive result from a PCR test of the cerebrospinal fluid confirms this diagnosis. Treatment with acyclovir should be started as soon as possible.

Herpes zoster-associated voiding dysfunction in hematopoietic malignancy patients.

PubMed

Imafuku, Shinichi; Takahara, Masakazu; Uenotsuchi, Takeshi; Iwato, Koji; Furue, Masutaka

2008-01-01

Voiding dysfunction is a rare but important complication of lumbo-sacral herpes zoster. Although the symptoms are transient, the clinical impact on immunocompromised patients cannot be overlooked. To clarify the time course of voiding dysfunction in herpes zoster, 13 herpes zoster patients with voiding dysfunction were retrospectively analyzed. Of 13 patients, 12 had background disease, and six of these were hematopoietic malignancies; four of these patients were hematopoietic stem cell transplant (HSCT) recipients. Ten patients had sacral lesions, two had lumbar, and one had thoracic lesions. Interestingly, patients with severe rash, or with hematopoietic malignancy had later onset of urinary retention than did patients with mild skin symptoms (Mann-Whitney U analysis, P = 0.053) or with other background disease (P = 0.0082). Patients with severe skin rash also had longer durations (P = 0.035). In one case, acute urinary retention occurred as late as 19 days after the onset of skin rash. In immune compromised subjects, attention should be paid to patients with herpes zoster in the lumbo-sacral area for late onset of acute urinary retention even after the resolution of skin symptoms.

Effective treatment of dyssynergic defecation using sacral neuromodulation in a patient with cerebral palsy.

PubMed

Chan, Daniel K; Barker, Matthew A

2015-01-01

Dyssynergic defecation is a complex bowel problem that leads to chronic constipation and abdominal pain. Management is often challenging owing to the incoordination of multiple pelvic floor muscles involved in normal defecation. We report a case of dyssynergic defecatory dysfunction in a patient with cerebral palsy treated with sacral neuromodulation. At presentation, Sitz marker study and magnetic resonance defecography showed evidence of chronic functional constipation. Anorectal manometry, rectal anal inhibitory reflex, and rectal sensation study showed intact reflex and decreased first sensation of lower canal at 50 mL. After stage 2 of InterStim implant placement, bowel habits improved to once- to twice-daily soft solid bowel movements from no regular solid bowel movements. Fecal incontinence improved from daily liquid and small solid loss to no stool leakage. In patients with systemic medical problems contributing to defecatory dysfunction and bowel incontinence, such as cerebral palsy, sacral neuromodulation was found to provide significant relief of bowel symptoms in addition to associated abdominal pain. As a result of intervention, the patient reported significant improvement in quality of life and less limitations due to dyssynergic defecation.

Effects of Low-frequency Current Sacral Dermatome Stimulation on Idiopathic Slow Transit Constipation

PubMed Central

Kim, Jin-Seop; Yi, Seung-Ju

2014-01-01

[Purpose] This study aimed to determine whether low-frequency current therapy can be used to reduce the symptoms of idiopathic slow transit constipation (ISTC). [Subjects] Fifteen patients (ten male and five female) with idiopathic slow transit constipation were enrolled in the present study. [Results] Bowel movements per day, bowel movements per week, and constipation assessment scale scores significantly improved after low-frequency current simulation of S2-S3. [Conclusion] Our results show that stimulation with low-frequency current of the sacral dermatomes may offer therapeutic benefits for a subject of patients with ISTC. PMID:25013277

Effects of Low-frequency Current Sacral Dermatome Stimulation on Idiopathic Slow Transit Constipation.

PubMed

Kim, Jin-Seop; Yi, Seung-Ju

2014-06-01

[Purpose] This study aimed to determine whether low-frequency current therapy can be used to reduce the symptoms of idiopathic slow transit constipation (ISTC). [Subjects] Fifteen patients (ten male and five female) with idiopathic slow transit constipation were enrolled in the present study. [Results] Bowel movements per day, bowel movements per week, and constipation assessment scale scores significantly improved after low-frequency current simulation of S2-S3. [Conclusion] Our results show that stimulation with low-frequency current of the sacral dermatomes may offer therapeutic benefits for a subject of patients with ISTC.

Role of intraoperative radiotherapy in the treatment of sacral chordoma.

PubMed

Jullien-Petrelli, Ariel Christian; García-Sabrido, J L; Orue-Echebarria, M I; Lozano, P; Álvarez, A; Serrano, J; Calvo, F M; Calvo-Haro, J A; Lasso, J M; Asencio, J M

2018-04-01

Sacral chordoma is a rare entity with high local recurrence rates when complete resection is not achieved. To date, there are no series available in literature combining surgery and intraoperative radiotherapy (IORT). The objective of this study was to report the experience of our center in the management of sacral chordoma combining radical resection with both external radiotherapy and IORT. This is a retrospective case series. The patient sample included 15 patients with sacral chordoma resected in our center from 1998 to 2015. The outcome measures were overall survival (OS), disease-free survival (DFS), and rates of local and distant recurrences. We retrospectively reviewed the records of all the patients with sacral chordoma resected in our center from 1998 to December 2015. Overall survival, DFS, and rates of local and distant recurrences were calculated. Results between patients treated with or without IORT were compared. A total of 15 patients were identified: 8 men and 7 women. The median age was 59 years (range 28-77). Intraoperative radiotherapy was applied in nine patients and six were treated with surgical resection without IORT. In 13 patients, we performed the treatment of the primary tumor, and in two patients, we performed the treatment of recurrence disease. A posterior approach was used in four patients. Wide surgical margins (zero residue) were achieved in six patients, marginal margins (microscopic residue) were achieved in seven patients, and there were no patients with intralesional (R2) margins. At a median follow-up of 38 months (range 11-209 months), the 5-year OS in the IORT group was 100% versus 53% in the group of non-IORT (p=.05). The median DFS in the IORT group was 85 months, and that in the non-IORT group was 41 months. In the group without IORT, two patients died and nobody died during the follow-up in the group treated with IORT. High-sacrectomy treated patients had a median survival of 41 months, and low-sacrectomy treated patients had a median survival of 90 months. Disease-free survival in patients without gluteal involvement was 100% at 5 years, and that in patients with gluteal involvement was 40%. All patients with a recurrence in our study had gluteal involvement. Multidisciplinary management of sacral chordoma seems to improve local control. The use of IORT, in our experience, is associated with an increase in OS and DFS. The level of resection and gluteal involvement seems to affect survival. The posterior approach is useful in selected cases. Multicenter studies should be performed to confirm the utility of IORT. Copyright © 2017 Elsevier Inc. All rights reserved.

Transsacral Osseous Corridor Anatomy Is More Amenable To Screw Insertion In Males: A Biomorphometric Analysis of 280 Pelves.

PubMed

Gras, Florian; Gottschling, Heiko; Schröder, Manuel; Marintschev, Ivan; Hofmann, Gunther O; Burgkart, Rainer

2016-10-01

Percutaneous iliosacral screw placement is the standard procedure for fixation of posterior pelvic ring lesions, although a transsacral screw path is being used more frequently in recent years owing to increased fracture-fixation strength and better ability to fix central and bilateral sacral fractures. However, biomorphometric data for the osseous corridors are limited. Because placement of these screws in a safe and effective manner is crucial to using transsacral screws, we sought to address precise sacral anatomy in more detail to look for anatomic variation in the general population. We asked: (1) What proportion of healthy pelvis specimens have no transsacral corridor at the level of the S1 vertebra owing to sacral dysmorphism? (2) If there is no safe diameter for screw placement in the transsacral S1 corridor, is an increased and thus safe diameter of the transsacral S2 corridor expected? (3) Are there sex-specific differences in sacral anatomy and are these correlated with known anthropometric parameters? CT scans of pelves of 280 healthy patients acquired exclusively for medical indications such as polytrauma (20%), CT angiography (70%), and other reasons (10%), were segmented manually. Using an advanced CT-based image analysis system, the mean shape of all segmented pelves was generated and functioned as a template. On this template, the cylindric transsacral osseous corridor at the level of the S1 and S2 vertebrae was determined manually. Each pelvis then was registered to the template using a free-form registration algorithm to measure the maximum screw corridor diameters on each specimen semiautomatically. Thirty of 280 pelves (11%) had no transsacral S1 corridor owing to sacral dysmorphism. The average of maximum cylindrical diameters of the S1 corridor for the remaining 250 pelves was 12.8 mm (95% CI, 12.1-13.5 mm). A transverse corridor for S2 was found in 279 of 280 pelves, with an average of maximum cylindrical diameter of 11.6 mm (95% CI, 11.3-11.9 mm). Decreasing transsacral S1 corridor diameters are correlated with increasing transsacral S2 corridor diameters (R value for females, -0.260, p < 0.01; for males, -0.311, p < 0.001). Female specimens were more likely to have sacral dysmorphism (defined as a pelvis without a transsacral osseous corridor at the level of the S1 vertebra) than were male specimens (females, 16%; males, 7%; p < 0.003). Furthermore female pelves had smaller-corridor diameters than did male pelves (females versus males for S1: 11.7 mm [95% CI, 10.6-12.8 mm] versus 13.5 mm [95% CI, 12.6-14.4 mm], p < 0.01; and for S2: 10.6 mm [95% CI, 10.1-11.1 mm] versus 12.2 mm [95% CI, 11.8-12.6 mm ], p < 0.0001). Narrow corridors and highly individual, sex-dependent variance of morphologic features of the sacrum make transsacral implant placement technically demanding. Individual preoperative axial-slice CT scan analyses and orthogonal coronal and sagittal reformations are recommended to determine the prevalence of sufficient-sized osseous corridors on both levels for safe screw placements, especially in female patients, owing to their smaller corridor diameters and higher rate of sacral dysmorphism.

Transient neurologic deficit after spinal anesthesia: local anesthetic maldistribution with pencil point needles?

PubMed

Beardsley, D; Holman, S; Gantt, R; Robinson, R A; Lindsey, J; Bazaral, M; Stewart, S F; Stevens, R A

1995-08-01

Recent reports of transient neurologic deficits have raised concern about the potential toxicity of single-dose spinal 5% lidocaine in 7.5% dextrose. Two cases of volunteers who experienced minor local sensory deficits after slow (60 s) injections of 2 mL 5% lidocaine via Whitacre needles are described. One case was a result of a double injection because of a "failed" block. It seemed possible that the neurologic deficit in these cases resulted from neurotoxicity associated with maldistribution of local anesthetic. Using an in vitro spinal model, we investigated drug distribution resulting from injections through side-port spinal needles to determine whether the use of these needles could result in high local concentrations of hyperbaric solutions. A spinal canal model was fabricated using human magnetic resonance measurements. The model was placed in a surgical supine position and filled with lactated Ringer's solution to simulate the specific gravity of cerebral spinal fluid at 22 degrees C. A hyperbaric solution of phthalocyanine blue dye and dextrose (SG 1.042), simulating the anesthetic, was injected through three different needles (27-gauge 4 11/16-in. Whitacre, 25-gauge 3 1/2-in. Whitacre, 25-gauge 3 1/2-in. Quincke). Triplicate injections were done at rapid (2 mL/10 s) and slow (2 mL/60 s) rates, with needle side ports oriented in a sacral and cephalad direction. At slow rates of injection, using 27- or 25-gauge sacrally directed Whitacre needles, injections showed evidence of maldistribution with extrapolated peak sacral lidocaine concentrations reaching 2.0%. In contrast, distribution after slow injection through sacrally directed Quincke needles was uniform.(ABSTRACT TRUNCATED AT 250 WORDS)

Sacroplasty procedural extravasation with high viscosity bone cement: comparing the intraoperative long-axis versus short-axis techniques in osteoporotic cadavers.

PubMed

Miller, Jeffrey W; Diani, Art; Docsa, Steve; Ashton, Kristi; Sciamanna, Michele

2017-09-01

Percutaneous sacroplasty involves image-guided injection of bone cement for sacral insufficiency fractures to alleviate pain and facilitate mobility. Correct sacral placement of the cement and the risk of cement extravasation present procedural challenges. This study compares the occurrence, number, location, and surface area of high viscosity radiopaque bone cement extravasation via biplane fluoroscopy with Dyna CT between the fluoroscopically-guided intraoperative long-axis and short-axis sacroplasty techniques in osteoporotic cadavers. Ten osteoporotic cadavers underwent bilateral percutaneous instillation of VertaPlex HV High Viscosity Radiopaque Bone Cement. Long- and short-axis sacroplasty techniques were randomly assigned to zone 1 of the left or right sacral ala of each cadaver. Cement extravasation data were summarized by technique (long-axis vs short-axis) and time period (15-min and 3-hour post-procedure syngo DynaCT scan) in the form of point and CI estimates for the true proportions of cement extravasation. No procedural sacral extravasation differences were observed between the long-axis and short-axis sacroplasty techniques. There were no occurrences of intra-procedural or post-procedural cement extravasation at 15 min or 3 hours in association with either the long-axis sacroplasty technique or the short-axis sacroplasty technique. The long- and short-axis sacroplasty techniques, using high viscosity cement with careful post-procedural positioning, result in no occurrence of cement extravasation in porous osteoporotic cadaver bone. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Experimental results on mechanisms of action of electrical neuromodulation in chronic urinary retention.

PubMed

Schultz-Lampel, D; Jiang, C; Lindström, S; Thüroff, J W

1998-01-01

Sacral foramen neuromodulation--initially applied for the treatment of urinary incontinence--has proved to be effective in patients with chronic urinary retention. Thus far, the underlying neurophysiological mechanisms have not been elucidated. In an experimental study on the neurophysiological basis of sacral neurostimulation, one objective was to investigate the mechanisms responsible for initiation of micturition in chronic urinary retention. In ten female cats anesthetized with alpha-chloralose the clinical situation of sacral foramen stimulation was experimentally reproduced by isolated S2 nerve stimulation after L6-S3 laminectomy. Stimulation responses were recorded from the bladder, peripheral nerves, and striated muscles of the foot and pelvic floor. The effect of sudden cessation of prolonged S2 stimulation, during which the bladder was completely inhibited, was evaluated in 70 stimulation sequences in 5 cats. Sacral nerve stimulation induced excitatory and inhibitory effects on the bladder, depending on the frequency and intensity of stimulation. With unilateral S2 stimulation, bladder excitation was best at frequencies of 2-5 Hz and at intensities ranging between 0.8 and 1.4 times the threshold for the M-response of the foot muscle. Inhibition was the dominating effect at frequencies of 7-10 Hz and at intensities exceeding 1.4 times the threshold. Prolonged S2 stimulation above the threshold produced complete bladder inhibition during stimulation but induced strong bladder contractions after sudden interruption of stimulation, with amplitudes being significantly higher than that of spontaneous contractions preceding the stimulation. These results confirm the hypothesis of a "rebound" phenomenon as the mechanism of action for induction of spontaneous voiding in patients with chronic urinary retention.

Reinnervation of Urethral and Anal Sphincters With Femoral Motor Nerve to Pudendal Nerve Transfer

PubMed Central

Ruggieri, Michael R.; Braverman, Alan S.; Bernal, Raymond M.; Lamarre, Neil S.; Brown, Justin M.; Barbe, Mary F.

2012-01-01

Aims Lower motor neuron damage to sacral roots or nerves can result in incontinence and a flaccid urinary bladder. We showed bladder reinnervation after transfer of coccygeal to sacral ventral roots, and genitofemoral nerves (L1, 2 origin) to pelvic nerves. This study assesses the feasibility of urethral and anal sphincter reinnervation using transfer of motor branches of the femoral nerve (L2–4 origin) to pudendal nerves (S1, 2 origin) that innervate the urethral and anal sphincters in a canine model. Methods Sacral ventral roots were selected by their ability to stimulate bladder, urethral sphincter, and anal sphincter contraction and transected. Bilaterally, branches of the femoral nerve, specifically, nervus saphenous pars muscularis [Evans HE. Miller’s anatomy of the dog. Philadelphia: W.B. Saunders; 1993], were transferred and end-to-end anastomosed to transected pudendal nerve branches in the perineum, then enclosed in unipolar nerve cuff electrodes with leads to implanted RF micro-stimulators. Results Nerve stimulation induced increased anal and urethral sphincter pressures in five of six transferred nerves. Retrograde neurotracing from the bladder, urethral sphincter, and anal sphincter using fluorogold, fast blue, and fluororuby, demonstrated urethral and anal sphincter labeled neurons in L2–4 cord segments (but not S1–3) in nerve transfer canines, consistent with rein-nervation by the transferred femoral nerve motor branches. Controls had labeled neurons only in S1–3 segments. Postmortem DiI and DiO labeling confirmed axonal regrowth across the nerve repair site. Conclusions These results show spinal cord reinnervation of urethral and anal sphincter targets after sacral ventral root transection and femoral nerve transfer (NT) to the denervated pudendal nerve. These surgical procedures may allow patients to regain continence. PMID:21953679

Magnetic resonance imaging of the sacral plexus and piriformis muscles.

PubMed

Russell, J Matthew; Kransdorf, Mark J; Bancroft, Laura W; Peterson, Jeffrey J; Berquist, Thomas H; Bridges, Mellena D

2008-08-01

The objective was to evaluate the piriformis muscles and their relationship to the sacral nerve roots on T1-weighted MRI in patients with no history or clinical suspicion of piriformis syndrome. Axial oblique and sagittal T1-weighted images of the sacrum were obtained in 100 sequential patients (200 pairs of sacral roots) undergoing routine MRI examinations. The relationship of the sacral nerve roots to the piriformis muscles and piriformis muscle size were evaluated, as were clinical symptoms via a questionnaire. The S1 nerve roots were located above the piriformis muscle in 99.5% of cases (n=199). The S2 nerve roots were located above the piriformis muscle in 25% of cases (n=50), and traversed the muscle in 75% (n=150). The S3 nerve roots were located above the piriformis muscle in 0.5% of cases (n=1), below the muscle in 2.5% (n=5), and traversed the muscle in 97% (n=194). The S4 nerve roots were located below the muscle in 95% (n=190). The piriformis muscles ranged in size from 0.8-3.2 cm, with an average size of 1.9 cm. Nineteen percent of patients had greater than 3 mm of asymmetry in the size of the piriformis muscle, with a maximum asymmetry of 8 mm noted. The S1 nerve roots course above the piriformis muscle in more than 99% of patients. The S2 roots traverse the piriformis muscle in 75% of patients. The S3 nerve roots traverse the piriformis muscle in 97% of patients. Piriformis muscle size asymmetry is common, with muscle asymmetry of up to 8 mm identified.

Screw Loosening and Pelvic Canal Narrowing After Lateral Plating of Feline Ilial Fractures With Locking and Nonlocking Plates.

PubMed

Schmierer, Philipp A; Kircher, Patrick R; Hartnack, Sonja; Knell, Sebastian C

2015-10-01

To compare the frequency of complications, including screw loosening and pelvic canal narrowing, associated with dynamic compression plating, locking plating, and double locking plating of ilial fractures in cats. Historical cohort study. The radiographs and medical records of cats with pelvic fractures that were presented between 2004 and 2013 were reviewed. The cases were categorized based on the plate type and number as dynamic compression plate (DCP), single locking plate (LPS) and double locking plates (dLPS). The frequency of screw loosening was compared across categories using a Fisher's exact test. The change in pelvic alignment, described by the change in sacral index (postoperative sacral index-followup sacral index), was compared across plate categories using ANOVA. The frequency of screw loosening for DCP (5/10) was significantly higher than LPS (1/13) and dLPS (0/11) (P = .05, P = .012, respectively). There was no significant difference in the SI change across plate categories. The mean change in sacral index for DCP was -0.11 (95%CI -0.25 to 0.03), for LPS was 0.0007 (95%CI -0.07 to 0.08), and for dLPS was -0.01 (95%CI -0.04 to 0.02). None of the cats showed constipation postoperatively. Screw loosening occurred less often but the change in pelvic canal alignment was not significantly different in ilial fractures repaired with LPS or dLPS compared to ilial fractures repaired with DCP. Locking plating of ilial fractures in cats may offer advantages compared to nonlocking plating. © Copyright 2015 by The American College of Veterinary Surgeons.

How Did the Pelvis and Vertebral Column Become a Functional Unit during the Transition from Occasional to Permanent Bipedalism?

PubMed

Tardieu, Christine; Hasegawa, Kazuhiro; Haeusler, Martin

2017-05-01

The functional linkage between pelvis and spine remained long hidden to science. Here, we recount the history of research that led in 1992 to the discovery of the "angle of sacral incidence" by the team of G. Duval-Beaupère. This angle, formed between a ray from the hip joint center to the superior sacral surface and the perpendicular to the sacral surface, was later called pelvic incidence. Specific to each individual, pelvic incidence is tightly correlated with the degree of lumbar lordosis. It is each individual's "signature" for an efficient sagittal balance since it represents the sum of two positional parameters, sacral slope and pelvic tilt. The simultaneous experimental determination of the trunk line of gravity permitted Duval-Beaupère's team to elucidate the conditions of an efficient sagittal balance of the trunk on the lower limbs. We present an in vivo EOS study of eight spino-pelvic parameters describing the sagittal balance in 131 adults. We observe a chain of correlations between the six angular parameters and discuss the functional significance of these results. We show that pelvic incidence increases and lumbar lordosis develops when the infant learns to walk, leading to a correlation between these parameters. This process of association between pelvis and spine might have acquired a solid genetic basis during hominid evolution by natural selection acting on both pelvis and spine. We suggest that this process of functional integration was only possible in the context of bipedal locomotion becoming permanent and stereotyped, expressed by a relatively invariant, periodic walking cycle. Anat Rec, 300:912-931, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Sacral chordomas: Impact of high-dose proton/photon-beam radiation therapy combined with or without surgery for primary versus recurrent tumor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Lily; De Laney, Thomas F.; Liebsch, Norbert J.

2006-08-01

Purpose: To assess the efficacy of definitive treatment of sacral chordoma by high-dose proton/photon-beam radiation therapy alone or combined with surgery. Methods and Materials: The records of 16 primary and 11 recurrent sacral chordoma patients treated from November 1982 to November 2002 by proton/photon radiation therapy alone (6 patients) or combined with surgery (21 patients) have been analyzed for local control, survival, and treatment-related morbidity. The outcome analysis is based on follow-up information as of 2005. Results: Outcome results show a large difference in local failure rate between patients treated for primary and recurrent chordomas. Local control results by surgerymore » and radiation were 12/14 vs. 1/7 for primary and recurrent lesions. For margin-positive patients, local control results were 10 of 11 and 0 of 5 in the primary and recurrent groups, respectively; the mean follow-up on these locally controlled patients was 8.8 years (4 at 10.3, 12.8, 17, and 21 years). Radiation alone was used in 6 patients, 4 of whom received {>=}73.0 Gy (E); local control was observed in 3 of these 4 patients for 2.9, 4.9, and 7.6 years. Conclusion: These data indicate a high local control rate for surgical and radiation treatment of primary (12 of 14) as distinct from recurrent (1 of 7) sacral chordomas. Three of 4 chordomas treated by {>=}73.0 Gy (E) of radiation alone had local control; 1 is at 91 months. This indicates that high-dose proton/photon therapy offers an effective treatment option.« less

Extracorporeal Stimulation of Sacral Nerve Roots for Observation of Pelvic Autonomic Nerve Integrity: Description of a Novel Methodological Setup.

PubMed

Moszkowski, Tomasz; Kauff, Daniel W; Wegner, Celine; Ruff, Roman; Somerlik-Fuchs, Karin H; Kruger, Thilo B; Augustyniak, Piotr; Hoffmann, Klaus-Peter; Kneist, Werner

2018-03-01

Neurophysiologic monitoring can improve autonomic nerve sparing during critical phases of rectal cancer surgery. To develop a system for extracorporeal stimulation of sacral nerve roots. Dedicated software controlled a ten-electrode stimulation array by switching between different electrode configurations and current levels. A built-in impedance and current level measurement assessed the effectiveness of current injection. Intra-anal surface electromyography (sEMG) informed on targeting the sacral nerve roots. All tests were performed on five pig specimens. During switching between electrode configurations, the system delivered 100% of the set current (25 mA, 30 Hz, 200 μs cathodic pulses) in 93% of 250 stimulation trains across all specimens. The impedance measured between single stimulation array contacts and corresponding anodes across all electrode configurations and specimens equaled 3.7 ± 2.5 kΩ. The intra-anal sEMG recorded a signal amplitude increase as previously observed in the literature. When the stimulation amplitude was tested in the range from 1 to 21 mA using the interconnected contacts of the stimulation array and the intra-anal anode, the impedance remained below 250 Ω and the system delivered 100% of the set current in all cases. Intra-anal sEMG showed an amplitude increase for current levels exceeding 6 mA. The system delivered stable electric current, which was proved by built-in impedance and current level measurements. Intra-anal sEMG confirmed the ability to target the branches of the autonomous nervous system originating from the sacral nerve roots. Stimulation outside of the operative field during rectal cancer surgery is feasible and may improve the practicality of pelvic intraoperative neuromonitoring.

Complications and troubleshooting of sacral neuromodulation therapy.

PubMed

Hijaz, Adonis; Vasavada, Sandip

2005-02-01

As evident from the authors' series, the complications of sacral neuromodulation have changed with the introduction of the tined lead and the placement of the generator over the back. In the earlier series, most complications were related to pain at the generator site, which was rare in the authors' series. The posterior location of the generator seems to be better tolerated than the anterior location, which could explain the rare need for revisions for pain at the generator site. Lead migration was observed in 8.4% of the original sacral neuromodulation study group series. This was seen rarely in the authors' series in either stage-one or stage-two revisions. As part of the routine work-up of patients who present with decreased function after a successful period response in stage two, the authors obtain a lateral radiograph of the sacrum; the authors have made the diagnosis of lead migration rarely (1/130; 0.6%). Spinelli and colleagues reported on the use of the tined lead in 15 patients, and observed no lead migration during either the screening period (average 38.8 days) or during follow-up of IPG implantation cases (average 11 months). The total infection rate in the whole series was 18/180 (10%), which was slightly higher than that reported by the sacral neuromodulation study group (6.1%). Revision rates for stage one and stage two were 12.2% and 20%, respectively. The revision rate in the original study group was 33.3%. Thus, with advancing technology, new problems may arise, but the implanting physician should be aware of the ways to evaluate and manage these complications and appropriately troubleshoot patients with suboptimal responses.

Sophorolipid-induced dimpling and increased porosity in solvent-cast short-chain polyhydroxyalkanoate films: impact on thermo-mechanical properties

USDA-ARS?s Scientific Manuscript database

Sophorolipids (SL; microbial glycolipids) were used as additives in solvent-cast short-chain polyhydroxyalkanoate (sc-PHA) films to enhance surface roughness and porosity. Poly-3-hydroxybutyrate (PHB), poly-(6%)-3-hydroxybutyrate-co-(94%)-3-hydroxyvalerate (PHB/V), and poly-(90%)-3-hydroxybutyrate-c...

Gage for measuring displacements in rock samples

DOEpatents

Holcomb, D.J.; McNamee, M.J.

1985-07-18

A gage for measuring diametral displacement within a rock sample for use in a rock mechanics laboratory and in the field, comprises a support ring housing a linear variable differential transformer (LVDT), a mounting screw, and a leaf spring. The mounting screw is adjustable and defines a first point of contact with the rock sample. The leaf spring has opposite ends fixed to the inner periphery of the mounting ring. An intermediate portion of the leaf spring projecting radially inward from the ring is formed with a dimple defining a second point of contact with the sample. The first and second points of contact are diametrically opposed to each other. The LVDT is mounted in the ring with its axis parallel to the line of measurement and its core rod received in the dimple of the leaf spring. Any change in the length of the line between the first and second support points is directly communicated to the LVDT. The leaf spring is rigid to completely support lateral forces so that the LVDT is free of all load for improved precision.

Gage for measuring displacements in rock samples

DOEpatents

Holcomb, David J.; McNamee, Michael J.

1986-01-01

A gage for measuring diametral displacement within a rock sample for use in a rock mechanics laboratory and in the field, comprises a support ring housing a linear variable differential transformer, a mounting screw, and a leaf spring. The mounting screw is adjustable and defines a first point of contact with the rock sample. The leaf spring has opposite ends fixed to the inner periphery of the mounting ring. An intermediate portion of the leaf spring projecting radially inward from the ring is formed with a dimple defining a second point of contact with the sample. The first and second points of contact are diametrically opposed to each other. The LVDT is mounted in the ring with its axis parallel to the line of measurement and its core rod received in the dimple of the leaf spring. Any change in the length of the line between the first and second support points is directly communicated to the LVDT. The leaf spring is rigid to completely support lateral forces so that the LVDT is free of all load for improved precision.

Effect of hydrogen on void initiation in tensile test of carbon steel JIS-S25C

NASA Astrophysics Data System (ADS)

Sugawa, S.; Tsutsumi, N.; Oda, K.

2018-06-01

In order to investigate the effect of hydrogen on tensile fracture mechanism of a carbon steel, tensile tests were conducted. Pre-strain specimens (0%, 5% and 10%) were used to study the effect of hydrogen content, since saturated hydrogen content in specimens increases in increasing dislocation density. The tensile strength and the yield stress of hydrogen specimens were almost the same as uncharged. In contrast, the reduction of area of hydrogen charged specimens was smaller than that of uncharged. To reveal the reasons of decrease of the reduction of area, the fracture surface and longitudinal cross section near the fracture surface were observed. On the fracture surface of uncharged specimens, only dimples were observed. On the other hand, dimples and flat fracture surface were observed on the fracture surface of hydrogen charged. On the longitudinal cross section of hydrogen charged specimens, many voids were observed compared to uncharged. From these observations, it is showed that hydrogen gives a rise to the increase of voids and the hydrogen charged specimens break without sufficient necking, thus hydrogen makes the reduction of area smaller.

Influence of laser parameters in surface texturing of Ti6Al4V and AA2024-T3 alloys

NASA Astrophysics Data System (ADS)

Ahuir-Torres, J. I.; Arenas, M. A.; Perrie, W.; de Damborenea, J.

2018-04-01

Laser texturing can be used for surface modification of metallic alloys in order to improve their properties under service conditions. The generation of textures is determined by the relationship between the laser processing parameters and the physicochemical properties of the alloy to be modified. In the present work the basic mechanism of dimple generation is studied in two alloys of technological interest, titanium alloy Ti6Al4V and aluminium alloy AA2024-T3. Laser treatment was performed using a pulsed solid state Nd: Vanadate (Nd: YVO4) laser with a pulse duration of 10 ps, operating at a wavelength of 1064 nm and 5 kHz repetition rate. Dimpled surface geometries were generated through ultrafast laser ablation while varying pulse energy between 1 μJ and 20 μJ/pulse and with pulse numbers from 10 to 200 pulses per spot. In addition, the generation of Laser Induced Periodic Surface Structures (LIPSS) nanostructures in both alloys, as well as the formation of random nanostructures in the impact zones are discussed.

[Semiotics of the Currarino syndrome].

PubMed

Pankevych, T L; Lóniushkin, O I; Sitkovskyĭ, M B; Kaplan, V M; Iurchenko, M I; Cherniienko, Iu L

1993-01-01

The main criteria for diagnosis of the Currarino syndrome have been defined. Roentgenologic investigation of the lumbar-sacral spine in direct projection is indicated to all the patients with anorectal developmental defects, in particular with congenital anorectal stenosis. In detection of a specific defect of the terminal vertebrae, the performance of computed tomography of the pelvic bottom and nuclear magnetic resonance tomography of the lumbar-sacral spine is necessary. This permits to assess the nature of a presacral tumour and degree of dysplasia of the external and sphincter. Timely diagnosis of the Currarino syndrome in children with the anorectal developmental defects permits to avoid severe septic and functional complications in surgical intervention.

[Primary genital herpes with sacral meningoradiculitis].

PubMed

Carron, P-N; Anguenot, J-L; Dubuisson, J-B

2004-02-01

Herpetic genital infection is a common sexually transmitted disease, caused in most cases by type 2 Herpes simplex virus (HSV2). This virus is characterized by its neurotropic properties and its ability to establish latency in sacral sensory ganglions. Some cases of genital primo-infection are complicated by viral replication dissemination to neigbhoring nerve structures like meninges and radicular terminations. In such cases muco-cutaneous manifestations are associated with peripheral neurological impairment in the form of meningo-radiculitis. Physicians should be familiar with these neurological symptoms knowing that they always regress completely. The present report illustrates these complications and reviews the potential neurological implications described in the literature.

Sacral herpes-zoster infection presenting as sciatic pain.

PubMed

Ablin, J; Symon, Z; Mevorach, D

1996-06-01

Acute herpes-zoster infection is a painful dermatomal lesion that can be manifested by a wide array of neurologic symptoms. We present a 55-year-old female with non-Hodgkin's lymphoma, who developed a left sciatic pain involving the S roots. Two weeks later, the patient developed fever and vesicular rash over the left gluteal area. Herpes-zoster infection was diagnosed and confirmed by the presence of immunoglobulin M (IgM) antibodies against varicella-zoster. The pain and rash resolved, after treatment with acyclovir. In the appropriate clinical setting, sacral herpes-zoster infection ought to be considered in the differential diagnosis of new-onset sciatic pain.

Electrophysiological Basis of Fecal Incontinence and Its Implications for Treatment

PubMed Central

2017-01-01

The majority of patients with neuropathic incontinence and other pelvic floor conditions associated with straining at stool have damage to the pudendal nerves distal to the ischial spine. Sacral nerve stimulation appears to be a promising innovation and has been widely adopted and currently considered the standard of care for adults with moderate to severe fecal incontinence and following failed sphincter repair. From a decision-to-treat perspective, the short-term efficacy is good (70%–80%), but the long-term efficacy of sacral nerve stimulation is around 50%. Newer electrophysiological tests and improved anal endosonography would more effectively guide clinical decision making. PMID:29159162

Neoadjuvant denosumab for the treatment of a sacral osteoblastoma.

PubMed

Reynolds, Jeremy J; Rothenfluh, Dominique A; Athanasou, Nick; Wilson, Shaun; Kieser, David C

2018-01-22

To present a case of aggressive sacral osteoblastoma (OB) treated with neoadjuvant denosumab therapy and en bloc resection. Case report of a 14-year-old male with an aggressive OB affecting the superior articular process of the left first sacral segment. The lesion was lytic and metabolically active and involved the left-sided posterior elements of S1-S3 with extension into the spinal canal, affecting the left S1, S2, S3, S4 and S5 nerve roots. He was treated for 1 month with neoadjuvant denosumab followed by en bloc resection. Denosumab therapy caused regression of the tumour and converted the diffuse infiltrative mass into a well-defined solid (osteoma-like) structure, aiding surgical resection and preserving the S1, S4 and S5 nerve roots. Histologically, the treated lesion showed abundant sclerotic woven bone and osteoblasts with absence of osteoclasts. A short course of denosumab caused tumour regression, ossification and conversion of an aggressive OB into a sclerotic, well-defined lesion thus aiding surgical resection and preservation of neural structures. Neoadjuvant therapy reduced osteoclast numbers but PET showed that the lesion remained FDG avid post-therapy.

Distribution of herpes simplex virus types 1 and 2 genomes in human spinal ganglia studied by PCR and in situ hybridization.

PubMed

Obara, Y; Furuta, Y; Takasu, T; Suzuki, S; Suzuki, H; Matsukawa, S; Fujioka, Y; Takahashi, H; Kurata, T; Nagashima, K

1997-06-01

Clinical data indicate that the recurring herpes simplex virus (HSV) from oro-labial lesions is HSV subtype 1 and that the virus from genital lesions is HSV-2. This suggests that HSV-1 and HSV-2 reside in latent forms in the trigeminal ganglia and sacral ganglia, respectively. However, the distribution of latent HSV-1 and HSV-2 infections in human spinal ganglia has not been fully examined. This report concerns the application of polymerase chain reaction (PCR) and in situ hybridization (ISH) to such a study. By using PCR and employing the respective primers, HSV-1 and HSV-2 DNAs were detected in 207 of 524 samples from 262 spinal ganglia (from the cervical to the sacral ganglia) examined on both sides. The percentages of HSV-1 and HSV-2 detected in a given set of ganglia were similar, indicating an absence of site preference. By ISH, few but positive hybridization signals were detected evenly in sacral ganglia sections. The data suggest that regional specificity of recurrent HSV infections is not due to regional distribution of latent virus, but that local host factors may be important for recurrences.

Giant cell tumor of the spine.

PubMed

Ozaki, Toshifumi; Liljenqvist, Ulf; Halm, Henry; Hillmann, Axel; Gosheger, Georg; Winkelmann, Winfried

2002-08-01

Six patients with giant cell tumor of the spine had surgery between 1981 and 1995. Three lesions were located in the scrum, two lesions were in the thoracic spine, and one lesion was in the lumbar spine. Preoperatively, all patients had local pain and neurologic symptoms. Two patients had cement implanted after curettage or intralesional excision of the sacral tumor; one patient had a local relapse. After the second curettage and cement implantation, the tumor was controlled. One patient with a sacral lesion had marginal excision and spondylodesis; no relapse developed. Two patients with thoracic lesions had planned marginal excision and spondylodesis; the margins finally became intralesional, but no relapse developed. One patient with a lumbar lesion had incomplete removal of the tumor and received postoperative irradiation. At the final followup (median, 69 months), five of six patients were disease-free and one patient died of disease progression. Two of the five surviving patients had pain after standing or neurologic problems. Although some contamination occurred, planning a marginal excision of the lesion seems beneficial for vertebral lesions above the sacrum. Total sacrectomy of a sacral lesion seems to be too invasive when cement implantation can control the lesion.

En bloc sacrectomy and reconstruction: technique modification for pelvic fixation.

PubMed

Newman, C Benjamin; Keshavarzi, Sassan; Aryan, Henry E

2009-12-01

When the management of sacral tumors requires partial or complete sacrectomy, the spinopelvic apparatus must be reconstructed. This is a challenging and infrequently performed operation, and as such, many spine surgeons are unfamiliar with techniques available to carry out these procedures. A 34-year-old man presented with severe low back pain, mild left ankle dorsiflexion weakness, and left S1 paresthesias. Imaging revealed a large sacral mass extending into the L5/S1 and S1/S2 neural foramina as well as the presacral visceral and vascular structures. Needle biopsy of this mass demonstrated a low-grade chondrosarcoma. A 2-stage anterior/posterior en bloc sacrectomy with a novel modification of the Galveston L-rod pelvic ring reconstruction was carried out. Our modification takes advantage of new materials and implant technology to offer another alternative in reconstruction of the spinopelvic junction. Understanding the anatomy and biomechanics of the spinopelvic apparatus and the lumbosacral junction, as well as having a familiarity with the various techniques available for carrying out sacrectomy and pelvic ring reconstruction, will enable the spine surgeon to effectively manage sacral tumors. Copyright 2009 Elsevier Inc. All rights reserved.

Feasibility of Using Ultrasonography to Establish Relationships Among Sacral Base Position, Sacral Sulcus Depth, Body Mass Index, and Sex.

PubMed

Lockwood, Michael D; Kondrashova, Tatyana; Johnson, Jane C

2015-11-01

Identifying relationships among anatomical structures is key in diagnosing somatic dysfunction. Ultrasonography can be used to visualize anatomical structures, identify sacroiliac landmarks, and validate anatomical findings and measurements in relation to somatic dysfunction. As part of the osteopathic manipulative medicine course at A.T. Still University-Kirksville College of Osteopathic Medicine, first-year students are trained to use ultrasonography to establish relationships among musculoskeletal structures. To determine the ability of first-year osteopathic medical students to establish sacral base position (SBP) and sacral sulcus depth (SSD) using ultrasonography and to identify the relationship of SBP and SSD to body mass index (BMI) and sex. Students used ultrasonography to obtain the distance between the skin and the sacral base (the SBP) and the distance between the skin and the tip of the posterior superior iliac spine bilaterally. Next, students calculated the SSD (the distance between the tip of the posterior superior iliac spine and the SBP). Data were analyzed with respect to side of the body, BMI, sex, and age. The BMI data were subdivided into normal (18-25 mg/kg) and overweight (25-30 mg/kg) groups. Ultrasound images of 211 students were included in the study. The SBP was not significantly different between the left and right sides (36.5 mm vs 36.5 mm; P=.95) but was significantly different between normal and overweight BMI categories (33.0 mm vs 40.0 mm; P<.001) and between men and women (34.1 mm vs 39.0 mm; P<.001). The SSD was not significantly different between left and right sides (18.9 mm vs 19.8 mm; P=.08), normal and overweight BMI categories (18.9 mm vs 19.7 mm, P=.21), or men and women (19.7 mm vs 19.0 mm; P=.24). No significant relationship was identified between age and SBP (P=.46) or SSD (P=.39); however, the age range was narrow (21-33 years). The study yielded repeatable and reproducible results when establishing SBP and SSD using ultrasonography. The statistically significant relationship between SBP and higher BMI and between SBP and female sex may point to more soft tissue overlaying the sacrum in these groups. Further research is needed on the use of ultrasonography to establish criteria for somatic dysfunction.

The Thoracic Lordosis Correction Improves Sacral Slope and Walking Ability in Neuromuscular Scoliosis.

PubMed

Kim, Do Yeon; Moon, Eun Su; Park, Jin Oh; Chong, Hyon Su; Lee, Hwan Mo; Moon, Seong Hwan; Kim, Sung Hoon; Kim, Hak Sun

2016-10-01

Retrospective study. To report on neuromuscular patients with preserved walking ability, but forward bending of the body due to thoracic lordosis, and to suggest thoracic lordosis correction as the surgical treatment. It is an established fact that lumbar lordosis or pelvic parameter is directly related to thoracic sagittal balance. However, the reverse relationship has not been fully defined yet. Loss of thoracic kyphosis results in positive sagittal balance, which causes walking difficulty. Neuromuscular patients with thoracic lordosis have not been reported yet, and there have been no reports on their surgical treatments. This study analyzed 8 patients treated with thoracic lordosis correction surgery. Every patient was diagnosed with muscular dystrophy. In thoracic lordosis correction surgery, anterior release was performed in the first stage and posterior segmental instrumentation was performed in the second stage. Radiographic parameters were compared and walking ability was evaluated with gait analysis. All patients were classified according to the modified Rancho Los Amigos Hospital system preoperatively and 2 years postoperatively to evaluate functional ability. The average follow-up period was 2.9 years. Before surgery, the mean thoracic sagittal alignment was -2.1-degree lordosis, the mean Cobb angle and sacral slope increased to 36.3 and 56.6 degrees, respectively. The anterior pelvic tilt in gait analysis was 29.3 degrees. At last follow-up after surgery, the mean thoracic sagittal alignment changed to 12.6-degree kyphosis, and the Cobb angle and sacral slope decreased to 18.9 and 39.5 degrees, respectively. Lumbar lordosis and the sacral slope showed significant positive correlation (P<0.001). The improvement in thoracic lordosis showed a significant correlation to the preoperative flexibility of the major curve (P=0.028). The anterior pelvic tilt in gait analysis improved to 15.4 degrees. The functional ability improved in 2 (50%) of 4 patients in class 2 and maintained in remaining 6 patients 2 years after surgery. Thoracic lordosis correction surgery in neuromuscular scoliosis patients with thoracic lordosis improved the sacral slope in the standing position and the anterior pelvic tilt in gait. Sagittal imbalance was compensated by the spinopelvic mechanism, and back and hip extensor muscles seem to play a major role in this compensation.

Host-Selected Amino Acid Changes at the Sialic Acid Binding Pocket of the Parvovirus Capsid Modulate Cell Binding Affinity and Determine Virulence

PubMed Central

López-Bueno, Alberto; Rubio, Mari-Paz; Bryant, Nathan; McKenna, Robert; Agbandje-McKenna, Mavis; Almendral, José M.

2006-01-01

The role of receptor recognition in the emergence of virulent viruses was investigated in the infection of severe combined immunodeficient (SCID) mice by the apathogenic prototype strain of the parvovirus minute virus of mice (MVMp). Genetic analysis of isolated MVMp viral clones (n = 48) emerging in mice, including lethal variants, showed only one of three single changes (V325M, I362S, or K368R) in the common sequence of the two capsid proteins. As was found for the parental isolates, the constructed recombinant viruses harboring the I362S or the K368R single substitutions in the capsid sequence, or mutations at both sites, showed a large-plaque phenotype and lower avidity than the wild type for cells in the cytotoxic interaction with two permissive fibroblast cell lines in vitro and caused a lethal disease in SCID mice when inoculated by the natural oronasal route. Significantly, the productive adsorption of MVMp variants carrying any of the three mutations selected through parallel evolution in mice showed higher sensitivity to the treatment of cells by neuraminidase than that of the wild type, indicating a lower affinity of the viral particle for the sialic acid component of the receptor. Consistent with this, the X-ray crystal structure of the MVMp capsids soaked with sialic acid (N-acetyl neuraminic acid) showed the sugar allocated in the depression at the twofold axis of symmetry (termed the dimple), immediately adjacent to residues I362 and K368, which are located on the wall of the dimple, and approximately 22 Å away from V325 in a threefold-related monomer. This is the first reported crystal structure identifying an infectious receptor attachment site on a parvovirus capsid. We conclude that the affinity of the interactions of sialic-acid-containing receptors with residues at or surrounding the dimple can evolutionarily regulate parvovirus pathogenicity and adaptation to new hosts. PMID:16415031

Utopic ideas of cure and joint exploration in psychoanalytic supervision.

PubMed

Werbart, Andrzej

2007-12-01

The idea of the decisive and complete cure is deeply rooted in our unconscious and in the sacral roots of symbolic healing. Double sets of private theories of cure can frequently be found among patients in psychoanalysis and their analysts. The utopian cure involves a profound transformation of the personality by way of deep regression. The idea of an attainable and more limited cure includes new ways of managing old problems. The actual ongoing treatment is then seen as the 'next-best solution'. The utopian fantasy of creating 'the new person' by means of 'proper' psychoanalysis or analytic training has far-reaching consequences for psychoanalytic education and supervision. Our awareness of the inevitable temptation in the 'utopian state of mind' can help us to trace and focus on utopic elements in the supervisory process. Exploration of utopic ideas of all the three parties involved can itself be a fruitful and stimulating way of working in supervision. An important aim of psychoanalytic supervision is to promote a distinct state of mind that can counterbalance utopic ideas and counteract the phenomenon of a 'false analytic self'.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sabel, C.S.; Bell, G.A.; Wildish, G.M. comps.

A bibliography is presented consisting of 175 references to books, journal articles, reports, and patent literature concerning the Harwell reactors: BEPO, DIDO, DIMPLE, GLEEP, HAZEL, LIDO, NEPTUNE, PLUTO, Z EPHYR, ZETR-I, ZETR-II, and ZEUS. The main characteristics of the reactors are tabulated for: startup date, peak neutron flux, maximum heat output moderator, coolant, fuel, and purpose. An author complex is included. (B.O.G.)

Failure Analysis Handbook

DTIC Science & Technology

1989-08-18

conditions, strain rate , geometry, manufacturing variables, microstructure, surface conditions, and alloy contamination. Exzvples of service failures are...depends on the ductility of the material, strain rate and stress concentration. The macrosocpic appearances of two ductile overstress fractures are shown...distribution of nucleation sites, stress orientation, temperature, ductility and strain rate . The size of the dimples is oontrolled by the size, number ard

Retention of urine in anogenital herpetic infection.

PubMed

Oates, J K; Greenhouse, P R

1978-04-01

In 17 patients, 15 women and 2 men, acute retention of urine developed in association with an attack of anogenital herpes. Constipation, blunting of sensation over the 2nd and 3rd sacral dermatomes, and neuralgic pains in the same area (with absence of the bulbocavernosus reflex in some individuals) suggested localised lumbosacral meningomyelitis with involvement of mainly sacral-nerve roots. The urinary dysfunction persisted on average for ten days and in 4 patients was severe enough to warrant catheterisation. Anogenital herpes should always be considered as a possible cause of acute retention of urine in sexually active young people and the possibility of occult herpetic infection of the cervix and rectum should be investigated.

Sacral nerve stimulation for neuromodulation of the lower urinary tract.

PubMed

Hubsher, Chad P; Jansen, Robert; Riggs, Dale R; Jackson, Barbara J; Zaslau, Stanley

2012-10-01

Sacral neuromodulation (SNM) has become a standard treatment option for patients suffering from urinary urge incontinence, urgency-frequency, and/or nonobstructive urinary retention refractory to conservative and pharmacologic treatment. Since its initial development, the manufacturer of InterStim therapy (Medtronic, Inc., Minneapolis, MN, USA), has introduced technical modifications, while surgeons and researchers have adapted and published various innovations and alterations of the implantation technique. In this article, we feature our SNM technique including patient selection, comprehensive dialogue/evaluation, procedure details, and appropriate follow up. Although there is often great variability in patients with lower urinary tract dysfunction, we maintain that great success can be achieved with a systematic and methodical approach to SNM.

Morphometric study of the true S1 and S2 of the normal and dysmorphic sacralized sacra.

PubMed

Firat, Ayşegül; Alemdaroğlu, Kadir Bahadır; Özmeriç, Ahmet; Yücens, Mehmet; Göksülük, Dinçer

2017-06-12

This study aimed to generate data for the S1 and S2 alar pedicle and body and the alar orientations for both dysmorphic and normal sacra. The study comprised two groups: Group N consisted of 53 normal sacra and Group D included 10 dysmorphic sacra. Various features such as alar pedicle circumference; anterior, middle, and posterior axis of the sacral ala; sacral body height and width; and sagittal thickness were measured. In group N, the median anterior axis of the alae was observed to be 30° on the right and 25° on the left, the median midline axis was found to be 20° on the right and 15° on the left, and the median posterior alar axis was -15° on the right and -20° on the left. The true S1 and S2 alar pedicle circumferences were observed to be significantly smaller in group D, which demonstrated a shorter S1 alar pedicle mean circumference, significantly narrower S1 body mean width, and considerably tapered sagittal thickness. Our analysis indicated that dysmorphic sacra have a lower sagittal thickness and width of bodies and smaller alar pedicles, which explains the difficulties in their percutaneous fixation.

Neuromodulation by implant for treating lower urinary tract symptoms and dysfunction.

PubMed

Bemelmans, B L; Mundy, A R; Craggs, M D

1999-08-01

Patients with irritative micturition complaints, pelvic pain, involuntary urine loss or urinary retention are sometimes difficult to treat. The advent of direct sacral nerve stimulation offers a therapeutic alternative if conservative measures fail and surgery is considered. This paper reviews therapeutic neuromodulation by implant for treating lower urinary tract symptoms and dysfunction. The international literature is reviewed on topics such as the physiological basis of neuromodulation, techniques of acute testing and chronic implantation, and clinical results. Future developments and ways for possible improvement are discussed. The mode of action of neuromodulation is probably through restoring the correct balance between excitatory and inhibitory impulses from and to the pelvic organs at a sacral and supra-sacral level. Depending on the predefined success criteria, average success rates of definitive implants vary from 50 to 70%. From the data it seems that patients with urge incontinence and urinary retention are the best candidates for neuromodulation. In the literature the lack of standardisation of selection criteria, stimulation parameters and definitions of success is striking. Neuromodulation by implant is a useful therapeutic alternative. It should at least be considered in patients with therapy-resistant urge incontinence and urinary retention before proceeding to surgery. Issues such as underlying physiology, methodological standardisation, technical improvements, and patient selection must be addressed in future research.

Effects of acute urinary bladder overdistension on bladder response during sacral neurostimulation.

PubMed

Bross, S; Schumacher, S; Scheepe, J R; Zendler, S; Braun, P M; Alken, P; Jünemann, K

1999-10-01

Urinary retention and micturition disorders after overdistension are clinically well-known complications of subvesical obstruction. We attempted to evaluate whether bladder overdistension influences bladder response and whether overdistension supports detrusor decompensation. Following lumbal laminectomy in 9 male foxhounds, the sacral anterior roots S2 and S3 were placed into a modified Brindley electrode for reproducible and controlled detrusor activation. The bladder was filled in stages of 50 ml from 0 to 700 ml, corresponding to an overdistension. At each volume, the bladder response during sacral anterior root stimulation was registered. After overdistension, the bladder was refilled stepwise from 0 to 300 ml and stimulated. In all dogs, the bladder response was influenced by the intravesical volume. The maximum pressure (mean 69.1 cm H(2)O) was observed at mean volume of 100 ml. During overdistension, a significant reduction in bladder response of more than 80% was seen. After overdistension, a significant reduction in intravesical pressure of 19.0% was observed. In 2 cases, reduction in bladder response was more than 50% after a single overdistension. We conclude that motoric bladder function is influenced during and after overdistension. A single bladder overdistension can support acute and long-lasting detrusor decompensation. In order to protect motoric bladder function, bladder overdistension must be prevented.

Feasibility of controlled micturition through electric stimulation.

PubMed

Schmidt, R A; Tanagho, E A

1979-01-01

Historically, man has been aware of bioelectric phenomena for some 4,000 years. Yet it has only been during the last 20 years that technology has advanced to the stage where controlled bladder emptying has become feasible. A great deal of interest followed the introduction of transistor and bladder stimulation via the principle of radio frequency induction. Spinal cord, sacral, and pelvic nerve and direct bladder stimulation have all been attempted. Only direct bladder stimulation in lower motor neuron situations has shown any promise. The many difficulties associated with bladder stimulation include simultaneous sphincter contraction, pain, electrode and insulation difficulties, and fibroplasia due to movement of electrodes placed in pliable tissues. In addition, the role of the prostate, increased urethral length, and erection responses in the male have received little investigation. These problems are outlined and experimental observations of attempts to achieve controlled micturition in canines areresented. These studies were carried out over a 3-year period, and emphasize responses to stimulation of the spinal cord and sacral roots. It was concluded that the most efficient manner by which to effect simulated micturition is via stimulation of the ventral sacral root dominant for bladder responsiveness, and combine this with selective division of somatic fibers of only the root being stimulated.

Lumbosacral pain in ballet school students. Pilot study.

PubMed

Drężewska, Marlena; Śliwiński, Zbigniew

2013-01-01

The unique biomechanical demands placed on ballet students predispose to injury and pain. The aim of this study was to evaluate the prevalence of lumbosacral pain in ballet school students and to identify possible risk factors for the pain. The study group comprised 71 ballet school students, including 45 females and 26 males, aged 15-18 years (mean 16.5 years). In order to identify possible risk factors for pain, a survey was conducted, the angle of sacral bone inclination was measured using a mechanical inclinometer and the BMI was calculated. A VAS scale was used for a subjective assessment of pain intensity. Low back pain was reported by 44 patients (62%). A comparison of sacral inclination angles in a position with the feet placed parallel and in the turnout position showed statistically significant changes in the angle among respondents reporting pain (p <0.05). 1. Compensation in the turnout position by increas ed anterior tilt of the pelvis may increase the risk of low back pain. 2. An angle of sacral bone inclination in turnout above or equal to 30° can increase the intensity of low back pain. 3. A BMI below 18.5 in female ballet school stu dents can increase the risk of lumbosacral pain.

Failure of Urological Implants in Spinal Cord Injury Patients due to Infection, Malfunction, and Implants Becoming Obsolete due to Medical Progress and Age-Related Changes in Human Body Making Implant Futile: Report of Three Cases.

PubMed

Vaidyanathan, Subramanian; Soni, Bakul; Singh, Gurpreet; Hughes, Peter; Selmi, Fahed; Mansour, Paul

2013-01-01

Any new clinical data, whether positive or negative, generated about a medical device should be published because health professionals should know which devices do not work, as well as those which do. We report three spinal cord injury patients in whom urological implants failed to work. In the first, paraplegic, patient, a sacral anterior root stimulator failed to produce erection, and a drug delivery system for intracavernosal administration of vasoactive drugs was therefore implanted; however, this implant never functioned (and, furthermore, such penile drug delivery systems to produce erection had effectively become obsolete following the advent of phosphodiesterase type 5 inhibitors). Subsequently, the sacral anterior root stimulator developed a malfunction and the patient therefore learned to perform self-catheterisation. In the second patient, also paraplegic, an artificial urinary sphincter was implanted but the patient developed a postoperative sacral pressure sore. Eight months later, a suprapubic cystostomy was performed as urethral catheterisation was very difficult. The pressure sore had not healed completely even after five years. In the third case, a sacral anterior root stimulator was implanted in a tetraplegic patient in whom, after five years, a penile sheath could not be fitted because of penile retraction. This patient was therefore established on urethral catheter drainage. Later, infection with Staphylococcus aureus around the receiver block necessitated its removal. In conclusion, spinal cord injury patients are at risk of developing pressure sores, wound infections, malfunction of implants, and the inability to use implants because of age-related changes, as well as running the risk of their implants becoming obsolete due to advances in medicine. Some surgical procedures such as dorsal rhizotomy are irreversible. Alternative treatments such as intermittent catheterisations may be less damaging than bladder stimulator in the long term.

Contribution of GABAA, Glycine, and Opioid Receptors to Sacral Neuromodulation of Bladder Overactivity in Cats.

PubMed

Jiang, Xuewen; Fuller, Thomas W; Bandari, Jathin; Bansal, Utsav; Zhang, Zhaocun; Shen, Bing; Wang, Jicheng; Roppolo, James R; de Groat, William C; Tai, Changfeng

2016-12-01

In α-chloralose-anesthetized cats, we examined the role of GABA A , glycine, and opioid receptors in sacral neuromodulation-induced inhibition of bladder overactivity elicited by intravesical infusion of 0.5% acetic acid (AA). AA irritation significantly (P < 0.01) reduced bladder capacity to 59.5 ± 4.8% of saline control. S1 or S2 dorsal root stimulation at threshold intensity for inducing reflex twitching of the anal sphincter or toe significantly (P < 0.01) increased bladder capacity to 105.3 ± 9.0% and 134.8 ± 8.9% of saline control, respectively. Picrotoxin, a GABA A receptor antagonist administered i.v., blocked S1 inhibition at 0.3 mg/kg and blocked S2 inhibition at 1.0 mg/kg. Picrotoxin (0.4 mg, i.t.) did not alter the inhibition induced during S1 or S2 stimulation, but unmasked a significant (P < 0.05) poststimulation inhibition that persisted after termination of stimulation. Naloxone, an opioid receptor antagonist (0.3 mg, i.t.), significantly (P < 0.05) reduced prestimulation bladder capacity and removed the poststimulation inhibition. Strychnine, a glycine receptor antagonist (0.03-0.3 mg/kg, i.v.), significantly (P < 0.05) increased prestimulation bladder capacity but did not reduce sacral S1 or S2 inhibition. After strychnine (0.3 mg/kg, i.v.), picrotoxin (0.3 mg/kg, i.v.) further (P < 0.05) increased prestimulation bladder capacity and completely blocked both S1 and S2 inhibition. These results indicate that supraspinal GABA A receptors play an important role in sacral neuromodulation of bladder overactivity, whereas glycine receptors only play a minor role to facilitate the GABA A inhibitory mechanism. The poststimulation inhibition unmasked by blocking spinal GABA A receptors was mediated by an opioid mechanism. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Sacral neuromodulation for lower urinary tract dysfunction and impact on erectile function.

PubMed

Lombardi, Giuseppe; Mondaini, Nicola; Giubilei, Gianluca; Macchiarella, Angelo; Lecconi, Filippo; Del Popolo, Giulio

2008-09-01

The first sacral nerve stimulators were for urinary urgency incontinence, urgency-frequency, and nonobstructive urinary retention. Since then, observations have been made for benefits beyond voiding disorders. To evaluate if sacral neuromodulation (SNM) using the InterStim system (Medtronic Inc., Minneapolis, MN, USA) improves erectile function. From January 1999 to January 2007, 54 males, mean age 42.8, underwent a permanent SNM for lower urinary tract symptoms (LUTS). Pre-SNM only subjects with concomitant erectile impairment according to the five-item version of the International Index of Erectile Function (IIEF-5), with normal blood sexual hormonal status, and responding to an intracavernous injection test 10 microg were enrolled in our study. Three months after permanent implantation, the IIEF-5 was completed again. Those who benefited significantly in erectile function completed the IIEF-5 semiannually. A final checkup was performed in July 2007. A score of IIEF-5 equal to or higher than 25% compared to baseline indicated remarkable clinical enhancement. Presurgery, two patients were excluded. Overall, 22 subjects (42.3%) showed erectile impairment (14 were neurogenic). In the first visit post-SNM, five retentionists of neurogenic origin and two with overactive bladder syndrome of idiopathic origin achieved noticeable erectile improvement. Their median IIEF-5 score shifted from 14.6 to 22.2, and 15.5 to 22.5, respectively. During follow-up, two neurogenics lost the benefits concerning voiding and erection and recovered them after a new implant in the contralateral sacral S3 root. In the final visit, the seven responders reached an IIEF-5 score of at least 22. Our study showed a clinically important benefit of sexual function mainly for neurogenic retentionists. Future research should test SNM in a larger sample of subjects, exclusively with sexual dysfunctions, in order to better understand the mechanism of action of SNM on erectile function.

The effect of early operative stabilization on late displacement of zone I and II sacral fractures.

PubMed

Emohare, Osa; Slinkard, Nathaniel; Lafferty, Paul; Vang, Sandy; Morgan, Robert

2013-02-01

This study was designed to evaluate the effect on displacement of early operative stabilization on unstable fractures when compared to stable fractures of the sacrum. Patient consisted of those sustaining traumatic pelvic fractures that also included sacral fractures of Denis type I and type II classification, who were over 18 at the time of the study. Patients were managed emergently, as judged appropriate at the time and then subsequently divided into two cohorts, comprising those who were either treated operatively or non-operatively. The operative group comprised those treated with either internal fixation or external fixation. Twenty-eight patients had zone II fractures, and 20 had zone I fractures. Zone II fractures showed average displacements of 6.5mm and 6.9mm in the rostral-caudal and anteroposterior directions, respectively, at final follow up. Zone I fractures had average displacements of 6.6mm and 6.1mm in both directions. There were no significant differences between zone I and II sacral fractures (rostral-caudal P=0.74, anteroposterior P=0.24). Average changes in fracture displacement in patients with zone I fractures were 0.6-1.0mm in both directions. Average changes in zone II fractures were 1.8-1.5mm in both directions. There were no significant differences between the average changes in zone I and II fractures in any direction (rostral-caudal P=0.64, anteroposterior P=0.68) or in average displacements at final follow up in any of zone or the entire cohort. Statistically significant differences were noted in average changes in displacement in zone II fractures in the anteroposterior plane (P=0.03) and the overall cohort in the anteroposterior plane (P=0.02). Operative fixation for unstable sacral fractures ensures displacement at follow up is comparable with stable fractures treated non operatively. Copyright © 2012 Elsevier Ltd. All rights reserved.

Role of Anatomical Landmarks in Identifying Normal and Transitional Vertebra in Lumbar Spine Magnetic Resonance Imaging

PubMed Central

Indiran, Venkatraman; Hithaya, Fouzal; Alamelu, M.; Padmanaban, S.

2017-01-01

Study Design Retrospective study. Purpose Identification of transitional vertebra is important in spine imaging, especially in presurgical planning. Pasted images of the whole spine obtained using high-field magnetic resonance imaging (MRI) are helpful in counting vertebrae and identifying transitional vertebrae. Counting vertebrae and identifying transitional vertebrae is challenging in isolated studies of lumbar spine and in studies conducted in low-field MRI. An incorrect evaluation may lead to wrong-level treatment. Here, we identify the location of different anatomical structures that can help in counting and identifying vertebrae. Overview of Literature Many studies have assessed the vertebral segments using various anatomical structures such as costal facets (CF), aortic bifurcation (AB), inferior vena cava confluence (IC), right renal artery (RRA), celiac trunk (CT), superior mesenteric artery root (SR), iliolumbar ligament (ILL) psoas muscle (PM) origin, and conus medullaris. However, none have yielded any consistent results. Methods We studied the locations of the anatomical structures CF, AB, IC, RRA, CT, SR, ILL, and PM in patients who underwent whole spine MRI at our department. Results In our study, 81.4% patients had normal spinal segmentation, 14.7% had sacralization, and 3.8% had lumbarization. Vascular landmarks had variable origin. There were caudal and cranial shifts with respect to lumbarization and sacralization. In 93.8% of cases in the normal group, ILL emerged from either L5 alone or the adjacent disc. In the sacralization group, ILL was commonly seen in L5. In the lumbarization group, ILL emerged from L5 and the adjacent disc (66.6%). CFs were identified at D12 in 96.9% and 91.7% of patients in the normal and lumbarization groups, respectively. The PM origin was observed from D12 or D12–L1 in most patients in the normal and sacralization groups. Conclusions CF, PM, and ILL were good identification markers for D12 and L5, but none were 100% accurate. PMID:28670404

Application of posterior pelvic tilt taping for the treatment of chronic low back pain with sacroiliac joint dysfunction and increased sacral horizontal angle.

PubMed

Lee, Jung-hoon; Yoo, Won-gyu

2012-11-01

Kinesio Taping (KT) is a therapeutic method used by physical therapists and athletic trainers in combination with other treatment techniques for various musculoskeletal and neuromuscular problems. However, no research has evaluated the effect of KT in patients with low back pain (LBP). The purpose of this case was to describe the application of posterior pelvic tilt taping (PPTT) with Kinesio tape as a treatment for chronic LBP and to reduce the anterior pelvic tilt angle. Case report. The patien was a 20-year-old female amateur swimmer with a Cobb's angle (L1-S1) of 68°, a sacral horizontal angle of 45°, and pain in both medial buttock areas and sacroiliac joints. We performed PPTT with Kinesio tape for 2 weeks (six times per week for an average of 9 h each time). The patient’s radiographs showed that the Cobb's angle (L1-S1) had decreased from 68° to 47° and that the sacral horizontal angle had decreased from 45° to 31°. Reductions in hypomobility or motion asymmetry, as assessed by the motion palpation test, and in pain, as measured by the pain-provocation tests, were observed. On palpation for both medial buttock areas in the prone position, the patient felt no pain. The patient experienced no pain or stiffness in the low back area while performing forward flexion in the standing position with knees fully extended when washing dishes in the sink. The case study demonstrated that PPTT intervention favourably affected the pelvic inclination and sacral horizontal angle, leading to beneficial effects on sacroiliac joint dysfunction (SIJD) and medial buttock pain. Additional research on the clinical effects of this taping procedure requires greater numbers of athletes with SIJD or LBP who have inappropriate anterior pelvic tilt angles and hyperlordosis.

Onset of Action of Sacral Neuromodulation in Lower Urinary Tract Dysfunction-What is the Optimal Duration of Test Stimulation?

PubMed

Jairam, Ranjana; Drossaerts, Jamie; Marcelissen, Tom; van Koeveringe, Gommert; van Kerrebroeck, Philip

2018-06-01

Since the development of sacral neuromodulation, a large number of patients with lower urinary tract symptoms have been treated with this procedure. A test stimulation is performed prior to implantation. At centers worldwide the duration of this test stimulation varies considerably since it is not certain when the onset of the therapy effect can be expected. The objective of this prospective study was to evaluate the average onset time of sacral neuromodulation in patients with lower urinary tract symptoms. All patients who were eligible for treatment with sacral neuromodulation were asked to participate in this study. A voiding diary was filled out prior to and during test stimulation using an implanted tined lead. Success was defined as a 50% or greater improvement compared to baseline in any of the main complaint parameters. The Mann-Whitney U test was used to compare the mean time to success between patients with overactive bladder syndrome and patients with nonobstructive urinary retention. Of the 45 patients 24 with nonobstructive urinary retention and 21 with overactive bladder syndrome agreed to participate and were included in study. Test stimulation was successful in 29 patients (64%). Mean time to success in all patients was 3.3 days (range 1 to 9). There was no significant difference in mean time to success between cases of overactive bladder syndrome and nonobstructive urinary retention (3.25 and 3.5 days, respectively, p = 0.76). The results imply that a test stimulation of more than 2 weeks is not necessary if a cutoff of 50% or greater improvement is adopted. However, further improvement can be expected with prolonged test stimulation. This might be important since it might have implications for long-term results. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Electrical stimulation for lower urinary tract dysfunction in children: a systematic review of the literature.

PubMed

Barroso, Ubirajara; Tourinho, Rafael; Lordêlo, Patrícia; Hoebeke, Piet; Chase, Janet

2011-11-01

To review studies using electrical neural stimulation (ENS), to treat children with non-neurogenic lower urinary tract dysfunctions (LUTD), and to establish the efficacy of this treatment. This review was based on an electronic search of the MEDLINE database and the Cochrane Central Search library, from January 1990 to March 2010. (1) participants aged 0-17 years, (2) participants with a diagnosis of LUTD not related to congenital abnormalities or neurological disease, (3) English language, and (4) treatment by ENS. Seventeen papers were evaluated. Type of ENS varied among studies: sacral transcutaneous ENS in seven, sacral implanted device in four, posterior tibial percutaneous in three, and anogenital, endoanal, and intravesical in one each. There were two randomized clinical trials. Clarity regarding the LUTD being treated was variable. The populations studied were not homogeneous. The duration of treatment and the number of sessions a week were variable among the studies. Electrical parameters used also varied. A range of subjective and objective measures was used to measure treatment success. Rates of complete resolution of the symptoms of OAB, urgency, and daytime incontinence ranged from 31% to 86% [Trsinar and Kraij, Neurourol Urodyn 15: 133-42, 1996; Hagstroem et al., J Urol 182: 2072-8, 2009], 25% to 84% [Hoebeke et al., J Urol 168: 2605-8, 2002; Lordêlo et al., J Urol 182: 2900-4, 2009], 13% to 84% [Malm-Buatsi et al., Urology 70: 980-3, 2007; Lordêlo et al., J Urol 184: 683-9, 2010], respectively. For sacral transcutaneous ENS recurrence ranged from 10% to 25%. Apart from the sacral implantation studies, any reported side effects were mild and transitory. The literature in the area of interest is sparse. Parasacral TENS has been shown to be more effective than sham in randomized trials in treating OAB. This deserves further research to elucidate the optimal parameters and the children for whom it is most useful. Copyright © 2011 Wiley Periodicals, Inc.

[Three-dimensional computed tomography analysis and clinical application of sacroiliac screw placement].

PubMed

Yin, Y C; Zhang, R P; Li, S L; Hou, Z Y; Chen, W; Zhang, Y Z

2018-03-01

Objective: To evaluate the possibility of transverse sacroiliac screw placement in different segments of the sacrum. Methods: Data of 80 pelvic CT scans (slice thickness ≤1.0 mm) archived in CT department of the Third Hospital of Hebei Medical University from September 2016 to October 2017 were retrospectively collected. Mimics software was used to rebuild the pelvis three-dimensional model. According to whether the sacral 1(S(1)) segment could place the transverse sacroiliac screws or not, all the sacrums were divided into normal group ( n =55) and dysmorphic group ( n =25). Simulation the S(1), sacral 2(S(2)) transverse sacroiliac screw placement in 3-Matic software. Analysis whether there was any difference in maximum diameter and length of S(2) transverse sacroiliac screw between the normal group and the dysmorphic group. The pelvic CT data of the dysmorphic group were measured, and the optimal tilt angle and length of the oblique S(1) screw were obtained. The feasibility of transverse sacroiliac screw insertion in sacral 3(S(3)) segment was evaluated. t -test, rank sum test, and χ(2) test was used to analyze data, respectively. Results: In the dysmorphic group, the largest diameter of the S(1) transverse screw was (4.9±1.6)mm, and the normal group was (13.6±3.6)mm ( t =-15.07, P =0.00). In the dysmorphic group, the largest diameter of S(2) transverse screw was (13.8±3.0)mm, and was (12.4±2.2)mm in the normal group( t =2.11, P =0.04). There was no significant difference in the length of S(2) transverse sacroiliac screw between the two groups ( t =0.47, P =0.64). In the dysmorphic group, the anterior vertebral height of S(1) was (23.1±4.0)mm, which was significantly higher than that of the normal group ((14.1±4.2)mm)( t =9.01, P =0.00). The angle of S(1)S(2) in the dysmorphic group was 10.9°(3.8°, 17.6°), which was significantly larger than that of the normal group (2.0°(1.0°, 2.0°) ( Z =-4.03, P =0.00). In the dysmorphic group, the incline angle of the oblique S(1) sacroiliac screw was (35.6±6.2)°, the anteversion angle was (37.2±4.4)°, and the mean screw length was (90.2±4.7)mm. In the dysmorphic group, the placement rate of S(3) transverse sacroiliac screw was 48.0%, and that of the normal sacral group was 9.1%. Conclusions: There is often dysmorphic in the sacrum in patients with large S(1) anterior vertebral height and S(1)S(2) angle. Sacral dysmorphic patients with posterior pelvic ring injury may be treated with S(1) pedicle oblique sacroiliac screws. S(3) transverse sacroiliac screws should be carefully placed, especially for the absence of sacral dysmorphic in patients.

An Experimental Evaluation of the Effect of Hole Fabrication/Treatment Techniques on Residual Strength and Fatigue Life of Polycarbonate Specimens with Holes

DTIC Science & Technology

1993-08-01

34The Effect of Dimpling on the Fatigue Strength of Loaded Holes in a Corrosive Environment," Experimental Techniques, Vol. 9, September 1985, 33-36. 34...Expansion on the Fatigue Behavior of 7079-T652 Alluminium [sic] Alloy," NLR TR 74016 U, National Aerospace Laboratory (NLR), Amsterdam, The

Gold nanoparticle array formation on dimpled Ta templates using pulsed laser-induced thin film dewetting.

PubMed

El-Sayed, Hany A; Horwood, Corie A; Owusu-Ansah, Ebenezer; Shi, Yujun J; Birss, Viola I

2015-04-28

Here we show that pulsed laser-induced dewetting (PLiD) of a thin Au metallic film on a nano-scale ordered dimpled tantalum (DT) surface results in the formation of a high quality Au nanoparticle (NP) array. In contrast to thermal dewetting, PLiD does not result in deformation of the substrate, even when the Au film is heated to above its melting point. PLiD causes local heating of only the metal film and thus thermal oxidation of the Ta substrate can be avoided, also because of the high vacuum (low pO2) environment employed. Therefore, this technique can potentially be used to fabricate NP arrays composed of high melting point metals, such as Pt, not previously possible using conventional thermal annealing methods. We also show that the Au NPs formed by PLiD are more spherical in shape than those formed by thermal dewetting, likely demonstrating a different dewetting mechanism in the two cases. As the metallic NPs formed on DT templates are electrochemically addressable, a longer-term objective of this work is to determine the effect of NP size and shape (formed by laser vs. thermal dewetting) on their electrocatalytic properties.

Influence of combined thermomechanical treatment on impurity segregation in ferritic-martensitic and austenitic stainless steels

NASA Astrophysics Data System (ADS)

Ilyin, A. M.; Neustroev, V. S.; Shamardin, V. K.; Shestakov, V. P.; Tazhibaeva, I. L.; Krivchenkoa, V. A.

2000-12-01

In this study 13Cr2MoVNb ferritic-martensitic steel (FMS) and 16Cr15Ni3MoNb austenitic stainless steel (ASS) tensile specimens were subjected to standard heat treatments and divided into two groups. Specimens in group 1 (FMS only) were aged at 400°C in a stress free and in an elastically stressed state with a tensile load (100 MPa) then doped with hydrogen in an electrolytic cell. Specimens in group 2 were subjected to cold work (up to 10%) and exposed to short-time heating at 500° for 0.5 h. All specimens were fractured at room temperature in an Auger spectrometer and Auger analysis of the fracture surfaces was performed in situ after fracturing. A noticeable increase of N and P segregation levels and a widening of the depth distribution on the grain boundary facets were observed in the FMS after aging in the stressed state. Cold-worked FMS and ASS showed a ductile dimple mode of fracture, but relatively high levels of S, P and N were observed on the dimple surfaces. We consider the origin of such effects in terms of the stressed state and plastic-deformation-enhanced segregation.

Investigation on mechanical behavior and material characteristics of various weight composition of SiCp reinforced aluminium metal matrix composite

NASA Astrophysics Data System (ADS)

Pichumani, Sivachidambaram; Srinivasan, Raghuraman; Ramamoorthi, Venkatraman

2018-02-01

Aluminium - silicon carbide (Al - SiC) metal matrix composite is produced with following wt % of SiC reinforcement (4%, 8% & 12%) using stir casting method. Mechanical testing such as micro hardness, tensile testing and bend testing were performed. Characterizations, namely micro structure, X-ray diffraction (XRD) analysis, inductive coupled plasma - optical emission spectroscopy (ICP-OES) and scanning electron microscopy (SEM) analysis, were carried out on Al - SiC composites. The presence of SiC on Al - SiC composite is confirmed through XRD technique and microstructure. The percentage of SiC was confirmed through ICP-OES technique. Increase in weight percentage of SiC tends to increase micro hardness, ultimate strength & yield strength but it reduces the bend strength and elongation (%) of the material. SEM factrography of tensile tested fractured samples of Al - 8% SiC & Al - 12% SiC showed fine dimples on fractured surface & coarse dimples fractured surface respectively. This showed significant fracture differences between Al - 8% SiC & Al - 12% SiC. From the above experiment, Al - 8% SiC had good micro hardness, ultimate strength & yield strength without significant loss in elongation (%) & bend strength.

Effect of interfacial slip on the thin film drainage time for two equal-sized, surfactant-free drops undergoing a head-on collision: A scaling analysis

NASA Astrophysics Data System (ADS)

Ramachandran, A.; Leal, L. G.

2016-10-01

Using a scaling analysis, we assess the impact of interfacial slip on the time required for the thin liquid film between two drops undergoing a head-on collision to drain to the critical thickness for rupture by van der Waals forces. Interfacial slip is included in our continuum development using a Navier slip boundary condition, with the slip coefficient modeled using previous theories [Helfand and Tagami, J. Chem. Phys. 57, 1812 (1972), 10.1063/1.1678491; Goveas and Fredrickson, Eur. Phys. J. B 2, 79 (1998), 10.1007/s100510050228]. Slip decreases hydrodynamic resistance and speeds up film drainage. It renders the dependence of the drainage time on capillary number stronger in the spherical-film regime, but, interestingly, this dependence is altered only weakly in the dimpled-film regime. A subtle effect of slip is that it increases the range of capillary numbers in which the film remains predominantly spherical in shape during drainage (as opposed to being dimpled), leading to significantly faster drainage for these capillary numbers. Slip also leads to an increase in the critical capillary number beyond which coalescence is not possible in a head-collision.

INCOMPLETE REPAIR OF RETINAL STRUCTURE AFTER VITRECTOMY WITH INTERNAL LIMITING MEMBRANE PEELING.

PubMed

Hisatomi, Toshio; Tachibana, Takashi; Notomi, Shoji; Nakatake, Shunji; Fujiwara, Kohta; Murakami, Yusuke; Ikeda, Yasuhiro; Yoshida, Shigeo; Enaida, Hiroshi; Murata, Toshinori; Sakamoto, Taiji; Sonoda, Koh-Hei; Ishibashi, Tatsuro

2017-08-01

To examine retinal changes after vitrectomy with internal limiting membrane (ILM) peeling, we used a cynomolgus monkey model and focused on surgical damages of ILM peeling for long observational period of 3 years. Vitrectomy was performed followed by ILM peeling similar to clinical settings in humans. Ultrastructural changes of the retina were investigated by light, transmission, and scanning electron microscopy at 3 months and 3 years after ILM peeling. Ultrastructural study showed that the ILM peeled area was still clearly recognized after 3 years. The Müller cell processes covered most of the retina; however, the nerve fiber layer was partly uncovered and exposed to the vitreous space. The arcuate linear nerve fiber bundles were observed as comparable with dissociated optic nerve fiber layer appearance. Small round retinal surface defects were also observed around macula, resembling the dimple sign. Forceps-related retinal thinning was also found on the edge of ILM peeling, where we started peeling with fine forceps. The ultrastructural studies showed that most of ILM peeling area was covered with glial cells during wound healing processes. Retinal changes were found comparable with dissociated optic nerve fiber layer appearance or dimple sign, which were clinically observed with optical coherence tomography.

Tensile and fracture properties of type 316 stainless steel after creep

NASA Astrophysics Data System (ADS)

Gan, D.

1982-12-01

The effects of creep on the mechanical properties of type 316 stainless steel were studied. Tensile and Charpy specimens were machined from the oversize specimens crept at 750 °C and 103 MPa. The ambient fracture energy was found to deteriorate rapidly after creep. The ambient yield stress was increased moderately, but the tensile ductility was severely reduced. The effects of intergranular carbides alone on mechanical properties were studied with specimens thermal aged without load. These carbides were shown to cause a moderate reduction in fracture energy and tensile ductility but had little effect on yield stress. Extensive grain boundary separations were observed on the fracture surfaces. SEM studies showed that these grain boundaries were covered with micro voids initiated by the dense intergranular carbides. Frequently, large dimples on grain boundary joined up and initiated shear fracture into the grain. In the crept specimens additional microstructural changes in the form of intragranular carbides and subgrain boundaries were observed. Both are responsible for the increase in yield stress and the further reduction in tensile ductility and fracture energy. The intragranular carbides also modified the size and density of the dimples on the fracture surfaces.

Evaporative cooling in a compensated optical lattice

NASA Astrophysics Data System (ADS)

Duarte, P. M.; Hart, R.; Yang, T. L.; Liu, X.; Hulet, R. G.

2014-03-01

We present experimental results of evaporative cooling in a three-dimensional, red-detuned optical lattice. The lattice is compensated by the addition of three blue-detuned gaussian beams which overlap each of the lattice laser beams, but are not retro-reflected. The intensity of the compensating beams can be used to control the difference between the chemical potential in the lattice and the threshold for evaporation. We start with a two spin component degenerate Fermi gas of 6Li atoms at a temperature < 0 . 05TF in a dimple potential, which is obtained by rotating the polarization of the lattice retro beams to prevent the formation of standing waves. The temperature of the cloud is measured by releasing it from the dimple and fitting the momentum distribution to a Thomas-Fermi profile. We perform round-trip measurements into, and out of the lattice to study the adiabaticity of the loading as well as the effect of the compensating beams. Using the compensated lattice potential, we have reached temperatures low enough to produce antiferromagnetic spin correlations, which we detect via Bragg scattering of light. Supported by NSF, ONR, DARPA/ARO, and the Welch Foundation.

Single-molecule dynamics in nanofabricated traps

NASA Astrophysics Data System (ADS)

Cohen, Adam

2009-03-01

The Anti-Brownian Electrokinetic trap (ABEL trap) provides a means to immobilize a single fluorescent molecule in solution, without surface attachment chemistry. The ABEL trap works by tracking the Brownian motion of a single molecule, and applying feedback electric fields to induce an electrokinetic motion that approximately cancels the Brownian motion. We present a new design for the ABEL trap that allows smaller molecules to be trapped and more information to be extracted from the dynamics of a single molecule than was previously possible. In particular, we present strategies for extracting dynamically fluctuating mobilities and diffusion coefficients, as a means to probe dynamic changes in molecular charge and shape. If one trapped molecule is good, many trapped molecules are better. An array of single molecules in solution, each immobilized without surface attachment chemistry, provides an ideal test-bed for single-molecule analyses of intramolecular dynamics and intermolecular interactions. We present a technology for creating such an array, using a fused silica plate with nanofabricated dimples and a removable cover for sealing single molecules within the dimples. With this device one can watch the shape fluctuations of single molecules of DNA or study cooperative interactions in weakly associating protein complexes.

Development of forming and joining technology for TD-NiCr sheet

NASA Technical Reports Server (NTRS)

Torgerson, R. T.

1973-01-01

Forming joining techniques and properties data were developed for thin-gage TD-NiCr sheet in the recrystallized and unrecrystallized conditions. Theoretical and actual forming limit data are presented for several gages of each type of material for five forming processes: brake forming, corrugation forming, joggling, dimpling and beading. Recrystallized sheet can be best formed at room temperature, but unrecrystallized sheet requires forming at elevated temperature. Formability is satisfactory with most processes for the longitudinal orientation but poor for the transverse orientation. Dimpling techniques require further development for both material conditions. Data on joining techniques and joint properties are presented for four joining processes: resistance seam welding (solid-state), resistance spot welding (solid-state), resistance spot welding (fusion) and brazing. Resistance seam welded (solid-state) joints with 5t overlap were stronger than parent material for both material conditions when tested in tensile-shear and stress-rupture. Brazing studies resulted in development of NASA 18 braze alloy (Ni-16Cr-15Mo-8Al-4Si) with several properties superior to baseline TD-6 braze alloy, including lower brazing temperture, reduced reaction with Td-Ni-Cr, and higher stress-rupture properties.

Can Navigation-assisted Surgery Help Achieve Negative Margins in Resection of Pelvic and Sacral Tumors?

PubMed

Abraham, John A; Kenneally, Barry; Amer, Kamil; Geller, David S

2018-03-01

Navigation-assisted resection has been proposed as a useful adjunct to resection of malignant tumors in difficult anatomic sites such as the pelvis and sacrum where it is difficult to achieve tumor-free margins. Most of these studies are case reports or small case series, but these reports have been extremely promising. Very few reports, however, have documented benefits of navigation-assisted resection in series of pelvic and sacral primary tumors. Because this technology may add time and expense to the surgical procedure, it is important to determine whether navigation provides any such benefits or simply adds cost and time to an already complex procedure. (1) What proportion of pelvic and sacral bone sarcoma resections utilizing a computer-assisted resection technique achieves negative margins? (2) What are the oncologic outcomes associated with computer-assisted resection of pelvic and sacral bone sarcomas? (3) What complications are associated with navigation-assisted resection? Between 2009 and 2015 we performed 24 navigation-assisted resections of primary tumors of the pelvis or sacrum. Of those, four were lost to followup after the 2-year postoperative visit. In one patient, however, there was a failure of navigation as a result of inadequate imaging, so nonnavigated resection was performed; the remaining 23 were accounted for and were studied here at a mean of 27 months after surgery (range, 12-52 months). During this period, we performed navigation-assisted resections in all patients presenting with a pelvis or sacral tumor; there was no selection process. No patients were treated for primary tumors in these locations without navigation during this time with the exception of the single patient in whom the navigation system failed. We retrospectively evaluated the records of these 23 patients and evaluated the margin status of these resections. We calculated the proportion of patients with local recurrence, development of metastases, and overall survival at an average 27-month followup (range, 12-52 months). We queried a longitudinally maintained surgical database for any complications and noted which, if any, could have been directly related to the use of the navigation-assisted technique. In our series, 21 of 23 patients had a negative margin resection. In all patients the bone margin was negative, but two with sacral resections had positive soft tissue margins. Six of 23 patients experienced local recurrence within the study period. Three patients died during the study period. Seventeen patients demonstrated no evidence of disease at last recorded followup. We noted three intraoperative complications: one dural tear, one iliac vein laceration, and one bladder injury. Eight patients out of 23 had wound complications resulting in operative débridement. Two patients in the series developed transient postoperative femoral nerve palsy, which we believe were caused by stretch of the femoral nerve secondary to the placement of the reference array in the pubic ramus. Navigation-assisted resection of pelvic and sacral tumors resulted in a high likelihood of negative margin resection in this series, and we observed relatively few complications related specifically to the navigation. We have no comparison group without navigation, and future studies should indeed compare navigated with nonnavigated resection approaches in these anatomic locations. We did identify a potential navigation-related complication of femoral nerve palsy in this series and suggest careful placement and observation of the reference array during the operative procedure to lessen the likelihood of this previously unreported complication. We suggest it is worthwhile to consider the use of navigation-assisted surgery in resection of tumors of the pelvis and sacrum, but further study will be needed to determine its precise impact, if any, on local recurrence and other oncologic outcomes. Level IV, therapeutic study.

A problematic early tetrapod from the Mississippian of Nevada

USGS Publications Warehouse

Thomson, K.S.; Shubin, N.S.; Poole, F.G.

1998-01-01

We report here the discovery of a new taxon of Paleozoic tetrapod from the Late Mississippian of Nevada (330-340 Ma). It has a unique vertebral column with principal centra having vertical anterior and posterior faces, ventrally incomplete accessory centra located antero-dorsally in each centrum, and enlarged presacral/sacral vertebrae. The head and pectoral girdle were not preserved but the large femur, robust pelvic girdle and enlarged sacral vertebrae possibly indicate a terrestrial mode of life. This new form significantly extends the western geographic range of known Mississippian tetrapods. It presents a mosaic of primitive and derived features, indicating that continued revision of traditional accounts of vertebral homology and the early diversifications of Paleozoic tetrapods will be necessary.

Caudal dysgenesis in islet-1 transgenic mice

PubMed Central

Muller, Yunhua Li; Yueh, Yir Gloria; Yaworsky, Paul J.; Salbaum, J. Michael; Kappen, Claudia

2014-01-01

Maternal diabetes during pregnancy is responsible for the occurrence of diabetic embryopathy, a spectrum of birth defects that includes heart abnormalities, neural tube defects, and caudal dysgenesis syndromes. Here, we report that mice transgenic for the homeodomain transcription factor Isl-1 develop profound caudal growth defects that resemble human sacral/caudal agenesis. Isl-1 is normally expressed in the pancreas and is required for pancreas development and endocrine cell differentiation. Aberrant regulation of this pancreatic transcription factor causes increased mesodermal cell death, and the severity of defects is dependent on transgene dosage. Together with the finding that mutation of the pancreatic transcription factor HLXB9 causes sacral agenesis, our results implicate pancreatic transcription factors in the pathogenesis of birth defects associated with diabetes. PMID:12738808

Nonantimuscarinic treatment for overactive bladder: a systematic review.

PubMed

Olivera, Cedric K; Meriwether, Kate; El-Nashar, Sherif; Grimes, Cara L; Chen, Chi Chiung Grace; Orejuela, Francisco; Antosh, Danielle; Gleason, Jon; Kim-Fine, Shunaha; Wheeler, Thomas; McFadden, Brook; Balk, Ethan M; Murphy, Miles

2016-07-01

The purpose of the study was to determine the efficacy and safety of nonantimuscarinic treatments for overactive bladder. Medline, Cochrane, and other databases (inception to April 2, 2014) were used. We included any study design in which there were 2 arms and an n > 100, if at least 1 of the arms was a nonantimuscarinic therapy or any comparative trial, regardless of number, if at least 2 arms were nonantimuscarinic therapies for overactive bladder. Eleven reviewers double-screened citations and extracted eligible studies for study: population, intervention, outcome, effects on outcome categories, and quality. The body of evidence for categories of interventions were summarized and assessed for strength. Ninety-nine comparative studies met inclusion criteria. Interventions effective to improve subjective overactive bladder symptoms include exercise with heat and steam generating sheets (1 study), diaphragmatic (1 study), deep abdominal (1 study), and pelvic floor muscle training exercises (2 studies). Pelvic floor exercises are more effective in subjective and objective outcomes with biofeedback or verbal feedback. Weight loss with diet and exercise, caffeine reduction, 25-50% reduction in fluid intake, and pelvic floor muscle exercises with verbal instruction and or biofeedback were all efficacious. Botulinum toxin A improves urge incontinence episodes, urgency, frequency, quality of life, nocturia, and urodynamic testing parameters. Acupuncture improves quality of life and urodynamic testing parameters. Extracorporeal magnetic stimulation improves urodynamic parameters. Mirabegron improves daily incontinence episodes, nocturia, number of daily voids, and urine volume per void, whereas solabegron improves daily incontinence episodes. Short-term posterior tibial nerve stimulation is more efficacious than pelvic floor muscle training exercises and behavioral therapy for improving: urgency, urinary incontinence episodes, daily voids, volume per void, and overall quality of life. Sacral neuromodulation is more efficacious than antimuscarinic treatment for subjective improvement of overactive bladder and quality of life. Transvaginal electrical stimulation demonstrates subjective improvement in overactive bladder symptoms and urodynamic parameters. Multiple therapies, including physical therapy, behavioral therapy, botulinum toxin A, acupuncture, magnetic stimulation, mirabegron, posterior tibial nerve stimulation, sacral neuromodulation, and transvaginal electrical stimulation, are efficacious in the treatment of overactive bladder. Copyright © 2016 Elsevier Inc. All rights reserved.

Sputter coating of microspherical substrates by levitation

DOEpatents

Lowe, A.T.; Hosford, C.D.

Microspheres are substantially uniformly coated with metals or nonmetals by simltaneously levitating them and sputter coating them at total chamber pressures less than 1 torr. A collimated hole structure comprising a parallel array of upwardly projecting individual gas outlets is machined out to form a dimple. Glass microballoons,, which are particularly useful in laser fusion applications, can be substantially uniformly coated using the coating method and apparatus.

Clinical results of sacral neuromodulation for chronic voiding dysfunction using unilateral sacral foramen electrodes.

PubMed

Weil, E H; Ruiz-Cerdá, J L; Eerdmans, P H; Janknegt, R A; Van Kerrebroeck, P E

1998-01-01

The aim of this study was to determine the long-term clinical efficacy and complications of neuromodulation with a unilateral sacral foramen electrode in 36 patients with chronic voiding dysfunction. Following a positive effect of a percutaneous nerve evaluation test, patients underwent open surgery. A permanent electrode was implanted in 24 patients with urge incontinence, in 6 with urgency-frequency syndrome, and in 6 with nonobstructive urinary retention. After an average follow-up period of 37.8 months, 19 patients (52.8%) continue to benefit from the neuromodulation with a significant improvement of symptoms and urodynamic parameters. The median duration of the therapeutic effect for the total study population was longer than 60 months. No significant difference in the median duration of therapeutic effect with regard to sex, the type of voiding disorder, or the implant pulse generator was found. However, in patients with previous psychological disorders the median duration of therapeutic effect was only 12 months (P = 0.008). Complications were mild. In the group of patients in whom the therapeutic effect remains, 37 reoperations have had to be performed. We conclude that although reoperations were needed to overcome technical problems, patients can achieve lasting symptomatic improvement. Since technical changes in the equipment have reduced the number of complications, even better results can be expected in terms of the reoperation rate.

Delayed Union of a Sacral Fracture: Percutaneous Navigated Autologous Cancellous Bone Grafting and Screw Fixation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huegli, R. W.; Messmer, P.; Jacob, A. L.

2003-09-15

Delayed or non-union of a sacral fracture is a serious clinical condition that may include chronic pain, sitting discomfort, gait disturbances, neurological problems, and inability to work. It is also a difficult reconstruction problem. Late correction of the deformity is technically more demanding than the primary treatment of acute pelvic injuries. Open reduction, internal fixation (ORIF), excision of scar tissue, and bone grafting often in a multi-step approach are considered to be the treatment of choice in delayed unions of the pelvic ring. This procedure implies the risk of neurological and vascular injuries, infection, repeated failure of union, incomplete correctionmore » of the deformity, and incomplete pain relief as the most important complications. We report a new approach for minimally invasive treatment of a delayed union of the sacrum without vertical displacement. A patient who suffered a Malgaigne fracture (Tile C1.3) was initially treated with closed reduction and percutaneous screw fixation (CRPF) of the posterior pelvic ring under CT navigation and plating of the anterior pelvic ring. Three months after surgery he presented with increasing hip pain caused by a delayed union of the sacral fracture. The lesion was successfully treated percutaneously in a single step procedure using CT navigation for drilling of the delayed union, autologous bone grafting, and screw fixation.« less

[Sacral neuromodulation in urology - development and current status].

PubMed

Schwalenberg, T; Stolzenburg, J-U; Kriegel, C; Gonsior, A

2012-01-01

Sacral neuromodulation (SNM) in urology is employed to treat refractory lower urinary tract dysfunction as well as chronic pelvic pain. Electrical stimulation of the sacral afferents (S2 - S4) causes activation and conditioning of higher autonomic and somatic neural structures and thereby influences the efferents controlling the urinary bladder, the rectum and their related sphincter systems. It is therefore possible to treat overactivity as well as hypocontractility and functional bladder neck obstruction. SNM treatment is conducted biphasically. Initially, test electrodes are placed to evaluate changes in micturition and pain parameters. If, in this first phase - called peripheral nerve evaluation (PNE test) - sufficient improvements are observed, the patient progresses to phase two which involves implantation of the permanent electrodes and impulse generator system. In recent years, the "two stage approach" with initial implantation of the permanent electrodes has been favoured as it increases treatment success rates. Long-term success rates of SNM vary significantly in the literature (50 - 80 %) due to heterogeneous patient populations as well as improved surgical approaches. With the introduction of "tined lead electrodes" (2002), tissue damage is reduced to a minimum. Technical innovation, financial feasibility (reimbursed in Germany since 2004) and wider application, especially in otherwise therapy-refractory patients or complex dysfunctions of the pelvis, have established SNM as a potent treatment option in urology. © Georg Thieme Verlag KG Stuttgart · New York.

Evidence that the notochord may be pivotal in the development of sacral and anorectal malformations.

PubMed

Qi, Bao Quan; Beasley, Spencer W; Frizelle, Francis A

2003-09-01

The notochord is known to organize normal development of central axial structures, such as the spinal cord, vertebral column, and anorectum, but its role in abnormal development of these organs has not been well documented. The current study has used Ethylenethiourea to induce anorectal malformations in fetal rats, allowing investigation of abnormalities of the notochord and their relationship to the axial structural abnormalities that occur. Timed-mated pregnant rats were fed Ethylenethiourea by gavage on gestational day 10. Their embryos were harvested on gestational days 13 to 16 and sectioned in either the transverse or sagittal plane. Sections were stained with H and E and examined serially. Anorectal malformations were identified in 29 of 34 embryos and neural tube defects in 24, ranging from an accessory neural tube to lumbo-sacral rachischisis. There was no tail or only a rudimentary tail in the majority of embryos. Abnormalities of the notochord in the lumbo-sacral area included ventro-dorsal branching, ventral deviation, and ectopic notochordal tissue. Most abnormal notochord branches and ectopic notochordal tissue were abnormally close to or in contact with the wall of the cloaca or neural tube. Given the known role of the notochord in controlling normal development, this study would suggest that abnormal notochord development may be pivotal in producing neural tube defects and anorectal malformations, possibly by altering sonic hedgehog signalling.

Combined V-Y Fasciocutaneous Advancement and Gluteus Maximus Muscle Rotational Flaps for Treating Sacral Sores

PubMed Central

Choi, Eun Jeong; Moon, Suk Ho; Lee, Yoon Jae

2016-01-01

The sacral area is the most common site of pressure sore in bed-ridden patients. Though many treatment methods have been proposed, a musculocutaneous flap using the gluteus muscles or a fasciocutaneous flap is the most popular surgical option. Here, we propose a new method that combines the benefits of these 2 methods: combined V-Y fasciocutaneous advancement and gluteus maximus muscle rotational flaps. A retrospective review was performed for 13 patients who underwent this new procedure from March 2011 to December 2013. Patients' age, sex, accompanying diseases, follow-up duration, surgical details, complications, and recurrence were documented. Computed tomography was performed postoperatively at 2 to 4 weeks and again at 4 to 6 months to identify the thickness and volume of the rotational muscle portion. After surgery, all patients healed within 1 month; 3 patients experienced minor complications. The average follow-up period was 13.6 months, during which time 1 patient had a recurrence (recurrence rate, 7.7%). Average thickness of the rotated muscle was 9.43 mm at 2 to 4 weeks postoperatively and 9.22 mm at 4 to 6 months postoperatively (p = 0.087). Muscle thickness had not decreased, and muscle volume was relatively maintained. This modified method is relatively simple and easy for reconstructing sacral sores, provides sufficient padding, and has little muscle donor-site morbidity. PMID:27366755

Objective evaluation by reflectance spectrophotometry can be of clinical value for the verification of blanching/non blanching erythema in the sacral area.

PubMed

Sterner, Eila; Fossum, Bjöörn; Berg, Elisabeth; Lindholm, Christina; Stark, André

2014-08-01

Early detection of non blanching erythema (pressure ulcer category I) is necessary to prevent any further skin damage. An objective method to discriminate between blanching/non blanching erythema is presently not available. The purpose of this investigation was to explore if a non invasive objective method could differentiate between blanching/non blanching erythema in the sacral area of patients undergoing hip fracture surgery. Seventy-eight patients were included. The sacral area of all patients was assessed using (i) conventional finger-press test and (ii) digital reading of the erythema index assessed with reflectance spectrophotometry. The patients were examined at admission and during 5 days postsurgery. Reflectance spectrophotometry measurements proved able to discriminate between blanching/non blanching erythema. The reliability, quantified by the intra-class correlation coefficient, was excellent between repeated measurements over the measurement period, varying between 0·82 and 0·96, and a significant change was recorded in the areas from day 1 to day 5 (P < 0·0001). The value from the reference point did not show any significant changes over the same period (P = 0·32). An objective method proven to identify early pressure damage to tissue can be a valuable tool in clinical practice. © 2013 The Authors. International Wound Journal © 2013 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

[Effectiveness of Sacral Intervertebral Epidural Block for Umbilical Hernia Repair in Children].

PubMed

Nagamine, Norimitsu; Furuya, Atsushi; Suzuki, Sho; Kondo, Satoko; Kiuchi, Riko; Suzuki, Satomi; Nonaka, Akihiko

2015-02-01

Effectiveness of sacral intervertebral epidural block (S 2-3 block) for umbilical hernia repair has not been clarified. We investigate 24 children, undergoing umbilical hernia repair; mean age of 3 years (age range: 20-65 months). Under general anesthesia, epidural block was performed at S 2-3 interspace with 1 ml x kg(-1) ropivacaine (0.2%) at injecting rate of 1 ml x sec(-1) followed by 0.25 ml x kg(-1) normal saline. In all cases, neither systolic blood pressure nor heart rate increased > 15% from those just before the block. Postoperative analgesics were given in 6 patients (25%) rectally. Mean time between the block and the administration of analgesic was 10.5 hours. S 2-3 block can be effective for postoperative pain in umbilical hernia repair.

Comparison of Lumbar Lordosis in Lateral Radiographs in Standing Position with supine MR Imaging in consideration of the Sacral Slope.

PubMed

Benditz, Achim; Boluki, Daniel; Weber, Markus; Zeman, Florian; Grifka, Joachim; Völlner, Florian

2017-03-01

Purpose  To investigate the influence of sacral slope on the correlation between measurements of lumbar lordosis obtained by standing radiographs and magnetic resonance images in supine position (MRI). Little information is available on the correlation between measurements of lumbar lordosis obtained by radiographic and MR images. Most relevant studies have shown correlations for the thoracic spine, but detailed analyses on the lumbar spine are lacking. Methods  MR images and standing lateral radiographs of 63 patients without actual low back pain or radiographic pathologies of the lumbar spine were analyzed. Standing radiographic measurements included the sagittal parameters pelvic incidence (PI) pelvic tilt (PT), and sacral slope (SS); MR images were used to additionally measure lumbar L1-S1 lordosis and single level lordosis. Differences between radiographic and MRI measurements were analyzed and divided into 4 subgroups of different sacral slope according to Roussouly's classification. Results  Global lumbar lordosis (L1-S1) was 44.99° (± 10 754) on radiographs and 47.91° (± 9.170) on MRI, yielding a clinically relevant correlation (r = 0.61, p < 0.01). Measurements of single level lordosis only showed minor differences. At all levels except for L5 / S1, lordosis measured by means of standing radiographs was higher than that measured by MRI. The difference in global lumbar L1-S1 lordosis was -2.9°. Analysis of the Roussouly groups showed the largest difference for L1-S1 (-8.3°) in group 2. In group 4, when measured on MRI, L5 / S1 lordosis (25.71°) was lower than L4 / L5 lordosis (27.63°) compared to the other groups. Conclusions  Although measurements of global lumbar lordosis significantly differed between the two scanning technologies, the mean difference was just 2.9°. MRI in supine position may be used for estimating global lumbar lordosis, but single level lordosis should be determined by means of standing radiographs. Key Points   · Large difference between radiographic and MRI measurements of level L5 / S1.. · MRI can be used for estimating global lumbar lordosis.. · Analysis of single level lordosis necessitates measurement in standing radiographs.. Citation Format · Benditz A, Boluki D, Weber M et al. Comparison of Lumbar Lordosis in Lateral Radiographs in Standing Position with supine MR Imaging in consideration of the Sacral Slope. Fortschr Röntgenstr 2017; 189: 233 - 239. © Georg Thieme Verlag KG Stuttgart · New York.

[Infantile hemangiomas: the revolution of beta-blockers].

PubMed

Leaute-Labreze, Christine

2014-12-01

Infantile hemangioma is the consequence of both postnatal vasculogenesis and angiogenesis. Hypoxia appears to play an important role as a contributory factor. Infantile hemangiomas have variable clinical features: superficial, deep or mixed. They can be localized or segmental involving a large skin area. Localized infantile hemangiomas are usually benign, unless they are located near a noble structure (airway orbit...), while segmental infantile hemangioma may be associated with complex underlying birth defects (PHACES and SACRAL syndromes). Clinical follow-up of infants with infantile hemangioma must be particularly careful in the first weeks of life since 80% of all infantile hemangiomas have reached their final size at age 5 months. A majority of infantile hemangiomas are mild and do not required any treatment. Main indications for treatment are: vital risk (heart failure, respiratory distress), functional risk (amblyopia, swallowing disorders...), painful ulceration and disfigurement (face involvement of nose, lips...). Propranolol, has been quickly adopted as the first line medical treatment for complicated infantile hemangioma; and it is the only treatment to have a marketing authorization in this indication. It is recommended to begin the treatment as early as possible before three months of age to minimize the risk of complications and sequelae.

A CLASSICAL ANALOG FOR RELATIVISTIC CONTRACTION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Epstein, L.

1963-12-01

It is possible to construct a mechanical model that demonstrates the Fitzgerald contraction. An equation is derived to describe the shape of a dimple moving across an elastic membrane, clearly showing the analogy to the field of a point charge in free space, including the relativistic contraction in the direction of motion. This model should suggest some reason to the inquiring mind that persists in wondering---- what really makes it shrink.'' (auth)

Sputter coating of microspherical substrates by levitation

DOEpatents

Lowe, Arthur T.; Hosford, Charles D.

1981-01-01

Microspheres are substantially uniformly coated with metals or nonmetals by simultaneously levitating them and sputter coating them at total chamber pressures less than 1 torr. A collimated hole structure 12 comprising a parallel array of upwardly projecting individual gas outlets 16 is machined out to form a dimple 11. Glass microballoons, which are particularly useful in laser fusion applications, can be substantially uniformly coated using the coating method and apparatus.

Extensional, bending and twisting stiffness of Titanium Multiwall Thermal Protection System (TPS)

NASA Technical Reports Server (NTRS)

Meaney, J. E.

1982-01-01

A test program which determines the extensional, bending and torsional stiffness of various titanium multiwall sandwich configurations is described. It is shown that unlike honeycomb core, the dimpled core is a significant contributor to the stiffness and strength of the sandwich. the extensional stiffness test shows irregularities which are attributed to foil thickness variations and to the difficulty to determine linear values from nonlinear tests.

Characterization of molybdenum particles reinforced Al6082 aluminum matrix composites with improved ductility produced using friction stir processing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Selvakumar, S., E-mail: lathaselvam1963@gmail.com

Aluminum matrix composites (AMCs) reinforced with various ceramic particles suffer a loss in ductility. Hard metallic particles can be used as reinforcement to improve ductility. The present investigation focuses on using molybdenum (Mo) as potential reinforcement for Mo(0,6,12 and 18 vol.%)/6082Al AMCs produced using friction stir processing (FSP). Mo particles were successfully retained in the aluminum matrix in its elemental form without any interfacial reaction. A homogenous distribution of Mo particles in the composite was achieved. The distribution was independent upon the region within the stir zone. The grains in the composites were refined considerably due to dynamic recrystallization andmore » pinning effect. The tensile test results showed that Mo particles improved the strength of the composite without compromising on ductility. The fracture surfaces of the composites were characterized with deeply developed dimples confirming appreciable ductility. - Highlights: •Molybdenum particles used as reinforcement for aluminum composites to improve ductility. •Molybdenum particles were retained in elemental form without interfacial reaction. •Homogeneous dispersion of molybdenum particles were observed in the composite. •Molybdenum particles improved tensile strength without major loss in ductility. •Deeply developed dimples on the fracture surfaces confirmed improved ductility.« less

Safety and complications of absorbable threads made of poly-L-lactic acid and poly lactide/glycolide: Experience with 148 consecutive patients.

PubMed

Sarigul Guduk, Sukran; Karaca, Nezih

2018-04-01

Thread lifting is a minimally invasive procedure for lifting and repositioning tissues. Few articles with absorbable sutures exist in the literature. Furthermore there is no study focusing on complications of absorbable sutures. To describe complications of thread lifting using a totally absorbable suture composed of poly-L-lactic acid affixed with poly lactide/glycolide cones. Data regarding complications were analyzed retrospectively for 148 patients underwent thread lifting between June 2014 and February 2017. A total of 321 pairs of sutures used in the 148 patients studied. Overall 40 (27%) patients had complications regarded as minimal or moderate without permanent sequela. The most common complication was skin dimpling and irregularity (n = 17, 11.4%) followed by ecchymosis (n = 12, 8.1%), suture extrusion (n = 4, 2.7%), and pain (n = 4, 2.7%) Except one patient, dimpling, and irregularity resolved in all patients after 3-7 days spontaneously. Suture migration was observed in 2 (1.35%) patients. Hematoma and infection were seen in 2 patients one for each. The procedure using sutures made of absorbable poly-L-lactic acid and poly lactide/glycolide is a relatively safe procedure without major complications. © 2018 Wiley Periodicals, Inc.

Investigation on Microstructure and Impact Toughness of Different Zones in Duplex Stainless Steel Welding Joint

NASA Astrophysics Data System (ADS)

Zhang, Zhiqiang; Jing, Hongyang; Xu, Lianyong; Han, Yongdian; Li, Guolu; Zhao, Lei

2017-01-01

This paper investigated on microstructure and impact toughness of different zones in duplex stainless steel welding joint. High-temperature heat-affected zone (HTHAZ) contained coarse ferrite grains and secondary precipitates such as secondary austenite, Cr2N, and sigma. Intergranular secondary austenite was prone to precipitation in low-temperature heat-affected zone (LTHAZ). Both in weld metal (WM) and in HTHAZ, the austenite consisted of different primary and secondary austenite. The ferrite grains in base metal (BM) presented typical rolling texture, while the austenite grains showed random orientation. Both in the HTHAZ and in the LTHAZ, the ferrite grains maintained same texture as the ferrite in the BM. The secondary austenite had higher Ni but lower Cr and Mo than the primary austenite. Furthermore, the WM exhibited the highest toughness because of sufficient ductile austenite and unapparent ferrite texture. The HTHAZ had the lowest toughness because of insufficient austenite formation in addition to brittle sigma and Cr2N precipitation. The LTHAZ toughness was higher than the BM due to secondary austenite precipitation. In addition, the WM fracture was dominated by the dimple, while the cleavage was main fracture mode of the HTHAZ. Both BM and LTHAZ exhibited a mixed fracture mode of the dimple and quasi-cleavage.

Numerical study on the aerodynamics of a golf ball and its comparison with a smooth sphere

NASA Astrophysics Data System (ADS)

Li, Jing; Tsubokura, Makoto; Tsunoda, Masaya

2014-11-01

The present study has numerically investigated the flow over a golf ball and a smooth sphere by conducting large-eddy simulation (LES) using hundreds of millions of unstructured elements. Simulations were conducted at various Reynolds numbers ranging from the subcritical to the supercritical regimes. Special attention was paid to the phenomenon of drag crisis as well as the effect of surface roughness on the drag crisis. The simulation result shows that the surface roughness introduced by the dimples of the golf ball causes a local instability of the flow around the ball and subsequently leads to a momentum transfer in the near-wall region inside the dimples. The flow with high momentum in the near-wall region travels further downstream, which consequently results in the drag crisis occurring at a relatively lower Reynolds number compared with that of the smooth sphere. Moreover, the Magnus effect resulting from the rotating motion of a sphere was also one of the main concerns in this study. The simulation result shows that lift forces are imposed on both the rotating smooth sphere and rotating golf ball. For most cases the lift force points to the positive direction, however, the negative lift force appears also under certain conditions.

Effect of Plate Hardening Behavior on the Deformation of Stainless Steel Metal Bellows

NASA Astrophysics Data System (ADS)

Hao, Zengliang; Luo, Shuyi; Zhao, He; Zhang, Chunxiang; Luo, Junting

2017-11-01

Tensile tests of original plate samples from three types of stainless steel metal bellows were performed at room temperature. The constitutive equations for the three hardening curves were obtained and fitted. The analysis results of the microstructure and fracture morphology of the tensile specimens show that the grain size of the plate with a high logarithmic-exponential hardening rate is uneven and the dimple of the shear fracture is elongated into an ellipse. By contrast, the grain size of the plate with a relatively low linear hardening rate is even and the dimple of the fracture is uniformly equiaxial. Finite element simulations of the hydraulic bulging and repeated limit bending deformation of the metal bellows of the three types of materials were also conducted. The repeated limit bending deformation process was tested experimentally. Although the effect of the hardening exponent on the residual stress of the metal bellows after hydraulic bulging is minimal, this exponent considerably influences the repeated limit bending deformation of the metal bellows after subsequent use. The trough hardening phenomenon is serious in the repeated limit bending process. Moreover, when the hardening exponent of the original plate is high, the resistance to bending fracture at the trough area is poor.

Twin Dimples Intrigue Scientists

NASA Technical Reports Server (NTRS)

2004-01-01

This image from the Mars Exploration Rover Opportunity is part of the first set of pictures that was returned to Earth after the rover exited 'Eagle Crater.' Scientists are busy analyzing Opportunity's new view of the plains of Meridiani Planum. The plentiful ripples are a clear indication that wind is the primary geologic process currently in effect on the plains. On the left of the image are two depressions--each about a meter (about 3.3 feet) across--that feature bright spots in their centers. One possibility is that the bright material is similar in composition to the rocks in Eagle Crater's outcrop and the surrounding darker material is what's referred to as 'lag deposit,' or erosional remnants that are much harder and more difficult to wear away. These twin dimples might be revealing pieces of a larger outcrop that lies beneath. The depression closest to Opportunity is whimsically referred to as 'Homeplate' and the one behind it as 'First Base.' The rover's panoramic camera is set to take detailed images of the depressions today, on Opportunity's 58th sol. The backshell and parachute that helped protect the rover and deliver it safely to the surface of Mars are also visible near the horizon, in the center of the image. This image was taken by the rover's navigation camera.

Microstructures and impact toughness behavior of Al 5083 alloy processed by cryorolling and afterwards annealing

NASA Astrophysics Data System (ADS)

Singh, Dharmendra; Rao, P. Nageswara; Jayaganthan, R.

2013-08-01

The influence of rolling at liquid nitrogen temperature and annealing on the microstructure and mechanical properties of Al 5083 alloy was studied in this paper. Cryorolled samples of Al 5083 show significant improvements in strength and hardness. The ultimate tensile strength increases up to 340 MPa and 390 MPa for the 30% and 50% cryorolled samples, respectively. The cryorolled samples, with 30% and 50% reduction, were subjected to Charpy impact testing at various temperatures from -190°C to 100°C. It is observed that increasing the percentage of reduction of samples during cryorolling has significant effect on decreasing impact toughness at all temperatures by increasing yield strength and decreasing ductility. Annealing of samples after cryorolling shows remarkable increment in impact toughness through recovery and recrystallization. The average grain size of the 50% cryorolled sample (14 μm) after annealing at 350°C for 1 h is found to be finer than that of the 30% cryorolled sample (25 μm). The scanning electron microscopy (SEM) analysis of fractured surfaces shows a large-size dimpled morphology, resembling the ductile fracture mechanism in the starting material and fibrous structure with very fine dimples in cryorolled samples corresponding to the brittle fracture mechanism.

Influence of nano-size inclusions on spall fracture of copper single crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Razorenov, S. V.; Ivanchihina, G. E.; Kanel, G. I.

2007-12-12

Spall experiments have been carried out for copper in different structural states. The samples were copper single crystals, crystals of Cu+0.1% Si, copper crystals with silica particles of 180 nm average size, and polycrystalline copper. In experiments, the free surface velocity histories were recorded with the VISAR. The recovered samples were studied using optical microscopy and SEM. Solid solution Cu+0.1% Si demonstrates slower spall process than pure copper crystals. At longer pulse durations its spall strength is slightly less than that of pure crystals but approaches the latter with decreasing pulse duration. Fracture of copper with silica inclusions is completedmore » much faster. The spall strength of this material is close to that of Cu+0.1% Si crystals at longer pulse duration and approaches the strength of polycrystalline copper with decreasing the load duration. Fractography of the spall surfaces correlates with the free surface velocity histories. The main fracture surface of the Cu+0.1% Si grains consists of net of dimples {approx}4 {mu}m to 40 {mu}m mean diameter. The fracture surfaces of copper with silica inclusions is covered by a net of dimples of 1 {mu}m to 5 {mu}m size.« less

The Effects of Geometric and Loading Imperfections on the Response and Lower-Bound Buckling Load of a Compression-Loaded Cylindrical Shell

NASA Technical Reports Server (NTRS)

Kriegesmann, Benedikt; Hilburger, Mark W.; Rolfes, Raimund

2012-01-01

Results from a numerical study of the buckling response of a thin-walled compressionloaded isotropic circular cylindrical shell with initial geometric and loading imperfections are used to determine a lower bound buckling load estimate suitable for preliminary design. The lower bound prediction techniques presented herein include an imperfection caused by a lateral perturbation load, an imperfection in the shape of a single stress-free dimple (similar to the lateral pertubation imperfection), and a distributed load imperfection that induces a nonuniform load in the shell. The ABAQUS finite element code is used for the analyses. Responses of the cylinders for selected imperfection amplitudes and imperfection types are considered, and the effect of each imperfection is compared to the response of a geometrically perfect cylinder. The results indicate that compression-loaded shells subjected to a lateral perturbation load or a single dimple imperfection, and a nonuniform load imperfection, exhibit similar buckling behavior and lower bound trends and the predicted lower bounds are much less conservative than the corresponding design recommendation NASA SP-8007 for the design of buckling-critical shells. In addition, the lateral perturbation technique and the distributed load imperfection produce response characteristics that are physically meaningful and can be validated via laboratory testing.

Microstructure and Mechanical Properties of Fiber-Laser-Welded and Diode-Laser-Welded AZ31 Magnesium Alloy

NASA Astrophysics Data System (ADS)

Chowdhury, S. M.; Chen, D. L.; Bhole, S. D.; Powidajko, E.; Weckman, D. C.; Zhou, Y.

2011-07-01

The microstructures, tensile properties, strain hardening, and fatigue strength of fiber-laser-welded (FLW) and diode-laser-welded (DLW) AZ31B-H24 magnesium alloys were studied. Columnar dendrites near the fusion zone (FZ) boundary and equiaxed dendrites at the center of FZ, with divorced eutectic β-Mg17Al12 particles, were observed. The FLW joints had smaller dendrite cell sizes with a narrower FZ than the DLW joints. The heat-affected zone consisted of recrystallized grains. Although the DLW joints fractured at the center of FZ and exhibited lower yield strength (YS), ultimate tensile strength (UTS), and fatigue strength, the FLW joints failed at the fusion boundary and displayed only moderate reduction in the YS, UTS, and fatigue strength with a joint efficiency of ~91 pct. After welding, the strain rate sensitivity basically vanished, and the DLW joints exhibited higher strain-hardening capacity. Stage III hardening occurred after yielding in both base metal (BM) and welded samples. Dimple-like ductile fracture characteristics appeared in the BM, whereas some cleavage-like flat facets together with dimples and river marking were observed in the welded samples. Fatigue crack initiated from the specimen surface or near-surface defects, and crack propagation was characterized by the formation of fatigue striations along with secondary cracks.

Clinical outcome of trans-sacral interbody fusion after partial reduction for high-grade l5-s1 spondylolisthesis.

PubMed

Smith, J A; Deviren, V; Berven, S; Kleinstueck, F; Bradford, D S

2001-10-15

A clinical retrospective study was conducted. To evaluate the clinical and radiographic outcome of reduction followed by trans-sacral interbody fusion for high-grade spondylolisthesis. In situ posterior interbody fusion with fibula allograft has improved the fusion rates for patients with high-grade spondylolisthesis. The use of this technique in conjunction with partial reduction has not been reported. Nine consecutive patients underwent treatment of high-grade (Grade 3 or 4) spondylolisthesis with partial reduction followed by posterior interbody fusion using cortical allograft. The average age at the time of surgery was 27 years (range, 8-51 years), and the average follow-up period was 43 months (range, 24-72 months). Before surgery, eight patients had low back pain, seven patients had radiating leg pain, and five patients had hamstring tightness. The average grade of spondylolisthesis by Meyerding grading was 3.9 (range, 3-5). Charts and radiographs were evaluated, and outcomes were collected by use of the modified SRS outcomes instrument. Radiographic indexes demonstrated significant improvement with partial reduction and fusion. The slip angle, as measured from the inferior endplate of L5, improved from 41.2 degrees (range, 24-82 degrees ) before surgery to 21 degrees (range, 5-40 degrees ) after surgery. All the patients were extremely or somewhat satisfied with surgery. The two patients who underwent this operation without initial instrumentation experienced fractures of their interbody grafts. Both of these patients underwent repair of the pseudarthrosis with placement of trans-sacral pedicle screw instrumentation and subsequent fusion. Partial reduction followed by posterior interbody fusion is an effective technique for the management of high-grade spondylolisthesis in pediatric and adult patient populations, as assessed by radiographic and clinical criteria. Pedicle screw instrumentation with the sacral screws capturing L5 is recommended when this technique is used for the treatment of high-grade spondylolisthesis. According to the clinical and radiographic results from this study, partial reduction and posterior fibula interbody fusion supplemented with pedicle screw instrumentation is an effective technique for select patients with high-grade spondylolisthesis at L5-S1.

Mechanical comparison between lengthened and short sacroiliac screws in sacral fracture fixation: a finite element analysis.

PubMed

Zhao, Y; Zhang, S; Sun, T; Wang, D; Lian, W; Tan, J; Zou, D; Zhao, Y

2013-09-01

To compare the stability of lengthened sacroiliac screw and standard sacroiliac screw for the treatment of unilateral vertical sacral fractures; to provide reference for clinical applications. A finite element model of Tile type C pelvic ring injury (unilateral Denis type II fracture of the sacrum) was produced. The unilateral sacral fractures were fixed with lengthened sacroiliac screw and sacroiliac screw in six different types of models respectively. The translation and angle displacement of the superior surface of the sacrum (in standing position on both feet) were measured and compared. The stability of one lengthened sacroiliac screw fixation in S1 or S2 segment is superior to that of one sacroiliac screw fixation in the same sacral segment. The stability of one lengthened sacroiliac screw fixation in S1 and S2 segments respectively is superior to that of one sacroiliac screw fixation in S1 and S2 segments respectively. The stability of one lengthened sacroiliac screw fixation in S1 and S2 segments respectively is superior to that of one lengthened sacroiliac screw fixation in S1 or S2 segment. The stability of one sacroiliac screw fixation in S1 and S2 segments respectively is markedly superior to that of one sacroiliac screw fixation in S1 or S2 segment. The vertical and rotational stability of lengthened sacroiliac screw fixation and sacroiliac screw fixation in S2 is superior to that of S1. In a finite element model of type C pelvic ring disruption, S1 and S2 lengthened sacroiliac screws should be utilized for the fixation as regularly as possible and the most stable fixation is the combination of the lengthened sacroiliac screws of S1 and S2 segments. Even if lengthened sacroiliac screws cannot be systematically used due to specific conditions, one sacroiliac screw fixation in S1 and S2 segments respectively is recommended. No matter which kind of sacroiliac screw is used, if only one screw can be implanted, the fixation in S2 segment is more recommended than that in S1. Experimental study Level III. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Microcirculatory responses of sacral tissue in healthy individuals and inpatients on different pressure-redistribution mattresses.

PubMed

Bergstrand, S; Källman, U; Ek, A-C; Engström, M; Lindgren, M

2015-08-01

The aim of this study was to explore the interaction between interface pressure, pressure-induced vasodilation, and reactive hyperaemia with different pressure-redistribution mattresses. A cross-sectional study was performed with a convenience sample of healthy young individuals, and healthy older individuals and inpatients, at a university hospital in Sweden. Blood flow was measured at depths of 1mm, 2mm, and 10mm using laser Doppler flowmetry and photoplethysmography. The blood flow, interface pressure and skin temperature were measured in the sacral tissue before, during, and after load while lying on one standard hospital mattress and three different pressure-redistribution mattresses. There were significant differences between the average sacral pressure, peak sacral pressure, and local probe pressure on the three pressure-redistribution mattresses, the lowest values found were with the visco-elastic foam/air mattress (23.5 ± 2.5mmHg, 49.3 ± 11.1mmHg, 29.2 ± 14.0mmHg, respectively). Blood flow, measured as pressure-induced vasodilation, was most affected in the visco-elastic foam/air group compared to the alternating pressure mattress group at tissue depths of 2mm (39.0% and 20.0%, respectively), and 10mm (56.9 % and 35.1%, respectively). Subjects in all three groups, including healthy 18-65 year olds, were identified with no pressure-induced vasodilation or reactive hyperaemia on any mattress (n=11), which is considered a high-risk blood flow response. Interface pressure magnitudes considered not harmful during pressure-exposure on different pressure-redistribution mattresses can affect the microcirculation in different tissue structures. Despite having the lowest pressure values compared with the other mattresses, the visco-elastic foam/air mattress had the highest proportion of subjects with decreased blood flow. Healthy young individuals were identified with the high-risk blood flow response, suggesting an innate vulnerability to pressure exposure. Furthermore, the evaluation of pressure-redistribution support surfaces in terms of mean blood flow during and after tissue exposure is not feasible, but assessment of pressure-induced vasodilation and reactive hyperaemia could be a new way to assess individualised physiological measurements of mechanisms known to be related to pressure ulcer development.

Psoas compartment and sacral plexus block via electrostimulation for pelvic limb amputation in dogs.

PubMed

Congdon, Jonathon M; Boscan, Pedro; Goh, Clara S S; Rezende, Marlis

2017-07-01

To assess the efficacy of psoas compartment and sacral plexus block for pelvic limb amputation in dogs. Prospective clinical study. A total of 16 dogs aged 8±3 years and weighing 35±14 kg (mean±standard deviation). Dogs were administered morphine (0.5 mg kg -1 ) and atropine (0.02 mg kg -1 ); anesthesia was induced with propofol and maintained with isoflurane. Regional blocks were performed before surgery in eight dogs with bupivacaine (2.2 mg kg -1 ) and eight dogs were administered an equivalent volume of saline. The lumbar plexus within the psoas compartment was identified using electrolocation lateral to the lumbar vertebrae at the fourth-fifth, fifth-sixth and sixth-seventh vertebral interspaces. The sacral plexus, ventrolateral to the sacrum, was identified using electrolocation. Anesthesia was monitored using heart rate (HR), invasive blood pressure, electrocardiography, expired gases, respiratory frequency and esophageal temperature by an investigator unaware of the group allocation. Pelvic limb amputation by coxofemoral disarticulation was performed. Dogs that responded to surgical stimulation (>10% increase in HR or arterial pressure) were administered fentanyl (2 μg kg -1 ) intravenously for rescue analgesia. Postoperative pain was assessed at extubation; 30, 60 and 120 minutes; and the morning after surgery using a visual analog scale (VAS). The number of intraoperative fentanyl doses was fewer in the bupivacaine group (2.7±1.1 versus 6.0±2.2; p<0.01). Differences in physiologic variables were not clinically significant. VAS scores were lower in bupivacaine dogs at extubation (0.8±1.9 versus 3.8±2.5) and at 30 minutes (1.0±1.4 versus 4.3±2.1; p<0.05). Psoas compartment (lumbar plexus) and sacral plexus block provided analgesia during pelvic limb amputation in dogs. Copyright © 2017 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.

Investigating the role of capacitive coupling between the operating table and the return electrode of an electrosurgery unit in the modification of the current density distribution within the patients' body.

PubMed

Bifulco, Paolo; Massa, Rita; Cesarelli, Mario; Romano, Maria; Fratini, Antonio; Gargiulo, Gaetano D; McEwan, Alistair L

2013-08-12

Electrosurgery units are widely employed in modern surgery. Advances in technology have enhanced the safety of these devices, nevertheless, accidental burns are still regularly reported. This study focuses on possible causes of sacral burns as complication of the use of electrosurgery. Burns are caused by local densifications of the current, but the actual pathway of current within patient's body is unknown. Numerical electromagnetic analysis can help in understanding the issue. To this aim, an accurate heterogeneous model of human body (including seventy-seven different tissues), electrosurgery electrodes, operating table and mattress was build to resemble a typical surgery condition. The patient lays supine on the mattress with the active electrode placed onto the thorax and the return electrode on his back. Common operating frequencies of electrosurgery units were considered. Finite Difference Time Domain electromagnetic analysis was carried out to compute the spatial distribution of current density within the patient's body. A differential analysis by changing the electrical properties of the operating table from a conductor to an insulator was also performed. Results revealed that distributed capacitive coupling between patient body and the conductive operating table offers an alternative path to the electrosurgery current. The patient's anatomy, the positioning and the different electromagnetic properties of tissues promote a densification of the current at the head and sacral region. In particular, high values of current density were located behind the sacral bone and beneath the skin. This did not occur in the case of non-conductive operating table. Results of the simulation highlight the role played from capacitive couplings between the return electrode and the conductive operating table. The concentration of current density may result in an undesired rise in temperature, originating burns in body region far from the electrodes. This outcome is concordant with the type of surgery-related sacral burns reported in literature. Such burns cannot be immediately detected after surgery, but appear later and can be confused with bedsores. In addition, the dosimetric analysis suggests that reducing the capacity coupling between the return electrode and the operating table can decrease or avoid this problem.

F-18 FDG PET/CT findings of a case of sacral nerve root neurolymphomatosis that occurred during chemotherapy.

PubMed

Suga, Kazuyoshi; Yasuhiko, Kawakami; Matsunaga, Naofumi; Yujiri, Toshiaki; Nakazora, Tatsuki; Ariyoshi, Kouichi

2011-01-01

Neurolymphomatosis (NL) is a rare, unique subtype of lymphomatous infiltration of peripheral nerves. Clinical/radiologic diagnosis of NL is challenging. We report F-18 FDG PET/CT findings of a case of breast diffuse large B-cell lymphoma, in which NL developed regardless of regression of systemic lesions during induction chemotherapy. FDG PET/CT showed characteristic findings of well-demarcated, linear abnormal FDG uptake along a sacral vertebral foramen, leading to diagnosis of NL, with the finding of thickened nerve roots on magnetic resonance imaging. Altered chemotherapeutic regimen resulted in disappearance of these abnormal FDG uptake, with recovery of neurologic symptoms. Peripheral nerve NL may occur during chemotherapy, and FDG PET/CT can be a useful imaging modality in diagnosis and monitoring of therapeutic response of this disease.

Transient urinary retention and chronic neuropathic pain associated with genital herpes simplex virus infection.

PubMed

Haanpää, Maija; Paavonen, Jorma

2004-10-01

Genital herpes (GH) causes genital ulcer disease, severe transient pain, and often paresthesias. Whether or not GH can cause urinary retention or chronic neuropathic pain is not well known. We present two immunocompetent patients with GH associated with neuropathic symptoms. We also review the literature on GH and associated neurologic problems. Patient 1 had primary herpes simplex virus (HSV)-2 infection with transient urinary retention and chronic bilateral neuropathic pain in the sacral area. Patient 2 had recurrent HSV-1 associated with unitaleral chronic neuropathic pain in the sacral area. Although transient urinary retention associated with GH is not uncommon, chronic neuropathic pain has not been reported previously. Our cases show that chronic neuropathic pain, that is "pain initiated or caused by a primary lesion or dysfunction in the nervous system," can follow genital HSV infection.

Transient paraplegia due to accidental intrathecal bupivacaine infiltration following pre-emptive analgesia in a patient with missed sacral dural ectasia.

PubMed

Kanna, P Rishimugesh; Sekar, Chelliah; Shetty, Ajoy Prasad; Rajasekaran, Shanmughanathan

2010-11-15

A case report with review of the literature. To highlight the need for careful magnetic resonance imaging evaluation for the presence of incidental lumbosacral dural anomalies before attempting caudal epidural interventions. Pre-emptive analgesia through the caudal epidural route provides good postoperative pain relief in spine surgeries. Several precautions have been advised in the literature. Presence of sacral-dural ectasia should be considered a relative contraindication for this procedure. A 50-year old woman underwent posterior instrumented spinal fusion for L4-L5 spondylolisthesis under general anesthesia. She received single shot caudal epidural analgesia at the start of the procedure. After complete emergence from anesthesia, she had complete motor and sensory loss below the T12 spinal level, which reversed to normal neurology in 6 hours. Retrospective evaluation of the patient's magnetic resonance imaging showed an ectatic, low lying lumbosacral dural sac which had been overlooked in the initial evaluation. The drugs given by the caudal route have been accidentally administered into the thecal sac causing a brief period of neurologic deficit. This unexpected complication has been reported only in the pediatric literature before. It is important to look for the presence of lumbosacral dural anomalies before planning caudal epidural injections in adults also. Sacral dural ectasia and other lumbosacral anomalies must be recognized as contraindications for caudal epidural pre-emptive analgesia for spine surgery. Other modes of postoperative pain relief should be tried in these patients.

A new technique for long time catheterization of sacral epidural canal in rabbits.

PubMed

Erkin, Yüksel; Aydın, Zeynep; Taşdöğen, Aydın; Karcı, Ayşe

2013-01-01

In this study we aimed to develop a simple and practical technique for chronic sacral epidural catheterization of rabbits. We included ten rabbits weighing 2-2.5 kg in the study. After anesthesia and analgesia, we placed an epidural catheter by a 2 cm longitudinal skin incision in the tail above the sacral hiatus region. We confirmed localization by giving 1% lidocaine (leveling sensory loss and motor function loss of the lower extremity). The catheter was carried forward through a subcutaneous tunnel and fixed at the neck. Chronic caudal epidural catheter placement was succesful in all rabbits. The catheters stayed in place effectively for ten days. We encountered no catheter complications during this period. The localization of the catheter was reconfirmed by 1% lidocaine on the last day. After animals killing, we performed a laminectomy and verified localization of the catheter in the epidural space. Various methods for catheterization of the epidural space in animal models exist in the literature. Epidural catheterization of rabbits can be accomplished by atlanto-occipital, lumbar or caudal routes by amputation of the tail. Intrathecal and epidural catheterization techniques defined in the literature necessitate surgical skill and knowledge of surgical procedures like laminectomy and tail amputation. Our technique does not require substantial surgical skill, anatomical integrity is preserved and malposition of the catheter is not encountered. In conclusion, we suggest that our simple and easily applicable new epidural catheterization technique can be used as a model in experimental animal studies.

Prevention of internal hernias and pelvic adhesions following laparoscopic left-sided colorectal resection: the role of fibrin sealant.

PubMed

Angelini, Pierluigi; Sciuto, Antonio; Cuccurullo, Diego; Pirozzi, Felice; Reggio, Stefano; Corcione, Francesco

2017-07-01

Laparoscopy has increasingly become the standard of care for patients who undergo colorectal surgery for both benign and malignant diseases. This growing experience has also resulted in more reports of postoperative complications from the minimally invasive approach to primary colorectal resection. Small bowel obstruction from internal hernias and pre-sacral adhesions is an uncommon but not negligible complication. However, there is little literature specific to this topic with recommendations for different methods to prevent it. We report our original technique of closing the mesenteric defect and covering the pre-sacral fascia by using fibrin sealant to prevent this complication. From January 2005 to December 2014, a total of 1079 patients underwent elective laparoscopic left colorectal resection (left hemicolectomy or anterior rectal resection) in our department. In the first 298 procedures, the mesenteric defect was left open, while in the following 781 procedures, it was closed using fibrin sealant with the aim of preventing postoperative small bowel obstruction. Among the first 298 patients, three (1%) required reoperation for small bowel obstruction due to internal hernia (0.33%) or critical pre-sacral adhesions (0.66%). These complications did not occur in the subsequent series in which all 781 patients were treated with fibrin sealant prophylactic closure of the mesenteric defect. In our experience, fibrin sealant closure of the mesenteric defect has demonstrated to be safe and effective in preventing postoperative small bowel obstruction that remains a complication both in open and in laparoscopic colorectal surgeries.

Hydronephrosis Presenting 6 Months After Sacral Colpopexy: Case Report and Literature Review.

PubMed

Weber LeBrun, Emily; Santamaria, Estefania; Moy, Louis

The aim of this study was to describe a case of uterovaginal prolapse managed with robotic-assisted sacral colpopexy complicated by severe right-sided hydronephrosis despite normal intraoperative cystoscopy. A 68-year-old woman presented with a worsening vaginal bulge over the past 2 years. Tricompartment stage 2 uterovaginal prolapse, with dominant cystocele and skin erosion at the posterior fourchette from prolapse friction, was identified on physical examination, and the patient underwent pelvic reconstructive surgery, including sacral colpopexy. The patient was discharged on postoperative day 4 after being treated for a urinary tract infection. At her 6-week postoperative visit, the patient demonstrated normal vaginal support. She presented 6 months postoperatively with right-sided hydronephrosis with an almost imperceptible stricture where the right iliac vessels cross the pelvic brim, demonstrating a delayed manifestation of ureteral injury. She underwent open ureteroscopy, ureteroneocystostomy with vesicopsoas hitch, and ureteral stent placement. Ureteroscopy demonstrated a very mild narrowed caliber of the ureter just above the sacroiliac joint without overt obstruction. Follow-up intravenous pyelogram demonstrated no evidence of damage or obstruction. At nearly 1-year follow-up, the patient remained asymptomatic and had normal renal function. This case demonstrates the challenges of an uncommon, but highly morbid, complication of pelvic reconstructive surgery. Even when adequate visualization of the ureters and delicate ureteral dissection is achieved throughout surgery, occult injuries can still occur. Surgeons should maintain a high index of suspicion of ureteral injury when evaluating patients for late presentations of postoperative complications.

Frequency of an accessory popliteal efferent lymphatic pathway in dogs.

PubMed

Mayer, Monique N; Sweet, Katherine A; Patsikas, Michael N; Sukut, Sally L; Waldner, Cheryl L

2018-05-01

Staging and therapeutic planning for dogs with malignant disease in the popliteal lymph node are based on the expected patterns of lymphatic drainage from the lymph node. The medial iliac lymph nodes are known to receive efferent lymph from the popliteal lymph node; however, an accessory popliteal efferent pathway with direct connection to the sacral lymph nodes has also been less frequently reported. The primary objective of this prospective, anatomic study was to describe the frequency of various patterns of lymphatic drainage of the popliteal lymph node. With informed client consent, 50 adult dogs with no known disease of the lymphatic system underwent computed tomographic lymphography after ultrasound-guided, percutaneous injection of 350 mg/ml iohexol into a popliteal lymph node. In all 50 dogs, the popliteal lymph node drained directly to the ipsilateral medial iliac lymph node through multiple lymphatic vessels that coursed along the medial thigh. In 26% (13/50) of dogs, efferent vessels also drained from the popliteal lymph node directly to the internal iliac and/or sacral lymph nodes, coursing laterally through the gluteal region and passing over the dorsal aspect of the pelvis. Lymphatic connections between the right and left medial iliac and right and left internal iliac lymph nodes were found. Based on our findings, the internal iliac and sacral lymph nodes should be considered when staging or planning therapy for dogs with malignant disease in the popliteal lymph node. © 2018 American College of Veterinary Radiology.

Effectiveness of using a new polyurethane foam multi-layer dressing in the sacral area to prevent the onset of pressure ulcer in the elderly with hip fractures: A pragmatic randomised controlled trial.

PubMed

Forni, Cristiana; D'Alessandro, Fabio; Gallerani, Pina; Genco, Rossana; Bolzon, Andrea; Bombino, Caterina; Mini, Sandra; Rocchegiani, Laura; Notarnicola, Teresa; Vitulli, Arianna; Amodeo, Alfredo; Celli, Guglielmo; Taddia, Patrizia

2018-06-01

Hip fractures in the elderly are a serious problem for the health service due to the high rate of complications. One of these complications is pressure ulcers that, according to the literature, occur in 8.8% to 55% of patients and mainly arise in the sacral area. The present randomised controlled trial tests whether applying a new innovative multi-layer polyurethane foam dressing (ALLEVYN LIFE™), reduces the onset of pressure ulcers in the sacral area. From March to December 2016, 359 fragility hip fracture patients were randomly divided into 2 groups: 182 in the control group and 177 in the experimental group. Pressure ulcers occurred overall in 36 patients (10%): 8 patients (4.5%) in the experimental group compared to 28 (15.4%) in the control group: P = 0.001, relative risk 0.29 (95% CI 0.14-0.61) with NNT of 9 (95% CI 6-21). In the experimental group the onset of pressure ulcers occurred on average on the 6th day compared to the 4th day in the control group (HR 4.4). Using polyurethane foam is effective at reducing the rate of pressure ulcers in the sacrum in elderly patients with hip fracture. The adhesiveness of this device also enables costs to be kept down. © 2018 The Authors. International Wound Journal published by Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Hydrogen Embrittlement in 17-4PH Stainless Steel

DTIC Science & Technology

1982-08-01

is observed to exhibit microplastic tearing mixed with some quasi- cleavage. When exposed to longer hydrogen charging times, specimens in the higher...Hours, (a) Central Region Illustrating Dimpled Rupture, (b) and 0-) Shell Region Near Edge Exhibiting Microplastic Tearing. 20 NTAC TP 6 3 43 (a) (b) (c...Shell Region Near Edge Exhibiting Microplastic Tearing. 21 ’JWC TP 6343 FIGURE 15. SEM Fractographv Showing Intergranular Fracture (if 17-4PH- in

The effect of scandium addition on microstructure and mechanical properties of Al–Si–Mg alloy: A multi-refinement modifier

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Cong, E-mail: xucong55555@gmail.com; Xiao, Wenlong, E-mail: wlxiao@buaa.edu.cn; Hanada, Shuji

2015-12-15

Effect of scandium (Sc) additions on the microstructure, mechanical properties and fracture behavior of Al–Si–Mg casting alloy (F357) were systematically investigated. It was found that Sc addition caused a multi-refining efficiency on the microstructure of as-cast F357 alloy, including refinement of grains and secondary dendrite arm spacing (SDAS), modification of eutectic Si and harmless disposal of β-Al{sub 5}FeSi phase. Subsequent T6 heat treatment had further induced the complete spheroidization of eutectic Si and precipitation of fine secondary Al{sub 3}Sc dispersoids in the Sc modified alloys. Thus the mechanical properties, especially the ductility, were significantly enhanced by the addition of Scmore » combined with the heat treatment. The highest ultimate tensile strength, yield strength and elongation were achieved in 0.8 wt.% Sc modified F357 alloy combined with T6 heat treatment. Furthermore, fractographic examinations indicated that the ductile fracture mechanism served as a dominate role in the modified alloys due to the formation of fine, deep and uniformly distributed dimples. - Highlights: • Detailed characterization of the multi-refining microstructure of Sc modified F357 alloy was performed. • The multi-refinement was proposed to refine grain and SDAS, modify eutectic Si and β-phase. • Sc modifier combined with T6 treatment is effective in improving tensile properties. • Modification of eutectic Si in F357 alloy with Sc is consistent with the IIT mechanism.« less

Corrosion fatigue behaviors of two biomedical Mg alloys - AZ91D and WE43 - In simulated body fluid.

PubMed

Gu, X N; Zhou, W R; Zheng, Y F; Cheng, Y; Wei, S C; Zhong, S P; Xi, T F; Chen, L J

2010-12-01

Magnesium alloys have been recently developed as biodegradable implant materials, yet there has been no study concerning their corrosion fatigue properties under cyclic loading. In this study the die-cast AZ91D (A for aluminum 9%, Z for zinc 1% and D for a fourth phase) and extruded WE43 (W for yttrium 4%, E for rare earth mischmetal 3%) alloys were chosen to evaluate their fatigue and corrosion fatigue behaviors in simulated body fluid (SBF). The die-cast AZ91D alloy indicated a fatigue limit of 50MPa at 10⁷ cycles in air compared to 20MPa at 10⁶ cycles tested in SBF at 37°C. A fatigue limit of 110MPa at 10⁷ cycles in air was observed for extruded WE43 alloy compared to 40MPa at 10⁷ cycles tested in SBF at 37°C. The fatigue cracks initiated from the micropores when tested in air and from corrosion pits when tested in SBF, respectively. The overload zone of the extruded WE43 alloy exhibited a ductile fracture mode with deep dimples, in comparison to a brittle fracture mode for the die-cast AZ91D. The corrosion rate of the two experimental alloys increased under cyclic loading compared to that in the static immersion test. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Urinary Incontinence Surgery: When Other Treatments Aren't Enough

MedlinePlus

... surgery. Certain procedures to treat overactive bladder involve stimulation — using small, electrical impulses — of the nerves that signal the need to urinate. Sacral nerve stimulation. Your surgeon implants a small, pacemaker-like device ...

Testing the assumption of normality in body sway area calculations during unipedal stance tests with an inertial sensor.

PubMed

Kyoung Jae Kim; Lucarevic, Jennifer; Bennett, Christopher; Gaunaurd, Ignacio; Gailey, Robert; Agrawal, Vibhor

2016-08-01

The quantification of postural sway during the unipedal stance test is one of the essentials of posturography. A shift of center of pressure (CoP) is an indirect measure of postural sway and also a measure of a person's ability to maintain balance. A widely used method in laboratory settings to calculate the sway of body center of mass (CoM) is through an ellipse that encloses 95% of CoP trajectory. The 95% ellipse can be computed under the assumption that the spatial distribution of the CoP points recorded from force platforms is normal. However, to date, this assumption of normality has not been demonstrated for sway measurements recorded from a sacral inertial measurement unit (IMU). This work provides evidence for non-normality of sway trajectories calculated at a sacral IMU with injured subjects as well as healthy subjects.

Water-cooled radiofrequency neuroablation for sacroiliac joint dysfunctional pain

PubMed Central

Biswas, Binay Kumar; Dey, Samarjit; Biswas, Saumya; Mohan, Varinder Kumar

2016-01-01

Sacroiliac (SI) joint dysfunction is a common source of chronic low-back pain. Recent evidences from different parts of the world suggest that cooled radiofrequency (RF) neuroablation of sacral nerves supplying SI joints has superior pain alleviating properties than available existing treatment options for SI joint dysfunctional pain. A 35-year-old male had intractable bilateral SI joint pain (numeric rating scale [NRS] – 9/10) with poor treatment response to intra-articular steroid therapy. Bilateral water cooled = RF was applied for neuroablation of nerves supplying both SI joints. Postprocedure pain intensity was 5/10 and after 7 days it was 2/10. On 18th-month follow-up, he is pain free except for mild pain (NRS 2/10) on occasional extreme twisting of the back. This case attempts to highlight that sacral neuroablation based on cooled RF technique can be a long lasting remedial option for chronic SI joint pain unresponsive to conventional treatment. PMID:28096589

Water-cooled radiofrequency neuroablation for sacroiliac joint dysfunctional pain.

PubMed

Biswas, Binay Kumar; Dey, Samarjit; Biswas, Saumya; Mohan, Varinder Kumar

2016-01-01

Sacroiliac (SI) joint dysfunction is a common source of chronic low-back pain. Recent evidences from different parts of the world suggest that cooled radiofrequency (RF) neuroablation of sacral nerves supplying SI joints has superior pain alleviating properties than available existing treatment options for SI joint dysfunctional pain. A 35-year-old male had intractable bilateral SI joint pain (numeric rating scale [NRS] - 9/10) with poor treatment response to intra-articular steroid therapy. Bilateral water cooled = RF was applied for neuroablation of nerves supplying both SI joints. Postprocedure pain intensity was 5/10 and after 7 days it was 2/10. On 18 th -month follow-up, he is pain free except for mild pain (NRS 2/10) on occasional extreme twisting of the back. This case attempts to highlight that sacral neuroablation based on cooled RF technique can be a long lasting remedial option for chronic SI joint pain unresponsive to conventional treatment.

Managing the urinary tract in spinal cord injury

PubMed Central

Harrison, Simon C. W.

2010-01-01

This review sets out to provide an overview of the author’s approach to the management of the urinary tract in the patient who has suffered from an injury to their spinal cord. Emphasis is given to the need to understand the fundamental pathophysiological patterns that are seen with injuries that involve the sacral segments of the cord (the conus) and those that spare the conus but interrupt communication between the sacral parasympathetic and somatic centers and the brain (supraconal lesions). The importance of patient participation in management decisions is highlighted by considering the different ways in which the urinary tract can be managed and how the clinician needs to try to meet patient expectations and requirements while establishing safe urological management. Finally, consideration is given to the importance of establishing an appropriate follow up regime and managing urinary tract complications effectively. PMID:20877604

Sacral hemangiopericytoma involving the retrorectal space: report of a case.

PubMed

Zentar, Aziz; Sall, Ibrahima; Ali, Abdelmounaim Ait; Bouchentouf, Sidi Mohammed; Quamous, Mohammed; Chahdi, Hafsa; Hajjouji, Abderahmane; Fahssi, Mohammed; El Kaoui, Hakim; Al Bouzidi, Abderahmane; Marjani, Mohammed; Sair, Khalid; Bousselmame, Nabil

2009-01-01

A primary hemangiopericytoma (HP) of the bone is rare, because the vast majority of these tumors arise in soft tissue. This report presents a case of a hemangiopericytoma in the sacrum (S1-S2) with extension to the retrorectal space. Only a few cases of osseous hemangiopericytomas in the sacrum and involving the retrorectal space have so far been reported. The difficult diagnosis of HP and the surgical strategy was chosen according to the location of the lesion in the sacrum and retrorectal space. A local excision was indicated. A sacral resection should be considered for tumors below S4. This report demonstrated the safety of this strategy. Adjuvant radiotherapy is useful in HP. The value of chemotherapy is still doubtful, although patients with high-grade tumors or metastatic spread seem to gain substantial benefit. Due to the often unpredictable behavior of this neoplasm, extended follow-up is strongly recommended.

Multifocal Spinal Cord Nephroblastoma in a Dog.

PubMed

Henker, L C; Bianchi, R M; Vargas, T P; de Oliveira, E C; Driemeier, D; Pavarini, S P

2018-01-01

A 1-year-old male American pit bull terrier was presented with a history of proprioceptive deficits and mild lameness of the right hindlimb, which progressed after 5 months to paraparesis, culminating in tetraparesis after 2 weeks. Necropsy findings were limited to the spinal cord and consisted of multiple, intradural, extramedullary, slightly red masses which produced segmental areas of medullary swelling located in the cervical intumescence, thoracolumbar column, sacral segment and cauda equina. Histological evaluation revealed a tumour, composed of epithelial, stromal and blastemal cells, with structures resembling tubules, acini and embryonic glomeruli. Immunohistochemical labelling for vimentin, cytokeratin and S100 was positive for the stromal, epithelial and blastemal cells, respectively. A final diagnosis of multifocal spinal cord nephroblastoma was established. This is the first report of such a tumour showing concomitant involvement of the cervicothoracic, thoracolumbar, sacral and cauda equina areas of the spinal cord. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Significance of the sagittal profile and reposition of grade III-V spondylolisthesis].

PubMed

Dick, W; Elke, R

1997-09-01

The deformity in severe spondylolisthesis consists of two components: the parallel anterocaudad slip of the spondylolisthetic vertebra, and its tilt into kyphotic malposition. The influence of the two components is very different: the anterocaudad slippage has not much impact on the sagittal profile of the spine and is easily compensated for by a slight increase in lumbar lordosis. The kyphotic deformity has a high impact on trunk imbalance and the sagittal profile. There are two compensation mechanisms: hyperlordosis of the lumbar spine to its anatomical extremes and-if that is not sufficient-verticalisation of the sacral bone, performed by contracture of the hamstrings and uprighting of the pelvis around the hip joints. The latter mechanism is followed by functional disadvantages. Therefore, correction of the kyphosis of L5 may be considered during operative treatment if the lumbosacral kyphosis (angle delta) is less than 85 degrees and the sacral inclination less than 35 degrees.

Progressive dysautonomia in two patients with xeroderma pigmentosum group A.

PubMed

Kobayashi, Osamu; Miyahara, Hiroaki; Abe, Naho; Goto, Chika; Okanari, Kazuo; Akiyoshi, Kensuke; Korematsu, Seigo; Izumi, Tatsuro

2014-06-01

Xeroderma pigmentosum group A (XPA) is a rare autosomal-recessive disorder caused by a defect in nucleotide excision repair. Progressive dysautonomia in patients with XPA is rarely described. Two juvenile male patients with XPA suffered from dysphagia, sleep interruption, and dysuria from the age of 10 to 19 years, successively. These autonomic symptoms might have been caused by progressive descending degeneration of cranial nerves IX and X and the sacral parasympathetic nerve, including Onuf's nucleus. One patient died from sudden cardiopulmonary arrest during postural change and tracheal suction. Heart rate variability analyses of these patients revealed parasympathetic dysautonomia, based on decreased high-frequency values. The insidiously progressive dysautonomia in these two patients with XPA suggested progressive descending degeneration extending from the medulla oblongata to the sacral spinal cord, which is an ominous sign of end-stage disease and a risk factor of sudden death attributable to XPA. Copyright © 2014 Elsevier Inc. All rights reserved.

Intraoperative indocyanine green fluorescent angiography-assisted modified superior gluteal artery perforator flap for reconstruction of sacral pressure sores.

PubMed

Chang, Chun-Kai; Wu, Chien-Ju; Chen, Chun-Yu; Wang, Chi-Yu; Chu, Tzi-Shiang; Hsu, Kuo-Feng; Chiu, Han-Ting; Liu, Hung-Hui; Chou, Chang-Yi; Wang, Chih-Hsin; Lin, Chin-Ta; Dai, Niann-Tzyy; Tzeng, Yuan-Sheng

2017-12-01

Pressure sores are often observed in patients who are bedridden. They can be a severe problem not only for patients and their caregivers but also for plastic surgeons. Here, we describe a new method of superior gluteal artery perforator flap harvesting and anchoring with the assistance of intraoperative indocyanine green fluorescent angiography. In this report, we describe the procedure and outcomes for 19 patients with grades III and IV sacral pressure sores who underwent the operation between September 2015 and November 2016. All flaps survived, and two experienced wound-edge partial dehiscence. With the assistance of this imaging device, we were able to acquire a reliable superior gluteal artery perforator flap and perform modified operations with it that are safe, easy to learn and associated with fewer complications than are traditional. © 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

The biology of herpes simplex virus infection in humans.

PubMed

Baringer, J R

1976-01-01

Herpes simplex virus is a frequent cause of recurrent ocular, oral, genital or cutaneous eruptions in man. Lesions are highly localized and tend to recur at the same site. Among the most consistent factors provoking recurrence is root section of the trigeminal nerve. Clinical and experimental data suggest that herpes simplex virus is commonly resident within the trigeminal ganglia of man, where it may be responsible for recurrent oral or lip lesions, and is less frequently a resident of the second or third sacral ganglia where it might be responsible for genital eruptions. Generally, the trigeminal virus is type 1 and the sacral virus is type 2; the virus is only rarely recoverable from other sensory ganglia. Factors provoking the reactivation from the virus' latent site and the mechanism for reactivation remain largely unknown. Further study is needed to understand the behavior of HSV and other viruses in nervous system tissue.

Sacral Herpes Zoster Associated with Voiding Dysfunction in a Young Patient with Scrub Typhus.

PubMed

Hur, Jian

2015-06-01

When a patient presents with acute voiding dysfunction without a typical skin rash, it may be difficult to make a diagnosis of herpes zoster. Here, we present a case of scrub typhus in a 25-year-old man with the complication of urinary dysfunction. The patient complained of loss of urinary voiding sensation and constipation. After eight days, he had typical herpes zoster eruptions on the sacral dermatomes and hypalgesia of the S1-S5 dermatomes. No cases of dual infection with varicella zoster virus and Orientia tsutsugamushi were found in the literature. In the described case, scrub typhus probably induced sufficient stress to reactivate the varicella zoster virus. Early recognition of this problem is imperative for prompt and appropriate management, as misdiagnosis can lead to long-term urinary dysfunction. It is important that a diagnosis of herpes zoster be considered, especially in patients with sudden onset urinary retention.

Sacral Herpes Zoster Associated with Voiding Dysfunction in a Young Patient with Scrub Typhus

PubMed Central

2015-01-01

When a patient presents with acute voiding dysfunction without a typical skin rash, it may be difficult to make a diagnosis of herpes zoster. Here, we present a case of scrub typhus in a 25-year-old man with the complication of urinary dysfunction. The patient complained of loss of urinary voiding sensation and constipation. After eight days, he had typical herpes zoster eruptions on the sacral dermatomes and hypalgesia of the S1-S5 dermatomes. No cases of dual infection with varicella zoster virus and Orientia tsutsugamushi were found in the literature. In the described case, scrub typhus probably induced sufficient stress to reactivate the varicella zoster virus. Early recognition of this problem is imperative for prompt and appropriate management, as misdiagnosis can lead to long-term urinary dysfunction. It is important that a diagnosis of herpes zoster be considered, especially in patients with sudden onset urinary retention. PMID:26157595

Loss of urinary voiding sensation due to herpes zoster.

PubMed

Hiraga, Akiyuki; Nagumo, Kiyomi; Sakakibara, Ryuji; Kojima, Shigeyuki; Fujinawa, Naoto; Hashimoto, Tasuku

2003-01-01

A case of sacral herpes zoster infection in a 56-year-old man with the complication of loss of urinary voiding sensation is presented. He had typical herpes zoster eruption on the left S2 dermatome, hypalgesia of the S1-S4 dermatomes, and absence of urinary voiding sensation. There was no other urinary symptom at the first medical examination. Urinary complications associated with herpes zoster are uncommon, but two types, acute cystitis and acute retention, have been recognized. No cases of loss of urinary voiding sensation due to herpes zoster have been reported. In this case, hypalgesia of the sacral dermatomes was mild compared to the marked loss of urethral sensation. This inconsistency is explained by the hypothesis that the number of urethral fibers is very small as compared to that of cutaneous fibers, therefore, urethral sensation would be more severely disturbed than cutaneous sensation. Copyright 2003 Wiley-Liss, Inc.

Procedural techniques in sacral nerve modulation.

PubMed

Williams, Elizabeth R; Siegel, Steven W

2010-12-01

Sacral neuromodulation involves a staged process, including a screening trial and delayed formal implantation for those with substantial improvement. The advent of the tined lead has revolutionized the technology, allowing for a minimally invasive outpatient procedure to be performed under intravenous sedation. With the addition of fluoroscopy to the bilateral percutaneous nerve evaluation, there has been marked improvement in the placement of these temporary leads. Thus, the screening evaluation is now a better reflection of possible permanent improvement. Both methods of screening have advantages and disadvantages. Selection of a particular procedure should be tailored to individual patient characteristics. Subsequent implantation of the internal pulse generator (IPG) or explantation of an unsuccessful staged lead is straightforward outpatient procedure, providing minimal additional risk for the patient. Future refinement to the procedure may involve the introduction of a rechargeable battery, eliminating the need for IPG replacement at the end of the battery life.

Bounce Rock Dimple

NASA Technical Reports Server (NTRS)

2004-01-01

This panoramic camera image shows the hole drilled by the Mars Exploration Rover Opportunity's rock abrasion tool into the rock dubbed 'Bounce' on Sol 65 of the rover's journey. The tool drilled about 7 millimeters (0.3 inches) into the rock and generated small piles of 'tailings' or rock dust around the central hole, which is about 4.5 centimeters (1.7 inches) across. The image from sol 66 of the mission was acquired using the panoramic camera's 430 nanometer filter.

Interlocking egg-crate type grid assembly

DOEpatents

Kast, Steven J.

1987-01-01

Disclosed is an interlocking egg-crate hexagonal grid for supporting a nuclear fuel pin in a hexagonal array. The grid is formed from strips bent at an angle of about 120.degree. at each vertex. Over some faces of each hexagonal cell the strips are coplanar but are arranged, by stacking and interlocking, to avoid any double thickness of metal in that plane. Springs and dimples are formed in the faces of each cell to hold the fuel pin substantially centered.

Interlocking egg-crate type grid assembly

DOEpatents

Kast, S.J.

1985-03-15

Disclosed is an interlocking egg-crate hexagonal grid for supporting a nuclear fuel pin in a hexagonal array. The grid is formed from strips bent at an angle of about 120/sup 0/ at each vertex. Over some faces of each hexagonal cell the strips are coplanar but are arranged, by stacking interlocking, to avoid any double thickness of metal in that plane. Springs and dimples are formed in the faces of each cell to hold the fuel pin substantially centered.

Use of Dimples to Suppress Boundary Layer Separation on a Low Pressure Turbine Blade

DTIC Science & Technology

2002-12-01

Brayton cycle for an ideal gas turbine engine.............................................. 11 Figure 5. T-S diagram for a non-ideal turbine stage...engine efficiency is well illustrated with a T-S diagram, where T is temperature and S is entropy. The ideal jet engine is represented with the Brayton ...the Brayton cycle represents an ideal engine, no losses are present, and entropy is not produced. Between station 3 and 4, fuel (energy) is added

Support grid for fuel elements in a nuclear reactor

DOEpatents

Finch, Lester M.

1977-01-01

A support grid is provided for holding nuclear fuel rods in a rectangular array. Intersecting sheet metal strips are interconnected using opposing slots in the strips to form a rectangular cellular grid structure for engaging the sides of a multiplicity of fuel rods. Spring and dimple supports for engaging fuel and guide rods extending through each cell in the support grid are formed in the metal strips with the springs thus formed being characterized by nonlinear spring rates.

Strengthening of NiAl Matrix Composites

DTIC Science & Technology

1991-10-01

taille des sous-grains. Les donn&s obtenues pour une serie d’exp&iences indiquent que hit densitc de dislocations croit lorsque Ia fraction volumique de...electrical discharge 8. H. Fujita. T. Tabata , K. Yoshida. N. Summida and S. Katagiri, Japan J. appl. Phys. II, 1522 (1972).machining, dimpling and ion...milling does not intro- 9. H. Fujita and T. Tabata , Japan J. appl. Phys. 12, 471 duce dislocations into the matrix. (1973). * In order to obtain realistic

A mechanism of protein-mediated fusion: coupling between refolding of the influenza hemagglutinin and lipid rearrangements.

PubMed Central

Kozlov, M M; Chernomordik, L V

1998-01-01

Although membrane fusion mediated by influenza virus hemagglutinin (HA) is the best characterized example of ubiquitous protein-mediated fusion, it is still not known how the low-pH-induced refolding of HA trimers causes fusion. This refolding involves 1) repositioning of the hydrophobic N-terminal sequence of the HA2 subunit of HA ("fusion peptide"), and 2) the recruitment of additional residues to the alpha-helical coiled coil of a rigid central rod of the trimer. We propose here a mechanism by which these conformational changes can cause local bending of the viral membrane, priming it for fusion. In this model fusion is triggered by incorporation of fusion peptides into viral membrane. Refolding of a central rod exerts forces that pull the fusion peptides, tending to bend the membrane around HA trimer into a saddle-like shape. Elastic energy drives self-assembly of these HA-containing membrane elements in the plane of the membrane into a ring-like cluster. Bulging of the viral membrane within such cluster yields a dimple growing toward the bound target membrane. Bending stresses in the lipidic top of the dimple facilitate membrane fusion. We analyze the energetics of this proposed sequence of membrane rearrangements, and demonstrate that this simple mechanism may explain some of the known phenomenological features of fusion. PMID:9726939

Biconcave shape of human red-blood-cell ghosts relies on density differences between the rim and dimple of the ghost's plasma membrane.

PubMed

Hoffman, Joseph F

2016-12-20

The shape of the human red blood cell is known to be a biconcave disk. It is evident from a variety of theoretical work that known physical properties of the membrane, such as its bending energy and elasticity, can explain the red-blood-cell biconcave shape as well as other shapes that red blood cells assume. But these analyses do not provide information on the underlying molecular causes. This paper describes experiments that attempt to identify some of the underlying determinates of cell shape. To this end, red-blood-cell ghosts were made by hypotonic hemolysis and then reconstituted such that they were smooth spheres in hypo-osmotic solutions and smooth biconcave discs in iso-osmotic solutions. The spherical ghosts were centrifuged onto a coated coverslip upon which they adhered. When the attached spheres were changed to biconcave discs by flushing with an iso-osmotic solution, the ghosts were observed to be mainly oriented in a flat alignment on the coverslip. This was interpreted to mean that, during centrifugation, the spherical ghosts were oriented by a dense band in its equatorial plane, parallel to the centrifugal field. This appears to be evidence that the difference in the densities between the rim and the dimple regions of red blood cells and their ghosts may be responsible for their biconcave shape.

Biconcave shape of human red-blood-cell ghosts relies on density differences between the rim and dimple of the ghost's plasma membrane

PubMed Central

Hoffman, Joseph F.

2016-01-01

The shape of the human red blood cell is known to be a biconcave disk. It is evident from a variety of theoretical work that known physical properties of the membrane, such as its bending energy and elasticity, can explain the red-blood-cell biconcave shape as well as other shapes that red blood cells assume. But these analyses do not provide information on the underlying molecular causes. This paper describes experiments that attempt to identify some of the underlying determinates of cell shape. To this end, red-blood-cell ghosts were made by hypotonic hemolysis and then reconstituted such that they were smooth spheres in hypo-osmotic solutions and smooth biconcave discs in iso-osmotic solutions. The spherical ghosts were centrifuged onto a coated coverslip upon which they adhered. When the attached spheres were changed to biconcave discs by flushing with an iso-osmotic solution, the ghosts were observed to be mainly oriented in a flat alignment on the coverslip. This was interpreted to mean that, during centrifugation, the spherical ghosts were oriented by a dense band in its equatorial plane, parallel to the centrifugal field. This appears to be evidence that the difference in the densities between the rim and the dimple regions of red blood cells and their ghosts may be responsible for their biconcave shape. PMID:27930321

INTERNAL LIMITING MEMBRANE PEELING-DEPENDENT RETINAL STRUCTURAL CHANGES AFTER VITRECTOMY IN RHEGMATOGENOUS RETINAL DETACHMENT.

PubMed

Hisatomi, Toshio; Tachibana, Takashi; Notomi, Shoji; Koyanagi, Yoshito; Murakami, Yusuke; Takeda, Atsunobu; Ikeda, Yasuhiro; Yoshida, Shigeo; Enaida, Hiroshi; Murata, Toshinori; Sakamoto, Taiji; Sonoda, Koh-Hei; Ishibashi, Tatsuro

2018-03-01

To examine retinal changes after vitrectomy with internal limiting membrane (ILM) peeling, we used 3-dimensional optical coherence tomography (3D-OCT) in rhegmatogenous retinal detachment cases. The 68 eyes from 67 patients with rhegmatogenous retinal detachment were studied, including 35 detached macula cases (51%) and 33 attached macula cases. Internal limiting membrane peeling was performed with fine forceps after brilliant blue G staining. The 3D-OCT images were obtained with volume-rendering technologies from cross-sectional OCT images. The 3D-OCT detected 45 eyes (66%) with ILM peeling-dependent retinal changes, including dissociated optic nerve fiber layer appearance, dimple sign, temporal macular thinning, ILM peeling area thinning, or forceps-related retinal thinning. The ILM peeled area was detectable in only 9 eyes with 3D-OCT, whereas it was undetectable in other 59 eyes. The dissociated optic nerve fiber layer appearance was detected in 8 of the total cases (12%), and dimple signs were observed in 14 cases (21%). Forceps-related thinning was also noted in eight cases (24%) of attached macula cases and in four cases (11%) of detached macula cases. No postoperative macular pucker was noted in the observational period. The 3D-OCT clearly revealed spatial and time-dependent retinal changes after ILM peeling. The changes occurred in 2 months and remained thereafter.

Percutaneous cannulated screw fixation of sacral fractures and sacroiliac joint disruptions with CT-controlled guidewires performed by interventionalists: single center experience in treating posterior pelvic instability.

PubMed

Fischer, Sebastian; Vogl, Thomas J; Marzi, Ingo; Zangos, Stephan; Wichmann, Julian L; Scholtz, Jan-Erik; Mack, Martin G; Schmidt, Sven; Eichler, Katrin

2015-02-01

The purpose of our study was to evaluate minimally invasive sacroiliac screw fixation for treatment of posterior pelvic instability with the help of CT controlled guidewires, assess its accuracy, safety and effectiveness, and discuss potential pitfalls. 100 guidewires and hollow titan screws were inserted in 38 patients (49.6±19.5 years) suffering from 35 sacral fractures and/or 16 sacroiliac joint disruptions due to 33 (poly-)traumatic, 2 osteoporotic and 1 post-infectious conditions. The guidewire and screw positions were analyzed in multiplanar reconstructions. The mean minimal distance between guidewire and adjacent neural foramina was 4.5±2.01mm, with a distinctly higher precision in S1 than S2. Eight guidewires showed cortical contacts, resulting in a total of 2% mismatched screws with subsequent wall violation. The fracture gaps were reduced from 3.6±0.53mm to 1.2±0.54mm. During follow-up 3 cases of minor iatrogenic sacral impaction (<5mm) due to the bolting and 2 cases of screw loosening were observed. Interventional time was 84.0min with a mean of 2.63 screws per patient whilst acquiring a mean of 93.7 interventional CT-images (DLP 336.7mGycm). The treatment of posterior pelvic instability with a guidewire-based screw insertion technique under CT-imaging results in a very high accuracy and efficacy with a low complication rate. Careful attention should be drawn to radiation levels. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Anatomical organization and somatic axonal components of the lumbosacral nerves in female rabbits.

PubMed

Cruz, Yolanda; Hernández-Plata, Isela; Lucio, Rosa Angélica; Zempoalteca, René; Castelán, Francisco; Martínez-Gómez, Margarita

2017-09-01

To determine the anatomical organization and somatic axonal components of the lumbosacral nerves in female rabbits. Chinchilla adult anesthetized female rabbits were used. Anatomical, electrophysiological, and histological studies were performed. L7, S1, and some fibers from S2 and S3 form the lumbosacral trunk, which gives origin to the sciatic nerve and innervation to the gluteal region. From S2 to S3 originates the pudendal nerve, whose branches innervates the striated anal and urethra sphincters, as well as the bulbospongiosus, ischiocavernosus, and constrictor vulvae muscles. The sensory field of the pudendal nerve is ∼1800 mm 2 and is localized in the clitoral sheath and perineal and perigenital skin. The organization of the pudendal nerve varies between individuals, three patterns were identified, and one of them was present in 50% of the animals. From S3 emerge the pelvic nerve, which anastomoses to form a plexus localized between the vagina and the rectum. The innervation of the pelvic floor originates from S3 to S4 fibers. Most of the sacral spinal nerves of rabbit are mixed, carrying sensory, and motor information. Sacral nerves innervate the hind limbs, pelvic viscera, clitoris, perineal muscles, inguinal and anal glands and perineal, perigenital, and rump skin. The detailed description of the sacral nerves organization, topography, and axonal components further the knowledge of the innervation in pelvic and perinal structures of the female rabbit. This information will be useful in future studies about the physiology and physiopathology of urinary, fecal, reproductive, and sexual functions. © 2017 Wiley Periodicals, Inc.

Use of high-frequency ultrasonography for evaluation of skin thickness in relation to hydration status and fluid distribution at various cutaneous sites in dogs.

PubMed

Diana, Alessia; Guglielmini, Carlo; Fracassi, Federico; Pietra, Marco; Balletti, Erika; Cipone, Mario

2008-09-01

To assess the usefulness of high-frequency diagnostic ultrasonography for evaluation of changes of skin thickness in relation to hydration status and fluid distribution at various cutaneous sites in dogs. 10 clinically normal adult dogs (6 males and 4 females) of various breeds. Ultrasonographic examination of the skin was performed before and after hydration via IV administration of an isotonic crystalloid solution (30 mL/kg/h for 30 minutes). A 13-MHz linear-array transducer was used to obtain series of ultrasonographic images at 4 different cutaneous sites (the frontal, sacral, flank, and metatarsal regions). Weight and various clinicopathologic variables (PCV; serum osmolality; and serum total protein, albumin, and sodium concentrations) were determined before and after the infusion. These variables and ultrasonographic measurements of skin thickness before and after hydration were compared. Among the 10 dogs, mean preinfusion skin thickness ranged from 2,211 microm (metatarsal region) to 3,249 microm (sacral region). Compared with preinfusion values, weight was significantly increased, whereas PCV; serum osmolality; and serum total protein, albumin, and sodium concentrations were significantly decreased after infusion. After infusion, dermal echogenicity decreased and skin thickness increased significantly by 21%, 14%, 15%, and 13% in the frontal, sacral, flank, and metatarsal regions, respectively. Cutaneous site and hydration were correlated with cutaneous characteristics and skin thickness determined by use of high-frequency ultrasonography in dogs. Thus, diagnostic ultrasonography may be a useful tool for the noninvasive evaluation of skin hydration in healthy dogs and in dogs with skin edema.

Sacral medial telangiectatic vascular nevus: a study of 43 children.

PubMed

Patrizi, A; Neri, I; Orlandi, C; Marini, R

1996-01-01

Medial telangiectatic vascular nevi are capillary vascular malformations frequently observed at birth occurring mostly on the face or on the nape as a single lesion or as multiple macules affecting more than one site simultaneously. In 1990, Metzker and Shamir reported a medial telangiectatic vascular nevus (MTVN) in the sacral region along the midline and called this particular variety of MTVN 'butterfly-shaped mark'. Our study was performed to investigate the morphology and localization of an MTVN in the sacral region (sMTVN) in a group of Caucasian children. We observed 43 children with sMTVN, ranging in age from 1 month to 12 years (mean 8 years), for a period of 6 years. sMTVN was found as a red-violet macular lesion of rhomboid or triangular shape in 16 patients and as a group of little red-violet macules in 10 patients. In 16 patients moreover the whole back was involved with many small red-violet spots on and around the spinal column, and in 1 patient with classic sMTVN satellite macules were also present over both buttocks. Four patients suffered from epilepsy with mental deficiency. In 6 patients, the family history showed sMTVN in one or more members of the family. No case presented an association with spina bifida. In our study, sMTVN shows a morphological polymorphism while Metzker and Shamir reported the same clinical aspect in all 25 of their patients. In accordance with these authors, we noted that sMTVN persist into childhood and adult life in the same way as occipital MTVN.

The cost-benefit of using soft silicone multilayered foam dressings to prevent sacral and heel pressure ulcers in trauma and critically ill patients: a within-trial analysis of the Border Trial.

PubMed

Santamaria, Nick; Liu, Wei; Gerdtz, Marie; Sage, Sarah; McCann, Jane; Freeman, Amy; Vassiliou, Theresa; DeVincentis, Stephanie; Ng, Ai W; Manias, Elizabeth; Knott, Jonathan; Liew, Danny

2015-06-01

Little is known about the cost-benefit of soft silicone foam dressings in pressure ulcer (PU) prevention among critically ill patients in the emergency department (ED) and intensive care unit (ICU). A randomised controlled trial to assess the efficacy of soft silicone foam dressings in preventing sacral and heel PUs was undertaken among 440 critically ill patients in an acute care hospital. Participants were randomly allocated either to an intervention group with prophylactic dressings applied to the sacrum and heels in the ED and changed every 3 days in the ICU or to a control group with standard PU prevention care provided during their ED and ICU stay. The results showed a significant reduction of PU incidence rates in the intervention group (P = 0·001). The intervention cost was estimated to be AU$36·61 per person based on an intention-to-treat analysis, but this was offset by lower downstream costs associated with PU treatment (AU$1103·52). Therefore, the average net cost of the intervention was lower than that of the control (AU$70·82 versus AU$144·56). We conclude that the use of soft silicone multilayered foam dressings to prevent sacral and heel PUs among critically ill patients results in cost savings in the acute care hospital. © 2013 The Authors. International Wound Journal © 2013 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Effect of spinal anterior root stimulation and sacral deafferentation on bladder and sexual dysfunction in spinal cord injury.

PubMed

Zaer, Hamed; Rasmussen, Mikkel Mylius; Zepke, Franko; Bodin, Charlotte; Domurath, Burkhard; Kutzenberger, Johannes

2018-05-10

Spinal cord injury (SCI) is a highly devastating injury with a variety of complications; among them are neurogenic bladder, bowel, and sexual dysfunction. We aimed to evaluate the effect of sacral anterior root stimulation with sacral deafferentation (SARS-SDAF) on neurogenic bladder and sexual dysfunction in a large well-defined spinal cord injury cohort. In the manner of cross-sectional study, subjects undergone SARS-SDAF between September 1986 and July 2011 answered a questionnaire concerning conditions before and after surgery in the department of Neuro-Urology, Bad Wildungen, Germany. In total 287 of 587 subjects were analyzed. Median age was 49 years (range 19-80), median time from SCI to surgery was 10 years (range 0-49), and from surgery to follow-up 13 years (range 1-25). Of the analyzed subjects, 100% of both gender used SARS for bladder emptying. On the visual analogue scale (VAS) ranging from 0 to 10 (best), satisfaction with SARS-SDAF was 10 concerning bladder emptying, however 5 and 8 regarding sexual performance, for female and male users, respectively. Baseline and follow-up comparison showed a decline in self-intermittent catheterization (p < 0.0001), partial catheterization by attendant (p = 0.0125), complete catheterization and suprapubic catheterization (p < 0.0001), transurethral catheterization (p < 0.0011), and fewer cases of involuntary urine leakage (p < 0.0001). The SARS-SDAF is a beneficial multi-potential treatment method with simultaneous positive effect on multi-organ dysfunction among SCI subjects.

Anterior Cervical Discectomy and Fusion Alters Whole-Spine Sagittal Alignment

PubMed Central

Kim, Jang Hoon; Yi, Seong; Kim, Kyung Hyun; Kuh, Sung Uk; Chin, Dong Kyu; Kim, Keun Su; Cho, Yong Eun

2015-01-01

Purpose Anterior cervical discectomy and fusion (ACDF) has become a common spine procedure, however, there have been no previous studies on whole spine alignment changes after cervical fusion. Our purpose in this study was to determine whole spine sagittal alignment and pelvic alignment changes after ACDF. Materials and Methods Forty-eight patients who had undergone ACDF from January 2011 to December 2012 were enrolled in this study. Cervical lordosis, thoracic kyphosis, lumbar lordosis, sagittal vertical axis (SVA), and pelvic parameters were measured preoperatively and at 1, 3, 6, and 12 months postoperatively. Clinical outcomes were assessed using Visual Analog Scale (VAS) scores and Neck Disability Index (NDI) values. Results Forty-eight patients were grouped according to operative method (cage only, cage & plate), operative level (upper level: C3/4 & C4/5; lower level: C5/6 & C6/7), and cervical lordosis (high lordosis, low lordosis). All patients experienced significant improvements in VAS scores and NDI values after surgery. Among the radiologic parameters, pelvic tilt increased and sacral slope decreased at 12 months postoperatively. Only the high cervical lordosis group showed significantly-decreased cervical lordosis and a shortened SVA postoperatively. Correlation tests revealed that cervical lordosis was significantly correlated with SVA and that SVA was significantly correlated with pelvic tilt and sacral slope. Conclusion ACDF affects whole spine sagittal alignment, especially in patients with high cervical lordosis. In these patients, alteration of cervical lordosis to a normal angle shortened the SVA and resulted in reciprocal changes in pelvic tilt and sacral slope. PMID:26069131

Minimally invasive trans-sacral approach to L5-S1 interbody fusion: Preliminary results from 1 center and review of the literature.

PubMed

Bradley, W Daniel; Hisey, Michael S; Verma-Kurvari, Sunita; Ohnmeiss, Donna D

2012-01-01

Lumbar interbody fusion has long been used for the treatment of painful degenerative spinal conditions. The anterior approach is not feasible in some patients, and the posterior approach is associated with a risk of neural complications and possibly muscle injury. A trans-sacral technique was developed that allows access to the L5-S1 disc space. The purposes of this study were to investigate the clinical outcome of trans-sacral interbody fusion in a consecutive series of patients from 1 center and to perform a comprehensive review of the literature on this procedure. A literature search using PubMed was performed to identify articles published on trans-sacral axial lumbar interbody fusion (AxiaLIF). Articles reviewed included biomechanical testing, feasibility of the technique, and clinical results. The data from our center were collected retrospectively from charts for the consecutive series, beginning with the first case, of all patients undergoing fusion using the AxiaLIF technique. In most cases, posterior instrumentation was also used. A total of 41 patients with at least 6 months' follow-up were included (mean follow-up, 22.2 months). The primary clinical outcome measures were visual analog scales separately assessing back and leg pain and the Oswestry Disability Index. Radiographic assessment of fusion was also performed. In the group of 28 patients undergoing single-level AxiaLIF combined with posterior fusion, the visual analog scale scores assessing back and leg pain and mean Oswestry Disability Index scores improved significantly (P < .01). In the remaining 13 patients, back pain improved significantly with a trend for improvement in leg pain. Reoperation occurred in 19.5% of patients; in half of these, reoperation was not related to the anterior procedure. A review of the literature found that the AxiaLIF technique was similar to other fusion techniques with respect to biomechanical properties and produced acceptable clinical outcomes, although results varied among studies. The AxiaLIF approach allows access to the L5-S1 interspace without violating the annulus or longitudinal ligaments and with minimal risk to dorsal neural elements. It may be a viable alternative to other approaches to interbody fusion at the L5-S1 level. It is important that the patients be selected carefully and surgeons are familiar with the presacral anatomy and the surgical approach.

The perforator pedicled propeller (PPP) flap method: report of two cases.

PubMed

Hyakusoku, Hiko; Ogawa, Rei; Oki, Koichiro; Ishii, Nobuaki

2007-10-01

Perforator flaps are thin free-tissue transfers consisting of skin and subcutaneous tissue which have the advantage of decreasing donor site morbidity. We have reconstructed postburn scar contractures using "propeller flaps" of the remaining healthy skin around the recipient sites. In this paper, we report on two cases and describe the concept of using "perforator flaps" and "propeller flaps" together as what are called "perforator pedicled propeller (PPP) flaps." Patient 1 was an 18-year-old man with a sacral pressure ulcer. The soft tissue defect was reconstructed with a rotated superior gluteal artery PPP flap. Patient 2 was a 53-year-old woman who presented with an open fracture of the right elbow. The skin defect over the fracture was covered with a rotated deep brachial artery PPP flap raised on the lateral upper arm. The PPP flaps are useful for burn reconstruction and repairing various types of wound. Moreover, microsurgery is unnecessary. The PPP flap may be classified into two types: the central axis type and the acentric axis type. The central axis PPP flap is significant when used as a 90-degree-rotation island flap, and the acentric axis PPP flap is significant when used as a 180-degree-rotation island flap. Both types are easy to harvest and useful for repairing various kinds of wound.

Medical devices of the head, neck, and spine.

PubMed

Hunter, Tim B; Yoshino, Mark T; Dzioba, Robert B; Light, Rick A; Berger, William G

2004-01-01

There are many medical devices used for head, neck, and spinal diseases and injuries, and new devices are constantly being introduced. Many of the newest devices are variations on a previous theme. Knowing the specific name of a device is not important. It is important to recognize the presence of a device and to have an understanding of its function as well as to be able to recognize the complications associated with its use. The article discusses the most common and important devices of the head, neck, and spine, including cerebrospinal fluid shunts and the Codman Hakim programmable valve; subdural drainage catheters, subdural electrodes, intracranial electrodes, deep brain stimulators, and cerebellar electrodes; coils, balloons, adhesives, particles, and aneurysm clips; radiation therapy catheters, intracranial balloons for drug installation, and carmustine wafers; hearing aids, cochlear implants, and ossicular reconstruction prostheses; orbital prostheses, intraocular silicone oil, and lacrimal duct stents; anterior and posterior cervical plates, posterior cervical spine wiring, odontoid fracture fixation devices, cervical collars and halo vests; thoracic and lumbar spine implants, anterior and posterior instrumentation for the thoracic and lumbar spine, vertebroplasty, and artificial disks; spinal column stimulators, bone stimulators, intrathecal drug delivery pumps, and sacral stimulators; dental and facial implant devices; gastric and tracheal tubes; vagus nerve stimulators; lumboperitoneal shunts; and temperature- and oxygen-sensing probes. Copyright RSNA, 2004

Nucleation and growth of chimney pores during electron-beam additive manufacturing

DOE PAGES

Cordero, Zachary C.; Dinwiddie, Ralph B.; Immel, David; ...

2016-12-05

The nucleation and growth of chimney pores during powder-bed, electron-beam additive manufacturing is investigated using in-situ infrared thermography as well as microcomputed tomography of as-printed parts. The pores are found to nucleate at dimples on the part s surface, clearly demonstrating how process parameters can affect surface roughness, which can in turn affect the internal defect structure in an additive manufactured part. Based on the results of this study, several strategies for suppressing the formation of chimney pores are discussed.

Design and fabrication of titanium multi-wall Thermal Protection System (TPS) test panels

NASA Technical Reports Server (NTRS)

Blair, W.; Meaney, J. E., Jr.; Rosenthal, H. A.

1980-01-01

A titanium multiwall thermal protection system panel was designed. The panel is a nine sheet sandwich structure consisting of an upper and lower face sheet; four dimpled sheets, three septum sheets, and clips for attachment to a vehicle structure. An acceptable fabrication process was developed, and the panel design was verified through mechanical and thermal testing of component specimens. A design was completed which takes into consideration fabrication techniques, thermal properties, mechanical properties, and materials availability.

Forensic applications of metallurgy - Failure analysis of metal screw and bolt products

NASA Astrophysics Data System (ADS)

Tiner, Nathan A.

1993-03-01

It is often necessary for engineering consultants in liability lawsuits to consider whether a component has a manufacturing and/or design defect, as judged by industry standards, as well as whether the component was strong enough to resist service loads. Attention is presently given to the principles that must be appealed to in order to clarify these two issues in the cases of metal screw and bolt failures, which are subject to fatigue and brittle fractures and ductile dimple rupture.

Three-dimensional navigation is more accurate than two-dimensional navigation or conventional fluoroscopy for percutaneous sacroiliac screw fixation in the dysmorphic sacrum: a randomized multicenter study.

PubMed

Matityahu, Amir; Kahler, David; Krettek, Christian; Stöckle, Ulrich; Grutzner, Paul Alfred; Messmer, Peter; Ljungqvist, Jan; Gebhard, Florian

2014-12-01

To evaluate the accuracy of computer-assisted sacral screw fixation compared with conventional techniques in the dysmorphic versus normal sacrum. Review of a previous study database. Database of a multinational study with 9 participating trauma centers. The reviewed group included 130 patients, 72 from the navigated group and 58 from the conventional group. Of these, 109 were in the nondysmorphic group and 21 in the dysmorphic group. Placement of sacroiliac (SI) screws was performed using standard fluoroscopy for the conventional group and BrainLAB navigation software with either 2-dimensional or 3-dimensional (3D) navigation for the navigated group. Accuracy of SI screw placement by 2-dimensional and 3D navigation versus conventional fluoroscopy in dysmorphic and nondysmorphic patients, as evaluated by 6 observers using postoperative computerized tomography imaging at least 1 year after initial surgery. Intraobserver agreement was also evaluated. There were 11.9% (13/109) of patients with misplaced screws in the nondysmorphic group and 28.6% (6/21) of patients with misplaced screws in the dysmorphic group, none of which were in the 3D navigation group. Raw agreement between the 6 observers regarding misplaced screws was 32%. However, the percent overall agreement was 69.0% (kappa = 0.38, P < 0.05). The use of 3D navigation to improve intraoperative imaging for accurate insertion of SI screws is magnified in the dysmorphic proximal sacral segment. We recommend the use of 3D navigation, where available, for insertion of SI screws in patients with normal and dysmorphic proximal sacral segments. Therapeutic level I.

Sacral neuromodulation and pregnancy: Results of a national survey carried out for the neuro-urology committee of the French Association of Urology (AFU).

PubMed

Roulette, Pauline; Castel-Lacanal, Evelyne; Sanson, Sylvain; Caremel, Romain; Phé, Véronique; Bart, Stéphane; Duchêne, Franck; De Sèze, Marianne; Even, Alexia; Manunta, Andréa; Scheiber-Nogueira, Maria C; Mouracade, Pascal; Loche, Catherine-Marie; Chartier-Kastler, Emmanuel; Ruffion, Alain; Karsenty, Gilles; Gamé, Xavier

2018-02-01

To assess the impact of sacral neuromodulation (SNM) on pregnancy and vice-versa, by identifying women who had received SNM for lower-urinary tract symptoms (LUTS) and had become pregnant. A cross-sectional descriptive study was carried out based on responses to an on-line questionnaire sent to practitioners listed on the InterStim enCaptureTM National Registry. Questions were related to pre-pregnancy health and SNM efficacy, deactivation of the device, its impact on LUTS, childbirth, the infant, its reactivation and postpartum effectiveness. Twenty-seven pregnancies were recorded among 21 women. Six women had had a pregnancy prior to implantation, two of whom had had a c-section. A total of 18.5% of women had the device disabled prior to conception. The others had their device disabled during the first trimester and did not reactivate it before delivery. Complications were reported in 25.9% of pregnancies: six women had urinary infections, including three of the four treated for chronic retention of urine (CRU), and 1 woman had pain at the stimulation site. There were 24 live births (including one premature birth and four c-sections), one spontaneous miscarriage and two voluntary interruptions of pregnancy. No neonatal disorders have been reported. Effectiveness of sacral neuromodulation decreased in 20% in postpartum. In 27 pregnancies established during SNM for LUTS, 18.5% of patients deactivated their case before pregnancy and the others switched it off during the first trimester. Three-quarters of women with CRU had urinary infection. No adverse effects on fetuses were found. SNM effectiveness deteriorated in 20% cases after childbirth. © 2017 Wiley Periodicals, Inc.

Characteristics Associated With Treatment Response in Women Undergoing OnabotulinumtoxinA and Sacral Neuromodulation for Refractory Urgency Urinary Incontinence

PubMed Central

Richter, HE; Amundsen, CL; Erickson, SW; Jelovsek, JE; Komesu, Y; Chermansky, C; Harvie, H; Albo, M; Myers, D; Gregory, WT; Wallace, D

2017-01-01

Purpose To identify clinical and demographic characteristics associated with onabotulinumtoxinA and sacral neuromodulation treatment response in women with refractory urgency urinary incontinence. Material and Methods Data were analyzed from the Refractory Overactive Bladder: Sacral Neuromodulation vs Botulinum Toxin Assessment trial. Baseline participant characteristics and clinical variables associated with two definitions of treatment response: 1) reduction in mean daily urgency incontinence episodes over 6 months 2) ≥50% decrease in urgency incontinence episodes across 6 months were identified. Linear and logistic regression models were fit to estimate mean reductions in incontinence episodes and adjusted odds ratios for incidence of ≥50% decrease with 95% confidence intervals, respectively. Results For both treatments, a greater reduction in mean daily urgency incontinence episodes was associated with higher Health Utility Index scores (P=0.002) and higher baseline incontinence episodes (P<0.001). Increased age was associated with less reduction in incontinence episodes (P<0.001). Increasing body mass index (aOR 0.82 per 5 points, 95% CI 0.70, 0.96) was associated with reduced achievement of ≥50% decrease in incontinence episodes after both treatments. Greater age (aOR 0.44 per 10 years, 95% CI 0.30, 0.65) and higher functional comorbidity index (aOR 0.84 per point, 95% CI 0.71, 0.99) were associated with reduced achievement of ≥50% decrease in urgency incontinence episodes in the onabotulinuntoxinA group only (P=0.016; P=0.031, respectively). Conclusion Increasing age, body mass index, and functional comorbidity are negatively associated with treatment response while greater incontinence frequency and health utility is associated with a greater response to third line treatments for refractory urgency incontinence. PMID:28501541

Morphometric anatomical and CT study of the human adult sacroiliac region.

PubMed

Postacchini, Roberto; Trasimeni, Guido; Ripani, Francesca; Sessa, Pasquale; Perotti, Stefano; Postacchini, Franco

2017-01-01

To identify and describe the morphometry and CT features of the articular and extra-articular portions of the sacroiliac region. The resulting knowledge might help to avoid complications in sacroiliac joint (SIJ) fusion. We analyzed 102 dry hemi-sacra, 80 ilia, and 10 intact pelves and assessed the pelvic computerized tomography (CT) scans of 90 patients, who underwent the examination for conditions not involving the pelvis. We assessed both the posterior aspect of sacrum with regard to the depressions located externally to the lateral sacral crest at the level of the proximal three sacral vertebrae and the posteroinferior aspect of ilium. Coronal and axial CT scans of the SIJ of patients were obtained and the joint space was measured. On each side, the sacrum exhibits three bone depressions, not described in anatomic textbooks or studies, facing the medial aspect of the posteroinferior ilium, not yet described in detail. Both structures are extra-articular portions situated posteriorly to the SIJ. Coronal CT scans of patients showing the first three sacral foramens and the interval between sacrum and ilium as a continuous space display only the S1 and S3 portions of SIJ, the intermediate portion being extra-articular. The S2 portion is visible on the most anterior coronal scan. Axial scans show articular and extra-articular portions and features improperly described as anatomic variations. Extra-articular portions of the sacroiliac region, not yet described exhaustively, have often been confused with SIJ. Coronal CT scans through the middle part of sacrum, the most used to evaluate degenerative and inflammatory conditions of SIJ, show articular and extra-articular portions of the region.

A reusable perforator-preserving gluteal artery-based rotation fasciocutaneous flap for pressure sore reconstruction.

PubMed

Lin, Pao-Yuan; Kuo, Yur-Ren; Tsai, Yun-Ta

2012-03-01

Perforator-based fasciocutaneous flaps for reconstructing pressure sores can achieve good functional results with acceptable donor site complications in the short-term. Recurrence is a difficult issue and a major concern in plastic surgery. In this study, we introduce a reusable perforator-preserving gluteal artery-based rotation flap for reconstruction of pressure sores, which can be also elevated from the same incision to accommodate pressure sore recurrence. The study included 23 men and 13 women with a mean age of 59.3 (range 24-89) years. There were 24 sacral ulcers, 11 ischial ulcers, and one trochanteric ulcer. The defects ranged in size from 4 × 3 to 12 × 10 cm(2) . Thirty-six consecutive pressure sore patients underwent gluteal artery-based rotation flap reconstruction. An inferior gluteal artery-based rotation fasciocutaneous flap was raised, and the superior gluteal artery perforator was preserved in sacral sores; alternatively, a superior gluteal artery-based rotation fasciocutaneous flap was elevated, and the inferior gluteal artery perforator was identified and dissected in ischial ulcers. The mean follow-up was 20.8 (range 0-30) months in this study. Complications included four cases of tip necrosis, three wound dehiscences, two recurrences reusing the same flap for pressure sore reconstruction, one seroma, and one patient who died on the fourth postoperative day. The complication rate was 20.8% for sacral ulcers, 54.5% for ischial wounds, and none for trochanteric ulcer. After secondary repair and reconstruction of the compromised wounds, all of the wounds healed uneventfully. The perforator-preserving gluteal artery-based rotation fasciocutaneous flap is a reliable, reusable flap that provides rich vascularity facilitating wound healing and accommodating the difficulties of pressure sore reconstruction. Copyright © 2011 Wiley Periodicals, Inc.

Combined cystometrography and electromyography of the external urethral sphincter following complete primary repair of bladder exstrophy.

PubMed

Borer, Joseph G; Strakosha, Ruth; Bauer, Stuart B; Diamond, David A; Pennison, Melanie; Rosoklija, Ilina; Khoshbin, Shahram

2014-05-01

Concern in patients with bladder exstrophy after reconstruction regarding potential injury to pelvic neurourological anatomy and a resultant functional deficit prompted combined (simultaneous) cystometrography and electromyography after complete primary repair of bladder exstrophy. We determined whether complete primary repair of bladder exstrophy would adversely affect the innervation controlling bladder and external urethral sphincter function. Complete primary repair of bladder exstrophy was performed via a modified Mitchell technique in newborns without osteotomy. Postoperative evaluation included combined cystometrography and needle electrode electromyography via the perineum, approximating the external urethral sphincter muscle complex. Electromyography was done to evaluate the external urethral sphincter response to sacral reflex stimulation and during voiding. Nine boys and 4 girls underwent combined cystometrography/electromyography after complete primary repair of bladder exstrophy. Age at study and time after complete primary repair of bladder exstrophy was 3 months to 10 years (median 11.5 months). Cystometrography revealed absent detrusor overactivity and the presence of a sustained detrusor voiding contraction in all cases. Electromyography showed universally normal individual motor unit action potentials of biphasic pattern, amplitude and duration. The external urethral sphincter sacral reflex response was intact with a normal caliber with respect to Valsalva, Credé, bulbocavernosus and anocutaneous (bilateral) stimulation. Synergy was documented by abrupt silencing of external urethral sphincter electromyography activity during voiding. After complete primary repair of bladder exstrophy combined cystometrography/electromyography in patients with bladder exstrophy showed normal neurourological findings, including sacral reflex responses, sustained detrusor voiding contraction and synergic voiding, in all patients postoperatively. These findings confirm the safety of complete primary repair of bladder exstrophy. Based on our results we have discontinued routine electromyography in these patients. Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

The inhibitory effect of sacral dorsal root ganglion stimulation on nociceptive and nonnociceptive bladder reflexes in cats.

PubMed

Wang, Zhaoxia; Liao, Limin; Deng, Han; Li, Xing; Chen, Guoqing

2018-05-01

To investigate the inhibitory effects of electrical stimulation of sacral dorsal root ganglion (DRG) on bladder activity under non-nociceptive and nociceptive bladder conditions in cats. 12 cats were divided into non-nociceptive and nociceptive groups. Saline was used to distend the bladder and induce non-nociceptive bladder activity, while acetic acid (AA, 0.25%) was used to induce nociceptive bladder overactivity, S1 or S2 DRG stimulation was applied via a pair of hook electrodes placed in the right S1 and S2 DRG. In both non-nociceptive and nociceptive groups, stimulation at 3 and 5 Hz significantly increased bladder capacity (BC) and no significantly different between the two frequencies. In non-nociceptive group, S1 DRG stimulation at 3 Hz was as effective (increasing BC to 139.7 ± 5.6 and 166.9 ± 12.21% of control at 1T and 3/2T, respectively) as S2 DRG stimulation (increases BC to 129.2 ± 5.6 and 160.5 ± 13.3% of control). In nociceptive group, AA reduced the BC to 62.6 ± 11.7% of saline control. S1 DRG stimulation at 3 Hz was also as effective (increasing BC to 54.9 ± 5.5 and 61.9 ± 6.0% of saline control at 1T and 3/2T, respectively) as S2 DRG stimulation (increases BC to 58.3 ± 3.7 and 65.6 ± 3.7% of control). This study showed the effective inhibition on bladder activity under both non-nociceptive and nociceptive conditions, suggesting the possibility of sacral DRG stimulation to treat bladder overactivity.

The different roles of opioid receptors in the inhibitory effects induced by sacral dorsal root ganglion stimulation on nociceptive and nonnociceptive conditions in cats.

PubMed

Wang, Zhaoxia; Liao, Limin; Deng, Han; Li, Xing; Chen, Guoqing; Liao, Xiwen

2018-06-04

To examine the roles of opioid receptors in the inhibition of nociceptive and nonnociceptive bladder reflexes by sacral dorsal root ganglion (DRG) stimulation in cats. Hook electrodes were placed in the right S1 and S2 DRG of cats. The bladders were infused with physiologic saline or 0.25% acetic acid (AA). Naloxone (0.1, 0.3, and 1 mg/kg), an opioid receptor antagonist, was administered intravenously. S1 or S2 DRG stimulation was applied before and after administering the drug. Multiple cystometrograms were performed to determine the effects of DRG stimulation and opioid receptors on the micturition reflex under nociceptive and non-nociceptive conditions. AA significantly (P < 0.01) reduced bladder capacity (BC). DRG stimulation at threshold (T) and 1.5 T significantly increased BC of the saline control under nociceptive and non-nociceptive conditions. When saline was infused, naloxone (0.1-1 mg/kg) significantly (P < 0.01) reduced BC; however, naloxone did not change BC during AA irritation. During saline infusion, naloxone (0.3 and 1 mg/kg) partly blocked S1 DRG stimulation-induced inhibition but had only a slight effect on S2 DRG stimulation. During AA infusion, naloxone (0.3 and 1 mg/kg) only partially blocked S1 DRG stimulation at T intensity but not during 1.5 T stimulation. However, no doses of naloxone significantly affected S2 DRG stimulation. Opioid receptors play a role in sacral DRG stimulation on non-nociceptive condition but are not involved in the inhibitory effect of stimulation in nociceptive conditions. © 2018 Wiley Periodicals, Inc.

Prevalence and clinical features of sports-related lumbosacral stress injuries in the young.

PubMed

Kaneko, Hideto; Murakami, Mototsune; Nishizawa, Kazuya

2017-05-01

Stress injuries (stress fractures and stress reactions) of the lumbosacral region are one of the causes of sports-related lower back pain in young individuals. These injuries can be detected by bone marrow edema lesion on MRI. However, little is known about the prevalence and clinical features of early stage lumbosacral stress injuries. This study aimed to evaluate the epidemiology of lumbosacral stress injuries. A total of 312 patients (under 18 years of age) who complained of sports-related lower back pain that had lasted for ≥7 days underwent magnetic resonance imaging (MRI) scans. We reviewed patients' records retrospectively. MRI showed that 33.0% of the patients had lumbar stress injuries and 1.6% had sacral stress injuries. Lumbar stress injuries were more common in males than in females and were found in 30% of 13- to 18-year-old patients. About 50% of the patients that participated in soccer or track and field were diagnosed with lumbar stress injuries. No clinical patterns in the frequencies of sacral stress injuries were detected due to the low number of patients that suffered this type of injury. Plain radiography is rarely able to detect the early stage lesions associated with lumbosacral stress injuries, but such lesions can be detected in the caudal-ventral region of the pars interarticularis on sagittal computed tomography scans. Thirty-three percent of young patients that complained of sports-related lower back pain for ≥7 days had lumbar stress injuries, while 1.6% of them had sacral stress injuries. Clinicians should be aware of the existence of these injuries. MRI is useful for diagnosing lumbosacral stress injuries.

The Unresolved Case of Sacral Chordoma: From Misdiagnosis to Challenging Surgery and Medical Therapy Resistance

PubMed Central

Garofalo, Fabio; Christoforidis, Dimitrios; di Summa, Pietro G.; Gay, Béatrice; Cherix, Stéphane; Raffoul, Wassim; Matter, Maurice

2014-01-01

Purpose A sacral chordoma is a rare, slow-growing, primary bone tumor, arising from embryonic notochordal remnants. Radical surgery is the only hope for cure. The aim of our present study is to analyse our experience with the challenging treatment of this rare tumor, to review current treatment modalities and to assess the outcome based on R status. Methods Eight patients were treated in our institution between 2001 and 2011. All patients were discussed by a multidisciplinary tumor board, and an en bloc surgical resection by posterior perineal access only or by combined anterior/posterior accesses was planned based on tumor extension. Results Seven patients underwent radical surgery, and one was treated by using local cryotherapy alone due to low performance status. Three misdiagnosed patients had primary surgery at another hospital with R1 margins. Reresection margins in our institution were R1 in two and R0 in one, and all three recurred. Four patients were primarily operated on at our institution and had en bloc surgery with R0 resection margins. One had local recurrence after 18 months. The overall morbidity rate was 86% (6/7 patients) and was mostly related to the perineal wound. Overall, 3 out of 7 resected patients were disease-free at a median follow-up of 2.9 years (range, 1.6-8.0 years). Conclusion Our experience confirms the importance of early correct diagnosis and of an R0 resection for a sacral chordoma invading pelvic structures. It is a rare disease that requires a challenging multidisciplinary treatment, which should ideally be performed in a tertiary referral center. PMID:24999463

Clinical Outcome of Sacral Chordoma With Carbon Ion Radiotherapy Compared With Surgery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishida, Yoshihiro, E-mail: ynishida@med.nagoya-u.ac.j; Kamada, Tadashi; Imai, Reiko

Purpose: To evaluate the efficacy, post-treatment function, toxicity, and complications of carbon ion radiotherapy (RT) for sacral chordoma compared with surgery. Methods and Materials: The records of 17 primary sacral chordoma patients treated since 1990 with surgery (n = 10) or carbon ion RT (n = 7) were retrospectively analyzed for disease-specific survival, local recurrence-free survival, complications, and functional outcome. The applied carbon ion dose ranged from 54.0 Gray equivalent (GyE) to 73.6 GyE (median 70.4). Results: The mean age at treatment was 55 years for the surgery group and 65 years for the carbon ion RT group. The medianmore » duration of follow-up was 76 months for the surgery group and 49 months for the carbon ion RT group. The local recurrence-free survival rate at 5 years was 62.5% for the surgery and 100% for the carbon ion RT group, and the disease-specific survival rate at 5 years was 85.7% and 53.3%, respectively. Urinary-anorectal function worsened in 6 patients (60%) in the surgery group, but it was unchanged in all the patients who had undergone carbon ion RT. Postoperative wound complications requiring reoperation occurred in 3 patients (30%) after surgery and in 1 patient (14%) after carbon ion RT. The functional outcome evaluated using the Musculoskeletal Tumor Society scoring system revealed 55% in the surgery group and 75% in the carbon ion RT group. Of the six factors in this scoring system, the carbon ion RT group had significantly greater scores in emotional acceptance than did the surgery group. Conclusion: Carbon ion RT results in a high local control rate and preservation of urinary-anorectal function compared with surgery.« less

Threshold dose for peripheral neuropathy following intraoperative radiotherapy (IORT) in a large animal model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kinsella, T.J.; DeLuca, A.M.; Barnes, M.

1991-04-01

Radiation injury to peripheral nerve is a dose-limiting toxicity in the clinical application of intraoperative radiotherapy, particularly for pelvic and retroperitoneal tumors. Intraoperative radiotherapy-related peripheral neuropathy in humans receiving doses of 20-25 Gy is manifested as a mixed motor-sensory deficit beginning 6-9 months following treatment. In a previous experimental study of intraoperative radiotherapy-related neuropathy of the lumbro-sacral plexus, an approximate inverse linear relationship was reported between the intraoperative dose (20-75 Gy range) and the time to onset of hind limb paresis (1-12 mos following intraoperative radiotherapy). The principal histological lesion in irradiated nerve was loss of large nerve fibers andmore » perineural fibrosis without significant vascular injury. Similar histological changes in irradiated nerves were found in humans. To assess peripheral nerve injury to lower doses of intraoperative radiotherapy in this same large animal model, groups of four adult American Foxhounds received doses of 10, 15, or 20 Gy to the right lumbro-sacral plexus and sciatic nerve using 9 MeV electrons. The left lumbro-sacral plexus and sciatic nerve were excluded from the intraoperative field to allow each animal to serve as its own control. Following treatment, a complete neurological exam, electromyogram, and nerve conduction studies were performed monthly for 1 year. Monthly neurological exams were performed in years 2 and 3 whereas electromyogram and nerve conduction studies were performed every 3 months during this follow-up period. With follow-up of greater than or equal to 42 months, no dog receiving 10 or 15 Gy IORT shows any clinical or laboratory evidence of peripheral nerve injury. However, all four dogs receiving 20 Gy developed right hind limb paresis at 8, 9, 9, and 12 mos following intraoperative radiotherapy.« less

Ultrasonography in Acupuncture-Uses in Education and Research.

PubMed

Leow, Mabel Qi He; Cui, Shu Li; Mohamed Shah, Mohammad Taufik Bin; Cao, Taige; Tay, Shian Chao; Tay, Peter Kay Chai; Ooi, Chin Chin

2017-06-01

This study aims to explore the potential use of ultrasound in locating the second posterior sacral foramen acupuncture point, quantifying depth of insertion and describing surrounding anatomical structures. We performed acupuncture needle insertion on a study team member. There were four steps in our experiment. First, the acupuncturist located the acupuncture point by palpation. Second, we used an ultrasound machine to visualize the structures surrounding the location of the acupuncture point and measure the depth required for needle insertion. Third, the acupuncturist inserted the acupuncture needle into the acupuncture point at an angle of 30°. Fourth, we performed another ultrasound scan to ensure that the needle was in the desired location. Results suggested that ultrasound could be used to locate the acupuncture point and estimate the depth of needle insertion. The needle was inserted to a depth of 4.0 cm to reach the surface of the sacral foramen. Based on Pythagoras theorem, taking a needle insertion angle of 30° and a needle insertion depth of 4.0 cm, the estimated perpendicular depth is 1.8 cm. An ultrasound scan corroborated the depth of 1.85 cm. The use of an ultrasound-guided technique for needle insertion in acupuncture practice could help standardize the treatment. Clinicians and students would be able to visualize and measure the depth of the sacral foramen acupuncture point, to guide the depth of needle insertion. This methodological guide could also be used to create a standard treatment protocol for research. A similar mathematical guide could also be created for other acupuncture points in future. Copyright © 2017. Published by Elsevier B.V.

Techniques of lumbar-sacral spine fusion in spondylosis: systematic literature review and meta-analysis of randomized clinical trials.

PubMed

Umeta, Ricardo S G; Avanzi, Osmar

2011-07-01

Spine fusions can be performed through different techniques and are used to treat a number of vertebral pathologies. However, there seems to be no consensus regarding which technique of fusion is best suited to treat each distinct spinal disease or group of diseases. To study the effectiveness and complications of the different techniques used for spinal fusion in patients with lumbar spondylosis. Systematic literature review and meta-analysis. Randomized clinical studies comparing the most commonly performed surgical techniques for spine fusion in lumbar-sacral spondylosis, as well as those reporting patient outcome were selected. Identify which technique, if any, presents the best clinical, functional, and radiographic outcome. Systematic literature review and meta-analysis based on scientific articles published and indexed to the following databases: PubMed (1966-2009), Cochrane Collaboration-CENTRAL, EMBASE (1980-2009), and LILACS (1982-2009). The general search strategy focused on the surgical treatment of patients with lumbar-sacral spondylosis. Eight studies met the inclusion criteria and were selected with a total of 1,136 patients. Meta-analysis showed that patients who underwent interbody fusion presented a significantly smaller blood loss (p=.001) and a greater rate of bone fusion (p=.02). Patients submitted to fusion using the posterolateral approach had a significantly shorter operative time (p=.007) and less perioperative complications (p=.03). No statistically significant difference was found for the other studied variables (pain, functional impairment, and return to work). The most commonly used techniques for lumbar spine fusion in patients with spondylosis were interbody fusion and posterolateral approach. Both techniques were comparable in final outcome, but the former presented better rates of fusion and the latter the less complications. Copyright © 2011 Elsevier Inc. All rights reserved.

Vascular Entrapment of Both the Sciatic and Pudendal Nerves Causing Persistent Sciatica and Pudendal Neuralgia.

PubMed

Kale, Ahmet; Basol, Gulfem; Usta, Taner; Cam, Isa

2018-04-24

To demonstrate the laparoscopic approach to malformed branches of the vessels entrapping the nerves of the sacral plexus. A step-by-step explanation of the surgery using video (educative video) (Canadian Task force classification II). The university's Ethics Committee ruled that approval was not required for this video. Kocaeli Derince Education and Research Hospital, Kocaeli, Turkey. A 26-year-old patient who had failed medical therapy and presented with complaints of numbness and burning pain on the right side of her vagina and pain radiating to her lower limbs for a period of approximately 36 months. The peritoneum was incised along the external iliac vessels, and these vessels were separated from the iliopsoas muscle on the right side of the pelvis. The laparoscopic decompression of intrapelvic vascular entrapment was performed at 3 sites: the lumbosacral trunk, sciatic nerve, and pudendal nerve. The aberrant dilated veins were gently dissected from nerves, and then coagulated and cut with the LigaSure sealing device (Medtronic, Minneapolis, Minn). The operation was completed successfully with no complications, and the patient was discharged from the hospital 24 hours after the operation. At a 6-month follow-up, she reported complete resolution of dyspareunia and sciatica (visual analog scale score 1 of 10). A less well-known cause of chronic pelvic pain is compression of the sacral plexus by dilated or malformed branches of the internal iliac vessels. Laparoscopic management of vascular entrapment of the sacral plexus has been described by Possover et al [1,2] and Lemos et al [3]. This procedure appears to be feasible and effective, but requires significant experience and familiarity with laparoscopy techniques and pelvic nerve anatomy. Copyright © 2018 American Association of Gynecologic Laparoscopists. Published by Elsevier Inc. All rights reserved.

Assessment of the Breakaway Torque at the Posterior Pelvic Ring in Human Cadavers.

PubMed

Bastian, Johannes Dominik; Bergmann, Mathias; Schwyn, Ronald; Keel, Marius Johann Baptist; Benneker, Lorin Michael

2015-01-01

To enhance the diminished screw purchase in cancellous, osteoporotic bone following the fixation of posterior pelvic ring injuries by iliosacral screws an increased bone-implant contact area using modificated screws, techniques or bone cement may become necessary. The aim of the study was to identify sites within the pathway of iliosacral screws requiring modifications of the local bone or the design of instrumentations placed at this site. The breakaway torque was measured mechanically at the iliosacral joint ("ISJ"), the sacral lateral mass ("SLM") and the center of the S1 ("CS1"), at a superior and an inferior site under fluoroscopic control on five human cadaveric specimens (3 female; mean age 87 years, range: 76-99) using the DensiProbe™Spine device. The measured median (range) breakaway torque was 0.63 Nm (0.31-2.52) at the "iliosacral joint", 0.14 Nm (0.05-1.22) at the "sacral lateral mass", 0.57 Nm (0.05-1.42) at the "S1 center." The "sacral lateral mass" breakaway torque was lower than compared to that at the "iliosacral joint" (p < .001) or "S1 center" (p < .001). The median (range) breakaway torque measured at all superior measurement points was 0.52 Nm (0.10-2.52), and 0.48 Nm (0.05-1.18) at all inferior sites. The observed difference was statistically significant (p < .05). The lateral mass of the sacrum provides the lowest bone quality for implant anchorage. Iliosacral screws should be placed as superior as safely possible, should bridge the iliosacral joint and may allow for cement application at the lateral mass of the sacrum through perforations.

PHASE II STUDY OF HIGH DOSE PHOTON/PROTON RADIOTHERAPY IN THE MANAGEMENT OF SPINE SARCOMAS

PubMed Central

DeLaney, Thomas F.; Liebsch, Norbert J.; Pedlow, Francis X.; Adams, Judith; Dean, Susan; Yeap, Beow Y.; McManus, Patricia; Rosenberg, Andrew E.; Nielsen, G. Petur; Harmon, David C.; Spiro, Ira J.; Raskin, Kevin A.; Suit, Herman D.; Yoon, Sam S.; Hornicek, Francis J.

2009-01-01

Purpose Radiotherapy (XRT) for spine sarcomas is constrained by spinal cord, nerve, and viscera tolerance. Negative surgical margins are uncommon; hence, doses of ≥ 66 Gy are recommended. A Phase II clinical trial evaluated high dose photon/proton XRT for spine sarcomas. Materials/Methods Eligible patients had non-metastatic, thoracic, lumbar, and/or sacral spine/paraspinal sarcomas. Treatment included pre- and/or post-op photon/proton XRT +/- radical resection; patients with osteosarcoma and Ewing's sarcoma received chemotherapy. Shrinking fields delivered 50.4 cobalt Gray equivalent (GyRBE) to subclinical disease, 70.2 GyRBE to microscopic disease in the tumor bed, and 77.4 GyRBE to gross disease at 1.8 GyRBE q.d. Doses were reduced for radiosensitive histologies, concurrent chemoradiation, or when diabetes or autoimmune disease present. Spinal cord dose was limited to 63/54 GyRBE to surface/center. Intra-operative boost doses of 7.5-10 Gy could be given by dural plaque. Results 50 patients (29 chordoma, 14 chondrosarcoma, 7 other) underwent gross total (n=25) or subtotal (n=12) resection or biopsy (n=13). With 48 month median follow-up, five-year actuarial local control, recurrence-free survival, and overall survival are: 78%, 63%, and 87% respectively. Two of 36 (5.6%) patients treated for primary versus 7/14 (50%) for recurrent tumor developed local recurrence, p<0.001. Five patients developed late radiation-associated complications; no myelopathy developed but three sacral neuropathies appeared following 77.12-77.4 GyRBE. Conclusions Local control with this treatment is high in patients radiated at the time of primary presentation. Spinal cord dose constraints appear to be safe. Sacral nerves receiving 77.12-77.4 GyRBE are at risk for late toxicity. PMID:19095372

Increased yield pressure in the anal canal during sacral nerve stimulation: a pilot study with the functional lumen imaging probe.

PubMed

Haas, S; Liao, D; Gregersen, H; Lundby, L; Laurberg, S; Krogh, K

2017-02-01

Sacral nerve stimulation (SNS) is a well-established treatment for fecal incontinence but its mode of action remains obscure. Anal sphincter function is usually evaluated with manometry but resistance to distension may be a more appropriate parameter than luminal pressure. The functional lumen imaging probe allows detailed description of distension properties of the anal canal. Our objective in this study was to characterize the impact of SNS on distension properties of the anal canal in patients with idiopathic fecal incontinence. We studied 10 women (median age 64 [44-79] years) with idiopathic fecal incontinence at baseline and during SNS. The luminal geometry of the anal canal was examined with the FLIP at rest and during squeeze and the distensibility of the anal canal was investigated during filling of the bag. All patients were successfully treated with SNS and the mean Wexner Incontinence Score was reduced from 14.9 ± 4 to 7.1 ± 4.8 (P<.001). The pressure required to open the narrowest point of the anal canal during distension (yield pressure) increased from 14.5 ± 12.2 mmHg at baseline to 20.5 ± 13.3 mmHg during SNS (P<.01). The pressure-strain elastic modulus increased non-significantly from 2.2 ± 0.5 to 2.9 ± 1.6 kPa, indicating increased stiffness of the anal canal. The yield pressure and the resistance to distension increased in response to SNS for idiopathic fecal incontinence. This will inevitably increase the resistance to flow through the anal canal, which may contribute to the benefits of sacral nerve stimulation. © 2016 John Wiley & Sons Ltd.

"Music Appreciation" as Praxis

ERIC Educational Resources Information Center

Regelski, Thomas A.

2006-01-01

Aesthetic doctrine hypothesizes a for-its-own-sake, "disinterested" autonomy of music from life and assumes, then, that "good" music exists only to be contemplated, and that proper "appreciation" depends on informed "understanding." This distantiation of music from life creates a gap between aesthetes who have (unfortunately) sacralized classical…

Neuromodulation: urodynamic effects of sacral (S3) spinal nerve stimulation in patients with detrusor instability or detrusor hyperflexia.

PubMed

Bosch, J L; Groen, J

1998-05-01

The aim of this study was to determine the urodynamic effects of sacral (S3) nerve stimulation in patients with urge incontinence due to detrusor overactivity which has been refractory to conservative treatment. A total of 24 patients with idiopathic detrusor instability and five with neurogenic hyperreflexia were studied urodynamically before and 6 months after a permanent S3 foramen electrode implant. The urodynamic studies at follow-up were done with the stimulus on. Clinically, the average voiding frequency, the number of leakage episodes and pad use per 24 h decreased significantly. Improvement in several urodynamic parameters was noted. In the idiopathic as well as in the neurogenic group, the correlation between symptomatic and urodynamic improvement was incomplete. Neuromodulation leads to improvement of several urodynamic parameters in patients with urge incontinence due to detrusor overactivity which has been refractory to conservative treatment and appears to be a valuable treatment option in these patients.

Comparison of abdominal ultrasound and magnetic resonance imaging for detection of abdominal lymphadenopathy in dogs with metastatic apocrine gland adenocarcinoma of the anal sac.

PubMed

Anderson, C L; MacKay, C S; Roberts, G D; Fidel, J

2015-06-01

Imaging studies in humans with anal and rectal cancer indicate that magnetic resonance imaging (MRI) is a more sensitive technique than abdominal ultrasound (AUS) for the detection of abdominal lymphadenopathy. The purpose of this retrospective study was to directly compare the efficacy of these two techniques in detecting abdominal lymphadenopathy in dogs with apocrine gland adenocarcinoma of the anal sac (AGAAS). Six dogs with histologically confirmed AGAAS and histopathologic confirmation of metastasis to abdominal lymph nodes (LNs) had AUS and abdominal MRI. AUS identified lymphadenopathy in two of six dogs, whereas MRI identified lymphadenopathy in all the six dogs. Lymphadenopathy was predominantly sacral in location, with involvement of the medial iliac and hypogastric LNs in only two cases. These data suggest that MRI is more sensitive than AUS for detecting sacral abdominal lymphadenopathy in dogs with AGAAS. As such, MRI could be considered in any patient with AGAAS for initial staging of this disease. © 2013 Blackwell Publishing Ltd.

Morality and Intimate Partner Violence: Do Men in Court-Mandated Psychological Treatment Hold a Sacred Moral Vision of the World and Themselves?

PubMed

Vecina, María L; Chacón, José C

2016-01-01

This article examines the characterization of men in a court-mandated treatment for violence against their partners as holding a sacred vision of the 5 moral foundations and of their own morality. This characterization is compatible with the assumption that a sacred moral world is easily threatened by reality and that may be associated to violent defensive actions. The results from latent class analyses reveal (a) a 4-class distribution depending exclusively on the intensity with which all participants (violent and nonviolent) tend to sacralize the actions proposed in the Moral Foundations Sacredness Scale and (b) a greater prevalence of the violent participants among the classes that are more prone to sacralize. They also show that they hold an inflated moral vision of themselves: They think they are much more moral than intelligent than others who have never been charged with criminal behavior (Muhammad Ali effect).

Biotinylated dextran amine anterograde tracing of the canine corticospinal tract.

PubMed

Han, Xiao; Lv, Guangming; Wu, Huiqun; Ji, Dafeng; Sun, Zhou; Li, Yaofu; Tang, Lemin

2012-04-15

In this study, biotinylated dextran amine (BDA) was microinjected into the left cortical motor area of the canine brain. Fluorescence microscopy results showed that a large amount of BDA-labeled pyramidal cells were visible in the left cortical motor area after injection. In the left medulla oblongata, the BDA-labeled corticospinal tract was evenly distributed, with green fluorescence that had a clear boundary with the surrounding tissue. The BDA-positive corticospinal tract entered into the right lateral funiculus of the spinal cord and descended into the posterior part of the right lateral funiculus, close to the posterior horn, from cervical to sacral segments. There was a small amount of green fluorescence in the sacral segment. The distribution of BDA labeling in the canine central nervous system was consistent with the course of the corticospinal tract. Fluorescence labeling for BDA gradually diminished with time after injection. Our findings indicate that the BDA anterograde tracing technique can be used to visualize the localization and trajectory of the corticospinal tract in the canine central nervous system.

[An adult case of intradural lumbo-sacral lipoma].

PubMed

Hatayama, T; Sakoda, K; Tokuda, Y; Uozumi, T

1992-10-01

A rare case of lumbo-sacral lipoma in an adult case is reported. A 55-year-old male was admitted to the Department of Neurosurgery, Mazda Hospital, after a history of one year of urinary incontinence. Neurologically, no motor or sensory disturbance of the lower extremities was found in this patient. MRI showed a mass with high signal intensity on T2-weighted image, located between L3 to S2 vertebral segments. Metrizamide-CT scan demonstrated the outline of this hypodense mass at the same location as shown on MRI image. A L3 through L5 laminectomy was performed and the tumor was subtotally removed. Microscopic examination revealed that the tumor mass was made up of mature lipoma cells. Postoperative course of the patient was uneventful. The urinary incontinence was improved slightly. No motor or sensory deficit was found. We thought that MRI was useful for the correct diagnosis of lumbosacral lipoma. And it is best managed by operative removal of the tumor as early as possible after it is diagnosed.

An Alternative Technique in the Control of Massive Presacral Rectal Bleeding: Fixation of GORE-TEX® Aortic Patch.

PubMed

Ozsoy, Mustafa; Ozsoy, Zehra; Sahin, Suleyman; Arikan, Yüksel

2018-01-01

The presacral venous system is located under the pelvic fascia covering the anterior of the sacrum and consists of two lateral sacral veins, middle sacral vein, and the veins that communicate them. The presacral venous system can be easily damaged and causes serious bleeding which is difficult to control and may cause intraoperative mortality. Its incidence varies between 3% and 9.4%. Although several methods have been tried to control presacral bleeding, the definitive method of treatment has not yet been identified. We present here our alternative technique in control of massive presacral massive bleeding developed from the presacral plexus secondary to the traction of the specimen during the dissection. The bleeding could not be controlled despite the use of all technical possibilities such as packing, ligation, and hemostatic agents. Bleeding control was provided by GORE-TEX ® graft. We conclude that fıxatıon of GORE-TEX ® aortic patch should be kept in mind for uncontrolled massive presacral bleeding.

Enlargement of sacral subcutaneous meningocele associated with retained medullary cord.

PubMed

Shirozu, Noritoshi; Morioka, Takato; Inoha, Satoshi; Imamoto, Naoyuki; Sasaguri, Takakazu

2018-04-27

A retained medullary cord (RMC) is a rare closed spinal dysraphism with a robust elongated neural structure continuous from the conus and extending to the dural cul-de-sac. Four cases of RMC extending down to the base of an associated subcutaneous meningocele at the sacral level have been reported. We report an additional case of RMC, in whom serial MRI examination revealed an enlargement of the meningocele associated with RMC over a 3-month period between 8 and 11 months of age, when he began to stand. At the age of 12 months, untethering of the cord was performed. Histologically, the presence of ependyma-lined central canals in the dense neuroglial cores was noted in all cord-like structures in the intradural and intrameningocele sacs and at the attachment to the meningocele. It is conceivable that the hydrodynamic pressure with standing position and the check valve phenomenon were involved in meningocele enlargement. We should be mindful of these potential morphological changes.

A comparison of healing rates on two pressure-relieving systems.

PubMed

Russell, L; Reynolds, T; Carr, J; Evans, A; Holmes, M

The authors have previously reported the preliminary results of a randomized-controlled trial comparing the relative efficacy of two pressure-relieving systems: Huntleigh Nimbus 3 and Aura Cushion, and Pegasus Cairwave Therapy System and ProActive Seating Cushion (Russell et al, 2000). Although both the mattresses and cushions were effective treatments for pressure ulcers, the Huntleigh equipment was demonstrated to be statistically more effective for heel ulcers, but no differences were demonstrated for sacral ulcers. This article gives a more detailed analysis of the 141 patients assessed using computerized-image analysis of the digital images of sacral ulcers captured during the trial and specifically discusses the healing rates and other patient characteristics. Ninety-eight per cent of ulcers examined were deemed superficial (Torrance grade 2a, 2b, 3). Precision of image analysis assessed by within- and between-batch coefficients of variation was excellent: calibration CV 0.93-1.84%; area CV 4.61-5.72%. The healing rates on the two mattresses were not shown to be statistically different from each other.

The impact of faceplate surface characteristics on detection of pulmonary nodules

NASA Astrophysics Data System (ADS)

Toomey, R. J.; Ryan, J. T.; McEntee, M. F.; McNulty, J.; Evanoff, M. G.; Cuffe, F.; Yoneda, T.; Stowe, J.; Brennan, P. C.

2009-02-01

Introduction In order to prevent specular reflections, many monitor faceplates have features such as tiny dimples on their surface to diffuse ambient light incident on the monitor, however, this "anti-glare" surface may also diffuse the image itself. The purpose of the study was to determine whether the surface characteristics of monitor faceplates influence the detection of pulmonary nodules under low and high ambient lighting conditions. Methods and Materials Separate observer performance studies were conducted at each of two light levels (<1 lux and >250 lux). Twelve examining radiologists with the American Board of Radiology participated in the darker condition and eleven in the brighter condition. All observers read on both smooth "glare" and dimpled "anti-glare" faceplates in a single lighting condition. A counterbalanced methodology was utilized to minimise memory effects. In each reading, observers were presented with thirty chest images in random order, of which half contained a single simulated pulmonary nodule. They were asked to give their confidence that each image did or did not contain a nodule and to mark the suspicious location. ROC analysis was applied to resultant data. Results No statistically significant differences were seen in the trapezoidal area under the ROC curve (AUC), sensitivity, specificity or average time per case at either light level for chest specialists or radiologists from other specialities. Conclusion The characteristics of the faceplate surfaces do not appear to affect detection of pulmonary nodules. Further work into other image types is being conducted.

Microstructure-Texture-Mechanical Properties in Hot Rolling of a Centrifugal Casting Ring Blank

NASA Astrophysics Data System (ADS)

Qin, Fang-cheng; Li, Yong-tang; Qi, Hui-ping; Ju, Li

2016-03-01

Deformation characteristic of centrifugal casting 25Mn steel was investigated by compression tests, and then processing maps were established. According to the deformation parameters identified from the established processing maps and hot ring rolling (HRR) process, the industrial test for the 25Mn ring blank was performed. Optical microscope (OM) and electron backscatter diffraction (EBSD) techniques were used for detecting grain boundary features and textures of deformation structures. The morphologies and mechanisms of tensile and impact fracture were revealed. The results show that softening effect plays a dominant role in higher temperatures of 1050-1150 °C and strain rates lower than 0.1 s-1. The average grain size of the rolled 25Mn ring is about 28 μm, but the grains are more coarse and inhomogeneous on the middle layer than that on rest of the areas. The texture on the outer layer is characterized by strong {110} <112> and weak {112} <111>, followed by {001} <100> and {001} <110> on the inner layer and {110} <110> on the center layer, which is mainly associated with the shear deformation. The rolled ring with precise geometrical dimensions and sound mechanical properties is fabricated by HRR. Tensile fracture is composed of clear river-shaped pattern and a little dimple near the inner layer and outer layer, and the fracture mechanism is mainly quasi-cleavage fracture, accompanied by dimple fracture. The morphologies of impact fracture consist of tear ridge and cleavage platform.

Kinetic electron and ion instability of the lunar wake simulated at physical mass ratio

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haakonsen, Christian Bernt, E-mail: chaako@mit.edu; Hutchinson, Ian H., E-mail: ihutch@mit.edu; Zhou, Chuteng, E-mail: ctzhou@mit.edu

2015-03-15

The solar wind wake behind the moon is studied with 1D electrostatic particle-in-cell (PIC) simulations using a physical ion to electron mass ratio (unlike prior investigations); the simulations also apply more generally to supersonic flow of dense magnetized plasma past non-magnetic objects. A hybrid electrostatic Boltzmann electron treatment is first used to investigate the ion stability in the absence of kinetic electron effects, showing that the ions are two-stream unstable for downstream wake distances (in lunar radii) greater than about three times the solar wind Mach number. Simulations with PIC electrons are then used to show that kinetic electron effectsmore » can lead to disruption of the ion beams at least three times closer to the moon than in the hybrid simulations. This disruption occurs as the result of a novel wake phenomenon: the non-linear growth of electron holes spawned from a narrow dimple in the electron velocity distribution. Most of the holes arising from the dimple are small and quickly leave the wake, approximately following the unperturbed electron phase-space trajectories, but some holes originating near the center of the wake remain and grow large enough to trigger disruption of the ion beams. Non-linear kinetic-electron effects are therefore essential to a comprehensive understanding of the 1D electrostatic stability of such wakes, and possible observational signatures in ARTEMIS data from the lunar wake are discussed.« less

Improved adaptability of polyaryl-ether-ether-ketone with texture pattern and graphite-like carbon film for bio-tribological applications

NASA Astrophysics Data System (ADS)

Ren, Siming; Huang, Jinxia; Cui, Mingjun; Pu, Jibin; Wang, Liping

2017-04-01

With the development of surface treatment technology, an increasing number of bearings, seals, dynamic friction drive or even biomedical devices involve a textured surface to improve lubrication and anti-wear. The present investigation has been conducted in order to evaluate the friction and wear behaviours of textured polyaryl-ether-ether-ketone (PEEK) coated with a graphite-like carbon (GLC) film sliding against stainless steel pin in biological medium. Compared with pure PEEK, the PEEK coated with GLC film shows excellent tribological performance with a low friction of 0.08 and long lifetime (wear volumes are about 3.78 × 10-4 mm3 for un-textured one and 2.60 × 10-4 mm3 for textured GLC film after 36,000 s of sliding) under physiological saline solution. In particular, the GLC film with appropriate dimple area density is effective to improve friction reduction and wear resistance properties of PEEK substrate under biological solution, which is attributed to the entrapment of wear debris in the dimples to inhibit the graphitization and the fluid dynamic pressure effect derived from the texture surface to increase the thickness in elastohydrodynamic lubrication (EHL) film during sliding motions. Moreover, the friction coefficient of GLC film under physiological saline solution decreases with the increase in the applied load. With the increasing applied load, the texture surface is responsible for accounting the improved wear resistance and a much lower graphitization of the GLC film during whole test.

Dermoscopy of accessory nipples in authors’ own study

PubMed Central

Szymszal, Jan; Silny, Wojciech

2014-01-01

Introduction The accessory nipple (AN) is characterised by its network-like structures, which may suggest the diagnosis of a melanocytic lesion. The knowledge about additional dermoscopic features of AN may greatly minimise the risk of unnecessary surgical excisions. Aim To analyse and present different clinical and dermoscopic forms, in which the AN may appear. Material and methods Ninety AN with dermoscopic features were evaluated in the study, detected in 14 patients between the years 2008 and 2014. Results The most common dermoscopic features of the AN were central, scar-like areas (15/19) and peripheral network-like structures (12/19). A number of cleft-like appearances (8/19) and central network-like structures (7/19) had also been observed. Moreover, among the dermoscopic features, white cobblestone-like structures (7/19), a central round dimpling with a plug (6/19) and fisheye-like structures resembling comedo-like openings (9/19) have all also been noted. There is a statistical significance in the occurrence of white cobblestone-like structures with central network-like structures (Fisher's exact test p = 0.0449). The presence of peripheral network-like structures with the occurrence of central scar-like areas was statistically highly significant (p = 0.0091). The central round dimpling was never observed alongside any central network-like structures in any of the lesions (p = 0.0436). Conclusions Accessory nipples are most commonly characterised by the occurrence of a peripheral network-like structure accompanied by the presence of a scar-like area. PMID:25097482

Effect of Stress Triaxiality on the Flow and Fracture of Mg Alloy AZ31

NASA Astrophysics Data System (ADS)

Kondori, Babak; Benzerga, A. Amine

2014-07-01

The microscopic damage mechanisms operating in a hot-rolled magnesium alloy AZ31B are investigated under both uniaxial and controlled triaxial loadings. Their connection to macroscopic fracture strains and fracture mode (normal vs shear) is elucidated using postmortem fractography, interrupted tests, and microscopic analysis. The fracture locus (strain-to-failure vs stress triaxiality) exhibits a maximum at moderate triaxiality, and the strain-to-failure is found to be greater in notched specimens than in initially smooth ones. A transition from twinning-induced fracture under uniaxial loading to microvoid coalescence fracture under triaxial loading is evidenced. It is argued that this transition accounts in part for the observed greater ductility in notched bars. The evolution of plastic anisotropy with stress triaxiality is also investigated. It is inferred that anisotropic plasticity at a macroscopic scale suffices to account for the observed transition in the fracture mode from flat (triaxial loading) to shear-like (uniaxial loading). Damage is found to initiate at second-phase particles and deformation twins. Fracture surfaces of broken specimens exhibit granular morphology, coarse splits, twin-sized crack traces, as well as shallow and deep dimples, in proportions that depend on the overall stress triaxiality and fracture mode. An important finding is that AZ31B has a greater tolerance to ductile damage accumulation than has been believed thus far, based on the fracture behavior in uniaxial specimens. Another finding, common to both tension and compression, is the increase in volumetric strain, the microscopic origins of which remain to be elucidated.

A computed tomographic anatomical study of the upper sacrum. Application for a user guide of pelvic fixation with iliosacral screws in adult spinal deformity.

PubMed

Dubory, Arnaud; Bouloussa, Houssam; Riouallon, Guillaume; Wolff, Stéphane

2017-12-01

Widely used in traumatic pelvic ring fractures, the iliosacral (IS) screw technique for spino-pelvic fixation remains anecdotal in adult spinal deformity. The objective of this study was to assess anatomical variability of the adult upper sacrum and to provide a user guide of spino-pelvic fixation with IS screws in adult spinal deformity. Anatomical variability of the upper sacrum according to age, gender, height and weight was sought on 30 consecutive pelvic CT-scans. Thus, a user guide of spino-pelvic fixation with IS screws was modeled and assessed on ten CT-scans as described below. Two invariable landmarks usable during the surgical procedure were defined: point A (corresponding to the connector binding the IS screw to the spinal rod), equidistant from the first posterior sacral hole and the base of the S1 articular facet and 10 mm-embedded into the sacrum; point B (corresponding to the tip of the IS screw) located at the junction of the anterior third and middle third of the sacral endplate in the sagittal plane and at the middle of the endplate in the coronal plane. Point C corresponded to the intersection between the A-B direction and the external facet of the iliac wing. Three-dimensional reconstructions modeling the IS screw optimal direction according to the A-B-C straight line were assessed. Age had no effect on the anatomy of the upper sacrum. The distance between the base of the S1 superior articular facet and the top of the first posterior sacral hole was correlated with weight (r = 0.6; 95% CI [0.6-0.9]); p < 0.001). Sacral end-plate thickness increased for male patients (p < 0.001) and was strongly correlated with height (r = 0.6; 95% CI [0.29-0.75]); p < 0.001) and weight (r = 0.8; 95% CI [0.6-0.9]); p < 0.001). The thickness of the inferior part of the S1 vertebral body increased in male patients (p < 0.001). Other measured parameters slightly varied according to gender, height and weight. Simulating the described technique of pelvic fixation, no misplaced IS screw was found whatever the age, gender and morphologic parameters. This user guide of spinopelvic fixation with IS screws seems to be reliable and reproducible independently of age, gender and morphologic characteristics but needs clinical assessment. Level IV.

PROXIMAL JUNCTIONAL KYPHOSIS IN ADULT RECONSTRUCTIVE SPINE SURGERY RESULTS FROM INCOMPLETE RESTORATION OF THE LUMBAR LORDOSIS RELATIVE TO THE MAGNITUDE OF THE THORACIC KYPHOSIS

PubMed Central

Mendoza-Lattes, Sergio; Ries, Zachary; Gao, Yubo; Weinstein, Stuart L

2011-01-01

Background Proximal junctional kyphosis (PJK) is defined as: 1) Proximal junction sagittal Cobb angle >≥10°, and 2) Proximal junction sagittal Cobb angle of at least 10° greater than the pre-operative measurement PJK is a common complication which develops in 39% of adults following surgery for spinal deformity. The pathogenesis, risk factors and prevention of this complication are unclear. Methods Of 54 consecutive adults treated with spinal deformity surgery (age≥59.3±10.1 years), 19 of 54 (35%) developed PJK. The average follow-up was 26.8months (range 12 - 42). Radiographic parameters were measured at the pre-operative, early postoperative (4-6 weeks), and final follow-up visits. Sagittal alignment was measured by the ratio between the C7-plumbline and the sacral-femoral distance. Binary logistic regression model with predictor variables included: Age, BMI, C7-plumbline, and whether lumbar lordosis, thoracic kyphosis and sacral slope were present Results Patients who developed PJK and those without PJK presented with comparable age, BMI, pelvic incidence and sagittal imbalance before surgery. They also presented with comparable sacral slope and lumbar lordosis. The average magnitude of thoracic kyphosis was significantly larger than the lumbar lordosis in the proximal junctional kyphosis group, both at baseline and in the early postoperative period, as represented by [(-lumbar )lordosis - (thoracic kyphosis)]; no- PJK versus PJK; 6.6°±23.2° versus -6.6°±14.2°; p≥0.012. This was not effectively addressed with surgery in the PJK group [(-LL-TK): 6.2°±13.1° vs. -5.2°±9.6°; p≥0.004]. This group also presented with signs of pelvic retroversion with a sacral slope of 29.3°±8.2° pre-operatively that was unchanged after surgery (30.4°±8.5° postoperatively). Logistic regression determined that the magnitude of thoracic kyphosis and sagittal balance (C7-plumbline) was the most important predictor of proximal junctional kyphosis. Conclusions Proximal junctional kyphosis developed in those patients where the thoracic kyphosis remained greater in magnitude relative to the lumbar lordosis, and where the sagittal balance seemed corrected, but part of thise correction was secondary to pelvic retroversion. Level of Evidence Prognostic case-control study – Level III. PMID:22096442

Energy Landscape of Social Balance

NASA Astrophysics Data System (ADS)

Marvel, Seth A.; Strogatz, Steven H.; Kleinberg, Jon M.

2009-11-01

We model a close-knit community of friends and enemies as a fully connected network with positive and negative signs on its edges. Theories from social psychology suggest that certain sign patterns are more stable than others. This notion of social “balance” allows us to define an energy landscape for such networks. Its structure is complex: numerical experiments reveal a landscape dimpled with local minima of widely varying energy levels. We derive rigorous bounds on the energies of these local minima and prove that they have a modular structure that can be used to classify them.

Mass action at the single-molecule level.

PubMed

Shon, Min Ju; Cohen, Adam E

2012-09-05

We developed a system to reversibly encapsulate small numbers of molecules in an array of nanofabricated "dimples". This system enables highly parallel, long-term, and attachment-free studies of molecular dynamics via single-molecule fluorescence. In studies of bimolecular reactions of small numbers of confined molecules, we see phenomena that, while expected from basic statistical mechanics, are not observed in bulk chemistry. Statistical fluctuations in the occupancy of sealed reaction chambers lead to steady-state fluctuations in reaction equilibria and rates. These phenomena are likely to be important whenever reactions happen in confined geometries.

Golf Aerodynamics

NASA Technical Reports Server (NTRS)

1995-01-01

A former Martin Marietta Manned Space Systems engineer, Robert T. Thurman went from analyzing airloads on the Space Shuttle External Tank to analyzing airloads on golf balls for Wilson Sporting Goods Company. Using his NASA know-how, Thurman designed the Ultra 500 golf ball, which has three different-sized dimples in 60 triangular faces (instead of the usual 20) formed by a series of intersecting "parting" lines. This balances the asymmetry caused by the molding line in all golf balls. According to Wilson, the ball sustains initial velocity longer and produces the most stable ball flight for "unmatched" accuracy and distance.

Energy landscape of social balance.

PubMed

Marvel, Seth A; Strogatz, Steven H; Kleinberg, Jon M

2009-11-06

We model a close-knit community of friends and enemies as a fully connected network with positive and negative signs on its edges. Theories from social psychology suggest that certain sign patterns are more stable than others. This notion of social "balance" allows us to define an energy landscape for such networks. Its structure is complex: numerical experiments reveal a landscape dimpled with local minima of widely varying energy levels. We derive rigorous bounds on the energies of these local minima and prove that they have a modular structure that can be used to classify them.

Fracture Characteristics of Structural Steels and Weldments

DTIC Science & Technology

1975-11-01

CARACTERISTICS 0F.$ýTRUCTURAL TEL/ - "AD E NTSA .INAL 1 A7 sk S. CONTRACT OR GRANT NUMBER(&) Y.2G. im 9. PERFORMING ORGANIZATION NAME AND ADDRESS -017...36, T- 1,and HY-Y130 Steel and AX. Il 30 15 I Tensile F~racture Surface of A-36 Steel, 12x 31 16 Dimple Rupture in A-6Sel 0X 31 17 Plastic ...sites and the relative plasticity of thle The objective of this study was to use a scanning metal. If many fracture icleation sites initiate mticro

Herpes zoster producing temporary erectile dysfunction.

PubMed

Rix, G H; Carroll, D N; MacFarlane, J R

2001-12-01

Varicella Zoster affecting the sacral dermatomes is a rare but well recognised cause of urinary retention. Only one case of erectile dysfunction associated with Varicella Zoster has previously been described, which was longstanding, but no cases of transient erectile dysfunction following Zoster infection are recorded. We present one such case.

Herpes zoster-induced acute urinary retention: Two cases and literature review.

PubMed

He, H; Tang, C; Yi, X; Zhou, W

2018-04-01

We report two uncommon cases of acute urinary retention in Chinese patients caused by reactivation of sacral herpes zoster and requiring bladder drainage. Indwelling urinary catheterization, antiviral medication (ganciclovir), and physiotherapy with infrared light (830 nm) led to successful recovery of the micturition reflex in both cases.

Surgical Interventions and the Use of Device-Aided Therapy for the Treatment of Fecal Incontinence and Defecatory Disorders.

PubMed

Bharucha, Adil E; Rao, Satish S C; Shin, Andrea S

2017-12-01

The purpose of this clinical practice update expert review is to describe the key principles in the use of surgical interventions and device-aided therapy for managing fecal incontinence (FI) and defecatory disorders. The best practices outlined in this review are based on relevant publications, including systematic reviews and expert opinion (when applicable). Best Practice Advice 1: A stepwise approach should be followed for management of FI. Conservative therapies (diet, fluids, techniques to improve evacuation, a bowel training program, management of diarrhea and constipation with diet and medications if necessary) will benefit approximately 25% of patients and should be tried first. Best Practice Advice 2: Pelvic floor retraining with biofeedback therapy is recommended for patients with FI who do not respond to the conservative measures indicated above. Best Practice Advice 3: Perianal bulking agents such as intra-anal injection of dextranomer may be considered when conservative measures and biofeedback therapy fail. Best Practice Advice 4: Sacral nerve stimulation should be considered for patients with moderate or severe FI in whom symptoms have not responded after a 3-month or longer trial of conservative measures and biofeedback therapy and who do not have contraindications to these procedures. Best Practice Advice 5: Until further evidence is available, percutaneous tibial nerve stimulation should not be used for managing FI in clinical practice. Best Practice Advice 6: Barrier devices should be offered to patients who have failed conservative or surgical therapy, or in those who have failed conservative therapy who do not want or are not eligible for more invasive interventions. Best Practice Advice 7: Anal sphincter repair (sphincteroplasty) should be considered in postpartum women with FI and in patients with recent sphincter injuries. In patients who present later with symptoms of FI unresponsive to conservative and biofeedback therapy and evidence of sphincter damage, sphincteroplasty may be considered when perianal bulking injection and sacral nerve stimulation are not available or have proven unsuccessful. Best Practice Advice 8: The artificial anal sphincter, dynamic graciloplasty, may be considered for patients with medically refractory severe FI who have failed treatment or are not candidates for barrier devices, sacral nerve stimulation, perianal bulking injection, sphincteroplasty and a colostomy. Best Practice Advice 9: Major anatomic defects (eg, rectovaginal fistula, full-thickness rectal prolapse, fistula in ano, or cloaca-like deformity) should be rectified with surgery. Best Practice Advice 10: A colostomy should be considered in patients with severe FI who have failed conservative treatment and have failed or are not candidates for barrier devices, minimally invasive surgical interventions, and sphincteroplasty. Best Practice Advice 11: A magnetic anal sphincter device may be considered for patients with medically refractory severe FI who have failed or are not candidates for barrier devices, perianal bulking injection, sacral nerve stimulation, sphincteroplasty, or a colostomy. Data regarding efficacy are limited and 40% of patients had moderate or severe complications. Best Practice Advice 12: For defecatory disorders, biofeedback therapy is the treatment of choice. Best Practice Advice 13: Based on limited evidence, sacral nerve stimulation should not be used for managing defecatory disorders in clinical practice. Best Practice Advice 14: Anterograde colonic enemas are not effective in the long term for management of defecatory disorders. Best Practice Advice 15: The stapled transanal rectal resection and related procedures should not be routinely performed for correction of structural abnormalities in patients with defecatory disorders. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Pelvic girdle and fin of Tiktaalik roseae

PubMed Central

Shubin, Neil H.; Daeschler, Edward B.; Jenkins, Farish A.

2014-01-01

A major challenge in understanding the origin of terrestrial vertebrates has been knowledge of the pelvis and hind appendage of their closest fish relatives. The pelvic girdle and appendage of tetrapods is dramatically larger and more robust than that of fish and contains a number of structures that provide greater musculoskeletal support for posture and locomotion. The discovery of pelvic material of the finned elpistostegalian, Tiktaalik roseae, bridges some of these differences. Multiple isolated pelves have been recovered, each of which has been prepared in three dimensions. Likewise, a complete pelvis and partial pelvic fin have been recovered in association with the type specimen. The pelves of Tiktaalik are paired and have broad iliac processes, flat and elongate pubes, and acetabulae that form a deep socket rimmed by a robust lip of bone. The pelvis is greatly enlarged relative to other finned tetrapodomorphs. Despite the enlargement and robusticity of the pelvis of Tiktaalik, it retains primitive features such as the lack of both an attachment for the sacral rib and an ischium. The pelvic fin of Tiktaalik (NUFV 108) is represented by fin rays and three endochondral elements: other elements are not preserved. The mosaic of primitive and derived features in Tiktaalik reveals that the enhancement of the pelvic appendage of tetrapods and, indeed, a trend toward hind limb-based propulsion have antecedents in the fins of their closest relatives. PMID:24449831