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Sample records for external tibial torque

  1. External fixation in the treatment of open tibial shaft fractures

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    Golubović Zoran

    2008-01-01

    Full Text Available Background/Aim. Besides the conquasant fractures, open tibia shaft fractures belong to the group of the most severe fractures of tibia. Open tibia shaft fracture is one of the most common open fractures of long bones. They most frequently occur as a result of traffic accidents caused by the influence of a strong direct force. Methods. Within the period from January, 2000 to December 31, 2005. at the Clinic for Orthopaedics and Traumatology, Clinical Center Nis, 107 patients with open tibial fractures were treated. We analyzed 96 patients with open tibial fracture. In the series analyzed, the male sex was prevalent - there were 74 men (77.08%. The mean age was 47.3 years. The youngest patient was 17 years old, while the oldest patient was 79. According to the classification of the Gustilo et al. in the analysed group there were 30 (31.25% open tibial fractures of the I degree, 31 (32.29% of the II degree, 25 (26.05% of the III A degree, 8 (8.33% of the III B degree and 2 (2.08% of the III C degree. In 95 of the patients the treatment of open tibia shaft fractures consisted of the surgical treatment of wound and the external fixation of the fractured bone using "Mitkovic" type external fixator with a convergent method of pin applications. One primary amputations had been done in patients with grade IIIC open tibial fracture with large soft tissue defect. Results. Of the 96 open tibial fractures available for follow-up, 73 (76.04% healed without severe complications (osteitis, pseudoarthrosis, valgus malunion and amputation. Ther were nine (9.38% soft tissue pin track infections and six (6.25% superficial wound infections. The mean time of union was 21 (14-36 week. Among severe local complications associated with open tibial fractures, in eight patients (8.33% was registered osteitis, and in nine patients (9.38% fracture nonunion and the development of pseudoarthrosis. Three of the patients (3.13% had more than 10 degree valgus malunion. In one

  2. Van der Waals torque induced by external magnetic fields

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    Esquivel-Sirvent, R; Palomono-Ovando, M

    2010-01-01

    We present a method for inducing and controlling van der Waals torques between two parallel slabs using a constant magnetic field. The torque is calculated using the Barash theory of dispersive torques. In III-IV semiconductors such as $InSb$, the effect of an external magnetic field is to induce an optical anisotropy, in an otherwise isotropic material, that will in turn induce a torque. The calculations of the torque are done in the Voigt configuration, with the magnetic field parallel to the surface of the slabs. As a case study we consider a slab made of calcite and a second slab made of $InSb$. In the absence of magnetic field there is no torque. As the magnetic field increases, the optical anisotropy of $InSb$ increases and the torque becomes different from zero, increasing with the magnetic field. The resulting torque is of the same order of magnitude as that calculated using permanent anisotropic materials when the magnetic fields is close to 1 T.

  3. Van der Waals torque induced by external magnetic fields

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    Esquivel-Sirvent, R.; Cocoletzi, G. H.; Palomino-Ovando, M.

    2010-01-01

    We present a method for inducing and controlling van der Waals torques between two parallel slabs using a constant magnetic field. The torque is calculated using the Barash theory of dispersive torques. In III–IV semiconductors such as InSb, the effect of an external magnetic field is to induce an optical anisotropy, in an otherwise isotropic material, that will in turn induce a torque. The calculations of the torque are done in the Voigt configuration, with the magnetic field parallel to the surface of the slabs. As a case study we consider a slab made of calcite and a second slab made of InSb. In the absence of magnetic field there is no torque. As the magnetic field increases, the optical anisotropy of InSb increases and the torque becomes different from zero, increasing with the magnetic field. The resulting torque is of the same order of magnitude as that calculated using permanent anisotropicmaterials when the magnetic fields is close to 1 T.

  4. Results of open tibial fracture treatment using external fixation

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    Golubović Ivan

    2016-01-01

    Full Text Available Introduction. Open lower leg fractures are the most common open fractures of the locomotor system and their treatment is associated with a number of complications. Objective. The aim of the paper was to present the results of the treatment of 68 patients with open lower leg fractures, as well as the complications that accompany the treatment of these fractures. Methods. In the analyzed group, there were 45 (66.18% men and 23 (33.82% women. The majority of patients - 33 (48.53% of them - were injured in motor vehicle accidents, whereas 24 (35.29% patients sustained injuries due to falls from heights. In two (2.94% patients the cause of open tibial fractures was gunshot injuries. In the analyzed group, there were 18 (26.47% type I open fractures, 21 (30.88% type II open fractures, 19 (27.94% type IIIA open fractures, seven (10.29% type IIIB open fractures, and three (4.41% type IIIC open fractures. Results. The tibial shaft fracture healed without serious complications in 50 (73.53% patients, whereas in 18 (26.47% patients we observed some complications. Nonunion was found in 10 (14.71% patients, osteitis in four (5.88, malunion in two (2.94% patients. Milder complications such as soft tissue pin tract infection developed in 13 (19.12% patients, infection of the open fracture wound soft tissue was observed in four (5.88% patients. Conclusion. Basic principles in the treatment of open lower leg fractures in this study are thorough primary open fracture wound treatment followed by the delayed wound closure, stable fracture fixation using unilateral external skeletal device, proper antibiotic treatment and tetanus prophylaxis. The results correlate with similar studies. [Projekat Ministarstva nauke Republike Srbije, br. III 41017: Virtual Human Osteoarticular System and its Application in Preclinical and Clinical Practice

  5. Tosic external fixator in the management of proximal tibial fractures in adults.

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    Tosic, A; Ebraheim, N A; Abou Chakra, I; Emara, K

    2001-06-01

    This retrospective clinical study assessed proximal tibial fractures managed with the Tosic external fixator. Nineteen patients with 21 proximal tibial fractures treated with the Tosic external fixator between July 1997 and October 1998 comprised the study population. Eleven fractures were graded as 41A2, 3 fractures as 41 A3, 4 fractures as 41C1, and 3 fractures as 41 C2. Fourteen fractures were closed, and 7 fractures were open. Average time to healing was 1 7 weeks. No revision of fixation was needed. There were five cases of pin tract infection. Average range of knee motion was 2 degrees-135 degrees. These results indicate the Tosic external fixator is an efficient and simple way to treat proximal tibial metaphyseal fractures.

  6. Design of Low-Torque-Ripple Synchronous Reluctance Motor with External Rotor

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    Lavrinovicha L.

    2017-02-01

    Full Text Available The paper presents new designs for synchronous reluctance motors that have external rotor (segment-shaped rotor, rotor with additional non-magnetic space to the quadrature axis of the rotor, and rotor with several flux barriers. Impact of the external rotor configuration on the electromagnetic torque and torque ripple is analysed. Electromagnetic torque ripple factor is calculated for each studied motor using the results of magnetic field numerical calculations.

  7. Outcome of complex tibial plateau fractures treated with external fixator

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    Sushil H Mankar

    2012-01-01

    Conclusion: We believe that minimally invasive treatment by percutaneous techniques and external fixation is a fairly reasonable treatment alternative, if near anatomical reduction of joint surface can be confirmed on fluoroscopy.

  8. External versus internal fixation for bicondylar tibial plateau fractures: systematic review and meta-analysis.

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    Metcalfe, David; Hickson, Craig J; McKee, Lesley; Griffin, Xavier L

    2015-12-01

    It is uncertain whether external fixation or open reduction internal fixation (ORIF) is optimal for patients with bicondylar tibial plateau fractures. A systematic review using Ovid MEDLINE, Embase Classic, Embase, AMED, the Cochrane Library, Open Grey, Orthopaedic Proceedings, WHO International Clinical Trials Registry Platform, Current Controlled Trials, US National Institute for Health Trials Registry, and the Cochrane Central Register of Controlled Trials. The search was conducted on 3rd October 2014 and no language limits were applied. Inclusion criteria were all clinical study designs comparing external fixation with open reduction internal fixation of bicondylar tibial plateau fractures. Studies of only one treatment modality were excluded, as were those that included unicondylar tibial plateau fractures. Treatment effects from studies reporting dichotomous outcomes were summarised using odds ratios. Continuous outcomes were converted to standardized mean differences to assess the treatment effect, and inverse variance methods used to combine data. A fixed effect model was used for meta-analyses. Patients undergoing external fixation were more likely to have returned to preinjury activities by six and twelve months (P = 0.030) but not at 24 months follow-up. However, external fixation was complicated by a greater number of infections (OR 2.59, 95 % CI 1.25-5.36, P = 0.01). There were no statistically significant differences in the rates of deep infection, venous thromboembolism, compartment syndrome, or need for re-operation between the two groups. Although external fixation and ORIF are associated with different complication profiles, both are acceptable strategies for managing bicondylar tibial plateau fractures.

  9. Torque Ripple Suppression in an External-Meshed Magnetic Gear Train

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    Yi-Chang Wu

    2013-01-01

    Full Text Available Magnetic gear trains transmit torque through noncontact magnetic couplings rather than conjugate gear teeth; they have the unique advantages of reduced maintenance and improved reliability, inherent overload protection, high efficiency, precise peak torque transmission, and tolerance for misalignment. Smooth and steadily transmitted torque is an important characteristic for a magnetic gear train. It is necessary for the reduction of possible mechanical vibration, position inaccuracy, and acoustic noise. This paper investigates the transmitted torque characteristics, especially torque ripple reduction, of an external-meshed magnetic gear train using finite-element analysis (FEA. The topological structure and working principles of a simple magnetic gear train with parallel axes are introduced. With the aid of a commercial FEA package, the transmitted torque waveform of a magnetic gear train is numerically calculated. The effects of geometrical parameters on the maximum transmitted torque and torque ripple are further discussed in terms of obtaining a magnetic gear train with high transmitted torque or low torque ripple. This examination offers insights beneficial to future magnetic gear mechanism design.

  10. Distal tibial fracture: An ideal indication for external fixation using locking plate

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    Jing-wei Zhang; Nabil A.Ebraheim; Ming Li; Xian-Feng He; Joshua Schwind; Li-Mei Zhu; Yi-Hui Yu

    2016-01-01

    Objective:To evaluate the feasibility and efficiency of one-stage external fixation by using locking plate in distal tibial fractures.Methods:In this non-control prospective study,28 patients with distal tibial fractures were included and underwent one-stage external fixation by using locking plate.There were 21 males and 7 females,with a mean age of 43 years (19-63).According to AO/OTA fracture classification,there were 9 cases of Type A1,9 of Type A2,10 of Type A3 fractures.There were 21 close and 7 open fractures.The locking plate was placed on the anteromedial aspect of the tibia with 4-5 bicortical screws inserted in both distal metaphysis and diaphysis.The radiographic and clinic results were evaluated.Results:All patients were followed up for the average of 16 months (ranging from 12 to 21 months).The average surgery duration was 38 (25-60) minutes.The mean time to fracture healing were 14.6 ± 2.67,17.5 ± 3.66,and 18.4 ± 3.37 (p < 0.05) weeks in type A1,A2,and A3 fractures respectively.By the end of the follow-ups,the mean AOFAS score were 96.11 ± 2.32,92.67 ± 1.80 and 92.00 ± 2.06 (p > 0.05) in type A1,A2,and A3 fractures respectively.None of nonunion,deep infection,or breakage of screw or plate were observed.Conclusions:Distal tibial fracture was the ideal indication for external fixation using locking plate.The external plating is characterized by ease of performance,less invasive,fewer soft tissue impingement,improved cosmesis,and convenient for removal.

  11. Treatment of tibial defect and bone nonunion with limb shortening with external fixator and reconstituted bone xenograft

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    王志刚; 刘建; 胡蕴玉; 孟国林; 金格勒; 袁志; 王海强; 戴先文

    2003-01-01

    Objective: To explore the effect of external fixator and reconstituted bone xenograft (RBX) in the treatment of tibial bone defect, tibial bone nonunion and congenital pseudarthrosis of the tibia with limb shortening. Methods: Twenty patients ( 13 males and 7 females) with tibial bone defect, tibial bone nonunion or congenital pseudarthrosis of the tibia with limb shortening were treated with external fixation. Two kinds of external fixators were used: a half ring sulcated external fixator used in 13 patients and a combined external fixator in 7 patients. Foot-drop was corrected at the same time with external fixation in 4 patients. The shortened length of the tibia was in the range of 2-9 cm, with an average of 4.8 cm. For bone grafting, RBX was used in 12 patients, autogenous ilium was used in 3 patients and autogenous fibula was implanted as a bone plug into the medullary canal in 1 case, and no bone graft was used in 4 patients. Results: All the 20 patients were followed-up for 8 months to 7 years, averaging 51 months. Satisfactory function of the affected extremities was obtained. All the shortened extremities were lengthened to the expected length. For all the lengthening area and the fracture sites, bone union was obtained at the last. The average healing time of 12 patients treated with RBX was 4.8 months. Conclusions: Both the half ring sulcated external fixator and the combined external fixator have the advantages of small trauma, simple operation, elastic fixation without stress shielding and non-limitation from local soft tissue conditions, and there is satisfactory functional recovery of affected extremities in the treatment of tibial bone defects, tibial bone nonunion and congenital pseudarthrosis of the tibia combined with limb shortening. RBX has good biocompatibility and does not cause immunological rejections. It can also be safely used in treatment of bone nonunion and has reliable effect to promote bone healing.

  12. Ingenious method of external fixator use to maintain alignment for nailing a proximal tibial shaft fracture.

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    Behera, Prateek; Aggarwal, Sameer; Kumar, Vishal; Kumar Meena, Umesh; Saibaba, Balaji

    2015-09-01

    Fractures of the tibia are one of the most commonly seen orthopedic injuries. Most of them result from a high velocity trauma. While intramedullary nailing of tibial diaphyseal fractures is considered as the golden standard form of treatment for such cases, many metaphyseal and metaphyseal-diaphyseal junction fractures can also be managed by nailing. Maintenance of alignment of such fractures during surgical procedure is often challenging as the pull of patellar tendon tends to extend the proximal fragment as soon as one flexes the knee for the surgical procedure. Numerous technical modifications have been described in the literature for successfully nailing such fractures including semi extended nailing, use of medial plates and external fixators among others. In this study, it was aimed to report two cases in which we used our ingenious method of applying external fixator for maintaining alignment of the fracture and aiding in the entire process of closed intramedullary nailing of metaphyseal tibial fractures by the conventional method. We were able to get good alignment during and after the closed surgery as observed on post-operative radiographs and believe that further evaluation of this technique may be of help to surgeons who want to avoid other techniques.

  13. Adaptive external torque estimation by means of tracking a Lyapunov function

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    Schaub, H.; Junkins, J.L. [Texas A and M Univ., College Station, TX (United States); Robinett, R.D. [Sandia National Labs., Albuquerque, NM (United States)

    1996-03-01

    A real-time method is presented to adoptively estimate three-dimensional unmodeled external torques acting on a spacecraft. This is accomplished by forcing the tracking error dynamics to follow the Lyapunov function underlying the feedback control law. For the case where the external torque is constant, the tracking error dynamics are shown to converge asypmtotically. The methodology applies not only to the control law used in this paper, but can also be applied to most Lyapunov derived feedback control laws. The adaptive external torque estimation is very robust in the presence of measurement noise, since a numerical integration is used instead of a numerical differentiation. Spacecraft modeling errors, such as in the inertia matrix, are also compensated for by this method. Several examples illustrate the practical significance of these ideas.

  14. Distal tibial fracture treated by minimally invasive plate osteosynthesis after external fixation Retrospective clinical and radiographic assessment

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    Al. Șerban

    2014-02-01

    Full Text Available Fractures of the horizontal surface of the distal tibia are known commonly as pylon or plafond fractures, and represent 1-5% of lower extremity fractures, 7-10% of all tibial fractures. The protocol consisted of immediate (within eight to 24 hours open reduction and internal fixation of the fibula, using a fibular plate or one third tubular plate and application of an external fixator spanning the ankle joint. In the second stage, the treatment of proximal and distal tibial fractures with close reduction and MIPPO technique can preserve soft tissue, simplify operative procedure and decrease wound, obtain rigid internal fixation and guarantee early function exercises of ankle joint. In this study we evaluated 22 patients treated in Clinical Emergency Hospital Constanta between April 2012 - July 2013 diagnosed with multifragmentary fractures of the distal tibia. This study evaluates the treatment of complex fractures of distal tibia with locked plate after external fixation. There were 17 males and 5 females of mean age 51,7 years (31-68. The mean follow-up period was 14 weeks. (Ranging from 9-16 weeks. All patients were fully weight bearing at 16 weeks (ranging 9-16 weeks showing radiological union. There were no cases of failures of fixation, or rotational misalignment. No significant complication was observed in our patients. MIPO is an effective method of treatment for distal tibial fractures, reduce surgical trauma and maintain a more biologically favorable environment for fracture healing, reducing risks of infection and nonunion.

  15. Spin-orbit torque switching without an external field using interlayer exchange coupling

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    Lau, Yong-Chang; Betto, Davide; Rode, Karsten; Coey, J. M. D.; Stamenov, Plamen

    2016-09-01

    Manipulation of the magnetization of a perpendicular ferromagnetic free layer by spin-orbit torque (SOT) is an attractive alternative to spin-transfer torque (STT) in oscillators and switches such as magnetic random-access memory (MRAM) where a high current is passed across an ultrathin tunnel barrier. A small symmetry-breaking bias field is usually needed for deterministic SOT switching but it is impractical to generate the field externally for spintronic applications. Here, we demonstrate robust zero-field SOT switching of a perpendicular CoFe free layer where the symmetry is broken by magnetic coupling to a second in-plane exchange-biased CoFe layer via a nonmagnetic Ru or Pt spacer. The preferred magnetic state of the free layer is determined by the current polarity and the sign of the interlayer exchange coupling (IEC). Our strategy offers a potentially scalable solution to realize bias-field-free switching that can lead to a generation of SOT devices, combining a high storage density and endurance with a low power consumption.

  16. Evaluation of Aerodynamic Drag and Torque for External Tanks in Low Earth Orbit.

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    Stone, William C; Witzgall, Christoph

    2006-01-01

    A numerical procedure is described in which the aerodynamic drag and torque in low Earth orbit are calculated for a prototype Space Shuttle external tank and its components, the "LO2" and "LH2" tanks, carrying liquid oxygen and hydrogen, respectively, for any given angle of attack. Calculations assume the hypersonic limit of free molecular flow theory. Each shell of revolution is assumed to be described by a series of parametric equations for their respective contours. It is discretized into circular cross sections perpendicular to the axis of revolution, which yield a series of ellipses when projected according to the given angle of attack. The drag profile, that is, the projection of the entire shell is approximated by the convex envelope of those ellipses. The area of the drag profile, that is, the drag area, and its center of area moment, that is, the drag center, are then calculated and permit determination of the drag vector and the eccentricity vector from the center of gravity of the shell to the drag center. The aerodynamic torque is obtained as the cross product of those vectors. The tanks are assumed to be either evacuated or pressurized with a uniform internal gas distribution: dynamic shifting of the tank center of mass due to residual propellant sloshing is not considered.

  17. Molecular dynamics on nonequilibrium motion of a colloidal particle driven by an external torque

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    Yoo, Donghwan; Jung, Youngkyun; Kwon, Chulan

    2017-03-01

    We investigate the motion of a colloidal particle driven out of equilibrium by an external torque. We use molecular dynamics simulation as an alternative to the Langevin dynamics. We prepare a heat bath composed of thousands of particles interacting with each other through the Lennard–Jones potential and impose the Langevin thermostat to maintain the heat bath in equilibrium. We consider a single colloidal particle interacting with with the particles of the heat bath also by the Lennard–Jones potential, without applying any types of dissipative or fluctuating forces used in Langevin dynamics. We set up simulation protocol fit for the overdamped limit as in real experiments, by increasing the size and mass of the colloidal particle. We study nonequilibrium fluctuations for work and heat produced incessantly in time and compare the results with those obtained from the previous studies via the overdamped Langevin dynamics. We confirm the Gallavotti–Cohen symmetry and the fluctuation theorem.

  18. Distal tibial pilon fractures (AO/OTA type B, and C treated with the external skeletal and minimal internal fixation method

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    Milenković Saša

    2013-01-01

    Full Text Available Background/Aim. Distal tibial pilon fractures include extra-articular fractures of the tibial metaphysis and the more severe intra-articular tibial pilon fractures. There is no universal method for treating distal tibial pilon fractures. These fractures are treated by means of open reduction, internal fixation (ORIF and external skeletal fixation. The high rate of soft-tissue complications associated with primary ORIF of pilon fractures led to the use of external skeletal fixation, with limited internal fixation as an alternative technique for definitive management. The aim of this study was to estimate efficacy of distal tibial pilon fratures treatment using the external skeletal and minimal internal fixation method. Methods. We presented a series of 31 operated patients with tibial pilon fractures. The patients were operated on using the method of external skeletal fixation with a minimal internal fixation. According to the AO/OTA classification, 17 patients had type B fracture and 14 patients type C fractures. The rigid external skeletal fixation was transformed into a dynamic external skeletal fixation 6 weeks post-surgery. Results. This retrospective study involved 31 patients with tibial pilon fractures, average age 41.81 (from 21 to 60 years. The average follow-up was 21.86 (from 12 to 48 months. The percentage of union was 90.32%, nonunion 3.22% and malunion 6.45%. The mean to fracture union was 14 (range 12-20 weeks. There were 4 (12.19% infections around the pins of the external skeletal fixator and one (3.22% deep infections. The ankle joint arthrosis as a late complication appeared in 4 (12.90% patients. All arthroses appeared in patients who had type C fractures. The final functional results based on the AOFAS score were excellent in 51.61%, good in 32.25%, average in 12.90% and bad in 3.22% of the patients. Conclusion. External skeletal fixation and minimal internal fixation of distal tibial pilon fractures is a good method for

  19. Outcome Assessment of Hybrid External Fixation in the Treatment of Comminuted Distal Femur and Proximal Tibial Fractures

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    Sarrafan

    2016-02-01

    Full Text Available Background Treatment of comminuted fractures of the distal femur and proximal tibia is difficult, and a challenge in the field of orthopedic trauma. Objectives The aim of this study was to assess the short-term results of hybrid external fixation in the treatment of these fractures. Patients and Methods In a prospective study, 44 patients with comminuted fractures of the distal femur or proximal tibia, with an overlying soft tissue injury treated by closed reduction and hybrid external fixation, were included. Parameters such as pin-track infection, union, limb shortening, knee motion, and alignment were evaluated during a mean follow-up period of 14 months. Results Forty-four patients with distal femoral (n = 23 and proximal tibial (n = 21 fractures were treated using hybrid external fixation. Bone union was seen in 35 (80% of the patients. Pin tract infection was seen in three patients (6.8%, one case (4.6% with a PTF and two cases (8% with DFFs. Malunion was observed in 4 patients (9.1%; of these, three cases (13% had DFF and one case (4.8% of pain was detected in the DFF group. One case had malunion and three cases had union. Findings showed satisfactory results in more than 80% of patients. In general, lower postoperative complications were detected in the proximal tibial fractures than the distal femoral fractures. According to a chi-square test, the difference between the patients with PTFs and those with DFFs was not clinically significant. Conclusions Closed reduction and hybrid external fixation can be used as a definitive treatment for severe comminuted fractures of the distal femur and proximal tibia, when the concomitant contusion of the skin and soft tissue damage prohibits safe open reduction and internal fixation.

  20. Surgical treatment of tibial nonunion after wounding by high velocity missile and external fixators: A case report

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    Golubović Ivan

    2012-01-01

    Full Text Available Introduction. The missiles of modern firearms can cause severe fractures of the extremity. High velocity missile fractures of the tibia are characterized by massive tissue destruction and primary contamination with polymorphic bacteria. Treatment of these fractures is often complicated by delayed healing, poor position healing, nonhealing and bone tissue infection. Case Outline. We present the management of tibial nonunion after wounding by high velocity missile and primary treatment by external fixation in a 25-year-old patient. The patient was primarily treated with external fixation and reconstructive operations of the soft tissue without union of the fracture. Seven months after injury we placed a compression-distraction external fixator type Mitkovic and started with compression and distraction in the fracture focus after osteotomy of the fibula and autospongioplasty. We recorded satisfactory fracture healing and good functional outcome. Conclusion. Contamination and devitalization of the softtissue envelope increase the risk of infection and nonunion in fractures after wounding by high velocity missile. The use of the compression-distraction external fixator type Mitkovic may be an effective method in nonunions of the tibia after this kind of injury. [Projekat Ministarstva nauke Republike Srbije, br. III 41004

  1. A meta-analysis of external fixation versus open reduction and internal fixation for complex tibial plateau fractures.

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    Zhao, Xing-Wen; Ma, Jian-Xiong; Ma, Xin-Long; Jiang, Xuan; Wang, Yin; Li, Fei; Lu, Bin

    2017-03-01

    Both external fixation (ExFx) and open reduction and internal fixation(ORIF) were used to treat complex tibial plateau fractures, but it was not sure which one was better. So we did this meta-analysis to evaluate the outcomes of ExFx and ORIF in managing complex tibial plateau fractures. Articles published before August 5, 2016 were selected from PubMed, Cochrane library, and some other electronic database. Relevant journals were also searched manually with no language limited. Two independent reviewers searched and assessed the literature. A fixed effect model was initially used for meta-analyses with RevMan 5.3. When compared with ORIF, cases undergoing ExFx were more likely to return to the preinjury state at the early stage, but no difference in the later period of follow-up. However, ExFx group had higher infection rate (OR 1.98, 95% CI 1.08-3.63, P = 0.03), higher venous thromboembolism rate (OR 1.56, 95% CI 0.49-4.96, P = 0.45), higher re-operation rate (OR 0.87, 95% CI 0.47-1.62, P = 0.66) and lower compartment syndrome rate (OR 0.61, 95% CI 0.12-3.22, P = 0.56), lower TKA rate (OR 0.51, 95% CI 0.20-1.34, P = 0.17). There were no statistically significant differences in the rate of deep infection, venous thromboembolism, compartment syndrome and VTE between the two groups. Although external fixation may offer some advantages, both were acceptable strategies in managing complex tibial plateau fractures. According to our analysis results, we strongly recommend that selection of definitive fixators should base on the fracture patterns, soft-tissue condition as well as the injury stages in clinical practice. More important, further multicentered, randomized controlled studies should be implemented to get a more reliable and clear result. Copyright © 2017 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

  2. Comparison of concentric isokinetic dominant shoulder internal and external rotator torque between professional female volleyball and tennis players

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    S. Talebian

    2006-08-01

    Full Text Available Background: The purpose of this study was to measure isokinetic maximum and average peak torque of internal and external rotators of glenohumeral joint in volley ball and tennis players Methods: This study was performed on 17 professional female athletes (7 tennis players &10 volleyball players with age ranged 18-28 years. The subjects had played in a skilled team for more than 3 years. They were free from injury to their dominant shoulder in the past year. Subjects performed a five minute warm up by shoulder wheel and Maximum average Peak Torque (APT were obtained unilaterally by a Biodex System 3 with the arm of players in 90 degree abduction at 120,180 & 210 o/s. Players performed five trails of concentric movements with 30 second rest between them. Results: Maximum and average of maximum torques of shoulder rotator, in both groups, expect for internal rotators of tennis players, reduced by increase of movement speed (P<0.05. There are not significant difference between two groups in maximum, average of maximum torques and normalized data (ratio of maximum torque to weight. There is significant difference between two groups in percentage of APT of External rotator / Internal rotator ratio at 210 o/s (P<0.05. Conclusion: Volleyball and tennis have no effect on isokinetic strength of shoulder rotators. In high speed, ratio of External rotator / Internal rotator is reduced. This indicates that increase in movement speed increase internal rotator in comparison to external rotator in these professional female athletes.

  3. Torque Ripple Suppression in an External-Meshed Magnetic Gear Train

    OpenAIRE

    Yi-Chang Wu; Wan-Tsun Tseng; Yueh-Tung Chen

    2013-01-01

    Magnetic gear trains transmit torque through noncontact magnetic couplings rather than conjugate gear teeth; they have the unique advantages of reduced maintenance and improved reliability, inherent overload protection, high efficiency, precise peak torque transmission, and tolerance for misalignment. Smooth and steadily transmitted torque is an important characteristic for a magnetic gear train. It is necessary for the reduction of possible mechanical vibration, position inaccuracy, and acou...

  4. Torque Ripple Suppression in an External-Meshed Magnetic Gear Train

    OpenAIRE

    Yi-Chang Wu; Wan-Tsun Tseng; Yueh-Tung Chen

    2013-01-01

    Magnetic gear trains transmit torque through noncontact magnetic couplings rather than conjugate gear teeth; they have the unique advantages of reduced maintenance and improved reliability, inherent overload protection, high efficiency, precise peak torque transmission, and tolerance for misalignment. Smooth and steadily transmitted torque is an important characteristic for a magnetic gear train. It is necessary for the reduction of possible mechanical vibration, position inaccuracy, and acou...

  5. Posterior Tibial Slope Angle Correlates With Peak Sagittal and Frontal Plane Knee Joint Loading During Robotic Simulations of Athletic Tasks.

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    Bates, Nathaniel A; Nesbitt, Rebecca J; Shearn, Jason T; Myer, Gregory D; Hewett, Timothy E

    2016-07-01

    Tibial slope angle is a nonmodifiable risk factor for anterior cruciate ligament (ACL) injury. However, the mechanical role of varying tibial slopes during athletic tasks has yet to be clinically quantified. To examine the influence of posterior tibial slope on knee joint loading during controlled, in vitro simulation of the knee joint articulations during athletic tasks. Descriptive laboratory study. A 6 degree of freedom robotic manipulator positionally maneuvered cadaveric knee joints from 12 unique specimens with varying tibial slopes (range, -7.7° to 7.7°) through drop vertical jump and sidestep cutting tasks that were derived from 3-dimensional in vivo motion recordings. Internal knee joint torques and forces were recorded throughout simulation and were linearly correlated with tibial slope. The mean (±SD) posterior tibial slope angle was 2.2° ± 4.3° in the lateral compartment and 2.3° ± 3.3° in the medial compartment. For simulated drop vertical jumps, lateral compartment tibial slope angle expressed moderate, direct correlations with peak internally generated knee adduction (r = 0.60-0.65), flexion (r = 0.64-0.66), lateral (r = 0.57-0.69), and external rotation torques (r = 0.47-0.72) as well as inverse correlations with peak abduction (r = -0.42 to -0.61) and internal rotation torques (r = -0.39 to -0.79). Only frontal plane torques were correlated during sidestep cutting simulations. For simulated drop vertical jumps, medial compartment tibial slope angle expressed moderate, direct correlations with peak internally generated knee flexion torque (r = 0.64-0.69) and lateral knee force (r = 0.55-0.74) as well as inverse correlations with peak external torque (r = -0.34 to -0.67) and medial knee force (r = -0.58 to -0.59). These moderate correlations were also present during simulated sidestep cutting. The investigation supported the theory that increased posterior tibial slope would lead to greater magnitude knee joint moments, specifically

  6. External fixation versus open reduction and internal fixation for tibial pilon fractures: A meta-analysis based on observational studies

    Institute of Scientific and Technical Information of China (English)

    Yi-Chen Meng; Xu-Hui Zhou

    2016-01-01

    Purpose:Tibial pilon fractures remain challenging for an orthopaedic surgeon to repair.External fixation (ExFix) and open reduction and internal fixation (ORIF) are two widely used methods for repairing tibial pilon fractures.However,conclusions of comparative studies regarding which method is superior are controversial.Our aim is to compare ORIF and ExFix and clarify which method is better in terms of reduction and union results and major complications.Methods:A computerized research of MEDLINE,EMBASE,Springer,and Cochrane Library (before December 2014) for studies of any design comparing ORIF and ExFix was conducted.Weighted mean difference (WMD),risk ratio (RR) and corresponding 95% confidence intervals (CI) were used for estimating the effects of the two methods.Statistical analyses were done using Review Manager Version 5.2.Results:Ten cohort studies and one randomized clinical trial were included in our ultimate analysis.And the analysis found no significant difference between the two methods in deep infection (p =0.13),reduction (p =0.11),clinical evaluation (p =0.82),post-traumatic arthrosis (p =0.87),and union time (p =0.35).Besides,ExFix group was found to have a higher rate of superficial infection (p =0.001),malunion (p =0.01) and nonunion (p =0.02),but have a lower risk of unplanned hardware removal (p =0.0002).Conclusions:We suggest that ORIF has a relatively lower incidence rate of superficial infection,malunion and nonunion,but a higher rate of unplanned hardware removal.No difference was found in deep infection,reduction,clinical evaluation,post-traumatic arthrosis and union time.

  7. External fixation versus open reduction and internal fixation for tibial pilon fractures: A meta-analysis based on observational studies.

    Science.gov (United States)

    Meng, Yi-Chen; Zhou, Xu-Hui

    2016-10-01

    Tibial pilon fractures remain challenging for an orthopaedic surgeon to repair. External fixation (ExFix) and open reduction and internal fixation (ORIF) are two widely used methods for repairing tibial pilon fractures. However, conclusions of comparative studies regarding which method is superior are controversial. Our aim is to compare ORIF and ExFix and clarify which method is better in terms of reduction and union results and major complications. A computerized research of MEDLINE, EMBASE, Springer, and Cochrane Library (before December 2014) for studies of any design comparing ORIF and ExFix was conducted. Weighted mean difference (WMD), risk ratio (RR) and corresponding 95% confidence intervals (CI) were used for esti- mating the effects of the two methods. Statistical analyses were done using Review Manager Version 5.2. Ten cohort studies and one randomized clinical trial were included in our ultimate analysis. And the analysis found no significant difference between the two methods in deep infection (p = 0.13), reduction (p = 0.11), clinical evaluation (p = 0.82), post-traumatic arthrosis (p = 0.87), and union time (p = 0.35). Besides, ExFix group was found to have a higher rate of superficial infection (p =0.001), malunion (p = 0.01) and nonunion (p = 0.02), but have a lower risk of unplanned hardware removal (p = 0.0002). We suggest that ORIF has a relatively lower incidence rate of superficial infection, malunion and nonunion, but a higher rate of unplanned hardware removal. No difference was found in deep infection, reduction, clinical evaluation, post-traumatic arthrosis and union time.

  8. Metaphyseal locking plate as a definitive external fixator for treating open tibial fractures--clinical outcome and a finite element study.

    Science.gov (United States)

    Ma, Ching-Hou; Wu, Chin-Hsien; Tu, Yuan-Kun; Lin, Ting-Sheng

    2013-08-01

    We evaluated both the outcome of using a locking plate as a definitive external fixator for treating open tibial fractures and, using finite element analysis, the biomechanical performance of external and internal metaphyseal locked plates in treating proximal tibial fractures. Eight open tibial patients were treated using a metaphyseal locked plate as a low-profile definitive external fixator. Then, finite element models of internal (IPF) as well as two different external plate fixations (EPFs) for proximal tibial fractures were reconstructed. The offset distances from the bone surface to the EPFs were 6 cm and 10 cm. Both axial stiffness and angular stiffness were calculated to evaluate the biomechanical performance of these three models. The mean follow-up period was 31 months (range, 18-43 months). All the fractures united and the mean bone healing time was 37.5 weeks (range, 20-52 weeks). All patients had excellent or good functional results and were walking freely at the final follow-up. The finite element finding revealed that axial stiffness and angular stiffness decreased as the offset distance from the bone surface increased. Compared to the IPF models, in the two EPF models, axial stiffness decreased by 84-94%, whereas the angular stiffness decreased by 12-21%. The locking plate used as a definitive external fixator provided a high rate of union. While the locking plate is not totally rigid, it is clinically stable and may be advisable for stiffness reduction of plating constructs, thus promoting fracture healing by callus formation. Our patients experienced a comfortable clinical course, excellent knee and ankle joint motion, satisfactory functional results and an acceptable complication rate.

  9. MANAGEMENT OF INFECTED NON UNION TIBIAL FRACTURES WITH ILIZAROV EXTERNAL FIXATION

    Directory of Open Access Journals (Sweden)

    Nageshwara Rao

    2015-10-01

    Full Text Available BACKGROUND & OBJECTIVES: Infected non - union of tibia per se is a challenge to treat. Subcutaneous bone causes susceptibility to compartment syndrome, non - responsive infection, non - union, fibrosis, sinuses, deformities, shortening and various other sets of problems which are assoc iated with it. Ilizarov External fixation provides correction of all the complications associated with non - union, bone gap, infection, shortening, and deformities. Objective of this study is to assess the efficacy and safety of Ilizarov fixator method of t reatment in infected non - union tibia and to study various complications associated with Ilizarov external fixation. MATERIALS AND METHODS: 23 patients admitted and treated in Government General Hospital under the Department of Orthopaedics during the perio d of May 2010 to December 2012 were included in the study. Results were evaluated according to ASAMI criteria . 1 RESULTS : 59% patients had excellent bony results, 27.3% had good bony results, 9.1% had fair bony results, 4.6% had poor bony results. 68.1% had excellent functional results, 9.1% had good functional results, 9.1% had fair functional results, 13.7% had poor functional results. CONCLUSION : Ilizarov external fixator system is the best device and best solution for infected non - union tibia management.

  10. Early urbanization and mobility at Tell Brak, NE Syria: the evidence from femoral and tibial external shaft shape.

    Science.gov (United States)

    Sołtysiak, Arkadiusz

    2015-04-01

    Urbanization at Tell Brak began in the late 5th millennium BCE and the site reached its maximum size in the Late Chalcolithic (LC) 3, ca. 3900-3600 BCE. During that time, a large midden was formed at the edge of the early city, now known as Tell Majnuna. Rescue excavations at Tell Majnuna revealed several clusters of commingled human remains and a cemetery on the top. Several human skeletons dated to the LC 3 and Early Bronze Age (EBA) were found also at Tell Brak itself and it was possible to investigate differences in cross-sectional femoral and tibial shaft shapes between LC 3 and EBA to test the hypothesis that rapid and extensive urbanization in the LC 3 induced increase in mobility. External midshaft and subtrochanteric measurements of at least 152 femora and measurements of 55 tibiae at the nutrient foramen were taken to investigate the differences in the level of terrestrial mobility between four LC 3 and one EBA chronological subsets. Also the correlation was examined between shaft cross-sectional shapes and frequency of linear enamel hypoplasia (LEH) in canines, as a proxy indicator of population stress. Due to post-mortem damage, sex assessment was based only on the size of measured bones. In spite of the limited quality of the gathered data, significant differences in femoral midshaft shape in males were observed between the LC 3 and EBA subsets and the average shape index scores appeared to be correlated with the LEH frequencies. No such result was obtained for females, suggesting that only males were more mobile in the LC 3 and their mobility level was associated with general population stress. In contrast, in females the average shape of subtrochanteric femoral cross-section was more variable between temporal subsets. The patterns of temporal differences in tibial cross-section at the nutrient foramen were not conclusive due to the small sample size. Obtained results suggest that males in the LC 3, the period of rapid urbanization, were more mobile

  11. A Meta-Analysis for Postoperative Complications in Tibial Plafond Fracture: Open Reduction and Internal Fixation Versus Limited Internal Fixation Combined With External Fixator.

    Science.gov (United States)

    Wang, Dong; Xiang, Jian-Ping; Chen, Xiao-Hu; Zhu, Qing-Tang

    2015-01-01

    The treatment of tibial plafond fractures is challenging to foot and ankle surgeons. Open reduction and internal fixation and limited internal fixation combined with an external fixator are 2 of the most commonly used methods of tibial plafond fracture repair. However, conclusions regarding the superior choice remain controversial. The present meta-analysis aimed to quantitatively compare the postoperative complications between open reduction and internal fixation and limited internal fixation combined with an external fixator for tibial plafond fractures. Nine studies with 498 fractures in 494 patients were included in the present study. The meta-analysis found no significant differences in bone healing complications (risk ratio [RR] 1.17, 95% confidence interval [CI] 0.68 to 2.01, p = .58], nonunion (RR 1.09, 95% CI 0.51 to 2.36, p = .82), malunion or delayed union (RR 1.24, 95% CI 0.57 to 2.69, p = .59), superficial (RR 1.56, 95% CI 0.43 to 5.61, p = .50) and deep (RR 1.89, 95% CI 0.62 to 5.80) infections, arthritis symptoms (RR 1.20, 95% CI 0.92 to 1.58, p = .18), or chronic osteomyelitis (RR 0.31, 95% CI 0.05 to 1.84, p = .20) between the 2 groups. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  12. A novel gripper design for multi hand tools grasping under tight clearance constraints and external torque effect

    KAUST Repository

    Shaqura, Mohammad

    2017-08-29

    A robotic multi tool gripper design and implementation is presented in this paper. The proposed design targets applications where an actuation task is performed using a wide selection of standard hand tools. The manipulation motion is assumed to be rotational which requires a firm grip to account for external torque on the grasped tool. The setup is assumed to be a conventional workshop panel with hand tools being hanged close to each other, which constraints lateral clearance around the target, and near the wall of the panel, which constraints the depth clearance. Off the shelf grippers are mostly heavy and bulky which make them unsuitable for these requirements. Moreover, they are not optimized in terms of power consumption, simplicity and compactness. These generic grippers are mostly designed for pick and place tasks where no external torques other than those caused by the object weight affects the gripper. The design challenge involves building a gripper that is capable of operating in limited clearance space, firmly grip a variety of standard hand tools with different sizes and shapes. The proposed design is optimized for these objectives and offers a low cost and power consumption solution. The design has been validated in lab and outdoor experiments and has been deployed in real operating platform used in an international robotics competition.

  13. Role of Joshi's external stabilization system with percutaneous screw fixation in high-energy tibial condylar fractures associated with severe soft tissue injuries

    Institute of Scientific and Technical Information of China (English)

    Ashish Kumar Gupta; Rahul Sapra; Rakesh Kumar; Som Prakash Gupta; Devwart Kaushik; Sahil Gaba; Mahesh Chand Bansal

    2015-01-01

    Purpose: The treatment of high-energy tibial condylar fractures which are associated with severe sott tissue injuries remains contentious and challenging.In this study, we assessed the results of Joshi's external stabilization system (JESS) by using the principle of ligamentotaxis and percutaneous screw fixation for managing high-energy tibial condylar fractures associated with severe soft tissue injuries.Methods: Between June 2008 and June 2010, 25 consecutive patients who were 17-71 years (mean, 39.7), underwent the JESS fixation for high-energy tibial condylar fractures associated with severe soft tissue injuries.Out of 25 patients, 2 were lost during follow-up and in 1 case early removal of frame was done, leaving 22 cases for final follow-up.Among them, 11 had poor skin condition with abrasions and blisters and 2 were open injuries (Gustilo-Anderson grade Ⅰ & Ⅱ).The injury mechanisms were motor vehicle accidents (n =19), fall from a height (n =2) and assault (n =1).The fractures were classified according to Schatzker classification system.Results: There were 7 type-Ⅴ, 14 type-Ⅵ and 1 type-Ⅳ Schatzker's tibial plateau fractures.The average interval between the injury and surgery was 6.8 days (range 2-13).The average hospital stay was 13 days (range, 7-22).The average interval between the surgery and full weight bearing was 13.6 weeks (range 11-20).The average range of knee flexion was 121° (range 105°-135°).The normal extension of the knee was observed in 20 patients, and an extensor lag of 5°-8° was noted in 2 patients.The complications included superficial pin tract infections (n =4) with no knee stiffness.Conclusion: JESS with lag screw fixation combines the benefit of traction, external fixation, and limited internal fixation, at the same time as allowing the ease of access to the soft tissue for wound checks, pin care, dressing changes, measurement of compartment pressure, and the monitoring of the neurovascular status.In a nutshell, JESS

  14. A non-invasive device to objectively measure tibial rotation: verification of the device.

    Science.gov (United States)

    Lorbach, Olaf; Wilmes, P; Maas, S; Zerbe, T; Busch, L; Kohn, D; Seil, R

    2009-07-01

    The purpose of this study was the correlation of the results of a new measurement device for tibial rotation (Rotameter) in comparison with the measurements of a knee navigation system as standard method. In a biomechanical laboratory study, all soft tissues were removed from 20 human cadaveric knees leaving only the intact capsule and the bone. Specific tracers were bicortically fixed in the bone in order to measure tibial rotation using a knee navigation system. The knees were fixed to a custom-made inside-boot to rule out undesirable rotation of the reconstruction inside the Rotameter measurement device. Internal and external rotation values were measured at an applied torque of 5, 10 and 15 Nm. The different methods to evaluate tibial rotation were compared using the Pearson correlation coefficient. The correlations were deemed to be reliable if a value of >or=0.80 was achieved. At 5 Nm of applied torque, high correlations for the internal rotation, external rotation and the entire rotational range were found in the Pearson correlation coefficient between the Rotameter testing device in comparison with the knee navigation system as invasive reference method. These results were also confirmed at an applied torque of 10 and 15 Nm. In conclusion, the Rotameter testing device showed high correlations compared with the knee navigation system as an invasive standard method. It might be used as a non-invasive and easy alternative to investigate tibial rotation.

  15. Evaluation of the toroidal torque driven by external non-resonant non-axisymmetric magnetic field perturbations in a tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Kasilov, Sergei V. [Fusion@ÖAW, Institut für Theoretische Physik—Computational Physics, Technische Universität Graz Petersgasse 16, A–8010 Graz (Austria); Institute of Plasma Physics National Science Center “Kharkov Institute of Physics and Technology” ul. Akademicheskaya 1, 61108 Kharkov (Ukraine); Kernbichler, Winfried; Martitsch, Andreas F.; Heyn, Martin F. [Fusion@ÖAW, Institut für Theoretische Physik—Computational Physics, Technische Universität Graz Petersgasse 16, A–8010 Graz (Austria); Maassberg, Henning [Max-Planck Institut für Plasmaphysik, D-17491 Greifswald (Germany)

    2014-09-15

    The toroidal torque driven by external non-resonant magnetic perturbations (neoclassical toroidal viscosity) is an important momentum source affecting the toroidal plasma rotation in tokamaks. The well-known force-flux relation directly links this torque to the non-ambipolar neoclassical particle fluxes arising due to the violation of the toroidal symmetry of the magnetic field. Here, a quasilinear approach for the numerical computation of these fluxes is described, which reduces the dimension of a standard neoclassical transport problem by one without model simplifications of the linearized drift kinetic equation. The only limiting condition is that the non-axisymmetric perturbation field is small enough such that the effect of the perturbation field on particle motion within the flux surface is negligible. Therefore, in addition to most of the transport regimes described by the banana (bounce averaged) kinetic equation also such regimes as, e.g., ripple-plateau and resonant diffusion regimes are naturally included in this approach. Based on this approach, a quasilinear version of the code NEO-2 [W. Kernbichler et al., Plasma Fusion Res. 3, S1061 (2008).] has been developed and benchmarked against a few analytical and numerical models. Results from NEO-2 stay in good agreement with results from these models in their pertinent range of validity.

  16. Surgical treatment of tibial nonunion after wounding by high velocity missile and external fixators: A case report

    OpenAIRE

    2012-01-01

    Introduction. The missiles of modern firearms can cause severe fractures of the extremity. High velocity missile fractures of the tibia are characterized by massive tissue destruction and primary contamination with polymorphic bacteria. Treatment of these fractures is often complicated by delayed healing, poor position healing, nonhealing and bone tissue infection. Case Outline. We present the management of tibial nonunion after wounding by high velocity missile and primary treatment by...

  17. Management of paediatric tibial fractures using two types of circular external fixator: Taylor spatial frame and Ilizarov circular fixator.

    Science.gov (United States)

    Tafazal, Suhayl; Madan, Sanjeev S; Ali, Farhan; Padman, Manoj; Swift, Simone; Jones, Stanley; Fernandes, James A

    2014-05-01

    The use of circular fixators for the treatment of tibial fractures is well established in the literature. The aim of this study was to compare the Ilizarov circular fixator (ICF) with the Taylor spatial frame (TSF) in terms of treatment results in consecutive patients with tibial fractures that required operative management. A retrospective analysis of patient records and radiographs was performed to obtain patient data, information on injury sustained, the operative technique used, time duration in frame, healing time and complications of treatment. The minimum follow-up was 24 months. Ten patients were treated with ICF between 2000 and 2005, while 15 patients have been treated with TSF since 2005. Two of the 10 treated with ICF and 5 of the 15 treated with TSF were open fractures. All patients went on to achieve complete union. Mean duration in the frame was 12.7 weeks for ICF and 14.8 weeks for the TSF group. Two patients in the TSF group had delayed union and required additional procedures including adjustment of fixator and bone grafting. There was one malunion in the TSF group that required osteotomy and reapplication of frame. There were seven and nine pin-site infections in the ICF and TSF groups, respectively, all of which responded to antibiotics. There were no refractures in either group. In an appropriate patient, both types of circular fixator are equally effective but have different characteristics, with TSF allowing for postoperative deformity correction. Of concern are the two cases of delayed union in the TSF group, all in patients with high-energy injuries. We feel another larger study is required to provide further clarity in this matter. Level II-comparative study.

  18. Solitary Tibial Osteolytic Lesion

    Directory of Open Access Journals (Sweden)

    Emilios E. Pakos

    2009-01-01

    Full Text Available We report an unusual case of solitary osteolytic tibial metastasis from a primary endometrial cancer in a 62-year-old woman. The primary cancer was treated with total abdominal hysterectomy and bilateral salpingo-oophorectomy combined with postoperative external beam radiotherapy, while the tibial metastasis was treated with an above knee amputation. The rarity of the case lies on the fact that metastases distally to the elbow and knee are uncommon and endometrial cancer rarely gives distal bone metastases and particularly solitary to the extremities.

  19. 儿童胫腓骨骨折的外固定架治疗%External fixation for treatment of tibial and fibula fractures in children

    Institute of Scientific and Technical Information of China (English)

    伊力夏提·赛吾来提

    2015-01-01

    Objective:To analyze the therapeutic effect of external fixator for the treatment of children with fractures of the tibia and fibula. Methods:June 2009 to September 2014 in the treatment of children’s tibia and fibula fractures in 30 cases, using Orthofix unilateral external fixator in the treatment, in the C-arm X-ray under closed or open reduction of tibial fracture. Results:30 cases of patients with tibia and fibula fracture have healing with removal of the external fixator weight bearing walking and postoperative 6-8 months removal of external fixator, 3 cases about 1 month after surgery appeared pin tract local red, swollen, seepage considering the liquid I degree infection. After oral antibiotics and local dressing can be controlled without a cases due to severe pin tract infection caused by external fixation failure or osteomyelitis. Conclusion: external fixator for the treatment of tibial and fibula fractures of convenient operation, no damage to the folding end blood circulation, firm fixation, and adjacent joint can be early, beneficial to fracture healing and prevent the occurrence of osteoporosis, and other treatment methods compared has obvious superiority.%目的:分析儿童胫腓骨骨折的外固定架的治疗效果。方法选取2009年6月至2014年9月治疗的儿童胫腓骨干骨折30例,均采用orthofix单臂外固定架治疗,在C型臂透视下闭合或直视下复位胫骨骨折。结果30例患者胫腓骨骨折均已愈合并拆除外固定架重负重行走,术后6~8个月拆除外固定架,3例患者术后1个月左右曾出现针道局部有红、肿、渗液考虑为I度感染,经口服抗生素及局部换药后得以控制,无一例因发生严重针道感染等而导致外固定架失效或发生骨髓炎。结论外固定架治疗胫腓骨骨折操作方便、不破坏折端血运、固定牢固,且邻近关节可进行早期活动,利于骨折愈合及防止骨质疏松的发生;与其他治疗手法相比具有明显的优越性。

  20. Calculation method of external characteristic for sheet-metal hydraulic torque converter%钣金型液力变矩器外特性计算方法

    Institute of Scientific and Technical Information of China (English)

    惠记庄; 张广辉; 聂春鹏; 刘琼

    2015-01-01

    The signal processing and hydraulic system of original test bench was improved,and the traction test of YJH315 sheet-metal hydraulic torque converter was carried out.Based on the numerical calculation method of three dimensional flow field,the angular momentum equation, torque equation and the calculation method of performance parameter of external characteristic for YJH315 sheet-metal hydraulic torque converter were put out.The efficiencies,torque coefficients and nominal torques under different rotating speed ratios were gotten by using MATLAB simulation software and measured test respectively,and simulation result and test result were compared.Analysis result shows that when rotating speed ratio is from 0 to 0.9,the maximum efficiency is 0.82 under test condition,the value is 0.82 under simulation condition,and the maximum error of efficiency is about 2%.The maximum torque coefficient is 2.41 under test condition,the value is 2.29 under simulation condition,and the maximum error of torque coefficient is about 3%.The maximum nominal torque is 28.7 N·m under test condition,the value is 27.3 N ·m under simulation condition,and the maximum error of nominal torque is about 3%.All the errors of three indexes are within the acceptable range,so the proposed calculation method of external characteristic for sheet-metal hydraulic torque converter is feasible.1 tab,22 figs,21 refs.%对原有试验台架的信号处理和液压系统进行改进,进行了 YJH315钣金型液力变矩器的牵引试验。应用三维流场数值计算方法,提出了 YJH315钣金型液力变矩器外特性的动量矩方程、力矩方程与性能参数计算方法。分别通过 MATLAB 仿真软件和实测试验得到了不同转速比下的效率、变矩系数和公称力矩,并将仿真结果与试验结果进行对比分析。分析结果表明:当转速比在0~0.9时,试验工况下的最大效率为0.82,仿真工况下的最大效率为0.79,

  1. Micromagnetic study of high-power spin–torque oscillator with perpendicular magnetization in half-metallic Heusler alloy spin valve nanopillar under external magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H.B., E-mail: houbinghuang@gmail.com [Department of Physics, University of Science and Technology Beijing, Beijing 100083 (China); Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Ma, X.Q.; Zhao, C.P.; Liu, Z.H. [Department of Physics, University of Science and Technology Beijing, Beijing 100083 (China); Chen, L.Q. [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802 (United States)

    2015-01-01

    We investigated the high-power spin–torque oscillator in a half-metallic Heusler alloy Co{sub 2}MnSi spin-valve nanopillars with perpendicular magnetization under external magnetic field using micromagnetic simulations. Our simulations show that the narrow optimum current of magnetization precession in the Heusler-based spin valve is broadened by introducing the surface anisotropy. The linear decrease of frequency with the out-of-plane magnetic field is obtained in our simulation. Additionally, the in-plane magnetic field dependence of frequency shows a parabolic curve which is explained by the magnetization trajectory tilting. Furthermore, we also discussed the decrease of output power using the excitation of non-uniform magnetization precession in the in-plane magnetic fields. - Highlights: • We investigated spin–torque oscillator in Co{sub 2}MnSi spin-valve under magnetic fields. • The narrow optimum current is broadened by introducing the surface anisotropy. • The frequency dependences of out-of-plane and in-plane magnetic fields show linear and parabola. • The results may give the guidance for designing Heusler-based spin–torque oscillator.

  2. Posterior Tibial Tendon Dysfunction

    Science.gov (United States)

    .org Posterior Tibial Tendon Dysfunction Page ( 1 ) Posterior tibial tendon dysfunction is one of the most common problems of the foot and ankle. It occurs when the posterior tibial tendon becomes inflamed or torn. As a result, the ...

  3. Pseudo-aneurisma de artéria tibial posterior pós-tratamento de fratura de perna com fixador externo: relato de caso e revisão da literatura Pseudoaneurysm of the posterior tibial artery after external fixation for leg fracture: case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Domingos de Morais Filho

    2007-06-01

    Full Text Available Este trabalho descreve um caso de pseudo-aneurisma da artéria tibial posterior devido ao uso de fixador externo para tratamento de fratura dos ossos da perna (técnica de Ilizarov, bem como as técnicas utilizadas para seu tratamento. A compressão guiada por ultra-som e a injeção de trombina guiada por ultra-som foram realizadas, sem sucesso. O tratamento definitivo do pseudo-aneurisma e reconstrução arterial foi conseguido através do tratamento cirúrgico clássico, usando enxerto interposto de veia safena magna homóloga invertida. As indicações, vantagens e desvantagens das técnicas de tratamento não invasivo (compressão guiada por ultra-som e injeção de trombina guiada por ultra-som e as possíveis causas de sua incapacidade na obliteração do pseudo-aneurisma são discutidas. Também foi realizada a revisão de casos de pseudo-aneurisma da artéria tibial posterior na literatura médica, encontrando-se apenas um caso semelhante, entre 24 publicados.We describe a case of pseudoaneurysm in the posterior tibial artery following treatment for tibial and fibula fractures using external fixation (Ilizarov technique, as well as the techniques used for its treatment. Ultrasound-guided compression and ultrasound-guided thrombin injection were unsuccessfully performed. Definite treatment of pseudoaneurysm and arterial reconstruction was achieved through the traditional surgical treatment, using interposed graft of inverted homologous great saphenous vein. Indications, advantages and disadvantages of noninvasive treatment techniques (ultrasound-guided compression and ultrasound-guided thrombin injection and the possible causes of their inability in obliterating the pseudoaneurysm are discussed. A literature review of pseudoaneurysms of the posterior tibial artery was also carried out, resulting in only one similar case out of 24 published cases.

  4. van der Waals torque

    Science.gov (United States)

    Esquivel-Sirvent, Raul; Schatz, George

    2014-03-01

    The theory of generalized van der Waals forces by Lifshtz when applied to optically anisotropic media predicts the existence of a torque. In this work we present a theoretical calculation of the van der Waals torque for two systems. First we consider two isotropic parallel plates where the anisotropy is induced using an external magnetic field. The anisotropy will in turn induce a torque. As a case study we consider III-IV semiconductors such as InSb that can support magneto plasmons. The calculations of the torque are done in the Voigt configuration, that occurs when the magnetic field is parallel to the surface of the slabs. The change in the dielectric function as the magnetic field increases has the effect of decreasing the van der Waals force and increasing the torque. Thus, the external magnetic field is used to tune both the force and torque. The second example we present is the use of the torque in the non retarded regime to align arrays of nano particle slabs. The torque is calculated within Barash and Ginzburg formalism in the nonretarded limit, and is quantified by the introduction of a Hamaker torque constant. Calculations are conducted between anisotropic slabs of materials including BaTiO3 and arrays of Ag nano particles. Depending on the shape and arrangement of the Ag nano particles the effective dielectric function of the array can be tuned as to make it more or less anisotropic. We show how this torque can be used in self assembly of arrays of nano particles. ref. R. Esquivel-Sirvent, G. C. Schatz, Phys. Chem C, 117, 5492 (2013). partial support from DGAPA-UNAM.

  5. Análise da translação anterior da tíbia, pico de torque e atividade eletromiográfica do quadríceps e isquiotibiais em indivíduos com lesão do ligamento cruzado anterior em cadeia cinética aberta Analysis of anterior tibial translation, peak torque, and quadriceps and hamstrings coactivation in individuals with anterior cruciate ligament injuries performing isometric open kinetic chain exercises

    Directory of Open Access Journals (Sweden)

    Rodrigo Antunes de Vasconcelos

    2007-01-01

    Full Text Available Os objetivos deste estudo foram avaliar a translação anterior da tíbia (TAT, pico de torque isométrico e atividade eletromiográfica de indivíduos com lesão do ligamento cruzado anterior (LCA realizando contrações isométricas em cadeia cinética aberta no ângulo de 30º de flexão do joelho. Foram avaliados 20 voluntários do sexo masculino (31.1 ± 7.45 anos com ruptura completa do LCA e 20 indivíduos controle (22.2 ± 3.15 anos. Eletromiografia de superfície, artrômetro KT 1000 e um Dinamômetro isocinético foram utilizados para avaliar a atividade EMG do Quadríceps e Isquiotibiais, TAT passiva e ativa e pico de torque isométrico respectivamente durante três contrações isométricas voluntária máxima a 30 º de flexão do joelho. Os resultados demonstraram que a TAT passiva e ativa é significativamente maior em joelhos com lesão do LCA comparado ao joelho contralateral, lado dominante e não dominante do grupo controle, porém os valores da TAT ativa foram menores do que a passiva. Não houve diferenças estatisticamente significativas entre os grupos na atividade EMG do quadríceps e isquiotibiais e no pico de torque isométrico produzido durante o tarefa motora requisitada. Os resultados deste estudo demonstram que indivíduos com lesão do LCA e indivíduos controle se comportam de maneira similar em relação a pico de torque isométrico e controle motor embora a artrocinemática da articulação tibiofemural mostrou-se diferente em joelhos lesados.The aim of this study was to evaluated the anterior tibial translation (ATT, isometric peak torque and EMG activity in individuals with acl rupture performing isometric contraction in open kinetic chain in angle that provoke substantial ATT. It was evaluated 20 male subjects (31.1± 7.45 years with acl total rupture and 20 control subjects (22.2 ± 3.15 years. Electromyography, arthrometric kt 1000 and isokinetic dynamometry was used to evaluate the quadriceps and

  6. Treatment of Chronic Tibial Osteomyelitis Using External Fixation with Debridement and vacuum Sealing Drainage%外固定架结合 VSD 治疗慢性胫骨骨髓炎

    Institute of Scientific and Technical Information of China (English)

    张清华; 刘正; 张光武; 刘家帮

    2015-01-01

    目的:探讨外固定架结合彻底清创、真空负压引流术(vacuum sealing drainage,VSD)治疗慢性胫骨骨髓炎的疗效。方法2009年1月至2012年12月,采用外固定架结合彻底清创、真空负压引流方法治疗慢性胫骨骨髓炎69例,男62例,女7例。通过观察创面愈合情况、有无复发等指标评估疗效。结果清创术后13~42 d(平均23.3 d),67例患者感染得到控制,创面愈合,感染控制率97%,随访6~34个月(平均17. 4个月),无复发;2例患者多次行清创和真空负压引流术,感染无法控制,最终行截肢手术。结论外固定架结合彻底清创、真空负压引流术是治疗慢性胫骨骨髓炎的有效方法。%Objective To explore the therapeutic effect of chronic tibial osteomyelitis with external fixator,debridement and vacuum sealing drainage. Methods From January 2009 to December 2012,69 patients with chronic tibial osteomyelitis were treated by external fixation ,debridement and vacuum sealing drainage. Through the long - term following up,analyze its curative effect. Results Postoperation 13 to 42 days(mean 23. 3 days),the infection were cured in 67cases with sinus disap-peared and wound healing,the recovery rate of infection is 97% ,no relapse or fracture occurred during 6 to 34 months(aver-age of 17. 4 months)follow - up. Two patients after multiple(2 to 7,mean 4. 2)debridement and vacuum sealing drainage,in-fection can not be controlled,and amputation surgery were ultimately carried out. Conclusion External fixator combined de-bridement,vacuum drainage technique is an effective method for the treatment of chronic tibial osteomyelitis.

  7. Effectiveness of a Home-Based Eccentric-Exercise Program on the Torque-Angle Relationship of the Shoulder External Rotators: A Pilot Study.

    Science.gov (United States)

    Uhl, Timothy L; Rice, Thomas; Papotto, Brianna; Butterfield, Timothy A

    2017-04-01

    The role of the rotator cuff is to provide dynamic stability to the glenohumeral joint. Human and animal studies have identified sarcomerogenesis as an outcome of eccentric training indicated by more torque generation with the muscle in a lengthened position. The authors hypothesized that a home-based eccentric-exercise program could increase the shoulder external rotators' eccentric strength at terminal internal rotation (IR). Prospective case series. Clinical laboratory and home exercising. 10 healthy subjects (age 30 ± 10 y). All participants performed 2 eccentric exercises targeting the posterior shoulder for 6 wk using a home-based intervention program using side-lying external rotation (ER) and horizontal abduction. Dynamic eccentric shoulder strength measured at 60°/s through a 100° arc divided into 4 equal 25° arcs (ER 50-25°, ER 25-0°, IR 0-25°, IR 25-50°) to measure angular impulse to represent the work performed. In addition, isometric shoulder ER was measured at 5 points throughout the arc of motion (45° IR, 30° IR, 15° IR, 0°, and 15° ER). Comparison of isometric and dynamic strength from pre- to posttesting was evaluated with a repeated-measure ANOVA using time and arc or positions as within factors. The isometric force measures revealed no significant differences between the 5 positions (P = .56). Analysis of the dynamic eccentric data revealed a significant difference between arcs (P = .02). The percentage-change score of the arc of IR 25-50° was found to be significantly greater than that of the arc of IR 0-25° (P = .007). After eccentric training the only arc of motion that had a positive improvement in the capacity to absorb eccentric loads was the arc of motion that represented eccentric contractions at the longest muscle length.

  8. Correlation between the knee adduction torque and medial contact force for a variety of gait patterns.

    Science.gov (United States)

    Zhao, Dong; Banks, Scott A; Mitchell, Kim H; D'Lima, Darryl D; Colwell, Clifford W; Fregly, Benjamin J

    2007-06-01

    The external knee adduction torque has been proposed as a surrogate measure for medial compartment load during gait. However, a direct link between these two quantities has not been demonstrated using in vivo measurement of medial compartment load. This study uses in vivo data collected from a single subject with an instrumented knee implant to evaluate this link. The subject performed five different overground gait motions (normal, fast, slow, wide, and toe-out) with simultaneous collection of instrumented implant, video motion, and ground reaction data. For each trial, the knee adduction torque was measured externally while the total axial force applied to the tibial insert was measured internally. Based on data collected from the same subject performing treadmill gait under fluoroscopic motion analysis, a regression equation was developed to calculate medial contact force from the implant load cell measurements. Correlation analyses were performed for the stance phase and entire gait cycle to quantify the relationship between the knee adduction torque and both the medial contact force and the medial to total contact force ratio. When the entire gait cycle was analyzed, R(2) for medial contact force was 0.77 when all gait trials were analyzed together and between 0.69 and 0.93 when each gait trial was analyzed separately (p knee adduction torque is highly correlated with medial compartment contact force and medial to total force ratio during gait.

  9. [Tibial periostitis ("medial tibial stress syndrome")].

    Science.gov (United States)

    Fournier, Pierre-Etienne

    2003-06-01

    Medial tibial stress syndrome is characterised by complaints along the posteromedial tibia. Runners and athletes involved in jumping activities may develop this syndrome. Increased stress to stabilize the foot especially when excessive pronation is present explain the occurrence this lesion.

  10. Control of motion of tibial fractures with use of a functional brace or an external fixator. A study of cadavera with use of a magnetic motion sensor.

    Science.gov (United States)

    McKellop, H; Hoffmann, R; Sarmiento, A; Ebramzadeh, E

    1993-07-01

    A computer-linked magnetic motion transducer was used to monitor and record the six components of motion of the bone fragments in eight cadaveric tibiae in which a simulated, oblique fracture of the middle of the shaft had been stabilized with a functional brace. The limbs were mounted in a servo-hydraulic testing frame, and a cyclic load of 150 newtons was applied along the axis of the tibia. Motion sensors, attached to each side of the fracture, measured and displayed the values of the three translations (axial, anterior-posterior, and medial-lateral), the axial rotation, and the two angulations (anterior-posterior and varus-valgus) as they occurred. Although only an axial load was applied, the off-axis motions were comparable in magnitude with the motion along the axis. The elastic (recoverable) translations of the fragments ranged from 0.5 to 1.9 millimeters, about four to ten times larger than the corresponding motions that were recorded in an earlier study of such fractures that had been stabilized with two types of external fixators. The recoverable rotation and angulations of the fragments of the limbs in the functional brace ranged from 0.7 to 1.2 degrees, about ten times those recorded when the external fixators were used.

  11. Analysis of the Effect of the Treatment of Open Tibial Fracture With External Fixation%浅析胫骨开放性骨折患者采用骨外固定加压治疗的效果

    Institute of Scientific and Technical Information of China (English)

    刘国华; 王建萍; 付明; 秦松媛

    2016-01-01

    Objective To investigate the clinical effect of the treatment of open tibial fracture with external ifxation. Methods 40 patients with open fracture of tibia were collected. The patients were treated with external fixation and compression method. For patients with thorough wound debridement, internal fixation with bone cross method. Direct stability after reduction of the fracture patients were pressurized ifxation, bone end instability and bone block patient can be broken down into the reduction by screws are fixed, the perioste(2.5)um without stripping, fracture and bone mass after separation come close to each other so that patients with fracture in order to improve the stability. Reconstruction of the medial head of the gastrocnemius muscle and the lfap of the upper and lower segment of the soft tissue of the upper and lower leg of the defect, the adjacent fascia flap was used to cover the soft tissue of the middle and lower segment. Results In 40 cases, 35 cases had wound healing, the average healing time was (2.5 ± 0.5) months, and the healing rate was 87.5%. Conclusion Open tibial fracture patients with bone compressive external fixation treatment is an ideal method. The method is easy to operate, can be clearly fixed, on bone growth environment has greater impact, for fracture healing is very favorable, the needle distance fracture far end, not on bone end blood circulation produced larger disturbances.%目的:针对胫骨开放性骨折患者采用骨外固定加压方法进行临床治疗的效果进行初步探讨。方法收集40例胫骨开放性骨折患者有关资料,患者采用骨外固定加压方法进行治疗。彻底对患者伤口进行清创后,骨外固定采用交叉穿针方法。可直接对复位后的稳定性骨折患者进行加压固定,骨端不稳定及骨块粉碎患者对其整复后采用螺钉进行固定,骨膜不进行剥离,骨折端和骨块分离后互相靠拢使患者骨折端提高稳定性。缺损小

  12. Tibial Plateau Fractures

    DEFF Research Database (Denmark)

    Elsøe, Rasmus

    This PhD thesis reported an incidence of tibial plateau fractures of 10.3/100,000/year in a complete Danish regional population. The results reported that patients treated for a lateral tibial plateau fracture with bone tamp reduction and percutaneous screw fixation achieved a satisfactory level...... with only the subgroup Sport significantly below the age matched reference population. The thesis reports a level of health related quality of life (Eq5d) and disability (KOOS) significantly below established reference populations for patients with bicondylar tibial plateau fracture treated with a ring...... fixator, both during treatment and at 19 months following injury. In general, the thesis demonstrates that the treatment of tibial plateau fractures are challenging and that some disabilities following these fractures must be expected. Moreover, the need for further research in the area, both with regard...

  13. TIBIAL LANDMARKS IN ACL ANATOMIC REPAIR

    Directory of Open Access Journals (Sweden)

    M. V. Demesсhenko

    2016-01-01

    Full Text Available Purpose: to identify anatomical landmarks on tibial articular surface to serve as reference in preparing tibial canal with respect to the center of ACL footprint during single bundle arthroscopic repair.Materials and methods. Twelve frozen knee joint specimens and 68 unpaired macerated human tibia were studied using anatomical, morphometric, statistical methods as well as graphic simulation.Results. Center of the tibial ACL footprint was located 13,1±1,7 mm anteriorly from posterior border of intercondylar eminence, at 1/3 of the distance along the line connecting apexes of internal and external tubercles and 6,1±0,5 mm anteriorly along the perpendicular raised to this point.Conclusion. Internal and external tubercles, as well as posterior border of intercondylar eminence can be considered as anatomical references to determine the center of the tibial ACL footprint and to prepare bone canals for anatomic ligament repair.

  14. Tibial lengthening over humeral and tibial intramedullary nails in patients with sequelae of poliomyelitis: a comparative study.

    Science.gov (United States)

    Chen, Daoyun; Chen, Jianmin; Jiang, Yao; Liu, Fanggang

    2011-06-01

    Leg discrepancy is common after poliomyelitis. Tibial lengthening is an effective way to solve this problem. It is believed lengthening over a tibial intramedullary nail can provide a more comfortable lengthening process than by the conventional technique. However, patients with sequelae of poliomyelitis typically have narrow intramedullary canals allowing limited space for inserting a tibial intramedullary nail and Kirschner wires. To overcome this problem, we tried using humeral nails instead of tibial nails in the lengthening procedure. In this study, we used humeral nails in 20 tibial lengthening procedures and compared the results with another group of patients who were treated with tibial lengthening over tibial intramedullary nails. The mean consolidation index, percentage of increase and external fixation index did not show significant differences between the two groups. However, less blood loss and shorter operating time were noted in the humeral nail group. More patients encountered difficulty with the inserted intramedullary nail in the tibial nail group procedure. The complications did not show a statistically significant difference between the two techniques on follow-up. In conclusion, we found the humeral nail lengthening technique was more suitable in leg discrepancy patients with sequelae of poliomyelitis.

  15. Bending strength and holding power of tibial locking screws.

    Science.gov (United States)

    Lin, J; Lin, S J; Chiang, H; Hou, S M

    2001-04-01

    The bending strength and holding power of two types of specially designed tibial locking devices, a both-ends-threaded screw and an unthreaded bolt, were studied and compared with four types of commercially available tibial interlocking screws: Synthes, Howmedica, Richards, and Osteo AG. To test bending strength, the devices were inserted into a high molecular weight polyethylene tube and loaded at their midpoint by a materials testing machine to simulate a three point bending test. Single loading yielding strength and cyclic loading fatigue life were measured. To test holding power, the devices were inserted into tubes made of polyurethane foam, and their tips were loaded axially to measure pushout strength. The devices were tested with two different densities of foam materials and two different sizes of pilot holes. Insertion torque and stripping torque of the screws were measured first. Pushout tests were performed with each screw inserted with a tightness equal to 60% of its stripping torque. Test results showed that the yielding strength and the fatigue life were related closely to the inner diameter of the screws. The stripping torque predicted the pushout strength more reliably than did the insertion torque. All tested devices showed greater holding power in the foam with the higher density and with the smaller pilot holes. The both-ends-threaded screw had the highest pushout strength and a satisfactory fatigue strength. The unthreaded bolt had the highest fatigue strength but only fair holding power. Clinical studies of the use of these two types of locking devices are worthwhile.

  16. The Effect of Malrotation of Tibial Component of Total Knee Arthroplasty on Tibial Insert during High Flexion Using a Finite Element Analysis

    Directory of Open Access Journals (Sweden)

    Kei Osano

    2014-01-01

    Full Text Available One of the most common errors of total knee arthroplasty procedure is a malrotation of tibial component. The stress on tibial insert is closely related to polyethylene failure. The objective of this study is to analyze the effect of malrotation of tibial component for the stress on tibial insert during high flexion using a finite element analysis. We used Stryker NRG PS for analysis. Three different initial conditions of tibial component including normal, 15° internal malrotation, and 15° external malrotation were analyzed. The tibial insert made from ultra-high-molecular-weight polyethylene was assumed to be elastic-plastic while femoral and tibial metal components were assumed to be rigid. Four nonlinear springs attached to tibial component represented soft tissues around the knee. Vertical load was applied to femoral component which rotated from 0° to 135° while horizontal load along the anterior posterior axis was applied to tibial component during flexion. Maximum equivalent stresses on the surface were analyzed. Internal malrotation caused the highest stress which arose up to 160% of normal position. External malrotation also caused higher stress. Implanting prosthesis in correct position is important for reducing the risk of abnormal wear and failure.

  17. Internal tibial torsion correction study. [measurements of strain for corrective rotation of stressed tibia

    Science.gov (United States)

    Cantu, J. M.; Madigan, C. M.

    1974-01-01

    A quantitative study of internal torsion in the entire tibial bone was performed by using strain gauges to measure the amount of deformation occuring at different locations. Comparison of strain measurements with physical dimensions of the bone produced the modulus of rigidity and its behavior under increased torque. Computerized analysis of the stress distribution shows that more strain occurs near the torqued ends of the bones where also most of the twisting and fracturing takes place.

  18. 应用半环槽外固定器建立山羊胫骨缺损模型%Constructing a goat tibial defect model by half-ring sulcated external fixator

    Institute of Scientific and Technical Information of China (English)

    简月奎; 田晓滨; 赵筑川; 安荣泽; 李波; 邱冰; 杨震

    2008-01-01

    Lane-Sandhu组织学评分均为0分.结论:应用半环槽外固定器在造成山羊胫骨20%缺损的条件下构建的骨缺损动物模型,术后15周经检X线及组织学检测未出现骨愈合现象,证明该方法具有可操作性及可重复性,适用于组织工程用大段骨缺损动物模型的建立.%BACKGROUND:Half-ring sulcated external fixator is a bone external fixation device.Its structure is relatively simple,with multi-plane fixed,and small occupying space.So far,there are few experimental reports about construction of tibial defect model by it in large animals.OBJECTIVE:To validate the practicality and repeatability of half-ring sulcated external fixator in establishing tibial defect models in goats.DESIGN,TIME AND SETTING:The randomized controlled observation was performed at the Animal Laboratory of the Third Military Medical University from March 2005 to February 2007.MATERIALS:Nine healthy adult(Animal Center of Third Military Medical University);Half-ring sulcated external fixator,made by Professor Li of the Third Military Medical University;Osseous pin,ψ2.5 mm,Shanghai Medicai Instruments Co.,Ltd.METHODS:After animals were anesthetized,two needles were threaded in the same plane of cancellous bone about 1.5-2.0 cm above the superior articular surface of the tibia,named group 1.The angle between the two needles was 40°.One needle was threaded at the place of 3.0 to 5.0 cm under the group 1 and parallel with optional needle of the group 1,named group 2.Needles of group 4 were threaded at the cancellous bone that was 2.0 cm from the joint surface of inferior extremity of the tibia.One needle was threaded at the place of 3.0 to 5.0 cm from group 4 and parallel with optional needle of the group 4.The included angle between these two needles of group 2 and group 3 was 60°.There were totally 6 needles.Tibia was fixed by half-ring sulcated external fixator.According to the length of the tibia from X-ray,tibia and periosteum were amputated by wire saw between the two

  19. Tibial torsion in non-arthritic Indian adults: A computer tomography study of 100 limbs

    Directory of Open Access Journals (Sweden)

    Mullaji Arun

    2008-01-01

    Full Text Available Background: Knowledge of normal tibial torsion is mandatory during total knee replacement (TKR, deformity correction and fracture management of tibia. Different values of tibial torsion have been found in different races due to biological and mechanical factors. Value of normal tibial torsion in Indian limbs is not known, hence this study to determine the norm of tibial torsional value in normal Indian population. Materials and Methods: Computer tomography (CT scans were performed in 100 non-arthritic limbs of 50 Indian adults (42 males, eight females; age 26-40 years. Value of tibial torsion was measured using dorsal tangent to tibial condyles proximally and bimalleolar axis distally. Results: Normal tibial torsion was found to be 21.6 ± 7.6 (range 4.8 to 39.5 with none of the values in internal rotation. Right tibia was externally rotated by 2 degrees as compared to the left side ( P 0.029. No significant difference was found in male and female subjects. Value of tibial torsion was less than in Caucasian limbs, but was comparable to Japanese limbs when studies using similar measurement technique were compared. Conclusions: Indian limbs have less tibial torsion than Caucasian limbs but the value of tibial torsion is comparable to Japanese limbs.

  20. Comparison of Ilizarov external fixator and elastic nails's methods in the treatment of distal tibial and fibula fracture%Ilizarov外固定与弹性髓内钉治疗儿童胫腓骨远端骨折的比较

    Institute of Scientific and Technical Information of China (English)

    戴广新; 王晓东

    2011-01-01

    Objective: To compare the therapeutic efficacy of Ilizarovs extemal fixator and elastic nails in the treatment of distal children's tibial and fibula fracture. Methods: The data of 102 children with distal tibial and fibula fracture was analyzed retrospectively, group Ilizarov was 26 cases with Ilizarov extemal flxator, group elastic nails was 76 cases. Results:The average hospitalized days, fracture type were not remarkable difference (P>0.05); fracture average cured time, activing on the ground and bearing a heavy time on fracture leg. The numbers of incised fracture position, the average operational time, after the operations. phenomenon of a nail infection and bad articular activity, elastic nails group surpasses Ilizarov group (all P<0.05) . Conclusion: Ilizarov external fixator and the elastic nails which treat children's distal tibial are fibula fracture are two effective methods, but from the therapeutic efficacy, the author think effects of Ilizarov external fixator which treated children's dital tibial and fibula fracture surpassed elastic nails.%目的:比较Ilizarov外固定器和弹性髓内钉治疗儿童胫腓骨远端骨折的疗效.方法:分析102例胫腓骨远端骨折患儿的临床资料,其中用Ilizarov外圊定器治疗组26例,弹性髓内钉组76例.结果:两组患儿平均住院时间、骨折分型比较,差异无统计学意义(P>0.05);骨折平均愈合时间、下床活动、负重时间、断端切开复位例数以及关节功能障碍等并发症间比较,外固定组优于髓内钉组(P<0.05);外固定组平均手术时间、术后钉道感染例数高于髓内钉组(P<0.05).结论:Ilizarov外固定器治疗儿童胫腓骨远端骨折总体优于弹性髓内钉.

  1. Rotational alignment of the tibial component in total knee arthroplasty is better at the medial third of tibial tuberosity than at the medial border

    Directory of Open Access Journals (Sweden)

    Günther Klaus-Peter

    2010-03-01

    Full Text Available Abstract Background Correct rotational alignment of the femoral and tibial component is an important factor for successful TKA. The transepicondylar axis is widely accepted as a reference for the femoral component. There is not a standard reference for the tibial component. CT scans were used in this study to measure which of 2 tibial landmarks most reliably reproduces a correct femoro-tibial rotational alignment in TKA. Methods 80 patients received a cemented, unconstrained, cruciate-retaining TKA with a rotating platform. CT scans were performed 5-7 days postoperatively but before discharge. The rotational mismatch between the femoral and tibial components was measured. Furthermore, the rotational variance between the transepicondylar line, as a reference for the orientation of the femoral component and different tibial landmarks, was measured. Results There was notable rotational mismatch between the femoral and tibial components. The median mismatch was 0° (range: 16.2 degrees relative external to 14.4 degrees relative internal rotation of the femoral component. Using the transepicondylar line as a reference for femoral rotational alignment and the medial third of the tuberosity as a reference for tibial rotational alignment, 67.5% of all TKA had a femoro-tibial variance within ± 5 degrees, 85% within ± 10 degrees and 97.5% within ± 20 degrees. Using the medial border of the tibial tubercle as a reference this variance was greater, only 3.8% had a femoro-tibial variance within ± 5 degrees, 15% within ± 10 degrees and 68.8% within ± 20 degrees. Conclusion Using fixed bone landmarks for rotational alignment leads to a notable variance between femoral and tibial components. Referencing the tibial rotation on a line from the medial third of the tibial tubercle to the center of the tibial tray resulted in a better femoro-tibial rotational alignment than using the medial border of tibial tubercle as a landmark. Surgeons using fixed bearings

  2. Transosseous osteosynthesis with annular external fixator for the treatment of long bone defect after tibial traumatic%环形外固定架骨搬运治疗胫骨创伤后大段骨缺损

    Institute of Scientific and Technical Information of China (English)

    龙超; 刘炳胜; 王玮; 沈作佳

    2013-01-01

    Objective:To investigate the efficacy of the application of transosseous osteosynthesis with annular external fixator for the treatment of traumatic large bone defects of the tibia. Methods: From 2002 to 2011,17 cases of traumatic tibial long bone defect were treated by transosseous osteosynthesis with annular external fixator including 11 males and 6 females with an average age of (31.00±2.35) years old ranging from 22 to 45 years. The length of defect was from 5 to 13.1 cm with an average of (7.50+1.01) cm. The fixed time, bone healing time and the extend length of the affected limb were observed, and the degree of recovery of limb function after surgery were assessed ccording to the Paley's limb function evaluation. Results:All patients were followed up from 12 to 48 months with an average of (30.00±2.35) months,the bone defects of 17 patients achieved bone healing. The average bone healing time was (10.10±0.59) months (8 to 15 months) ;the average time of fixed time was (14.10±0.65 ) months (12 to 16 months) ;the average extend length of the affected limb was (7.50±1.01) cm. The results of Paley's functional evaluation was excellent in 9 cases,good in 6,fair in 2. Conclusion:Transosseous osteosynthesis with annular external fixator is an effective method for treatment of large bone defects of the tibia. It is successful reconstruction of limb length, simple operation, less soft tissue injury, and is clinical worthy of promotion.%目的:探讨应用环形外固定架辅助骨搬运术治疗创伤后胫骨大段骨缺损的疗效.方法:自2002年至2011年采用骨搬运术对17例创伤性胫骨长段骨缺损进行治疗,男11例,女6例;年龄22 ~45岁,平均(31.00±2.35)岁.骨缺损范围5~13.1 cm,平均(7.50±1.01) cm.观察外固定时间、骨性愈合时间、术后患肢延长长度.术后患肢功能恢复程度参照Paley评价标准进行功能评价.结果:全部病例获随访,时间12~48个月,平均(30.00±2.35)个月.17例

  3. Epidemiology of tibial shaft fractures

    Directory of Open Access Journals (Sweden)

    Grecco Marco Aurélio Sertório

    2002-01-01

    Full Text Available In this work an epidemiological analysis on tibial shaft fractures was performed. During four years, our service treated 179 fractures, 132 in male, 47 in female, aged 14 to 83 years. The 21 to 30-year-old patiens were the more injured. Of these, 120 were open and 59 close fractures of which prevailing cause was road traffic accident. The study based on patients promptuaries analyses and radiographs. The fractures occurred 97 times in the middle third (54.18%; 102 times (56.98% presented simple fragments, and 57 (31.38% oblique lines. We treated close and open fractures, respectively, 48 and 38 cases with plaster cast immobilization; 3 and 67 with external fixation after plaster cast immobilization; 5 and 12 with osteosynthesis by means of plate and screws, and 2 and 3 with external fixation only. In both close and open fractures, respectively, 7 and 20 cases of pseudarthrosis and 1 and 11 of infections have occurred. With the data obtained we verified an actual validity of the epidemiological studies as a contribution for better identifying lesions features and their treatment and complications. This allows proceedings and apprenticeship refinement.

  4. Bilateral tibial hemimelia I.

    Science.gov (United States)

    Suganthy, J; Rassau, Marina; Koshi, Rachel; Battacharjee, Suranjan

    2007-05-01

    Congenital absence of tibia is a rare anomaly. We report a case of bilateral tibial hemimelia born to phenotypically normal parents. The two amputated legs with tibial dysplasia obtained from a 3-year-old boy were studied by radiography and anatomical dissection. The radiological evaluation revealed a normal hip joint. The lower end of femur was normal without any bifurcation, shortening or bowing. Fibula was present on both legs and there was no sign of bowing or doubling. Both right and left tibiae were absent. In addition, on the right side, five tarsal bones, two metatarsals and the corresponding digital rays were absent. On the left side, three tarsal bones were absent. Dissection of the amputated segments showed the presence of extensor digitorum longus, peroneus tertius, peroneus longus and brevis, gastrocnemius, and soleus. Following bilateral knee disarticulation the patient was fitted with prosthesis and is doing well.

  5. Tibial shaft fracture

    DEFF Research Database (Denmark)

    Larsen, Peter

    IV also showed a significant worse outcome in 3 of the 5 KOOS subscales compared to a reference population at 12-months follow-up. Moreover, this study showed that increasing difference in muscle strength for knee extension between legs was associated with a decreasing QOL. The results of this thesis...... suggested that regaining pre injured QOL and muscle strength following a tibial shaft fracture takes considerable time....

  6. Fraturas do planalto tibial Tibial plateau fractures

    Directory of Open Access Journals (Sweden)

    Maurício Kfuri Júnior

    2009-01-01

    Full Text Available As fraturas do planalto tibial são lesões articulares cujos princípios de tratamento envolvem a redução anatômica da superfície articular e a restauração funcional do eixo mecânico do membro inferior. Contribuem para a tomada de decisões no tratamento dessas fraturas o perfil do paciente, as condições do envelope de tecidos moles, a existência de outros traumatismos associados e a infraestrutura disponível para abordagens cirúrgicas. Para as fraturas de alta energia, o tratamento estagiado, seguindo o princípio do controle de danos, tem como prioridade a manutenção do alinhamento do membro enquanto se aguarda a resolução das más condições de tecidos moles. Já nos traumas de baixa energia, desde que os tecidos moles não sejam um fator adverso, o tratamento deve ser realizado em tempo único, com osteossíntese definitiva. Fixação estável e movimento precoce são variáveis diretamente relacionadas com os melhores prognósticos. Desenvolvimentos recentes, como os implantes com estabilidade angular, substitutos ósseos e imagens tridimensionais para controle intraoperatório, deverão contribuir para cirurgias menos invasivas e melhores resultados.Tibial plateau fractures are joint lesions that require anatomical reduction of joint surface and functional restoration of mechanical axis of a lower limb. Patient profile, soft tissue conditions, presence of associated injuries and the available infrastructure for the treatment all contribute to the decision making about the best treatment for these fractures. High-energy fractures are usually approached in a staged manner respecting the principle of damage control, and are primarily targeted to maintain limb alignment while the resolution unfavorable soft tissue conditions is pending. Low-energy trauma can be managed on a single-stage basis, provided soft tissues are not an adverse factor, with open reduction and internal f-ixation. Stable fixation and early painless joint

  7. Motor adaptation to prosthetic cycling in people with trans-tibial amputation.

    Science.gov (United States)

    Lee Childers, W; Prilutsky, Boris I; Gregor, Robert J

    2014-07-18

    The neuromusculoskeletal system interacts with the external environment via end-segments, e.g. feet. A person with trans-tibial amputation (TTAmp) has lost a foot and ankle; hence the residuum with prosthesis becomes the new end-segment. We investigated changes in kinetics and muscle activity in TTAmps during cycling with this altered interface with the environment. Nine unilateral TTAmps and nine subjects without amputation (NoAmp) pedaled at a constant torque of 15 Nm and a constant cadence of 90 rpm (~150 watts). Pedal forces and limb kinematics were used to calculate resultant joint moments. Electromyographic activity was recorded to determine its magnitude and timing. Biomechanical and EMG variables of the amputated limb were compared to those of the TTAmp sound limb and to the dominant limb in the NoAmp group using a one-way ANOVA. Results showed maximum angular displacement between the residuum and prosthesis was 4.8±1.8 deg. The amputated limb compared to sound limb and NoAmp group produced lower extensor moments averaged over the cycle about the ankle (13±2.3, 20±5.7, and 19±5.3 Nm, respectfully) and knee (8.4±5.0, 15±4.5, and 12.7±5.9 Nm, respectfully) (pprosthetic socket control and highlight prosthetic control as an interaction between the residuum, prosthesis and external environment.

  8. Tibial hypoplasia with a bifid tibia: an unclassified tibial hemimelia.

    Science.gov (United States)

    Shah, Krupa; Shah, Hitesh

    2016-08-16

    Tibial hemimelia is a rare congenital limb deficiency which is characterised by a hypoplastic/aplastic tibia. It actually represents a spectrum of anomalies, ranging from mild hypoplasia of the tibia to total absence of the tibia. Several classifications based on radiological description exist in the literature. The tibial hemimelia is usually described with preaxial mirror polydactyly, split hand/foot syndrome-ectrodactyly, polydactyly-triphalangeal thumb syndrome (Werner syndrome) and micromelia-trigonal brachycephaly syndrome. We describe a child with unclassified tibial hemimelia. The child had right incomplete tibial hemimelia with bifid tibia, left complete tibial hemimelia, bilateral split hands and left split foot. This is the first report of the bifid tibia in the literature.

  9. Collagen turnover after tibial fractures

    DEFF Research Database (Denmark)

    Joerring, S; Krogsgaard, M; Wilbek, H

    1994-01-01

    Collagen turnover after tibial fractures was examined in 16 patients with fracture of the tibial diaphysis and in 8 patients with fracture in the tibial condyle area by measuring sequential changes in serological markers of turnover of types I and III collagen for up to 26 weeks after fracture...... collagen. A group comparison showed characteristic sequential changes in the turnover of types I and III collagen in fractures of the tibial diaphysis and tibial condyles. The turnover of type III collagen reached a maximum after 2 weeks in both groups. The synthesis of type I collagen reached a maximum...... after 2 weeks in the diaphyseal fractures and after 6 weeks in the condylar fractures. The degradation of type I collagen increased after 4 days and reached a maximum at 2 weeks in both groups. The interindividual variation was wide. On a group basis, the turnover of types I and III collagen had...

  10. Comparison of the effect of transplantation of fibula flap with vascular pedicle vs. Ilizarov external fixation in the treatment of nonunion of tibial bone defect%带血管蒂的腓骨瓣移植和Ilizarov外固定骨牵引术治疗胫骨骨缺损骨不连的比较

    Institute of Scientific and Technical Information of China (English)

    陈时高; 孙军锁; 景斗星; 蔡雅楠; 杨森; 王铁涛

    2016-01-01

    Objective To analyze and compare the curative effect of transplantation of fibula flap with vascular pedicle vs. Ilizarov external fixation in the treatment of nonunion of tibia bone defect. Methods The clinical data of 64 patients with nonunion of tibial bone defect from May 2009 to May 2013 were analyzed retro-spectively. From May 2009 to April 2012, 30 patients were given Ilizarov external fixation and bone traction therapy (bone traction group); from May 2012 to May 2013, 34 patients were subjected to vascularized fibula flap transplantation (fibula flap transplantation group). The medical indicators and Johner-Wruhs tibial shaft fracture efficacy evaluation criteria were compared between two groups. Results As compared with fibula flap transplantation group, operative time and hospital stay were significantly shortened in bone traction group ( P0.05). The healing time was significantly reduced in the fibula flap transplantation group as compared with bone traction group (P0.05).治疗后的Johner-Wruhs评分,腓骨瓣移植术组优良率为82.4%(28/34),骨牵引术组为60.0%(18/30),差异有统计学意义(P<0.05).结论 对比Ilizarov外固定骨牵引术,带血管蒂的腓骨瓣移植术治疗胫骨骨缺损骨不连患者具有骨折愈合时间短、疗效更佳的特点,但是其手术时间以及住院时间均显著延长.

  11. Improved tibial component rotation in TKA using patient-specific instrumentation.

    Science.gov (United States)

    Heyse, Thomas J; Tibesku, Carsten O

    2015-05-01

    Patient-specific instrumentation (PSI) was introduced in an attempt to reduce positional outliers of components in total knee arthroplasty (TKA). It was hypothesized that PSI could help with the positioning of tibial components in optimal rotational alignment. A magnetic resonance imaging (MRI) analysis of 58 patients following TKA was conducted. Of these, 30 operations were performed using PSI and 28 using conventional instrumentation. The rotation of the tibial components was determined in MRI using three different reference lines: a tangent to the dorsal tibial condyles, the tibial epicondylar line, and the tibial tubercle. Deviations >9° were considered outliers. Also internal rotation >1° was considered an outlier. Data were analyzed statistically for positional outliers using the Chi-squared test. There was excellent inter- and intraobserver reliability with low standard deviations for the determination of tibial component rotation using the tangent to the dorsal condyles and the tibial epicondylar line as reference. Using the dorsal tangent as reference, there were eight components in excessive external rotation (28.6 %) and one component being in relative internal rotation (5.4°) in the conventional group, while there were two components in excessive external rotation in the PSI group (6.7 %). Using the tibial epicondyles as reference, there were seven components in excessive external rotation (21.4 %) and one component being in relative internal rotation (4.4°) in the conventional group; while there were two components in excessive external rotation in the PSI group (6.7 %). These differences were statistically significant (p rotational tibial component alignment during TKA. Anatomy of the proximal tibia does not deliver clear landmarks that are prominent and consistent. This makes both, MRI analysis as well as cutting jig production and intraoperative placement a challenge.

  12. Comparison of different passive knee extension torque-angle assessments.

    Science.gov (United States)

    Freitas, Sandro R; Vaz, João R; Bruno, Paula M; Valamatos, Maria J; Mil-Homens, Pedro

    2013-11-01

    Previous studies have used isokinetic dynamometry to assess joint torques and angles during passive extension of the knee, often without reporting upon methodological errors and reliability outcomes. In addition, the reliability of the techniques used to measure passive knee extension torque-angle and the extent to which reliability may be affected by the position of the subjects is also unclear. Therefore, we conducted an analysis of the intra- and inter-session reliability of two methods of assessing passive knee extension: (A) a 2D kinematic analysis coupled to a custom-made device that enabled the direct measurement of resistance to stretch and (B) an isokinetic dynamometer used in two testing positions (with the non-tested thigh either flexed at 45° or in the neutral position). The intra-class correlation coefficients (ICCs) of torque, the slope of the torque-angle curve, and the parameters of the mathematical model that were fit to the torque-angle data for the above conditions were measured in sixteen healthy male subjects (age: 21.4 ± 2.1 yr; BMI: 22.6 ± 3.3 kg m(-2); tibial length: 37.4 ± 3.4 cm). The results found were: (1) methods A and B led to distinctly different torque-angle responses; (2) passive torque-angle relationship and stretch tolerance were influenced by the position of the non-tested thigh; and (3) ICCs obtained for torque were higher than for the slope and for the mathematical parameters that were fit to the torque-angle curve. In conclusion, the measurement method that is used and the positioning of subjects can influence the passive knee extension torque-angle outcome.

  13. Medial tibial stress syndrome: a critical review.

    Science.gov (United States)

    Moen, Maarten H; Tol, Johannes L; Weir, Adam; Steunebrink, Miriam; De Winter, Theodorus C

    2009-01-01

    Medial tibial stress syndrome (MTSS) is one of the most common leg injuries in athletes and soldiers. The incidence of MTSS is reported as being between 4% and 35% in military personnel and athletes. The name given to this condition refers to pain on the posteromedial tibial border during exercise, with pain on palpation of the tibia over a length of at least 5 cm. Histological studies fail to provide evidence that MTSS is caused by periostitis as a result of traction. It is caused by bony resorption that outpaces bone formation of the tibial cortex. Evidence for this overloaded adaptation of the cortex is found in several studies describing MTSS findings on bone scan, magnetic resonance imaging (MRI), high-resolution computed tomography (CT) scan and dual energy x-ray absorptiometry. The diagnosis is made based on physical examination, although only one study has been conducted on this subject. Additional imaging such as bone, CT and MRI scans has been well studied but is of limited value. The prevalence of abnormal findings in asymptomatic subjects means that results should be interpreted with caution. Excessive pronation of the foot while standing and female sex were found to be intrinsic risk factors in multiple prospective studies. Other intrinsic risk factors found in single prospective studies are higher body mass index, greater internal and external ranges of hip motion, and calf girth. Previous history of MTSS was shown to be an extrinsic risk factor. The treatment of MTSS has been examined in three randomized controlled studies. In these studies rest is equal to any intervention. The use of neoprene or semi-rigid orthotics may help prevent MTSS, as evidenced by two large prospective studies.

  14. The effect of tibial lengthening on gastrosoleus muscle function: an electrophysiological study

    OpenAIRE

    Sarisozen, Bartu; Sadik Bilgen, Muhammet; Dinc, Mustafa; Murat Aksakal, Ahmet; Coskun, Ergür

    2004-01-01

    Objectives: We evaluated the changes in electrophysiological characteristics of the contraction forces of the gastrosoleus complex due to stretching in experimental tibial lengthening. Methods: Distraction histiogenesis was performed in 22 guinea pigs weighing 600 to 800 g. Following the application of a semicircular external fixator and right tibial osteotomy, distraction was applied at a rate of 0.25 mm two times a day for 15 days without a latency period. The animals were randomized to ...

  15. Medial tibial stress syndrome.

    Science.gov (United States)

    Reshef, Noam; Guelich, David R

    2012-04-01

    MTSS is a benign, though painful, condition, and a common problem in the running athlete. It is prevalent among military personnel, runners, and dancers, showing an incidence of 4% to 35%. Common names for this problem include shin splints, soleus syndrome, tibial stress syndrome, and periostitis. The exact cause of this condition is unknown. Previous theories included an inflammatory response of the periosteum or periosteal traction reaction. More recent evidence suggests a painful stress reaction of bone. The most proven risk factors are hyperpronation of the foot, female sex, and history of previous MTSS. Patient evaluation is based on meticulous history taking and physical examination. Even though the diagnosis remains clinical, imaging studies, such as plain radiographs and bone scans are usually sufficient, although MRI is useful in borderline cases to rule out more significant pathology. Conservative treatment is almost always successful and includes several options; though none has proven more superior to rest. Prevention programs do not seem to influence the rate of MTSS, though shock-absorbing insoles have reduced MTSS rates in military personnel, and ESWT has shortened the duration of symptoms. Surgery is rarely indicated but has shown some promising results in patients who have not responded to all conservative options.

  16. Tibial lengthening for unilateral Crowe type-IV developmental dysplasia of the hip

    Directory of Open Access Journals (Sweden)

    Jun Wan

    2014-01-01

    Conclusions: Tibial lengthening may effectively correct gait and satisfactorily improve body image in young patients with unilateral Crowe type-IV DDH. Mono-lateral external fixator allows for accelerated postoperative rehabilitation and optimal preservation of ankle movements. Lengthening along with intramedullary nails may significantly reduce the external fixation time and the risk of fixator-related complications.

  17. Diffusion of torqued active Brownian particles

    Science.gov (United States)

    Sevilla, Francisco J.

    An analytical approach is used to study the diffusion of active Brownian particles that move at constant speed in three-dimensional space, under the influence of passive (external) and active (internal) torques. The Smoluchowski equation for the position distribution of the particles is obtained from the Kramer-Fokker-Planck equation corresponding to Langevin equations for active Brownian particles subject to torques. In addition of giving explicit formulas for the mean square-displacement, the non-Gaussian behavior is analyzed through the kurtosis of the position distribution that exhibits an oscillatory behavior in the short-time limit. FJS acknowledges support from PAPIIT-UNAM through the grant IN113114

  18. Posterior bicondylar tibial plateau fractures.

    Science.gov (United States)

    Carlson, DuWayne A

    2005-02-01

    To present a case series of patients with posterior bicondylar tibial plateau fractures treated by direct fracture exposure and fixation through dual incisions. Retrospective clinical study. Level 1 trauma centers. Eight patients were identified that had posterior bicondylar tibial plateau fractures. Two patients had depressed posterolateral tibial plateau fractures with contained defects and did not have direct fracture exposure. One patient died of medical problems leaving 5 patients who underwent direct fracture exposure, reduction, and fixation. Posteromedial followed by posterolateral open reduction and internal fixation of posterior bicondylar tibial plateau fractures. At 6 to 24 months follow-up (mean 13 months), all patients returned to near full activities, each with aching after prolonged standing (8-hour shift). Range of motion averaged 2 degrees to 121 degrees of flexion. Three of 5 returned to manual labor jobs; the others were not employed at the time of injury. Posterior bicondylar tibial plateau fractures have a high association with lateral meniscal pathology and can be associated with anterior cruciate ligament injury. Reduction of the posterior plateau condyles is easiest with the knee in full extension. Flexion contractures can be a problem, and patients should be encouraged to regain/maintain knee extension. The dual-incision approach to these challenging fractures can result in good to excellent knee function for these patients.

  19. Posterior tibial tendon dysfunction and flatfoot: analysis with simulated walking.

    Science.gov (United States)

    Watanabe, Kota; Kitaoka, Harold B; Fujii, Tadashi; Crevoisier, Xavier; Berglund, Lawrence J; Zhao, Kristin D; Kaufman, Kenton R; An, Kai-Nan

    2013-02-01

    Many biomechanical studies investigated pathology of flatfoot and effects of operations on flatfoot. The majority of cadaveric studies are limited to the quasistatic response to static joint loads. This study examined the unconstrained joint motion of the foot and ankle during stance phase utilizing a dynamic foot-ankle simulator in simulated stage 2 posterior tibial tendon dysfunction (PTTD). Muscle forces were applied on the extrinsic tendons of the foot using six servo-pneumatic cylinders to simulate their action. Vertical and fore-aft shear forces were applied and tibial advancement was performed with the servomotors. Three-dimensional movements of multiple bones of the foot were monitored with a magnetic tracking system. Twenty-two fresh-frozen lower extremities were studied in the intact condition, then following sectioning peritalar constraints to create a flatfoot and unloading the posterior tibial muscle force. Kinematics in the intact condition were consistent with gait analysis data for normals. There were altered kinematics in the flatfoot condition, particularly in coronal and transverse planes. Calcaneal eversion relative to the tibia averaged 11.1±2.8° compared to 5.8±2.3° in the normal condition. Calcaneal-tibial external rotation was significantly increased in flatfeet from mean of 2.3±1.7° to 8.1±4.0°. There were also significant changes in metatarsal-tibial eversion and external rotation in the flatfoot condition. The simulated PTTD with flatfoot was consistent with previous data obtained in patients with PTTD. The use of a flatfoot model will enable more detailed study on the flatfoot condition and/or effect of surgical treatment.

  20. Ilizarov环形外固定架治疗胫腓骨骨折的研究与进展%Research and development of Ilizarov ring external fixator in the treatment of tibial and fibula fractures

    Institute of Scientific and Technical Information of China (English)

    高骏凯; 蒋杰

    2015-01-01

    Tibia and fibula fracture is a common clinical fracture, fixation and external fixation of two kinds, in which the external fixator has a protective effect on the surrounding soft tissue and blood flow. And with external fixation of the advantages of the Ilizarov ring external fixation, more unique biomechanical properties, in the clinical practice should be used for a variety of complex fractures of the tibia and fibula and can achieve satisfactory results.%胫腓骨骨折是临床较常见的骨折,固定方式有内固定和外固定两种,其中外固定架有保护周围软组织和血运的作用。而具有外固定优点的基础的Ilizarov环形外固定支架,更有其独特的生物力学性能,在临床上常应用于各种复杂型的胫腓骨骨折并能取得满意效果。

  1. Análise da translação anterior da tíbia, pico de torque e atividade eletromiográfica do quadríceps e isquiotibiais em indivíduos com lesão do ligamento cruzado anterior em cadeia cinética aberta Analysis of anterior tibial translation, peak torque, and quadriceps and hamstrings coactivation in individuals with anterior cruciate ligament injuries performing isometric open kinetic chain exercises

    OpenAIRE

    Rodrigo Antunes de Vasconcelos; Juliano Coelho Arakaki; Adriano P. Simão; Anamaria Siriani de Oliveira; Cleber Jansen Paccola; Débora Bevilaqua-Grossi

    2007-01-01

    Os objetivos deste estudo foram avaliar a translação anterior da tíbia (TAT), pico de torque isométrico e atividade eletromiográfica de indivíduos com lesão do ligamento cruzado anterior (LCA) realizando contrações isométricas em cadeia cinética aberta no ângulo de 30º de flexão do joelho. Foram avaliados 20 voluntários do sexo masculino (31.1 ± 7.45 anos) com ruptura completa do LCA e 20 indivíduos controle (22.2 ± 3.15 anos). Eletromiografia de superfície, artrômetro KT 1000 e um Dinamômetr...

  2. Dynamic Torque Calibration Unit

    Science.gov (United States)

    Agronin, Michael L.; Marchetto, Carl A.

    1989-01-01

    Proposed dynamic torque calibration unit (DTCU) measures torque in rotary actuator components such as motors, bearings, gear trains, and flex couplings. Unique because designed specifically for testing components under low rates. Measures torque in device under test during controlled steady rotation or oscillation. Rotor oriented vertically, supported by upper angular-contact bearing and lower radial-contact bearing that floats axially to prevent thermal expansion from loading bearings. High-load capacity air bearing available to replace ball bearings when higher load capacity or reduction in rate noise required.

  3. Torque-wrench extension

    Science.gov (United States)

    Peterson, D. H.

    1981-01-01

    Torque-wrench extension makes it easy to install and remove fasteners that are beyond reach of typical wrenches or are located in narrow spaces that prevent full travel of wrench handle. At same time, tool reads applied torque accurately. Wrench drive system, for torques up to 125 inch-pounds, uses 2 standard drive-socket extensions in aluminum frame. Extensions are connected to bevel gear that turns another bevel gear. Gears produce 1:1 turn ratio through 90 degree translation of axis of rotation. Output bevel has short extension that is used to attach 1/4-inch drive socket.

  4. Self-induced torque in hyperbolic metamaterials.

    Science.gov (United States)

    Ginzburg, Pavel; Krasavin, Alexey V; Poddubny, Alexander N; Belov, Pavel A; Kivshar, Yuri S; Zayats, Anatoly V

    2013-07-19

    Optical forces constitute a fundamental phenomenon important in various fields of science, from astronomy to biology. Generally, intense external radiation sources are required to achieve measurable effects suitable for applications. Here we demonstrate that quantum emitters placed in a homogeneous anisotropic medium induce self-torques, aligning themselves in the well-defined direction determined by an anisotropy, in order to maximize their radiation efficiency. We develop a universal quantum-mechanical theory of self-induced torques acting on an emitter placed in a material environment. The theoretical framework is based on the radiation reaction approach utilizing the rigorous Langevin local quantization of electromagnetic excitations. We show more than 2 orders of magnitude enhancement of the self-torque by an anisotropic metamaterial with hyperbolic dispersion, having negative ratio of permittivity tensor components, in comparison with conventional anisotropic crystals with the highest naturally available anisotropy.

  5. Ultrasound Guidance in Performing a Tendoscopic Surgery to Treat Posterior Tibial Tendinitis: A Useful Tool?

    Directory of Open Access Journals (Sweden)

    Akinobu Nishimura

    2016-01-01

    Full Text Available A 25-year-old man with a pronation-external rotation type of fracture was surgically treated using a fibular plate. Five years later, he underwent resection of bone hyperplasia because of the ankle pain and limitation of range of motion. Thereafter, the left ankle became intermittently painful, which persisted for about one year. He presented at the age of 43 with persistent ankle pain. Physical and image analysis findings indicated a diagnosis of posttraumatic posterior tibial tendinitis, which we surgically treated using tendoscopy. Endoscopic findings showed tenosynovitis and fibrillation on the tendon surface. We cleaned and removed the synovium surrounding the tendon and deepened the posterior tibial tendon groove to allow sufficient space for the posterior tibial tendon. Full weight-bearing ambulation was permitted one day after surgery and he returned to his occupation in the construction industry six weeks after surgery. The medial aspect of the ankle was free of pain and symptoms at a review two years after surgery. Although tendoscopic surgery for stage 1 posterior tibial tendon dysfunction has been reported, tendoscopic surgery to treat posttraumatic posterior tibial tendinitis has not. Our experience with this patient showed that tendoscopic surgery is useful not only for stage 1 posterior tibial dysfunction, but also for posttraumatic posterior tibial tendinitis.

  6. Displaceable Gear Torque Controlled Driver

    Science.gov (United States)

    Cook, Joseph S., Jr. (Inventor)

    1997-01-01

    Methods and apparatus are provided for a torque driver including a displaceable gear to limit torque transfer to a fastener at a precisely controlled torque limit. A biasing assembly biases a first gear into engagement with a second gear for torque transfer between the first and second gear. The biasing assembly includes a pressurized cylinder controlled at a constant pressure that corresponds to a torque limit. A calibrated gage and valve is used to set the desired torque limit. One or more coiled output linkages connect the first gear with the fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. The torque limit is adjustable and may be different for fasteners within the same fastener configuration.

  7. [Treatment of tibial pseudoarthrosis. Complications after intramedullary, allogeneic fibular grafting].

    Science.gov (United States)

    Helfen, T; Prall, W C; Mutschler, W; Thaller, P H

    2015-04-01

    A 24-year-old woman underwent cosmetic bilateral tibial lengthening with severe complications. In all, 15 operations, including allogeneic fibular grafting of both tibia, were required to treat unstable bilateral non-union, malalignment, and osteomyelitis of the right tibia.The present article describes the surgical strategy of revision to achieve good recovery with full consolidation and proper alignment of the lower leg. Furthermore, the indications for allogeneic bone grafting, which was described by Erich Lexer 100 years ago, are discussed. For surgical revision, a T-external fixator was used on the right leg, while a customized tibial nail was used on the left leg. Using these techniques, full consolidation and proper alignment was achieved. Allogeneic bone grafts in upper extremity defects cannot be recommended.

  8. Measurement of tibial slope angle after medial opening wedge high tibial osteotomy: case series

    Directory of Open Access Journals (Sweden)

    Ricardo Hideki Yanasse

    Full Text Available CONTEXT AND OBJECTIVE: In the past, changes in tibial slope were not considered when planning or evaluating osteotomies, and success in high tibial osteotomy was related to the alignment and amount of femorotibial angular correction. The aim here was to measure changes in tibial slope after medial opening wedge tibial osteotomy and investigate the effect of tibial slope angle on the clinical results. DESIGN AND SETTING: Retrospective review study on a series of cases, at the Department of Orthopedics and Traumatology, Faculdade de Medicina de Marília (Famema, Marília, Brazil. METHODS: Twenty-eight patients were studied, and a total of thirty-one knees. Lateral roentgenograms of the tibia were used pre and postoperatively to measure the tibial slope based on the proximal tibial anatomical axis. The clinical results were measured using the Lysholm knee score. RESULTS: There was an average increase in tibial slope angle after surgery of 2.38° (95% confidence interval: ± 0.73°. There was no correlation (r = -0.28 between the postoperative Lysholm knee score and the difference in tibial slope angle from before to after surgery (P = 0.13. CONCLUSION: Medial opening wedge tibial osteotomy led to a small increase in tibial slope. No significant correlation was found between increased tibial slope and short-term clinical results after high tibial osteotomy. Other clinical studies are needed in order to establish whether extension or flexion osteotomy could benefit patients with medial compartment gonarthrosis.

  9. Ironless armature torque motor

    Science.gov (United States)

    Fisher, R. L.

    1972-01-01

    Four iron-less armature torque motors, four Hall device position sensor assemblies, and two test fixtures were fabricated. The design approach utilized samarium cobalt permanent magnets, a large airgap, and a three-phase winding in a stationary ironless armature. Hall devices were employed to sense rotor position. An ironless armature torque motor having an outer diameter of 4.25 inches was developed to produce a torque constant of 65 ounce-inches per ampere with a resistance of 20.5 ohms. The total weight, including structural elements, was 1.58 pounds. Test results indicated that all specifications were met except for generated voltage waveform. It is recommended that investigations be made concerning the generated voltage waveform to determine if it may be improved.

  10. Negative optical torque.

    Science.gov (United States)

    Chen, Jun; Ng, Jack; Ding, Kun; Fung, Kin Hung; Lin, Zhifang; Chan, C T

    2014-09-17

    Light carries angular momentum, and as such it can exert torques on material objects. Applications of these opto-mechanical effects were limited initially due to their smallness in magnitude, but later becomes powerful and versatile after the invention of laser. Novel and practical approaches for harvesting light for particle rotation have since been demonstrated, where the structure is always subjected to a positive optical torque along a certain axis if the incident angular momentum has a positive projection on the same axis. We report here an interesting phenomenon of "negative optical torque", meaning that incoming photons carrying angular momentum rotate an object in the opposite sense. Surprisingly this can be realized quite straightforwardly in simple planar structures. Field retardation is a necessary condition and discrete rotational symmetry of material object plays an important role. The optimal conditions are explored and explained.

  11. Modifications of the Torque-Bias Profile for Improved Tracking of Beam-Waveguide Antennas

    Science.gov (United States)

    Gawronski, W.; Brandt, J. J.; Ahlstrom, H. G., Jr.; Maneri, E.

    1999-07-01

    Gearboxes and gears are part of the DSN antenna drives. The drives show backlash at the gearboxes and at elevation bull gears due to a small gap between the gear teeth. Left uncorrected, backlash deteriorates the antenna pointing precision. Implementing two identical drives imposes two nonidentical torques and produces a torque difference (also known as torque bias or counter-torque) that eliminates backlash. The electronic circuit at the axis drive generates the torque-bias profile. The performance of the existing circuit is analyzed, and a modified circuit is designed that improves the antenna dynamics under external disturbances.

  12. Spin-Stabilized Spacecrafts: Analytical Attitude Propagation Using Magnetic Torques

    Directory of Open Access Journals (Sweden)

    Roberta Veloso Garcia

    2009-01-01

    Full Text Available An analytical approach for spin-stabilized satellites attitude propagation is presented, considering the influence of the residual magnetic torque and eddy currents torque. It is assumed two approaches to examine the influence of external torques acting during the motion of the satellite, with the Earth's magnetic field described by the quadripole model. In the first approach is included only the residual magnetic torque in the motion equations, with the satellites in circular or elliptical orbit. In the second approach only the eddy currents torque is analyzed, with the satellite in circular orbit. The inclusion of these torques on the dynamic equations of spin stabilized satellites yields the conditions to derive an analytical solution. The solutions show that residual torque does not affect the spin velocity magnitude, contributing only for the precession and the drift of the spacecraft's spin axis and the eddy currents torque causes an exponential decay of the angular velocity magnitude. Numerical simulations performed with data of the Brazilian Satellites (SCD1 and SCD2 show the period that analytical solution can be used to the attitude propagation, within the dispersion range of the attitude determination system performance of Satellite Control Center of Brazil National Research Institute.

  13. Tacón de torque. Análisis tensional y deformacional utilizando el Método de Elementos Finitos. // Torque heel: Tensional and deformational analysis using the Finite Elements Method.

    Directory of Open Access Journals (Sweden)

    R. A. González Carbonell

    2007-05-01

    Full Text Available En este trabajo se aborda la problemática del tratamiento en menores que presentan torsión tibial y la necesidad de undispositivo ortopédico para su corrección. En particular, se presentan los elementos necesarios para el diseño de un tacón detorque. Se estudiaron los fenómenos no lineales presentes en el diseño mecánico de piezas que no cumplen con la ley deHooke, específicamente para materiales hiperelásticos. El modelo de las cargas que actúan sobre el tacón de torque fuedefinido teniendo en cuenta la acción dinámica de las cargas producto de la marcha. Para realizar los cálculos de tensionesy visualizar las deformaciones durante su funcionamiento se utilizó el Método de los Elementos Finitos. Finalmente con losresultados obtenidos fue propuesto un diseño del tacón de torque.Palabras claves: Torsión tibial, dispositivo ortopédico, elastómeros, elementos finitos, tensión, diseñomecánico, análisis no lineal.______________________________________________________________________________Abstract:In this work a problem of treatment of the internal tibial torsion and the necessity of an orthopedic device werestudied. The needed knowledge for design the torque heel was mentioned. The study of non lineal phenomena inmechanical design of elastomers was carried out. The load model of the torque heels was defined taken into accountthe action of dynamic loads. The Stress and Strain of the torque heel were obtained using the Finite Elements Method.Finally, the results were analyzed and the definitive design of the torque heel was obtained.Key words: Tibial torsion, orthopedic device, elastomers, finite elements, stress, mechanic design, nonlinear analysis.

  14. Torque-Splitting Gear Drive

    Science.gov (United States)

    Kish, J.

    1991-01-01

    Geared drive train transmits torque from input shaft in equal parts along two paths in parallel, then combines torques in single output shaft. Scheme reduces load on teeth of meshing gears while furnishing redundancy to protect against failures. Such splitting and recombination of torques common in design of turbine engines.

  15. Does Tibial Slope Affect Perception of Coronal Alignment on a Standing Anteroposterior Radiograph?

    Science.gov (United States)

    Schwartz, Adam J; Ravi, Bheeshma; Kransdorf, Mark J; Clarke, Henry D

    2017-07-01

    A standing anteroposterior (AP) radiograph is commonly used to evaluate coronal alignment following total knee arthroplasty (TKA). The impact of coronal alignment on TKA outcomes is controversial, perhaps due to variability in imaging and/or measurement technique. We sought to quantify the effect of image rotation and tibial slope on coronal alignment. Using a standard extramedullary tibial alignment guide, 3 cadaver legs were cut to accept a tibial tray at 0°, 3°, and 7° of slope. A computed tomography scan of the entire tibia was obtained for each specimen to confirm neutral coronal alignment. Images were then obtained at progressive 10° intervals of internal and external rotation up to 40° maximum in each direction. Images were then randomized and 5 blinded TKA surgeons were asked to determine coronal alignment. Continuous data values were transformed to categorical data (neutral [0], valgus [L], and varus [R]). Each 10° interval of external rotation of a 7° sloped tibial cut (or relative internal rotation of a tibial component viewed in the AP plane) resulted in perception of an additional 0.75° of varus. The slope of the proximal tibia bone cut should be taken into account when measuring coronal alignment on a standing AP radiograph. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Tibial hyperostosis: A diagnostic approach

    Energy Technology Data Exchange (ETDEWEB)

    Touraine, Sébastien, E-mail: sebastien.touraine@lrb.aphp.fr [Radiologie ostéo-articulaire, Hôpital Lariboisière, 2 rue Ambroise Paré, 75475 Paris Cedex 10 (France); Parlier-Cuau, Caroline, E-mail: caroline.parlier@lrb.aphp.fr [Radiologie ostéo-articulaire, Hôpital Lariboisière, 2 rue Ambroise Paré, 75475 Paris Cedex 10 (France); Bousson, Valérie, E-mail: valerie.bousson@lrb.aphp.fr [Radiologie ostéo-articulaire, Hôpital Lariboisière, 2 rue Ambroise Paré, 75475 Paris Cedex 10 (France); Sverzut, Jean-Michel, E-mail: jmsverzut21@hotmail.com [Radiologie ostéo-articulaire, Hôpital Lariboisière, 2 rue Ambroise Paré, 75475 Paris Cedex 10 (France); Centre d’imagerie du centre cardiologique du Nord, 32-36 rue des Moulins Gémeaux, 93200 Saint-Denis (France); Genah, Idan, E-mail: idan.genah@lrb.aphp.fr [Radiologie ostéo-articulaire, Hôpital Lariboisière, 2 rue Ambroise Paré, 75475 Paris Cedex 10 (France); and others

    2013-12-01

    Tibial hyperostosis may be encountered in musculoskeletal imaging, incidentally or during the investigation of a leg pain. Hyperostosis involves the exuberant production of osseous tissue and results in cortical, periosteal and/or endosteal thickening of the bone. As a long bone with thick cortices, the tibia has a significant probability of being affected by ubiquitous bone diseases. As a tubular long bone, the tibia is likely to be involved in extensive infectious conditions such as osteomyelitis. As a bone of the lower limb, the tibia undergoes high stresses and may be affected by decrease in bone strength or repetitive submaximal stress. The tibia is also particularly involved in some bone sclerosing dysplasias and Paget's disease. In this work, we aim at highlighting the main conditions leading to tibial hyperostosis and try to provide key elements to narrow down the several diagnostic possibilities. Osteoid osteomas, fatigue or insufficiency fractures, infectious conditions, vascular lesions, sclerosing bone dysplasias and Paget's disease represent the main challenging diagnoses to discuss.

  17. Tibial lengthening over nails in children using modified Ender nails: preliminary results of a new treatment.

    Science.gov (United States)

    Saraph, Vinay; Roposch, Andreas; Zwick, Ernst-Bernhard; Linhart, Wolfgang E

    2004-11-01

    Tibial lengthening over nails, using modified Ender nails, was performed in nine children whose mean age at surgery was 12.8 years. The prerequisite for using this technique was the absence of axial malalignment and an indication for tibial lengthening only. Lengthening was not performed in one case due to the development of a compartment syndrome after the tibial osteotomy. Breakage of one interlocking screw without loss of alignment or length was observed in one case. Superficial pin tract infections were observed in two cases. An average of 4.1 cm (range 3-4.5 cm) lengthening of the tibia was achieved in eight of the nine cases. The modified Ender nails used permitted locking at both ends after achieving the desired distraction and permitted early removal of the external fixator. The advantage of this technique is that it permits early removal of the fixator and thus decreases the incidence of fixator related problems and facilitates early rehabilitation.

  18. Bone transport for limb reconstruction following severe tibial fractures

    Directory of Open Access Journals (Sweden)

    Julian Fürmetz

    2016-03-01

    Full Text Available A common treatment of tibial defects especially after infections is bone transport via external fixation. We compare complications and outcomes of 25 patients treated with a typical Ilizarov frame or a hybrid system for bone reconstruction of the tibia. Average follow up was 5.1 years. Particular interest was paid to the following criteria: injury type, comorbidities, development of osteitis and outcome of the different therapies. The reason for segmental resection was a second or third grade open tibia fractures in 24 cases and in one case an infection after plate osteosynthesis. Average age of the patients was 41 years (range 19 to 65 years and average defect size 6.6 cm (range 3.0 to 13.4 cm. After a mean time of 113 days 23 tibial defects were reconstructed, so we calculated an average healing index of 44.2 days/cm. Two patients with major comorbidities needed a below knee amputation. The presence of osteitis led to a more complicated course of therapy. In the follow up patients with an Ilizarov frame had better results than patients with hybrid systems. Bone transport using external fixation is suitable for larger defect reconstruction. With significant comorbidities, however, a primary amputation or other methods must be considered.

  19. Single-interface Casimir torque

    Science.gov (United States)

    Morgado, Tiago A.; Silveirinha, Mário G.

    2016-10-01

    A different type of Casimir-type interaction is theoretically predicted: a single-interface torque at a junction of an anisotropic material and a vacuum or another material system. The torque acts to reorient the polarizable microscopic units of the involved materials near the interface, and thus to change the internal structure of the materials. The single-interface torque depends on the zero-point energy of the interface localized and extended modes. Our theory demonstrates that the single-interface torque is essential to understand the Casimir physics of material systems with anisotropic elements and may influence the orientation of the director of nematic liquid crystals.

  20. Increasing lateral tibial slope: is there an association with articular cartilage changes in the knee?

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Nasir; Shepel, Michael; Leswick, David A.; Obaid, Haron [University of Saskatchewan, Department of Medical Imaging, Royal University Hospital, and College of Medicine, Saskatoon, Saskatchewan (Canada)

    2014-04-15

    The geometry of the lateral tibial slope (LTS) plays an important role in the overall biomechanics of the knee. Through this study, we aim to assess the impact of LTS on cartilage degeneration in the knee. A retrospective analysis of 93 knee MRI scans (1.5 T or 3 T) for patients aged 20-45 years with no history of trauma or knee surgery, and absence of internal derangement. The LTS was calculated using the circle method. Chondropathy was graded from 0 (normal) to 3 (severe). Linear regression analysis was used for statistical analysis (p < 0.05). In our cohort of patients, a statistically significant association was seen between increasing LTS and worsening cartilage degenerative changes in the medial patellar articular surface and the lateral tibial articular surface (p < 0.05). There was no statistically significant association between increasing LTS and worsening chondropathy of the lateral patellar, medial trochlea, lateral trochlea, medial femoral, lateral femoral, and medial tibial articular surfaces. Our results show a statistically significant association between increasing LTS and worsening cartilage degenerative changes in the medial patella and the lateral tibial plateau. We speculate that increased LTS may result in increased femoral glide over the lateral tibial plateau with subsequent increased external rotation of the femur predisposing to patellofemoral articular changes. Future arthroscopic studies are needed to further confirm our findings. (orig.)

  1. Tibial cortical lesions: A multimodality pictorial review

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, P.A., E-mail: philippa.tyler@rnoh.nhs.uk [Department of Radiology, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore HA7 4LP (United Kingdom); Mohaghegh, P., E-mail: pegah1000@gmail.com [Department of Radiology, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore HA7 4LP (United Kingdom); Foley, J., E-mail: jfoley1@nhs.net [Department of Radiology, Glasgow Royal Infirmary, 16 Alexandra Parade, Glasgow G31 2ES (United Kingdom); Isaac, A., E-mail: amandaisaac@doctors.org.uk [Department of Radiology, King' s College Hospital, Denmark Hill, London SE5 9RS (United Kingdom); Zavareh, A., E-mail: ali.zavareh@gmail.com [Department of Radiology, North Bristol NHS Trust, Frenchay, Bristol BS16 1LE (United Kingdom); Thorning, C., E-mail: cthorning@doctors.org.uk [Department of Radiology, East Surrey Hospital, Canada Avenue, Redhill, Surrey RH1 5RH (United Kingdom); Kirwadi, A., E-mail: anandkirwadi@gmail.com [Department of Radiology, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL (United Kingdom); Pressney, I., E-mail: ipressney@hotmail.com [Department of Radiology, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore HA7 4LP (United Kingdom); Amary, F., E-mail: fernanda.amary@rnoh.nhs.uk [Department of Histopathology, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore HA7 4LP (United Kingdom); Rajeswaran, G., E-mail: grajeswaran@gmail.com [Department of Radiology, Chelsea and Westminster Hospital, 369 Fulham Road, London SW10 9NH (United Kingdom)

    2015-01-15

    Highlights: • Multimodality imaging plays an important role in the investigation and diagnosis of shin pain. • We review the multimodality imaging findings of common cortically based tibial lesions. • We also describe the rarer pathologies of tibial cortical lesions. - Abstract: Shin pain is a common complaint, particularly in young and active patients, with a wide range of potential diagnoses and resulting implications. We review the natural history and multimodality imaging findings of the more common causes of cortically-based tibial lesions, as well as the rarer pathologies less frequently encountered in a general radiology department.

  2. Measurement of tibial torsion by computer tomography

    Energy Technology Data Exchange (ETDEWEB)

    Jend, H.H.; Heller, M.; Dallek, M.; Schoettle, H. (Hamburg Univ. (Germany, F.R.))

    1981-01-01

    A CT procedure for objective measurements of tibial torsion independent of axial rotation in the nearby joints is described. Transverse sections in defined planes of the tibia permit easy calculation of normal and abnormal congenital or posttraumatic angles of torsion. In 69 limbs normal tibial torsion was 40/sup 0/+-9/sup 0/. In a series of 42 limbs with complicated healing of a fracture of both bones of the leg it is shown that tibial maltorsion is a deformity which in most cases leads to arthrosis of the ankle joint.

  3. Distal realignment (tibial tuberosity transfer).

    Science.gov (United States)

    Feller, Julian Ashley

    2012-09-01

    Although tibial tuberosity (TT) transfer has for many years been the basis of many protocols for the management of patellar instability, the role of pure medial transfer in particular appears to be declining. In contrast, the greater recognition of the importance of patella alta as a predisposing factor to recurrent patellar dislocation has resulted in a resurgence in the popularity of distal TT transfer. When TT transfer is performed, the direction and amount of transfer is based on the patellar height and the lateralization of the TT relative to the trochlear groove. Patellar height is best assessed on a lateral radiograph with the knee in flexion using a ratio that uses the articular surface of the patella in relation to the height above the tibia. Assessment of lateralization of the TT relative to the trochlear groove can be made using either computed tomography or magnetic resonance imaging scans.

  4. Torque-bias profile for improved tracking of the Deep Space Network antennas

    Science.gov (United States)

    Gawronski, W.; Beech-Brandt, J. J.; Ahlstrom, H. G.; Maneri, E.

    2000-12-01

    Measurements at the drives of the NASA Deep Space Network (DSN) antennas indicated that the small gap between gear teeth was causing backlash at the gearboxes and elevation bullgear. Left uncorrected, backlash will deteriorate the antenna's pointing precision. At DSN, the backlash was eliminated by implementing two identical drives that impose two nonidentical torques (a.k.a. torque bias, or counter-torque). The difference between these two torques depends on the antenna load, and is shaped by the drive's electronic circuits. The paper explains the shaping principles of the circuit, and shows how the circuits can be modified to improve the antenna dynamics under external disturbances.

  5. ESTIMATION OF GRASPING TORQUE USING ROBUST REACTION TORQUE OBSERVER FOR ROBOTIC FORCEPS

    OpenAIRE

    塚本, 祐介; Tsukamoto, Yusuke

    2015-01-01

    Abstract— In this paper, the estimation of the grasping torque of robotic forceps without the use of a force/torque sensor is discussed. To estimate the grasping torque when the robotic forceps driven by a rotary motor with a reduction gear grasps an object, a novel robust reaction torque observer is proposed. In the case where a conventional reaction force/torque observer is applied, the estimated torque includes not only the grasping torque, namely the reaction torque, but also t...

  6. [Retrograde nailing in a tibial fracture].

    Science.gov (United States)

    Valls-Mellado, M; Martí-Garín, D; Fillat-Gomà, F; Marcano-Fernández, F A; González-Vargas, J A

    2014-01-01

    We describe a case of a severely comminuted type iiia open tibial fracture, with distal loss of bone stock (7 cm), total involvement of the tibial joint surface, and severe instability of the fibular-talar joint. The treatment performed consisted of thorough cleansing, placing a retrograde reamed calcaneal-talar-tibial nail with proximal and distal blockage, as well as a fibular-talar Kirschner nail. Primary closure of the skin was achieved. After 3 weeks, an autologous iliac crest bone graft was performed to fill the bone defect, and the endomedullary nail, which had protruded distally was reimpacted and dynamized distally. The bone defect was eventually consolidated after 16 weeks. Currently, the patient can walk without pain the tibial-astragal arthrodesis is consolidated. Copyright © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

  7. Incidence and epidemiology of tibial shaft fractures

    DEFF Research Database (Denmark)

    Larsen, Peter; Elsøe, Rasmus; Hansen, Sandra Hope

    2015-01-01

    Introduction: The literature lacks recent population-based epidemiology studies of the incidence, trauma mechanism and fracture classification of tibial shaft fractures. The purpose of this study was to provide up-to-date information on the incidence of tibial shaft fractures in a large...... and complete population and report the distribution of fracture classification, trauma mechanism and patient baseline demographics. Methods: Retrospective reviews of clinical and radiological records. Results: A total of 196 patients were treated for 198 tibial shaft fractures in the years 2009 and 2010....... The mean age at time of fracture was 38.5 (21.2SD) years. The incidence of tibial shaft fracture was 16.9/100,000/year. Males have the highest incidence of 21.5/100,000/year and present with the highest frequency between the age of 10 and 20, whereas women have a frequency of 12.3/100,000/year and have...

  8. Rotational and peak torque stiffness of rugby shoes.

    Science.gov (United States)

    Ballal, Moez S; Usuelli, Federico Giuseppe; Montrasio, Umberto Alfieri; Molloy, Andy; La Barbera, Luigi; Villa, Tomaso; Banfi, Giuseppe

    2014-09-01

    Sports people always strive to avoid injury. Sports shoe designs in many sports have been shown to affect traction and injury rates. The aim of this study is to demonstrate the differing stiffness and torque in rugby boots that are designed for the same effect. Five different types of rugby shoes commonly worn by scrum forwards were laboratory tested for rotational stiffness and peak torque on a natural playing surface generating force patterns that would be consistent with a rugby scrum. The overall internal rotation peak torque was 57.75±6.26 Nm while that of external rotation was 56.55±4.36 Nm. The Peak internal and external rotational stiffness were 0.696±0.1 and 0.708±0.06 Nm/deg respectively. Our results, when compared to rotational stiffness and peak torques of football shoes published in the literature, show that shoes worn by rugby players exert higher rotational and peak torque stiffness compared to football shoes when tested on the same natural surfaces. There was significant difference between the tested rugby shoes brands. In our opinion, to maximize potential performance and lower the potential of non-contact injury, care should be taken in choosing boots with stiffness appropriate to the players main playing role. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Hybrid synchronous motor electromagnetic torque research

    Directory of Open Access Journals (Sweden)

    Suvorkova Elena E.

    2014-01-01

    Full Text Available Electromagnetic field distribution models in reluctance and permanent magnet parts were made by means of Elcut. Dependences of electromagnetic torque on torque angle were obtained.

  10. A multiaxial force-sensing implantable tibial prosthesis.

    Science.gov (United States)

    Kirking, Bryan; Krevolin, Janet; Townsend, Christopher; Colwell, Clifford W; D'Lima, Darryl D

    2006-01-01

    Accurate in vivo measurement of tibiofemoral forces is important in total knee arthroplasty. These forces determine polyethylene stresses and cold-flow, stress distribution in the implant, and stress transfer to the underlying implant bone interface. Theoretic estimates of tibiofemoral forces have varied widely depending on the mathematical models used. The six degrees of freedom of motion, complex articular surface topography, changing joint-contact position, intra- and extra-articular ligaments, number of muscles crossing the knee joint, and the presence of the patellofemoral joint contribute to the difficulty in developing reliable models of the knee. A prototype instrumented total knee replacement tibial prosthesis was designed, manufactured, and tested. This prosthesis accurately measured all six components of tibial forces (R2>0.997). The prosthesis was also instrumented with an internal microtransmitter for wireless data transmission. Remote powering of the sealed implanted electronics was achieved using magnetic coil induction. This device can be used to validate existing models of the knee that estimate these forces or to develop more accurate models. In conjunction with kinematic data, accurate tibiofemoral force data may be used to design more effective knee-testing rigs and wear simulators. Additional uses are intraoperative measurement of forces to determine soft-tissue balancing and to evaluate the effects of rehabilitation, external bracing, and athletic activities, and activities of daily living.

  11. Characteristics of unilateral tibial plateau fractures among adult patients hospitalized at an orthopaedic trauma centre in China

    Science.gov (United States)

    Liu, Yong; Liao, Zhengwen; Shang, Lei; Huang, Wenhua; Zhang, Dawei; Pei, Guoxian

    2017-01-01

    The aim of this study was to investigate the characteristics of unilateral tibial plateau fractures among hospitalized adult patients in Xijing Hospital, to evaluate the accuracy of Schatzker classification system and AO/OTA classification system to tibial plateau fractures. We retrospectively analysed clinical data on 274 patients admitted to Xijing Hospital between September 2006 and August 2015. The patients’ demographic characteristics, admission periods and seasons, external causes and fracture types were recorded and summarized. Then the characteristics of tibial plateau fractures and the accuracy rate of these two classification systems were analysed. Schatzker type II fractures and AO/OTA type 41-B3 fractures were the most common types. The external causes differed between genders, types of employment, urban-rural residents and both two systems. In addition, some fractures were difficult to classify using Schatzker or AO/OTA classification system. Rural male physical labourers aged between 30–59 years-old were most likely to suffer from unilateral tibial plateau fractures, due to traffic accidents, falls and indoor activity injuries, or falls from height. We should pay more attention to the related people and professions, which contributed to the high occurrence of tibial plateau fractures. Besides that, further improvements are required for both Schatzker and AO/OTA classification systems. PMID:28074894

  12. An outcome of surgical management of the tibial plateau fractures

    Directory of Open Access Journals (Sweden)

    Biju Ravindran

    2014-01-01

    Full Text Available Background: Advance in mechanization and acceleration of travel has been accompanied by an increase in number and severity of fractures and those of the tibial plateau are not an exception. As it is one of the major weight bearing joints of the body, fractures around it will be of at most importance. Aims: (1 To restore articular congruity and limb alignment by open reduction and rigid internal fixation. (2 To enable early knee motion and improve quadriceps and hamstring power. (3 To study the role of surgical treatment and functional outcome in tibial plateau fractures and its complications. Settings and Design: A prospective study was carried out, 32 cases of the tibial plateau fractures, which were admitted from August 2010 to April 2012 at Department of Orthopedics of our Hospital. Materials and Methods: 32 patients underwent surgical treatment for tibial plateau fractures. Fractures were classified according to the Schatzker′s system. The indications for surgery were defined as the presence of displacement, depression and instability being more than 4 mm, 10 mm and 10 degrees. The mean follow-up was 12 months. The selected patients were evaluated and were taken up for surgery. The indicated fractures were treated with closed reduction and internal fixation with percutaneous cannulated cancellous screws, external fixator, open reduction and internal fixation with buttress plate with or without bone grafting. The range of motion was started soon after surgery. The patients were advised nonweight bearing up to 6-8 weeks. Total weight bearing deferred until 12 weeks or complete union of fracture. Statistical Analysis: All parameters before and after the treatment were expressed in mean ± standard deviation and analyzed by the Student′s t-test using SPSS version 16. Results: The knee range of motion was excellent to very good and weight bearing after complete union was satisfactory. Malunion in two cases, knee stiffness in three

  13. Torque-stiffness-controlled dynamic walking with central pattern generators.

    Science.gov (United States)

    Huang, Yan; Vanderborght, Bram; Van Ham, Ronald; Wang, Qining

    2014-12-01

    Walking behavior is modulated by controlling joint torques in most existing passivity-based bipeds. Controlled Passive Walking with adaptable stiffness exhibits controllable natural motions and energy efficient gaits. In this paper, we propose torque-stiffness-controlled dynamic bipedal walking, which extends the concept of Controlled Passive Walking by introducing structured control parameters and a bio-inspired control method with central pattern generators. The proposed walking paradigm is beneficial in clarifying the respective effects of the external actuation and the internal natural dynamics. We present a seven-link biped model to validate the presented walking. Effects of joint torque and joint stiffness on gait selection, walking performance and walking pattern transitions are studied in simulations. The work in this paper develops a new solution of motion control of bipedal robots with adaptable stiffness and provides insights of efficient and sophisticated walking gaits of humans.

  14. Advanced torque converters for robotics and space applications

    Science.gov (United States)

    1985-01-01

    This report describes the results of the evaluation of a novel torque converter concept. Features of the concept include: (1) automatic and rapid adjustment of effective gear ratio in response to changes in external torque (2) maintenance of output torque at zero output velocity without loading the input power source and (3) isolation of input power source from load. Two working models of the concept were fabricated and tested, and a theoretical analysis was performed to determine the limits of performance. It was found that the devices are apparently suited to certain types of tool driver applications, such as screwdrivers, nut drivers and valve actuators. However, quantiative information was insufficient to draw final conclusion as to robotic applications.

  15. Zero torque gear head wrench

    Science.gov (United States)

    Mcdougal, A. R.; Norman, R. M. (Inventor)

    1976-01-01

    A gear head wrench particularly suited for use in applying torque to bolts without transferring torsional stress to bolt-receiving structures is introduced. The wrench is characterized by a coupling including a socket, for connecting a bolt head with a torque multiplying gear train, provided within a housing having an annulus concentrically related to the socket and adapted to be coupled with a spacer interposed between the bolt head and the juxtaposed surface of the bolt-receiving structure for applying a balancing counter-torque to the spacer as torque is applied to the bolt head whereby the bolt-receiving structure is substantially isolated from torsional stress. As a result of the foregoing, the operator of the wrench is substantially isolated from any forces which may be imposed.

  16. Planet migration and magnetic torques

    Science.gov (United States)

    Strugarek, A.; Brun, A. S.; Matt, S. P.; Reville, V.

    2016-10-01

    The possibility that magnetic torques may participate in close-in planet migration has recently been postulated. We develop three dimensional global models of magnetic star-planet interaction under the ideal magnetohydrodynamic (MHD) approximation to explore the impact of magnetic topology on the development of magnetic torques. We conduct twin numerical experiments in which only the magnetic topology of the interaction is altered. We find that magnetic torques can vary by roughly an order of magnitude when varying the magnetic topology from an aligned case to an anti-aligned case. Provided that the stellar magnetic field is strong enough, we find that magnetic migration time scales can be as fast as ~100 Myr. Hence, our model supports the idea that magnetic torques may participate in planet migration for some close-in star-planet systems.

  17. Comparison of a new braid fixation system to an interlocking intramedullary nail for tibial osteotomy repair in an ovine model.

    Science.gov (United States)

    Lu, Yan; Nemke, Brett; Lorang, Douglas M; Trip, Roel; Kobayashi, Hirohito; Markel, Mark D

    2009-06-01

    To compare bone healing of tibial osteotomy repaired with Nitinol wire braid and hardened steel rods (Braid system) and polymethylmethacrylate bone cement with an interlocking intramedullary (IM) nail fixation in an ovine model. In vitro and in vivo experimental study. Adult female sheep (n=22). Using sheep tibia, a middiaphyseal transverse osteotomy was performed in the right tibia, which were then randomly assigned to the Braid system group or IM nail group (n=5). The left tibia were used as controls. The torsional properties of tibial constructs were compared. The study was repeated in vivo in 12 sheep and mechanical properties and bone healing were evaluated at 12 weeks. In vitro, there was no significant difference in torsional stiffness between the groups. In vivo, operative time for the Braid system group was significantly shorter than the IM nail group. At 12 weeks, there were no significant differences in maximum torque and torsional stiffness between IM nail and Braid system groups nor were there significant radiographic or histologic differences between the groups. The Braid system might decrease operative time for repair of transverse middiaphyseal tibial fractures and result in similar bone healing at 12 weeks after surgery compared with an interlocking IM nail repair. A Nitinol Braid system may be a treatment option for transverse midshaft tibial fractures.

  18. 14 CFR 27.361 - Engine torque.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine torque. 27.361 Section 27.361... STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Flight Loads § 27.361 Engine torque. (a) For turbine engines, the limit torque may not be less than the highest of— (1) The mean torque for...

  19. Somatotype variables related to muscle torque and power in judoists.

    Science.gov (United States)

    Lewandowska, Joanna; Buśko, Krzysztof; Pastuszak, Anna; Boguszewska, Katarzyna

    2011-12-01

    The purpose of this study was to examine the relationship between somatotype, muscle torque and power output in judoists. Thirteen judoists (age 18.4±3.1 years, body height 178.6±8.2 cm, body mass 82.3±15.9 kg) volunteered to participate in this study. Somatotype was determined using the Heath-Carter method. Maximal muscle torques of elbow, shoulder, knee, hip and trunk flexors as well as extensors were measured under static conditions. Power outputs were measured in 5 maximal cycle ergometer exercise bouts, 10 s each, at increasing external loads equal to 2.5, 5.0, 7.5, 10.0 and 12.5% of body weight. The Pearson's correlation coefficients were calculated between all parameters. The mean somatotype of judoists was: 3.5-5.9-1.8 (values for endomorphy, mesomorphy and ectomorphy, respectively). The values (mean±SD) of sum of muscle torque of ten muscle groups (TOTAL) was 3702.2±862.9 N x m. The power output ranged from 393.2±79.4 to 1077.2±275.4 W. The values of sum of muscle torque of right and left upper extremities (SUE), sum of muscle torque of right and left lower extremities (SLE), sum of muscle torque of the trunk (ST) and TOTAL were significantly correlated with the mesomorphic component (0.68, 0.80, 0.71 and 0.78, respectively). The ectomorphic component correlated significantly with values of SUE, SLE, ST and TOTAL (-0.69, -0.81, -0.71 and -0.79, respectively). Power output was also strongly correlated with both mesomorphy (positively) and ectomorphy (negatively). The results indicated that the values of mesomorphic and ectomorphic somatotype components influence muscle torque and power output, thus body build could be an important factor affecting results in judo.

  20. Physeal growth arrest after tibial lengthening in achondroplasia

    OpenAIRE

    Song, Sang-Heon; Agashe, Mandar Vikas; Huh, Young-Jae; Hwang, Soon-Young; Song, Hae-Ryong

    2012-01-01

    Background and purpose Bilateral tibial lengthening has become one of the standard treatments for upper segment-lower segment disproportion and to improve quality of life in achondroplasia. We determined the effect of tibial lengthening on the tibial physis and compared tibial growth that occurred at the physis with that in non-operated patients with acondroplasia. Methods We performed a retrospective analysis of serial radiographs until skeletal maturity in 23 achondroplasia patients who und...

  1. 外固定架辅助复位结合微创钢板置入内固定修复复杂性胫腓骨粉碎性骨折%External fixation combined with minimally invasive plate fixation for complex tibial and fibular fracture

    Institute of Scientific and Technical Information of China (English)

    康国锋; 张光明; 王建炜; 梁英杰; 毕艳楠

    2011-01-01

    背景:高能量的胫腓骨粉碎性骨折常合并软组织损伤,若在内固定过程中复位方法不当可造成软组织的二次损伤;寻找一种既能达到稳定的内固定,又尽量避免加重软组织损伤的方法是骨科医生研究的目标.目的:观察应用临时外固定支架辅助复位结合微创钢板置入修复复杂性胫腓骨粉碎性骨折的临床疗效.方法:广州医学院附属广州市第一人民医院自2008-02/2010-03收治的复杂胫腓骨粉碎性骨折患者39例,在行微创内固定的同时采用临时外固定支架术中辅助复位,内固定安放牢固后拆除临时外固定.结果与结论:39例均获得随访,随访时间6~18个月.手术平均时间75 min,其中36例患者内固定后患肢肿胀程度轻,手术切口一期甲级愈合,2例患者伤口边缘水肿,结痂后瘢痕愈合,1例内固定后3个月出现急性骨髓炎,经保守抗炎治疗后恢复.未出现钉道感染、螺钉松动及切口感染、皮肤坏死、露骨露腱病例,依据AOFAS踝关节评分法,钢板置入半年后踝关节恢复情况:优29例,良8例,一般2例.踝关节屈伸活动范围≥30° 29例,20°~30° 8例,20°以下2例.%BACKGROUND:High-energy comminuted fracture of tibis and fibula is often associated with soft tissus injury, the improper reduction method during the operative process of internal fixation can cause secondary soft tissue damage, resulting in serious both to achieve stable internal fixation, and avoid aggravated soft tissue damage is the object of study for orthopaedic surgeon OBJECTIVE: To investigate the clinical therapeutic effect of external fixation combined with MIPO technology used in complex tibial and fibularfracture METHODS: Retrospective analysis was used in 39 cases of complex comminuted fracture of tibia and fibula selected from the temporary external fixation assisted reduction technology combined with MIPO technology used in all cases, and be removed after internal fixed

  2. The importance of tibial alignment: finite element analysis of tibial malalignment.

    Science.gov (United States)

    Perillo-Marcone, A; Barrett, D S; Taylor, M

    2000-12-01

    The influence of the tibial plateau orientation on cancellous bone stress was examined by finite element analysis for a cemented device. The objectives of the study were i) to examine the effect of the plateau-ankle angle on the cancellous bone stress, ii) to analyze the significance of the anteroposterior angles of the tibial component on these stresses, and iii) to compare the finite element predictions with clinical data. In general, positioning the tibial plateau in valgus resulted in lower cancellous bone stresses. These results support previous clinical studies, which suggest that overall alignment in valgus results in lower migration rates and lower incidence of loosening.

  3. Hydroxyapatite-enhanced tibial prosthetic fixation.

    Science.gov (United States)

    Toksvig-Larsen, S; Jorn, L P; Ryd, L; Lindstrand, A

    2000-01-01

    Sixty-two knees (60 patients) were randomized to four noncemented groups. In Groups 1, 3, and 4, the bone cuts were made with a cooled saw blade. In Group 1, 15 patients were operated on with the porous coated Osteonic 7000 tibial component. In Group 2, 15 patients were operated on with the same tibial component as in Group 1 but with the use of a standard saw blade. In Group 3, 16 patients were operated on with the hydroxyapatite-coated Osteonic tibial component, and in Group 4, 16 patients were operated on with the hydroxyapatite Duracon tibial component. All patients were followed up clinically and with roentgenstereometric analysis. There were no differences among the groups regarding clinical outcome. One knee was revised (Group 2) after 1 year because of loosening of the tibial component. The maximum migration at 1 year was 1.7 mm in Group 1, 1.9 mm in Group 2, 1.3 mm in Group 3, and 1 mm in Group 4. At the 2-year followup, the migrations were 1.8 mm, 1.5 mm, 1.4 mm, and 1 mm in Groups 1, 2, 3, and 4, respectively. The inducible displacement that occurred at 1 year was 0.6 mm in Group 1, 0.5 mm in Group 2, 0.4 mm in Group 3, and 0.4 mm in Group 4. The hydroxyapatite coating had a strong positive effect on the tibial component fixation. No prosthesis in the hydroxyapatite groups showed continuous migration.

  4. Torque control of underactuated tendon-driven fingers

    Directory of Open Access Journals (Sweden)

    M. E. Abdallah

    2011-02-01

    Full Text Available Given an underactuated tendon-driven finger, the finger posture is underdetermined and can move freely ("flop" in a region of slack tendons. This work shows that such an underactuated finger can be operated in tendon force control (rather than position control with effective performance. The force control eliminates the indeterminate slack while commanding a parameterized space of desired torques. The torque will either push the finger to the joint limits or wrap around an external object with variable torque – behavior that is sufficient for primarily gripping fingers. In addition, introducing asymmetric joint radii to the design allows the finger to command an expanded range of joint torques and to scan an expanded set of external surfaces. This study is motivated by the design and control of the secondary fingers of the NASA-GM R2 humanoid hand.

    This paper was presented at the IFToMM/ASME International Workshop on Underactuated Grasping (UG2010, 19 August 2010, Montréal, Canada.

  5. Load along the tibial shaft during activities of daily living.

    Science.gov (United States)

    D'Angeli, V; Belvedere, C; Ortolani, M; Giannini, S; Leardini, A

    2014-03-21

    External load at the tibia during activities of daily living provides baseline measures for the improvement of the design of the bone-implant interface for relevant internal and external prostheses. A motion analysis system was used together with an established protocol with skin markers to estimate three-dimensional forces and moments acting on ten equidistant points along the tibial shaft. Twenty young and able-bodied volunteers were analysed while performing three repetitions of the following tasks: level walking at three different speeds, in a straight-line and with sudden changes of direction to the right and to the left, stair ascending and descending, squatting, rising from a chair and sitting down. Moment and force patterns were normalised to the percentage of body weight per height and body weight, respectively, and then averaged over all subjects for each point, about the three tibial anatomical axes, and for each task. Load patterns were found to be consistent over subjects, but different among the anatomical axes, tasks and points. Generally, moments were higher in the medio/lateral axis and influenced by walking speed. In all five walking tasks and in ascending stairs with alternating feet, the more proximal the point was the smaller the mean moment was. For the remaining tasks the opposite trend was observed. The overall largest value was observed in the medio/lateral direction at the ankle centre in level walking at high speed (9.1% body weight * height on average), nearly three times larger than that of the anterior/posterior axis (2.9) during level walking with a sidestep turn. The present results should be of value also for in-vitro mechanical tests and finite element models. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Longitudinal tibial epiphyseal bracket in Nievergelt syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Burnstein, M.I.; De Smet, A.A.; Breed, A.L.; Thomas, J.R.; Hafez, G.R.

    1989-04-01

    A patient is described with lower extremity mesomelic dwarfism associated with bilateral congenital elbow, hip, and knee dislocations. Rhomboid-shaped tibiae and delayed ossification of the primary fibular ossification centers were demonstrated at birth. Plain films and magnetic resonance imaging revealed that the tibial deformities were due to the presence of longitudinal epiphyseal brackets. These brackets were observed at surgery and confirmed histologically. Recognition of the longitudinal epiphyseal bracket and its relationship to the tibial deformities seen in this patient with Nievergelt syndrome is important for planning surgical treatment. (orig.).

  7. Clinical and functional outcomes after operative management of Salter-Harris III and IV fractures of the proximal tibial epiphysis.

    Science.gov (United States)

    Hill, Brian W; Rizkala, Amir R; Li, Mengnai

    2014-09-01

    Pediatric proximal tibial epiphysis fractures are uncommon and have subsequently received little attention in terms of treatment and outcomes. We studied the clinical and functional outcomes of 13 patients with Salter-Harris III and IV fractures of the proximal tibial epiphysis after operative fixation. Associated meniscus, ligamentous, or neurovascular injury was present in 100% of this cohort. Provisional external fixation and locked plating spanning the open physis were used in the majority of cases. The mean clinical follow-up was 15.69 months, where all fractures progressed to union. Good functional outcomes with a low complication rate are possible after operative fixation of these infrequent injuries.

  8. Torque coordinating robust control of shifting process for dry dual clutch transmission equipped in a hybrid car

    Science.gov (United States)

    Zhao, Z.-G.; Chen, H.-J.; Yang, Y.-Y.; He, L.

    2015-09-01

    For a hybrid car equipped with dual clutch transmission (DCT), the coordination control problems of clutches and power sources are investigated while taking full advantage of the integrated starter generator motor's fast response speed and high accuracy (speed and torque). First, a dynamic model of the shifting process is established, the vehicle acceleration is quantified according to the intentions of the driver, and the torque transmitted by clutches is calculated based on the designed disengaging principle during the torque phase. Next, a robust H∞ controller is designed to ensure speed synchronisation despite the existence of model uncertainties, measurement noise, and engine torque lag. The engine torque lag and measurement noise are used as external disturbances to initially modify the output torque of the power source. Additionally, during the torque switch phase, the torque of the power sources is smoothly transitioned to the driver's demanded torque. Finally, the torque of the power sources is further distributed based on the optimisation of system efficiency, and the throttle opening of the engine is constrained to avoid sharp torque variations. The simulation results verify that the proposed control strategies effectively address the problem of coordinating control of clutches and power sources, establishing a foundation for the application of DCT in hybrid cars.

  9. Manipulating spin transfer torque with light

    Science.gov (United States)

    Vendelbjerg, Karsten Leding; Rontani, Massimo

    2017-08-01

    We study the spin transfer torque (STT) induced onto a nanomagnet as a spin-polarized current flows through a junction made of the magnet sandwiched between two semiconductors. This junction is one-dimensional and highly idealized, the thin magnetic layer being mimicked by a spin-dependent contact force. We show that the STT may be externally controlled by shining the junction at sub-bandgap frequency with an intense laser beam. The excitonic coherence driven by the laser dresses the virtual electron-hole pairs coupling conduction and valence bands and inducing evanescent waves at the junction interface. The Fano-like quantum interference between these localized states and the continuum spectrum, being different in the two spin channels, significantly affects the STT.

  10. Irreducible tibial pilon fracture caused by incarceration of the fibula in the tibial medullary canal.

    Science.gov (United States)

    Ellanti, Prasad; Hammad, Yassir; Kosutic, Damir; Grieve, Philip P

    2012-01-01

    Fractures can be irreducible for several reasons, including soft tissue or bone fragment interposition. We report an unusual fracture configuration of a comminuted tibial pilon fracture in which the distal fibular shaft fragment was occupying the medullary canal of the proximal tibial shaft fragment and inhibiting reduction and fixation. To the best of our knowledge, this has not been previously reported in a published study.

  11. Satellite's Motion under the Effect of Magnetic Torque

    Directory of Open Access Journals (Sweden)

    Rashmi Bhardwaj

    2006-01-01

    Full Text Available Non-integrability of planar oscillation of a satellite in an elliptic orbit under the influence of magnetic torque has been studied. The amplitude of the oscillation remains constant upto the second order of approximation. The analysis regarding the stability of the stationary planar oscillation of a satellite near the resonance frequency shows that discontinuity occurs in the amplitude of the oscillation at a frequency of the external periodic force which is less than the frequency of the natural oscillation.

  12. Acoustic interaction forces and torques acting on suspended spheres in an ideal fluid

    CERN Document Server

    Lopes, J Henrique; Silva, G T

    2014-01-01

    In this paper, the acoustic interaction forces and torques exerted by an arbitrary time-harmonic wave on a set of N spheres suspended in an inviscid fluid are theoretically analyzed. In so doing, we utilize the partial-wave expansion method to solve the related multiple scattering problem. The acoustic interaction force and torque are computed for a sphere using the farfield radiation force and torque formulas. To exemplify the method, we calculate the interaction forces exerted by an external traveling and standing plane wave on an arrangement of two and three olive-oil droplets in water. The droplets radii are comparable to the wavelength (i.e. Mie scattering regime). The results show that the radiation force may considerably deviates from that exerted solely by the external incident wave. In addition, we find that acoustic interaction torques arise on the droplets when a nonsymmetric effective incident wave interacts with the droplets.

  13. Increasing Elbow Torque Output of Stroke Patients by EMG-Controlled External Torque

    Science.gov (United States)

    2007-11-02

    Myoelectric signal processing: optimal estimation applied to electromyography � part 1: derivation of the optimal myprocessor,� IEEE Trans. Biomed...stroke patients. The control signal to the manipulator is the difference between the weighted biceps and triceps EMG, so that the system moves with the...EMG of biceps and triceps. Contrary to the many attempts in the past that used EMG signal for switch control, in the current study, we used EMG

  14. Casimir torque in weak coupling

    CERN Document Server

    Milton, Kimball A; Long, William

    2013-01-01

    In this paper, dedicated to Johan H{\\o}ye on the occasion of his 70th birthday, we examine manifestations of Casimir torque in the weak-coupling approximation, which allows exact calculations so that comparison with the universally applicable, but generally uncontrolled, proximity force approximation may be made. In particular, we examine Casimir energies between planar objects characterized by $\\delta$-function potentials, and consider the torque that arises when angles between the objects are changed. The results agree very well with the proximity force approximation when the separation distance between the objects is small compared with their sizes. In the opposite limit, where the size of one object is comparable to the separation distance, the shape dependence starts becoming irrelevant. These calculations are illustrative of what to expect for the torques between, for example, conducting planar objects, which eventually should be amenable to both improved theoretical calculation and experimental verific...

  15. High torque miniature rotary actuator

    Science.gov (United States)

    Nalbandian, Ruben

    2005-07-01

    This paper summarizes the design and the development of a miniature rotary actuator (36 mm diameter by 100 mm length) used in spacecraft mechanisms requiring high torques and/or ultra-fine step resolution. This actuator lends itself to applications requiring high torque but with strict volume limitations which challenge the use of conventional rotary actuators. The design challenge was to develop a lightweight (less than 500 grams), very compact, high bandwidth, low power, thermally stable rotary actuator capable of producing torques in excess of 50 N.m and step resolutions as fine as 0.003 degrees. To achieve a relatively high torsional stiffness in excess of 1000 Nm/radian, the design utilizes a combination of harmonic drive and multistage planetary gearing. The unique design feature of this actuator that contributes to its light weight and extremely precise motion capability is a redundant stepper motor driving the output through a multistage reducing gearbox. The rotary actuator is powered by a high reliability space-rated stepper motor designed and constructed by Moog, Inc. The motor is a three-phase stepper motor of 15 degree step angle, producing twenty-four full steps per revolution. Since micro-stepping is not used in the design, and un-powered holding torque is exhibited at every commanded step, the rotary actuator is capable of reacting to torques as high as 35 Nm by holding position with the power off. The output is driven through a gear transmission having a total train ratio of 5120:1, resulting in a resolution of 0.003 degrees output rotation per motor step. The modular design of the multi-stage output transmission makes possible the addition of designs having different output parameters, such as lower torque and higher output speed capability. Some examples of an actuator family based on this growth capability will be presented in the paper.

  16. Avaliação do ângulo de inclinação tibial e altura patelar após osteotomia tibial de abertura medial Assessment of tibial slope angle and patellar height after medial-opening tibial osteotomy

    Directory of Open Access Journals (Sweden)

    Alan de Paula Mozella

    2012-01-01

    Full Text Available OBJETIVO: Mensurar a variação do ângulo de inclinação tibial posterior e da altura patelar em pacientes submetidos à osteotomia valgizante tibial proximal com técnica de cunha de abertura medial. MÉTODOS: Foram analisadas radiografias panorâmicas de membros inferiores em anteroposterior e perfil do joelho pré e pós-operatórias de 46 pacientes com artrose unicompartimental do joelho, em que se realizou osteotomia tibial. RESULTADOS: Em 23 casos, utilizou-se fixador externo para confecção de cunha de abertura medial gradual e nos outros 23, foi utilizada placa bloqueada com batente como método de fixação. Foram excluídos deste estudo aqueles pacientes com doença tricompartimental do joelho e aqueles submetidos à osteotomias para tratamento de sequelas de fraturas. Após a cirurgia, a inclinação tibial proximal aumentou, em média, 1,7 graus (p OBJECTIVE: To measure the variation in posterior tibial slope angle and patellar height in patients who underwent proximal tibial valgus-producing osteotomy using the medial-opening wedge technique. METHODS: Anteroposterior panoramic radiographs of the lower limbs and lateral radiographs of the knee obtained before and after tibial valgus-producing osteotomy on 46 patients with unicompartmental arthrosis of the knee were analyzed. RESULTS: In 23 patients, an external fixator was used to gradually apply a medial-opening wedge; and in the other 23, a blocked plate with a stop bar was applied as a fixation method. Patients with tricompartmental knee disease and those who underwent osteotomy to treat fracture sequelae were excluded from this study. After surgery, the mean increase in the tibial slope was 1.7 degrees (p < 0.01 in the group in which the blocked plate with a stop bar was used; and 2.7 degrees (p < 0.05 in the group in which the external fixator was used. There was no statistical difference between the groups regarding the increase in the posterior tibial slope. CONCLUSION: The

  17. Landing strategies focusing on the control of tibial rotation in the initial contact period of one-leg forward hops.

    Science.gov (United States)

    Chen, W-L; Chen, Y-T; Huang, S-Y; Yang, C-Y; Wu, C-D; Chang, C-W

    2017-08-01

    Anterior cruciate ligament (ACL) reconstruction (ACLR) surgeries successfully restore anterior tibial translation but not tibial rotation. This study aimed to explore landing strategies focusing on the control of tibial rotation at landing when the ACL is most vulnerable. Three groups of male subjects (50 ACLRs, 26 basketball players, and 31 controls) participated in one-leg forward hop tests for determining the tibial rotatory landing strategies adopted during the initial landing phase. The differences in knee kinematics and muscle activities between internal and external tibial rotatory (ITR, ETR) landing strategies were examined. A higher proportion of basketball players (34.6%) were found to adopt ITR strategies (controls: 6.5%), exhibiting significantly greater hopping distance and knee strength. After adjusting for hopping distance, subjects adopting ITR strategies were found to hop faster with straighter knees at foot contact and with greater ITR and less knee adduction angular displacement during the initial landing phase. However, significantly greater angular displacement in knee flexion, greater medial hamstring activities, and greater co-contraction index of hamstrings and medial knee muscles were also found during initial landing. Our results support the importance of the recruitments of medial hamstrings or the local co-contraction in assisting the rotatory control of the knee during initial landing for avoiding ACL injuries. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Reconstruction of large tibial bone defects following osteosarcoma resection using bone transport distraction: A report of two cases

    Science.gov (United States)

    Yang, Zhengming; Jin, Libin; Tao, Huimin; Yang, Disheng

    2016-01-01

    The clinical efficiency of bone transport distraction osteogenesis in the reconstruction of large tibial defects following resection of osteosarcoma remains unclear. The current study presents two cases of large tibial defects treated with bone transport distraction using an Orthofix external fixator. Case 1 was a 29-year-old man with a tibial defect 11 cm in length, while case 2 was a 16-year-old girl with a 15-cm-long defect. Bone transport distraction osteogenesis was initiated for the both cases on day 14 following resection of the tibial osteosarcoma. Bone transport distraction in case 1 and 2 was continued for 16 and 28 months, respectively, and the patients were followed up for 51 and 56 months, respectively. The two patients did not exhibit any signs of tumor recurrence or tumor metastasis during the follow-up period. The Musculoskeletal Tumor Society functional scores at final follow-up visits were 22 and 18 for case 1 and 2, respectively. Based on the experience gained in these 2 cases, a bone transport is a viable option for the reconstruction of large tibial defects following osteosarcoma resection. PMID:27446450

  19. High tibial slope correlates with increased posterior tibial translation in healthy knees.

    Science.gov (United States)

    Schatka, Imke; Weiler, Andreas; Jung, Tobias M; Walter, Thula C; Gwinner, Clemens

    2017-09-09

    Notwithstanding the importance of the tibial slope (TS) for anterior tibial translation, little information is available regarding the implications on posterior laxity, particularly in healthy subjects. It was hypothesized that increased TS is associated with decreased posterior tibial translation (PTT) in healthy knees. A total of 124 stress radiographs of healthy knees were enrolled in this study. Tibial slope and the posterior tibial translation were evaluated using a Telos device with a 150-N force at 90° of knee flexion. Two blinded observers reviewed independently on two different occasions. One hundred and twenty-four patients [35 females and 89 males; 41 (range 18-75) years] were enrolled in this study, with a mean PTT of 2.8 mm (±1.9 mm; range 0-8 mm) and a mean TS of 8.6° (±2.6°; range 1°-14°). Pearson correlation showed a significant correlation between the PTT and TS in the overall patient cohort (P < 0.0001) with r = 0.76 and R (2) = 0.58. There was no statistical difference between female and male patients regarding the PTT or the TS. Subgrouping of the patient cohort (four groups with n = 31) according to their TS (groups I < 7°; II = 7°-8.5°; III = 9°-10.5°; IV ≥ 11°) revealed significant differences between each subgroup, respectively. Furthermore, there was a weak but significant correlation between age and PTT (P = 0.004, r = 0.26). In addition to the substantial variance in tibial slope and posterior laxity among healthy knees, high tibial slope significantly correlates with increased posterior tibial translation. Increasing age is further associated with a greater magnitude of posterior tibial translation. Consequently, knowledge of the tibial slope facilitates simple estimation of posterior knee laxity, which is mandatory for PCL reconstruction and knee arthroplasty.

  20. Torque/velocity properties of human knee muscles: peak and angle-specific estimates.

    Science.gov (United States)

    Caldwell, G E; Adams, W B; Whetstone, M R

    1993-09-01

    Angle-specific (AS) torque/velocity data have been used to avoid angle related variation in peak torque capacity. However, series elastic structures cause the contractile velocity of active force-producing tissue to differ from external joint velocity except at peak torque. Alternatively, angle related variation may be removed by normalizing peak torque to the isometric maximum at that angular position. The AS, peak (P), and normalized peak (NP) methods were compared in isovelocity knee flexion and extension at velocities between 50 and 250 degrees s-1 for 8 male subjects. The P and NP methods gave more similar torque/velocity relations than the AS method. Further, very little variation in peak torque was attributed to differences in joint angle. Both the P and AS methods illustrate that relative quadriceps/hamstrings torque capability (flexor/extensor ratio) increases slightly with velocity. It is proposed that antagonist muscle torque capabilities should be compared at different angular positions to assess muscular imbalance.

  1. Proximal tibial osteophytes and their relationship with the height of the tibial spines of the intercondylar eminence: paleopathological study

    Energy Technology Data Exchange (ETDEWEB)

    Hayeri, Mohammad Reza [Children' s National Medical Center, Department of Radiology, Washington, DC (United States); Shiehmorteza, Masoud; Trudell, Debra J.; Resnick, Donald [University of California San Diego, Department of Radiology, San Diego, CA (United States); Hefflin, Tori [Museum of Man San Diego, San Diego, CA (United States)

    2010-09-15

    Tibial spiking (i.e., spurring of tibial spines), eburnation, and osteophytes are considered features of osteoarthritis. This investigation employed direct inspection of the medial and lateral tibial plateaus in paleopathological specimens to analyze the frequency and morphological features of osteoarthritis and to define any relationship between the size of osteophytes and that of the intercondylar tibial spines. A total of 35 tibial bone specimens were evaluated for the degree of osteoarthritis and presence of eburnation. Each plateau was also divided into four quadrants and the presence and size of bone outgrowths were recorded in each quadrant. The ''medial/lateral tibial intercondylar spine index'' for each specimen was calculated as follows: (medial/lateral intercondylar tibial spine height)/(anteroposterior width of the superior tibial surface). The relationships between medial and lateral tibial height indexes with the degree of osteoarthritis were then tested. Osteophytes were observed more frequently in the anterior quadrants of both tibial plateaus than in the posterior quadrants (29 vs 16 for the medial tibial plateau [p = 0.01] and 28 vs 20 for the lateral tibial plateau [p = 0.04]). Eburnation was seen more frequently in the posterior regions of both tibial plateaus than in the anterior regions (17 vs 5, p < 0.01). In specimens with no signs of osteoarthritis the lateral intercondylar tibial index was significantly lower than that in specimens with some degree of osteoarthritis (p = 0.02). The medial intercondylar tibial index of the specimens with no signs of osteoarthritis was not significantly different from that of the specimens with some degree of osteoarthritis (p = 0.45). There was a positive correlation between the lateral spine height index and the overall grading of osteoarthritis, (r = 0.6, p < 0.01). In the anteromedial and posteromedial quadrants of the lateral tibial plateau, the association between the lateral

  2. Installation Torque Tables for Noncritical Applications

    Science.gov (United States)

    Rivera-Rosario, Hazel T.; Powell, Joseph S.

    2017-01-01

    The objective of this project is to define torque values for bolts and screws when loading is not a concern. Fasteners require a certain torque to fulfill its function and prevent failure. NASA Glenn Research Center did not have a set of fastener torque tables for non-critical applications without loads, usually referring to hand-tight or wrench-tight torqueing. The project is based on two formulas, torque and pullout load. Torque values are calculated giving way to preliminary data tables. Testing is done to various bolts and metal plates, torqueing them until the point of failure. Around 640 torque tables were developed for UNC, UNF, and M fasteners. Different lengths of thread engagement were analyzed for the 5 most common materials used at GRC. The tables were put together in an Excel spreadsheet and then formatted into a Word document. The plan is to later convert this to an official technical publication or memorandum.

  3. How well do the muscular synergies extracted via non-negative matrix factorisation explain the variation of torque at shoulder joint?

    Science.gov (United States)

    Moghadam, M Nassajian; Aminian, K; Asghari, M; Parnianpour, M

    2013-01-01

    The way central nervous system manages the excess degrees of freedom to solve kinetic redundancy of musculoskeletal system remains an open question. In this study, we utilise the concept of synergy formation as a simplifying control strategy to find the muscle recruitment based on summation of identified muscle synergies to balance the biomechanical demands (biaxial external torque) during an isometric shoulder task. A numerical optimisation-based shoulder model was used to obtain muscle activation levels when a biaxial external isometric torque is imposed at the shoulder glenohumeral joint. In the numerical simulations, 12 different shoulder torque vectors in the transverse plane are considered. For each selected direction for the torque vector, the resulting muscle activation data are calculated. The predicted muscle activation data are used for grouping muscles in some fixed element synergies by the non-negative matrix factorisation method. Next, torque produced by these synergies are computed and projected in the 2D torque space to investigate the magnitude and direction of torques that each muscle synergy generated. The results confirmed our expectation that few dominant synergies are sufficient to reconstruct the torque vectors and each muscle contributed to more than one synergy. Decomposition of the concatenated data, combining the activation and external torque, provided functional muscle synergies that produced torques in the four principal directions. Four muscle synergies were able to account for more than 95% of variation of the original data.

  4. Staged minimally invasive plate osteosynthesis of proximal tibial fractures with acute compartment syndrome.

    Science.gov (United States)

    Kim, Joon-Woo; Oh, Chang-Wug; Oh, Jong-Keon; Kyung, Hee-Soo; Park, Kyeong-Hyeon; Kim, Hee-June; Jung, Jae-Wook; Jung, Young-Soo

    2017-06-01

    High-energy proximal tibial fractures often accompany compartment syndrome and are usually treated by fasciotomy with external fixation followed by secondary plating. However, the initial soft tissue injury may affect bony union, the fasciotomy incision or external fixator pin sites may lead to postoperative wound infections, and the staged procedure itself may adversely affect lower limb function. We assess the results of staged minimally invasive plate osteosynthesis (MIPO) for proximal tibial fractures with acute compartment syndrome. Twenty-eight patients with proximal tibial fractures accompanied by acute compartment syndrome who underwent staged MIPO and had a minimum of 12 months follow-up were enrolled. According to the AO/OTA classification, 6 were 41-A, 15 were 41-C, 2 were 42-A and 5 were 42-C fractures; this included 6 cases of open fractures. Immediate fasciotomy was performed once compartment syndrome was diagnosed and stabilization of the fracture followed using external fixation. After the soft tissue condition normalized, internal conversion with MIPO was done on an average of 37 days (range, 9-158) after index trauma. At the time of internal conversion, the external fixator pin site grades were 0 in 3 cases, 1 in 12 cases, 2 in 10 cases and 3 in 3 cases, as described by Dahl. Radiographic assessment of bony union and alignment and a functional assessment using the Knee Society Score and American Orthopedic Foot and Ankle Society (AOFAS) score were carried out. Twenty-six cases achieved primary bony union at an average of 18.5 weeks. Two cases of nonunion healed after autogenous bone grafting. The mean Knee Society Score and the AOFAS score were 95 and 95.3 respectively, at last follow-up. Complications included 1 case of osteomyelitis in a patient with a grade IIIC open fracture and 1 case of malunion caused by delayed MIPO due to poor wound conditions. Duration of external fixation and the external fixator pin site grade were not related to the

  5. Do physical examination and CT-scan measures of femoral neck anteversion and tibial torsion relate to each other?

    Science.gov (United States)

    Sangeux, Morgan; Mahy, Jessica; Graham, H Kerr

    2014-01-01

    Informed clinical decision making for femoral and/or tibial de-rotation osteotomies requires accurate measurement of patient function through gait analysis and anatomy through physical examination of bony torsions. Validity of gait analysis has been extensively studied; however, controversy remains regarding the accuracy of physical examination measurements of femoral and tibial torsion. Comparison between CT-scans and physical examination measurements of femoral neck anteversion (FNA) and external tibial torsion (ETT) were retrospectively obtained for 98 (FNA) and 64 (ETT) patients who attended a tertiary hospital for instrumented gait analysis between 2007 and 2010. The physical examination methods studied for femoral neck anteversion were the trochanteric prominence angle test (TPAT) and the maximum hip rotation arc midpoint (Arc midpoint) and for external tibial torsion the transmalleolar axis (TMA). Results showed that all physical examination measurements statistically differed to the CT-scans (bias(standard deviation): -2(14) for TPAT, -10(12) for Arc midpoint and -16(9) for TMA). Bland and Altman plots showed that method disagreements increased with increasing bony torsions in all cases but notably for TPAT. Regression analysis showed that only TMA and CT-scan measurement of external tibial torsion demonstrated good (R(2)=57%) correlation. Correlations for both TPAT (R(2)=14%) and Arc midpoint (R(2)=39%) with CT-scan measurements of FNA were limited. We conclude that physical examination should be considered as screening techniques rather than definitive measurement methods for FNA and ETT. Further research is required to develop more accurate measurement methods to accompany instrumented gait analysis. Copyright © 2013. Published by Elsevier B.V.

  6. 14 CFR 29.361 - Engine torque.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine torque. 29.361 Section 29.361... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Flight Loads § 29.361 Engine torque. The limit engine torque may not be less than the following: (a) For turbine engines, the highest of— (1)...

  7. Measuring the uncertainty of tapping torque

    DEFF Research Database (Denmark)

    Belluco, Walter; De Chiffre, Leonardo

    An uncertainty budget is carried out for torque measurements performed at the Institut for Procesteknik for the evaluation of cutting fluids. Thirty test blanks were machined with one tool and one fluid, torque diagrams were recorded and the repeatability of single torque measurements was estimat...

  8. Calibration of the optical torque wrench

    NARCIS (Netherlands)

    Pedaci, F.; Huang, Z.; Van Oene, M.; Dekker, N.H.

    2012-01-01

    The optical torque wrench is a laser trapping technique that expands the capability of standard optical tweezers to torque manipulation and measurement, using the laser linear polarization to orient tailored microscopic birefringent particles. The ability to measure torque of the order of kBT (∼4 pN

  9. Tibial crest fracture correction after tibial tuberosity advancement (TTA using a modified TTA technique

    Directory of Open Access Journals (Sweden)

    Tiago Carmagnani Prada

    2015-06-01

    Full Text Available Corrective osteotomies are challenging techniques that require specialized training and acquisition of specific materials. Nevertheless, they have been increasingly studied and used in clinical routine in the world. Several variations on the model and the application technique have been developed and refined in search of the improvement of surgical techniques and development of implants more affordable to purchase. The tibial tuberosity advancement (TTA consists on stabilization of tibial plateau perpendicular to the patellar tendon through the tibial tuberosity advancement. Our goal is to report a surgical complication of fracture of the tibial crest after TTA procedure. A dog with a confirmed diagnosis of rupture of the cranial cruciate ligament (CCLR was operated using conventional technique of TTA. After 3 days of surgery, the same animal had a fracture of the proximal tibial crest. The animal was sent back to surgery and was used a variation of TTA technique, with autologous iliac wing and three cortical screws. This variation of the technique was able to replace the original technique successfully.

  10. [Magnetic resonance imaging of tibial periostitis].

    Science.gov (United States)

    Meyer, X; Boscagli, G; Tavernier, T; Aczel, F; Weber, F; Legros, R; Charlopain, P; Martin, J P

    1998-01-01

    Tibial periostitis frequently occurs in athletes. We present our experience with MRI in a series of 7 patients (11 legs) with this condition. The clinical presentation and scintigraphic scanning suggested the diagnosis. MRI exploration of 11 legs demonstrated a high band-like juxta-osseous signal enhancement of SE and IR T2 weighted sequences in 6 cases, a signal enhancement after i.v. contrast administration in 4. Tibial periostitis is a clinical diagnosis and MRI and scintigraphic findings can be used to assure the differential diagnosis in difficult cases with stress fracture. MRI can visualize juxta-osseous edematous and inflammatory reactions and an increased signal would appear to be characteristic when the band-like image is fixed to the periosteum.

  11. Finite element analysis of tibial fractures

    DEFF Research Database (Denmark)

    Wong, Christian Nai En; Mikkelsen, Mikkel Peter W; Hansen, Leif Berner

    2010-01-01

    INTRODUCTION: Fractures of the tibial shaft are relatively common injuries. There are indications that tibial shaft fractures share characteristics in terms of site, type and local fracture mechanisms. In this study, we aimed to set up a mathematical, computer-based model using finite element...... analysis of the bones of the lower leg to examine if such a model is adequate for prediction of fracture locations and patterns. In future studies, we aim to use these biomechanical results to examine fracture prevention, among others, and to simulate different types of osteosynthesis and the process...... of bony healing. The biomechanical results are the basis for fracture healing, biomechanical fall analysis and stability analysis of osteosynthesis. MATERIAL AND METHODS: A finite element model of the bony part of the lower leg was generated on the basis of computed tomography data from the Visible Human...

  12. Finite element analysis of tibial fractures

    DEFF Research Database (Denmark)

    Wong, Christian Nai En; Mikkelsen, Mikkel Peter W; Hansen, Leif Berner

    2010-01-01

    INTRODUCTION: Fractures of the tibial shaft are relatively common injuries. There are indications that tibial shaft fractures share characteristics in terms of site, type and local fracture mechanisms. In this study, we aimed to set up a mathematical, computer-based model using finite element...... analysis of the bones of the lower leg to examine if such a model is adequate for prediction of fracture locations and patterns. In future studies, we aim to use these biomechanical results to examine fracture prevention, among others, and to simulate different types of osteosynthesis and the process...... Project. The data consisted of 21,219 3D elements with a cortical shell and a trabecular core. Three types of load of torsion, a direct lateral load and axial compression were applied. RESULTS: The finite element linear static analysis resulted in relevant fracture localizations and indicated relevant...

  13. Anterior Tibial Artery Pseudoaneurysm: Case Report

    Directory of Open Access Journals (Sweden)

    Funda Tor

    2012-06-01

    Full Text Available The aneurysmsatic changes of the infrapopliteal arteries are rarely seen. They are pseudoaneurysms rather than true aneursyms. The most important cause of them is trauma. There is not a standart treatment for infrapopliteal aneursyms. In this study, we have evaluated a case operated for anterior tibial artery pseudoaneurysm developed after penetrant trauma and diagnosed two weeks later. [Cukurova Med J 2012; 37(3.000: 172-175

  14. Tibial forces measured in vivo after total knee arthroplasty.

    Science.gov (United States)

    D'Lima, Darryl D; Patil, Shantanu; Steklov, Nikolai; Slamin, John E; Colwell, Clifford W

    2006-02-01

    An instrumented tibial prosthesis was developed to measure forces in vivo after total tibial arthroplasty. This prosthesis was implanted in a 67-kg, 80-year-old man. The prosthesis measured forces at the 4 quadrants of the tibial tray. Tibial forces were measured postoperatively during rehabilitation, rising from a chair, standing, walking, and climbing stairs. By the sixth postoperative week, the peak tibial forces during walking averaged 2.2 times body weight (BW). Stair climbing increased from 1.9 times BW on day 6 to 2.5 times BW at 6 weeks. This represents the first direct in vivo measurement of tibial forces, which should lead to refined surgical techniques and enhanced prosthetic designs. Technical design improvements will enhance function, quality of life, and longevity of total knee arthroplasty.

  15. Wedged tibial components for total knee arthroplasty.

    Science.gov (United States)

    Jeffery, R S; Orton, M A; Denham, R A

    1994-08-01

    Severe coronal deformity of the knee is frequently associated with erosion of one tibial condyle. This can cause problems with fixation and alignment during total knee arthroplasty. If the tibia is cut to the level of the more worn side, valuable bone is sacrificed; if the less worn side is chosen, the deficiency must be filled with bone--graft, cement, or a prosthesis. Tibial components with an integral polyethylene wedge on the undersurface were introduced in 1980 for use in patients with a bony deficit on one tibial condyle. The authors believe that the Denham prosthesis (Biomet, Wales, U.K.) was the first knee arthroplasty to offer such spacers. Twenty-six patients with preoperative varus deformity in whom a wedged component was used were compared with 29 historic control subjects. None of the wedged components loosened after a median follow-up period of 8 years compared with loosening in five of the control subjects (P = .01). In three of the control subjects a fractured triangle of cement was present on the radiographs. Use of the wedges was not accompanied by an improvement in postoperative alignment. The authors conclude that the wedges resulted in improved fixation that was independent of postoperative alignment.

  16. Tibial Tubercle Osteotomy: Indication and Techniques.

    Science.gov (United States)

    Grawe, Brian; Stein, Beth Shubin

    2015-08-01

    Osteotomy of the tibial tubercle is a versatile procedure that can be utilized for several common pathologies about the patellofemoral joint. Most commonly, tuberosity transfer is employed for the treatment of patellar instability or symptomatic overload of the patella. The osteotomy can be combined with soft tissue realignment procedures or cartilage reconstructive techniques. A precise understanding of the surgical anatomy and the biomechanics of the patellofemoral articulation is essential for producing a successful outcome during surgery. Tailoring the direction of transfer to the pathoanatomy of each patient is critical for producing a durable and lasting result following a tibial tubercle osteotomy. When evaluating a patient for a possible transfer, a thorough history and physical evaluation must be undertaken, along with imaging to the patellofemoral joint. Several useful advanced imaging techniques can also be used to guide the surgeon toward the most appropriated osteotomy for the patient. The purpose of this article is to review the indications for performing a tibial tubercle osteotomy, and highlighting the various techniques for transfer.

  17. Systematic radiographic evaluation of tibial hemimelia with orthopedic implications

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan-List, Katia [Rochester General Hospital, Department of Diagnostic Imaging, Rochester, NY (United States); Klionsky, Nina B. [University of Rochester Medical Center, School of Medicine and Dentistry, Rochester, NY (United States); Golisano Children' s Hospital, Department of Radiology, Rochester, NY (United States); Sanders, James O. [University of Rochester Medical Center, School of Medicine and Dentistry, Rochester, NY (United States); Golisano Children' s Hospital, Department of Orthopaedics, Rochester, NY (United States); Golisano Children' s Hospital, Department of Pediatrics, Rochester, NY (United States); Katz, Michael E. [St. Mary' s Medical Center and Palm Beach Children' s Hospital, Department of Radiology, West Palm Beach, FL (United States)

    2017-04-15

    Tibial hemimelia is a rare lower-extremity pre-axial longitudinal deficiency characterized by complete or partial absence of the tibia. The reported incidence is 1 in 1 million live births. In this pictorial essay, we define tibial hemimelia and describe associated conditions and principles of preoperative imaging assessment for a child with tibial hemimelia. We also indicate the imaging findings that might influence the choice of treatment, describe the most widely used classification systems, and briefly discuss current treatment approaches. (orig.)

  18. Histological Analysis of the Tibial Anterior Cruciate Ligament Insertion

    OpenAIRE

    Siebold, Rainer; Oka, Shinya; Traut, Ulrike; Schuhmacher, Peter; Kirsch, Joachim

    2017-01-01

    Objective: To describe the morphology of the tibial ACL insertion by histological assessment in the sagittal plane. Methods: For histology the native (undissected) tibial ACL insertion of 6 fresh-frozen cadaveric knees was cut into 4 sagittal sections parallel to the long axis of the medial tibial spine. The slices were stained with hematoxylin and eosin, Safranin O and Russell-Movat pentachrome. All slices were digitalized and analyzed at a magnification of ?20. Results: From medial to later...

  19. Enhancing the injection locking range of spin torque oscillators through mutual coupling

    Science.gov (United States)

    Romera, M.; Talatchian, P.; Lebrun, R.; Merazzo, K. J.; Bortolotti, P.; Vila, L.; Costa, J. D.; Ferreira, R.; Freitas, P. P.; Cyrille, M.-C.; Ebels, U.; Cros, V.; Grollier, J.

    2016-12-01

    We investigate how the ability of the vortex oscillation mode of a spin-torque nano-oscillator to lock to an external microwave signal is modified when it is coupled to another oscillator. We show experimentally that the mutual electrical coupling can lead to locking range enhancements of a factor 1.64. Furthermore, we analyze the evolution of the locking range as a function of the coupling strength through experiments and numerical simulations. By uncovering the mechanisms at stake in the locking range enhancement, our results will be useful for designing spin-torque nano-oscillator arrays with high sensitivities to external microwave stimuli.

  20. Radiographic features of the development of the anterior tibial tuberosity.

    Science.gov (United States)

    Vergara-Amador, E; Davalos Herrera, D; Moreno, L Á

    2016-01-01

    Few studies have evaluated the radiologic characteristics of the development of the anterior tibial tuberosity. This study aimed to evaluate the radiologic characteristics of the anterior tibial tuberosity in a pediatric population broken down into age groups. We assessed 210 plain-film X-rays of the knee from patients aged from 10 to 17 years, divided into groups according to age and sex, for the presence of ossification of the anterior tibial tuberosity, the distance between the anterior tibial tuberosity and the metaphysis, and fusion with the epiphysis. At 10 years of age, the anterior tibial tuberosity was ossified in 50% of the girls but in only 25% of the boys. In all the girls, the anterior tibial tuberosity was ossified at 11 years, fusion of the anterior tibial tuberosity with the epiphysis had started at 12 years, and fusion was complete by 17 years. In boys, the process is delayed by one year compared to girls. A single center of ossification was found in all cases. The ossification of the anterior tibial tuberosity starts distally, then the proximal part fuses with the rest of the epiphysis, and finally the distal part fuses with the tibia. The results of this study help enable a better analysis of the anterior tibial tuberosity in cases of knee pain. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Torque Characteristic Analysis of a Transverse Flux Motor Using a Combined-Type Stator Core

    Directory of Open Access Journals (Sweden)

    Xiaobao Yang

    2016-11-01

    Full Text Available An external rotor transverse flux motor using a combined-type stator core is proposed for a direct drive application in this paper. The stator core is combined by two kinds of components that can both be manufactured conveniently by generic laminated silicon steel used in traditional motors. The motor benefits from the predominance of low manufacturing cost and low iron loss by using a silicon-steel sheet. Firstly, the basic structure and operation principles of the proposed motor are introduced. Secondly, the expressions of the electromagnetic torque and the cogging torque are deduced by theoretical analysis. Thirdly, the basic characteristics such as permanent magnet flux linkage, no-load back electromotive force, cogging torque and electromagnetic torque are analyzed by a three-dimensional finite element method (3D FEM. Then, the influence of structure parameters on the torque density is investigated, which provides a useful foundation for optimum design of the novel motor. Finally, the torque density of the proposed motor is calculated and discussed, and the result shows that the proposed motor in this paper can provide considerable torque density by using few permanent magnets.

  2. New Torque Estimation Method Considering Spatial Harmonics and Torque Ripple Reduction in Permanent Magnet Synchronous Motors

    Science.gov (United States)

    Hida, Hajime; Tomigashi, Yoshio; Ueyama, Kenji; Inoue, Yukinori; Morimoto, Shigeo

    This paper proposes a new torque estimation method that takes into account the spatial harmonics of permanent magnet synchronous motors and that is capable of real-time estimation. First, the torque estimation equation of the proposed method is derived. In the method, the torque ripple of a motor can be estimated from the average of the torque calculated by the conventional method (cross product of the fluxlinkage and motor current) and the torque calculated from the electric input power to the motor. Next, the effectiveness of the proposed method is verified by simulations in which two kinds of motors with different components of torque ripple are considered. The simulation results show that the proposed method estimates the torque ripple more accurately than the conventional method. Further, the effectiveness of the proposed method is verified by performing on experiment. It is shown that the torque ripple is decreased by using the proposed method to the torque control.

  3. Limited Angle Torque Motors Having High Torque Density, Used in Accurate Drive Systems

    Directory of Open Access Journals (Sweden)

    R. Obreja

    2011-01-01

    Full Text Available A torque motor is a special electric motor that is able to develop the highest possible torque in a certain volume. A torque motor usually has a pancake configuration, and is directly jointed to a drive system (without a gear box. A limited angle torque motor is a torque motor that has no rotary electromagnetic field — in certain papers it is referred to as a linear electromagnet. The main intention of the authors for this paper is to present a means for analyzing and designing a limited angle torque motor only through the finite element method. Users nowadays require very high-performance limited angle torque motors with high density torque. It is therefore necessary to develop the highest possible torque in a relatively small volume. A way to design such motors is by using numerical methods based on the finite element method.

  4. Experiences and lessons about soft-tissue flaps covering of severe open tibial fracture

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To sum up experiences and lessons about management of soft-tissue reconstruction in open tibial fracture over a 6-year period.Methods: Twenty-two flap reconstructions were performed to treat soft-tissue defect of 22 patients with open tibial fracture Type IIIB (Gustilo) from 1993 to 1998. The cases were analyzed and discussed retrospectively after follow up of 12-61 months.Results: The size of the flap ranged from 6.6 cm2 to 28.18 cm2 and the rate of flap failure was 13.6%. Besides, 3 partial necrosis and 2 postoperative infections occurred in this series.Conclusions: For soft tissuedefect of delayed open tibial fracture Type HIB, flap reconstruction is still an optimal option. The experiences we obtained are ① to design a triangular skin extension or a small Z-plasty over the pedicle to reduce the flap tension; ② to select a unilateral external fixation to provide convenience for anysecondary manipulation; and ③ to use serial debridementto diminish flap failure. de

  5. Application of Minimally Invasive Treatment of Locking Compression Plate in SchatzkerⅠ~Ⅲ Tibial Plateau Fracture

    Institute of Scientific and Technical Information of China (English)

    Zhao Guohui

    2014-01-01

    Objective:To investigate the clinical effect of minimally invasive treatment of locking compression plate (LCP) in SchatzkerⅠ~Ⅲ tibial plateau fracture. Methods: Thirty-eight patients with SchatzkerⅠ~Ⅲtibial plateau fracture in our hospital were given minimally invasive treatment of LCP, and the artificial bone was transplanted to the depressed bone. Adverse responses, wound healing time and clinical efifcacy were observed. Results:All patients were followed-up for 14~20 months, and the mean duration was 16 months. Within 1 week after operation, 1 patient suffered from short-term rejection reaction to artiifcial bone, but he healed after corresponding measures were taken. There were no complications like skin necrosis and externally-exposed steel plate among the patients. In addition, all fractures were recovered, and the recovery time was 2.6~4.1 months, with the mean duration being 3.4 months. The recovery of knee function was favorable, in which 20 cases were excellent, 14 were good, and 4 were general. The excellent and good rate was 89.5%. Conclusion: Minimally invasive treatment of LCP for SchatzkerⅠ~Ⅲ tibial plateau fracture can reduce the postoperative relocation loss, and has small trauma and stable ifxation.

  6. NUMERICAL ANALYSIS ON THREEDIMENSIONAL FLOW FIELD OF TURBINE IN TORQUE CONVERTER

    Institute of Scientific and Technical Information of China (English)

    LIU Yue; PAN Yuxue; LIU Chunbao

    2007-01-01

    Three-dimensional flow field of turbine in torque converter is simulated by numerical calculation in order to improve the performance of torque converter. Calculation model of a torque converter is presented based on the mixing-plane technology. In the calculation of flow field, the 3D N-S equations are separated by finite-volume method and solved by semi-implicit method for pressure-linked equations(SIMPLE). Based on flow field calculation, the flow field of turbine is simulated. The velocity and pressure in the flow field of turbine are analyzed. The external performance of the torque converter is also calculated. Results of flow simulation show that there are secondary flow, off flow and velocity gradient in turbine passage. The validity of numerical simulation is verified by comparing the results of numerical simulation with experiment data.

  7. Posterior cruciate ligament's tibial insertions: topographic anatomy and morphometric study

    Directory of Open Access Journals (Sweden)

    Julio Cesar Gali

    2013-06-01

    Full Text Available OBJECTIVE: To provide anatomical and morphometric basis of the posterior cruciate ligament's tibial insertions in order to assist the creation of anatomical tibial tunnels, in the ligament surgical reconstruction. MATERIAL AND METHODS: The topographic anatomy and morphometry of the posterior cruciate ligament's anterolateral and posteromedial bundles' tibial insertions were analyzed in 24 anatomical knee pieces. The pieces were photographed by a digital camera and the images obtained were studied by the software ImageJ, where the bundles' insertion areas were measured in square millimeters, and the length of structures and the distances between significant points were measured in millimeters. RESULTS: In 54.2% of the knees the insertion' shape was concave; in most pieces (41.6% the form of insertion was oval. The average posterior cruciate ligament's tibial insertion total area was 88.33 ± 21.66 mm2; the average anterolateral bundle's tibial insertion area was 46.79 ± 14.10 mm2 and it was 41.54 ± 9.75 mm2 for the posteromedial bundle. CONCLUSIONS: The anterolateral bundle has a tibial insertion area larger than the posteromedial bundle; the insertion areas of those bundles in our study, were smaller than the ones found in the literature. The variations in the posterior cruciate ligament's tibial insertion area suggest that there should be an indication for anatomical reconstructions of this ligament using single or double tibial tunnels according to individual characteristics.

  8. The soleal line: a cause of tibial pseudoperiostitis.

    Science.gov (United States)

    Levine, A H; Pais, M J; Berinson, H; Amenta, P S

    1976-04-01

    An unusually prominent soleal line (a normal anatomic variant) may mimic periosteal reaction along the posterior margin of the proximal tibial shaft. This area of pseudoperiostitis is differentiated from hyperostoses arising from the anterior tibial tubercle and the interosseous membrane. It is always associated with normal, undisturbed architecture of the underlying bone.

  9. Landau-Lifshitz theory of thermomagnonic torque

    Science.gov (United States)

    Kim, Se Kwon; Tserkovnyak, Yaroslav

    2015-07-01

    We derive the thermomagnonic torque associated with smooth magnetic textures subjected to a temperature gradient in the framework of the stochastic Landau-Lifshitz-Gilbert equation. Our approach captures on equal footing two distinct contributions: (i) a local entropic torque that is caused by a temperature dependence of the effective exchange field, the existence of which had been previously suggested based on numerics, and (ii) the well-known spin-transfer torque induced by thermally induced magnon flow. The dissipative components of two torques have the same structure, following a common phenomenology, but opposite signs, with the twice as large entropic torque leading to a domain-wall motion toward the hotter region. We compare the efficiency of the torque-driven domain-wall motion with the recently proposed Brownian thermophoresis.

  10. Clinical results of reversed V-shaped high tibial corticotomy with minimally invasive surgery without internal fixation devices.

    Science.gov (United States)

    Madadi, Firooz; Eajazi, Alireza; Madadi, Firoozeh; Daftari Besheli, Laleh; Rokni, Reza; Abbasian, Mohammad Reza; Bigdeli, Mohammad Reza

    2010-06-09

    High tibial osteotomy is a method of treating knee osteoarthritis due to genu varum in advanced stages. High tibial osteotomy-associated problems continue to be reported. The purpose of this study was to investigate the clinical results of a new, innovative method of high tibial osteotomy with 3- to 13-year follow-up. Between 1996 and 2006, our new surgical method was performed on 293 patients with medial compartment osteoarthritis and genu varum. All patients were examined preoperatively, 6 months postoperatively, and at final follow-up. The Hospital for Special Surgery Knee Scoring System (HSS) was used at final follow-up, and limb alignment and patient satisfaction were reassessed. Immediate postoperative complications included varus recurrence, knee instability, and peroneal nerve palsy, and no signs of tibial nonunion or infection were observed. At final follow-up, 3 cases of genu recurvatum, 2 cases of peroneal nerve palsy, and 25 cases of loss of correction were observed. Average postoperative HSS score was 85 (range, 47-97), and 97.8% of the patients were satisfied. This new method is a good alternative for the correction of genu varum because it requires a small incision, is soft tissue friendly, is a corticotomy instead of an osteotomy, requires no internal or external fixation devices, has a shorter duration and an acceptable complication and recurrence rate, and results in satisfactory HSS scores and higher patient satisfaction rates.

  11. Reaction torque minimization techniques for articulated payloads

    Science.gov (United States)

    Kral, Kevin; Aleman, Roberto M.

    1988-01-01

    Articulated payloads on spacecraft, such as antenna telemetry systems and robotic elements, impart reaction torques back into the vehicle which can significantly affect the performance of other payloads. This paper discusses ways to minimize the reaction torques of articulated payloads through command-shaping algorithms and unique control implementations. The effects of reaction torques encountered on Landsat are presented and compared with simulated and measured data of prototype systems employing these improvements.

  12. Histological analysis of the tibial anterior cruciate ligament insertion.

    Science.gov (United States)

    Oka, Shinya; Schuhmacher, Peter; Brehmer, Axel; Traut, Ulrike; Kirsch, Joachim; Siebold, Rainer

    2016-03-01

    This study was performed to investigate the morphology of the tibial anterior cruciate ligament (ACL) by histological assessment. The native (undissected) tibial ACL insertion of six fresh-frozen cadaveric knees was cut into four sagittal sections parallel to the long axis of the medial tibial spine. For histological evaluation, the slices were stained with haematoxylin and eosin, Safranin O and Russell-Movat pentachrome. All slices were digitalized and analysed at a magnification of 20×. The anterior tibial ACL insertion was bordered by a bony anterior ridge. The most medial ACL fibres inserted from the medial tibial spine and were adjacent to the articular cartilage of the medial tibial plateau. Parts of the bony insertions of the anterior and posterior horns of the lateral meniscus were in close contact with the lateral part of the tibial ACL insertion. A small fat pad was located just posterior to the functional ACL fibres. The anterior-posterior length of the medial ACL insertion was an average of 10.8 ± 1.1 mm compared with the lateral, which was only 6.2 ± 1.1 mm (p flat and 'c-shaped' way. The most anterior part of the tibial ACL insertion was bordered by a bony anterior ridge and the most medial by the medial tibial spine. No posterolateral fibres nor ACL bundles have been found histologically. This histological investigation may improve our understanding of the tibial ACL insertion and may provide important information for anatomical ACL reconstruction.

  13. A 2-year prospective study of patient-relevant outcomes in patients operated on for knee osteoarthritis with tibial osteotomy

    Directory of Open Access Journals (Sweden)

    Toksvig-Larsen Sören

    2005-04-01

    Full Text Available Abstract Background Tibial osteotomy is a treatment for younger and/or physically active patients suffering from uni-compartmental knee osteoarthritis. The open wedge osteotomy by the hemicallotasis technique includes the use of external fixation. The use of external fixation has several advantages, as early mobilization and the opportunity for optimal correction. However, the hemicallotasis technique has also been described as a cumbersome procedure for the patient. The aim of this study was to prospectively evaluate patient-relevant outcomes during the first 2 post-operative years. Especially the treatment period, during which external fixation was used, was closely monitored. Methods In an uncontrolled study, fifty-eight consecutive patients, 30 men and 28 women (mean age 54 years were operated on by the hemicallotasis technique were evaluated with the patient-relevant outcome measure Knee injury and Osteoarthritis Outcome Score (KOOS preoperatively, during the treatment with external fixation, one week after removal of the external fixation, at 6 months, and at one and two years postoperatively. Results At the 2-year postoperative follow-up, all subscales of the KOOS were improved (p Conclusion Tibial osteotomy by the hemicallotasis technique yields large improvement in self-rated pain, function and quality of life, which persists over two years. Surprisingly, large improvements occurred already during the immediate post-operative period when the external fixation was still used.

  14. Design of a new torque standard machine based on a torque generation method using electromagnetic force

    Science.gov (United States)

    Nishino, Atsuhiro; Ueda, Kazunaga; Fujii, Kenichi

    2017-02-01

    To allow the application of torque standards in various industries, we have been developing torque standard machines based on a lever deadweight system, i.e. a torque generation method using gravity. However, this method is not suitable for expanding the low end of the torque range, because of the limitations to the sizes of the weights and moment arms. In this study, the working principle of the torque generation method using an electromagnetic force was investigated by referring to watt balance experiments used for the redefinition of the kilogram. Applying this principle to a rotating coordinate system, an electromagnetic force type torque standard machine was designed and prototyped. It was experimentally demonstrated that SI-traceable torque could be generated by converting electrical power to mechanical power. Thus, for the first time, SI-traceable torque was successfully realized using a method other than that based on the force of gravity.

  15. Evolution and Future of Torque Measurement Technology

    Directory of Open Access Journals (Sweden)

    Dr. W. Krimmel

    2006-03-01

    Full Text Available The journey to the past of torque measurement technology begins in the 17th century. It takes us from the first incipiencies of torque measurement to the problem of the transfer of the measurement signal from a rotating shaft, which existed for several decades. This task was solved by the integration of high-precise digital measuring amplifiers in the torque sensors, which is expressed by broad application fields, today. The future will appertain to highly dynamic measuring sensors as well as to intelligent torque sensors, which are able to transmit their sensor-specific characteristics to evaluation devices.

  16. Determination and optimization of joint torques and joint reaction forces in therapeutic exercises with elastic resistance.

    Science.gov (United States)

    Biscarini, Andrea

    2012-01-01

    A model has been developed to definitively characterize the resistance properties and the joint loading (i.e., shear and compressive components of the joint reaction force) in single-joint exercises with ideal elastic bands. The model accounts for the relevant geometric and elastic properties of the band, the band pre-stretching, and the relative positioning among the joint center of rotation and the fixation points of the band. All the possible elastic torque profiles of ascending-descending, descending, or ascending type were disclosed in relation to the different ranges of joint angles. From these results the elastic resistance setting that best reproduces the average-user's knee extensor torque in maximal isometric/isokinetic efforts was determined. In this optimized setting, the shear tibiofemoral reaction force corresponding to an anterior (posterior) tibial displacement was 65% smaller than (nearly the same as) that obtained in a cam-equipped leg-extension equipment for equal values of resistance torque peak, whereas the compressive tibiofemoral reaction force was 22% higher. Compared to a weight-stack leg-extension equipment, an elastic resistance optimized setting has the potential to give a more effective quadriceps activation across the range of motion, and greatly reduces the anterior cruciate ligament strain force, which represents the main drawback of existing open kinetic-chain knee-extension exercises.

  17. Game programmer's guide to Torque under the hood of the Torque game engine

    CERN Document Server

    Maurina , Edward F

    2006-01-01

    game programmer working with the Torque game engine must have ""The Game Programmer's Guide To Torque"": it teaches everything needed to design your own game, using experiences of game makers and industry veterans well versed in Torque technology. A Torque Game engine demo is included on an accompanying cd while step-by-step examples tell how to use it. Its focus on all the basics makes for an exceptional coverage for all levels of game programmer. -Bookwatch, August 2006

  18. High-torque quiet gear

    Science.gov (United States)

    Moody, Paul E.

    1995-07-01

    A high-torque quiet gear construction consists of an inner hub having a plurality of circumferentially spaced arms extending radially outwardly therefrom, and an outer ring member having a plurality of circumferentially spaced-teeth extending radially inwardly therefrom. The ring member further includes a plurality of gear formations on an outer surface thereof for intermeshing with other gears. The teeth of the ring member are received in spaced relation in corresponding spaces formed between adjacent arms of the hub. An elastomeric member is received in the space formed between the hub and the ring member to form a resilient correction between the arms of the hub and the teeth of the ring member. The side surfaces of the arms and the teeth extend generally parallel to each other and at least partially overlap in a longitudinal direction. The purpose of this configuration is to place the elastomeric member in compression when torque is applied to the hub. Since elastomeric material is relatively incompressible, the result is low shear loads on the adhesive bonds which hold the elastomeric member to both the hub and outer ring member.

  19. Spin Orbit Torque in Ferromagnetic Semiconductors

    KAUST Repository

    Li, Hang

    2016-06-21

    Electrons not only have charges but also have spin. By utilizing the electron spin, the energy consumption of electronic devices can be reduced, their size can be scaled down and the efficiency of `read\\' and `write\\' in memory devices can be significantly improved. Hence, the manipulation of electron spin in electronic devices becomes more and more appealing for the advancement of microelectronics. In spin-based devices, the manipulation of ferromagnetic order parameter using electrical currents is a very useful means for current-driven operation. Nowadays, most of magnetic memory devices are based on the so-called spin transfer torque, which stems from the spin angular momentum transfer between a spin-polarized current and the magnetic order parameter. Recently, a novel spin torque effect, exploiting spin-orbit coupling in non-centrosymmetric magnets, has attracted a massive amount of attention. This thesis addresses the nature of spin-orbit coupled transport and torques in non-centrosymmetric magnetic semiconductors. We start with the theoretical study of spin orbit torque in three dimensional ferromagnetic GaMnAs. Using the Kubo formula, we calculate both the current-driven field-like torque and anti-damping-like torque. We compare the numerical results with the analytical expressions in the model case of a magnetic Rashba two-dimensional electron gas. Parametric dependencies of the different torque components and similarities to the analytical results of the Rashba two-dimensional electron gas in the weak disorder limit are described. Subsequently we study spin-orbit torques in two dimensional hexagonal crystals such as graphene, silicene, germanene and stanene. In the presence of staggered potential and exchange field, the valley degeneracy can be lifted and we obtain a valley-dependent Berry curvature, leading to a tunable antidamping torque by controlling the valley degree of freedom. This thesis then addresses the influence of the quantum spin Hall

  20. Deterministic Spin-Orbit Torque Switching of a Perpendicularly Polarized Magnet Using Wedge Shape of the Magnet

    Science.gov (United States)

    Bhowmik, Debanjan; Salahuddin, Sayeef

    2016-10-01

    Spin-orbit torque provides an efficient way to switch magnets for low power memory applications by reducing the current density needed to switch the magnetization. Perpendicularly polarized magnets are preferred for high density data storage applications because of their high thermal stability in scaled dimensions. However, spin-orbit torque cannot switch a perpendicularly polarized magnet deterministically from up to down and down to up in the absence of an external magnetic field because spin-orbit torque alone cannot break the symmetry of the system. This poses a severe challenge to the applicability of spin-orbit torque for memory devices. In this paper, we show through micromagnetic simulations that when spin-orbit torque is applied on a magnet with a wedge shape, the moments of the magnet are aligned in-plane. On removal of the spin-orbit torque the moments deterministically evolve to vertically upward or downward direction because the anisotropy axis of the magnet is tilted away from the vertical direction owing to the wedge shape of the magnet. Thus, spin-orbit torque driven deterministic switching of the magnet in the absence of an external magnetic field is possible.

  1. Octyl-a-cyanoacrylate adhesive in the treatment of tibial transverse fracture in rabbits

    Institute of Scientific and Technical Information of China (English)

    Lü Bo; TU Zhong-qi; PEI Fu-xing; LIU Lei

    2005-01-01

    Objective: To observe the effect of octyl-a-cyanoacrylate upon bone healing and its degradation in vitro after middle tibial transverse fracture in rabbits, and to establish treatment of higher efficacy with the application of octyl-a-cyanoacrylate.Methods: Middle tibial transverse fracture model of New Zealand rabbits was established. In the experimental group, internal fixation with 2 mm Kirschner wires was performed and the broken ends were fixed with octyl-a-cyanoacrylate. In the control group, only internal fixation with 2 mm Kirschner wires was conducted. Animals were killed at preset time intervals of 2, 4, 6, 8, 10 and 12 weeks postoperatively and samples were harvested.Results: Two weeks after operation, clear fracture lines were observed in both the experimental and the control groups. Fibrous soft tissue connection was noted between the broken ends and there was soft tissue adhesion around the fracture site. There was no callus formation and the broken ends were surrounded by adhesive soft tissues. Obvious external callus formation was confirmed at 8 weeks after operation in both groups with partial disappearance of fracture lines. Ten and twelve weeks after the operation, fracture lines disappeared completely and there was obvious external callus formation and bone union. In the fourth week, fibrous cells and chondrocytes were found to grow into the colloid and surround it at the 6th week. The adhesive material was degraded and gradually absorbed at the 8th week. Chondrification was observed.Conclusions: Two weeks after fixation for tibial fracture in rabbits, octyl-a-cyanoacrylate begins in vivo degradation. Chondrocytes and fibrocytes gradually grow into the degradation area and surround the adhesive material, which broke into pieces at 8 weeks. Complete degradation and disappearance of the adhesive material is present between 10 and12 weeks. No barrier effect hampering fracture healing is noted.

  2. A staged surgical treatment outcome of type 3 open tibial fractures.

    Science.gov (United States)

    Aslan, Ahmet; Uysal, Emin; Ozmeriç, Ahmet

    2014-01-01

    Aim. In these case series which are about type 3 open tibial fractures formed with three different high energy trauma etiologies in different parts of tibia. We aimed to assess our three-stage treatment approach and discuss final results of our elective surgery management with three different fixation methods. Patients and Methods. We assessed 19 patients with type 3 open tibial fractures between 2009 and 2012. Our treatment protocol consisted of three stages. Early intervention in operating room, which including vascular repairs or soft tissue closure, was done if necessary. Definitive surgery was performed using internal or external fixation in the first 15 days. Patients were followed up for at least one year. Last conditions of all our cases were evaluated according to modified Johner and Wruhs criteria. Results. Nine cases were type 3A, seven cases were type 3B, and three cases were type 3C in terms of fracture typing. All patients were followed up for at least one year and mean follow up time was 15 months. In terms of functional and clinical outcome, six cases were evaluated as excellent, eight cases as good, two cases as fair, and three cases as poor. Discussion. Staged treatment option in type 3 open tibial fractures seems to be a good method in reducing complication and achieving the best result. We think that definitive staged treatment protocol including internal fixation with plating or intramedullary nailing (IMN) of the fractures is a reliable method, especially to avoid complications as a result of external fixator and to provide patient rapport.

  3. Estudo do desvio rotacional da tíbia Study of the tibial rotational deviation

    Directory of Open Access Journals (Sweden)

    Pedro José Labronici

    2008-01-01

    Full Text Available OBJETIVO: avaliar o desvio rotacional pós-operatório das fraturas diafisárias da tíbia de pacientes tratadas com haste intramedular bloqueada não-fresada e placa em ponte, utilizando a tomografia computadorizada. MÉTODOS: foram tratados 113 pacientes com fraturas diafisárias da tíbia, sendo que em 42 fraturas os autores utilizaram haste intramedular bloqueada e em 71 foram utilizadas placa em ponte. O método tomográfico utilizado ara se obter as medidas da rotação tibial. Foi empregada a classificação AO das fraturas; à exposição: fechadas e expostas e a percentagem de desvios em rotação interna e externa. RESULTADOS: foi demonstrado não haver diferença significativa de rotação tibial nos seguintes parâmetros analisados: localização, rotação interna ou externa e nos tipos A e B da classificação AO. Porém, nas fraturas do tipo C e nas fraturas expostas, a haste intramedular bloqueada apresentou diferença rotacional significativamente menor (p = 0,028 e (p = 0,05, quando comparada à placa em ponte. CONCLUSÃO: independente da localização das fraturas diafisárias da tíbia, os desvios rotacionais estão relacionados à energia do trauma, apresentando uma maior dificuldade de controle com a técnica placa em ponte.OBJECTIVE: to evaluate the postoperative rotational deviation of diaphyseal tibial fractures in patients treated with non-reamed, interlocking intramedullary nailing and bridge plate, using computerized tomography for measurement. METHOD: one hundred and thirteen patients with diaphyseal tibial fractures were treated; 42 fractures were treated with non-reamed, interlocking intramedullary nailing, and 71 fractures were treated with bridge plate. Tibial rotation measurements were obtained by using the CT scan. All of the fractures were classified by the AO scale, by their presentation (closed and open and the percentage of deviation on internal and external rotation. RESULTS: no significant difference in

  4. Insertion torque, resonance frequency, and removal torque analysis of microimplants.

    Science.gov (United States)

    Tseng, Yu-Chuan; Ting, Chun-Chan; Du, Je-Kang; Chen, Chun-Ming; Wu, Ju-Hui; Chen, Hong-Sen

    2016-09-01

    This study aimed to compare the insertion torque (IT), resonance frequency (RF), and removal torque (RT) among three microimplant brands. Thirty microimplants of the three brands were used as follows: Type A (titanium alloy, 1.5-mm × 8-mm), Type B (stainless steel, 1.5-mm × 8-mm), and Type C (titanium alloy, 1.5-mm × 9-mm). A synthetic bone with a 2-mm cortical bone and bone marrow was used. Each microimplant was inserted into the synthetic bone, without predrilling, to a 7 mm depth. The IT, RF, and RT were measured in both vertical and horizontal directions. One-way analysis of variance and Spearman's rank correlation coefficient tests were used for intergroup and intragroup comparisons, respectively. In the vertical test, the ITs of Type C (7.8 Ncm) and Type B (7.5 Ncm) were significantly higher than that of Type A (4.4 Ncm). The RFs of Type C (11.5 kHz) and Type A (10.2 kHz) were significantly higher than that of Type B (7.5 kHz). Type C (7.4 Ncm) and Type B (7.3 Ncm) had significantly higher RTs than did Type A (4.1 Ncm). In the horizontal test, both the ITs and RTs were significantly higher for Type C, compared with Type A. No significant differences were found among the groups, and the study hypothesis was accepted. Type A had the lowest inner/outer diameter ratio and widest apical facing angle, engendering the lowest IT and highest RF values. However, no significant correlations in the IT, RF, and RT were observed among the three groups.

  5. Outcome of limb reconstruction system in open tibial diaphyseal fractures

    Directory of Open Access Journals (Sweden)

    Anand Ajmera

    2015-01-01

    Full Text Available Background: Management of open tibial diaphyseal fractures with bone loss is a matter of debate. The treatment options range from external fixators, nailing, ring fixators or grafting with or without plastic reconstruction. All the procedures have their own set of complications, like acute docking problems, shortening, difficulty in soft tissue management, chronic infection, increased morbidity, multiple surgeries, longer hospital stay, mal union, nonunion and higher patient dissatisfaction. We evaluated the outcome of the limb reconstruction system (LRS in the treatment of open fractures of tibial diaphysis with bone loss as a definative mode of treatment to achieve union, as well as limb lengthening, simultaneously. Materials and Methods: Thirty open fractures of tibial diaphysis with bone loss of at least 4 cm or more with a mean age 32.5 years were treated by using the LRS after debridement. Distraction osteogenesis at rate of 1 mm/day was done away from the fracture site to maintain the limb length. On the approximation of fracture ends, the dynamized LRS was left for further 15-20 weeks and patient was mobilized with weight bearing to achieve union. Functional assessment was done by Association for the Study and Application of the Methods of Illizarov (ASAMI criteria. Results: Mean followup period was 15 months. The mean bone loss was 5.5 cm (range 4-9 cm. The mean duration of bone transport was 13 weeks (range 8-30 weeks with a mean time for LRS in place was 44 weeks (range 24-51 weeks. The mean implant index was 56.4 days/cm. Mean union time was 52 weeks (range 31-60 weeks with mean union index of 74.5 days/cm. Bony results as per the ASAMI scoring were excellent in 76% (19/25, good in 12% (3/25 and fair in 4% (1/25 with union in all except 2 patients, which showed poor results (8% with only 2 patients having leg length discrepancy more than 2.5 cm. Functional results were excellent in 84% (21/25, good in 8% (2/25, fair in 8% (2/25. Pin

  6. Nonlinear damping effects in spin torque dynamics of magnetic tunnel junctions

    Science.gov (United States)

    Barsukov, Igor; Chen, Yu-Jin; Lee, Han Kyu; Goncalves, Alexandre; Katine, Jordan; Arias, Rodrigo; Ivanov, Boris; Krivorotov, Ilya

    2015-03-01

    Performance of nanoscale spin torque devices such as memory (STT-MRAM) and auto-oscillators critically depends on magnetic relaxation. It is commonly assumed that magnetization dynamics in the presence of spin torque can be understood as simple competition between antidamping arising from spin torque and Gilbert damping of the free layer. However our experiments reveal that the situation is more complex and that nonlinear damping processes in the free layer of magnetic tunnel junction (MTJ) nanopillars can strongly alter spin torque driven dynamics. We study elliptical MTJ nanopillars with in-plane magnetizations of the free layer and SAF layers by spin torque ferromagnetic resonance. We find an excitation spectrum associated with standing spin waves of the free layer. By varying the external field, the energy of a higher-order spin wave mode becomes twice the energy of the main mode. This opens up a nonlinear, resonant relaxation channel, giving rise to a damping increase of approximately 20 percent. With increasing spin torque provided by a DC bias current, we find that this relaxation channel competes with antidamping in a nonlinear manner, increasingly contributing to and even dominating the relaxation at subcritical currents.

  7. Sensorless sliding mode torque control of an IPMSM drive based on active flux concept

    Directory of Open Access Journals (Sweden)

    A.A. Hassan

    2012-03-01

    Full Text Available This paper investigates a novel direct torque control of a sensorless interior permanent magnet synchronous motor based on a sliding mode technique. The speed and position of the interior permanent magnet synchronous motor are estimated online based on active flux concept. To overcome the large ripple content associated with the direct torque, a torque/flux sliding mode controller has been employed. Two integral surface functions are used to construct the sliding mode controller. The command voltage is estimated from the torque and flux errors based on the two switching functions. The idea of the total sliding mode is used to eliminate the problem of reaching phase stability. The space vector modulation is combined with the sliding mode controller to ensure minimum torque and flux ripples and provides high resolution voltage control. The proposed scheme has the advantages of simple implementation, and does not require an external signal injection. In addition, it combines the merits of the direct torque control, sliding mode controller, and space vector modulation besides to the sensorless control. Simulation works are carried out to demonstrate the ability of the proposed scheme at different operating conditions. The results confirm the high performance of the proposed scheme at standstill, low and high speeds including load disturbance and parameters variation.

  8. Self-current induced spin-orbit torque in FeMn/Pt multilayers

    Science.gov (United States)

    Xu, Yanjun; Yang, Yumeng; Yao, Kui; Xu, Baoxi; Wu, Yihong

    2016-05-01

    Extensive efforts have been devoted to the study of spin-orbit torque in ferromagnetic metal/heavy metal bilayers and exploitation of it for magnetization switching using an in-plane current. As the spin-orbit torque is inversely proportional to the thickness of the ferromagnetic layer, sizable effect has only been realized in bilayers with an ultrathin ferromagnetic layer. Here we demonstrate that, by stacking ultrathin Pt and FeMn alternately, both ferromagnetic properties and current induced spin-orbit torque can be achieved in FeMn/Pt multilayers without any constraint on its total thickness. The critical behavior of these multilayers follows closely three-dimensional Heisenberg model with a finite Curie temperature distribution. The spin torque effective field is about 4 times larger than that of NiFe/Pt bilayer with a same equivalent NiFe thickness. The self-current generated spin torque is able to switch the magnetization reversibly without the need for an external field or a thick heavy metal layer. The removal of both thickness constraint and necessity of using an adjacent heavy metal layer opens new possibilities for exploiting spin-orbit torque for practical applications.

  9. The Casimir Torque on a Cylindrical Gear

    CERN Document Server

    Vaidya, Varun

    2013-01-01

    We utilize Effective Field Theory(EFT) techniques to calculate the casimir torque on a cylindrical gear in the presence of a polarizable but neutral object. We present results for the energy and torque as a function of angle for a gear with multiple cogs, as well as for the case of a concentric cylindrical gear.

  10. Casimir torque on a cylindrical gear

    Science.gov (United States)

    Vaidya, Varun

    2014-08-01

    I utilize effective field theory(EFT) techniques to calculate the Casimir torque on a cylindrical gear in the presence of a polarizable but neutral object and present results for the energy and torque as a function of angle for a gear with multiple cogs, as well as for the case of a concentric cylindrical gear.

  11. Radiation Forces and Torques without Stress (Tensors)

    Science.gov (United States)

    Bohren, Craig F.

    2011-01-01

    To understand radiation forces and torques or to calculate them does not require invoking photon or electromagnetic field momentum transfer or stress tensors. According to continuum electromagnetic theory, forces and torques exerted by radiation are a consequence of electric and magnetic fields acting on charges and currents that the fields induce…

  12. Forces and torques between nonintersecting straight currents

    Science.gov (United States)

    Binder, P.-M.; Cross, Felicity; Silva, J. K.

    2016-07-01

    We analyse two very long current-carrying straight wires that point in arbitrary directions without touching. We find general expressions for the forces and torques for arbitrary points on one wire due to the other. This allows us to make calculations for the overall forces and torques and statements about the stability of parallel and anti-parallel current arrangements.

  13. 14 CFR 23.361 - Engine torque.

    Science.gov (United States)

    2010-01-01

    ... Engine torque. (a) Each engine mount and its supporting structure must be designed for the effects of— (1... rational analysis, a factor of 1.6 must be used. (b) For turbine engine installations, the engine mounts... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine torque. 23.361 Section...

  14. 14 CFR 25.361 - Engine torque.

    Science.gov (United States)

    2010-01-01

    ... engine mount and its supporting structure must be designed for the effects of— (1) A limit engine torque.... (b) For turbine engine installations, the engine mounts and supporting structure must be designed to... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine torque. 25.361 Section...

  15. Radiation Forces and Torques without Stress (Tensors)

    Science.gov (United States)

    Bohren, Craig F.

    2011-01-01

    To understand radiation forces and torques or to calculate them does not require invoking photon or electromagnetic field momentum transfer or stress tensors. According to continuum electromagnetic theory, forces and torques exerted by radiation are a consequence of electric and magnetic fields acting on charges and currents that the fields induce…

  16. A non-unity torque sharing function for torque ripple minimization of switched reluctance generators

    DEFF Research Database (Denmark)

    Park, Kiwoo; Liu, Xiao; Chen, Zhe

    2013-01-01

    This paper presents a new torque ripple minimization technique for a Switched Reluctance Generator (SRG). Although the SRG has many advantageous characteristics as a generator, it has not been widely employed in the industry. One of the most notorious disadvantages of the SRG is its high torque r...... ripple. In this paper, a non-unity Torque Sharing Function (TSF) is proposed to minimize the torque ripple over a wide speed range of operation. Simulation results are presented to verify the effectiveness of the proposed torque ripple minimization technique....

  17. Tibial bowing in children - what is normal? A radiographic study

    Energy Technology Data Exchange (ETDEWEB)

    Zbinden, Isabella [University of Basel, Department of Radiology, Basel (Switzerland); Rutz, Erich [University Children' s Hospital, Department of Orthopedic Surgery, Basel (Switzerland); Jacobson, Jon A. [University of Michigan, Department of Radiology, Ann Arbor, MI (United States); Magerkurth, Olaf [University Children' s Hospital, Department of Radiology, Basel (Switzerland); Kantonsspital Baden, Department of Radiology, Baden (Switzerland)

    2015-12-15

    To define osseous landmarks on tibia radiographs in order to establish age-related normal values characterizing physiological tibial bowing in children. Five hundred and twenty-six patients aged 0-17 years with normal radiographs of the lower legs were identified and retrospectively reviewed by two blinded radiologists. In anteroposterior (ap)/lateral (lat)-views, 3 lines defined tibial length and angulation. Line-A connecting proximal to distal corner of tibial metaphysic, lines B and C corresponding to corners of tibial metaphysis. Angle A/B defines proximal, A/C distal tibial-angulation. Tibial curvature is defined by distance of line-D parallel to A and tangential to tibial cortex. Normal values were calculated with linear-regression. Intra-/Interreader agreement were tested with a Bland-Altman-plot. Intrareader-agreement: Reader 1 showed a bias of -0.1, standard-deviation of bias was 1.9 and 95 %-limits-of-agreement -3.9- 3.7. Reader 2: -0.01, 2.4 and -4.7- 4.7. Interreader: 0.2, 1.6 and -2.9- 3.3. Angle-A/B ap was 80-100 , increasing with age (86.5-88); angle-AC ap was 82-107 (96.8-90.5), angle-AB lat was 81-107 (93.0-98.0); angle-AC lat was 76-102 (89.5-86.5); depth of curve ap was 0-11 % (8-3.5) and lat 2-13 %, (8.5-3.5). Age dependent tibial bowing can be assessed with this new measurement system and age-related normal-values characterizing physiological tibial bowing in children is established. (orig.)

  18. Patella height changes post high tibial osteotomy

    Directory of Open Access Journals (Sweden)

    Siew Ghim Gooi

    2017-01-01

    Full Text Available Background: Medial opening wedge high tibial osteotomy (HTO is a well-described treatment in early medial compartmental osteoarthritis of the knee. However, two undesirable sequelae may follow –patella baja and changes in the posterior tibial slope (TS. Materials and Methods: We conducted a retrospective study in patients who underwent HTO in our center between September 2009 and February 2017. Preoperative and 6-week postoperative long-leg weight bearing films and lateral knee radiographs were assessed. Pre- and postoperative radiological measurements include the Caton-Deschamps Index (CDI, the mechanical axis deviation (MAD, and the posterior TS. Independant t-test and Pearson correlation test were performed. Results: A total of 106 knees were recruited. The mean age was 48.8 ± 10.8 years. 66 (62.3% and 40 (37.7% knees were from males and females, respectively. The mean pre- and postoperative measurements was (−9.70° ± 3.67° to 0.08° ± 2.80° (−varus; +valgus for the MAD, (7.14° ± 1.78° to 8.72° ± 3.11° for posterior TS, and (0.93° ± 0.084° to 0.82° ± 0.13° for CDI (P ≤ 0.001 for all. The association between patella height change and the level of osteotomy (supra-tubercle vs. infra-tubercle was statistically significant (P < 0.001. A supra-tubercle osteotomy cut significantly lowering patella height (P = 0.011. There was otherwise no statistically significant correlations between patella height changes and the correction angle (P = 0.187 or posterior TS change (P = 0.744. Conclusions: A medial opening wedge HTO above the tibial tubercle was significantly associated with lowering patella height or reducing CDI postoperatively. Based on our results, we would recommend the use of an infra-tubercle osteotomy during the corrective surgery to prevent the complication of patella baja.

  19. Tibial rotation in anterior cruciate ligament reconstructed knees during single limb hop and drop landings.

    Science.gov (United States)

    Webster, Kate E; Feller, Julian A

    2012-06-01

    Alterations in knee joint kinematics have been suggested as a potential mechanism that influences the development of osteoarthritis of the knee after anterior cruciate ligament reconstruction. Whilst previous work has shown changes in internal-external tibial rotation during level walking, many patients aim to return to high impact activities following surgery. This study examined tibial rotation during single limb hop and drop landings in anterior cruciate ligament reconstructed knees compared to a control group, and also evaluated the influence of graft type (hamstring or patellar tendon). In 48 participants (17 patellar tendon graft, 18 hamstring graft and 13 controls) internal-external rotation was measured during single limb hop and drop landings in a gait laboratory at mean of 10 months after surgery. There was no difference between the two graft types and both patient groups had less internal rotation when compared to the control group. For 60% of patients, internal rotation values were at least 5° less than the control group mean. Anterior cruciate ligament reconstructed knees with both hamstring tendon and patellar tendon grafts show altered rotational kinematic patterns during high impact dynamic load activities. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Lower extremity soft tissue reconstruction and amputation rates in patients with open tibial fractures in Sweden during 1998–2010

    Science.gov (United States)

    2014-01-01

    Background The rates of soft tissue reconstruction and amputation after open tibial fractures have not been studied on a national perspective. We aimed to determine the frequency of soft tissue coverage after open tibial fracture as well as primary and secondary amputation rates. Methods Data on all patients (> = 15 years) admitted to hospital with open tibial fractures were extracted from the Swedish National Patient Register (1998–2010). All surgical procedures, re-admissions, and mechanisms of injury were analysed accordingly. The risk of amputation was calculated using logistic regression (adjusted for age, sex, mechanism of injury, reconstructive surgery and fixation method). The mean follow-up time was 6 (SD 3.8) years. Results Of 3,777 patients, 342 patients underwent soft tissue reconstructive surgery. In total, there were 125 amputations. Among patients with no reconstructive surgery, 2% (n = 68 patients) underwent amputation. In an adjusted analysis, patients older than 70 years (OR = 2.7, 95%, CI = 1.1-6) and those who underwent reconstructive surgery (OR = 3.1, 95% CI = 1.6-5.8) showed higher risk for amputation. Fixations other than intramedullary nailing (plate, external fixation, closed reduction and combination) as the only method were associated with a significant higher risk for amputation (OR 5.1-14.4). Reconstruction within 72 hours (3 days) showed better results than reconstruction between 4–90 days (p = 0.04). Conclusions The rate of amputations after open tibial fractures is low (3.6%). There is a higher risk for amputations with age above 70 (in contrast: male sex and tissue reconstruction are rather indicators for more severe soft tissue injuries). Only a small proportion of open tibial fractures need soft tissue reconstructive surgery. Reconstruction with free or pedicled flap should be performed within 72 hours whenever possible. PMID:25323662

  1. Osteoarthritis Imaging by Quantification of Tibial Trabecular Bone

    DEFF Research Database (Denmark)

    Marques, Joselene

    The pathogenesis of osteoarthritis (OA) includes complex events in the whole joint. In this project, we combined machine-learning techniques in a texture analysis framework and evaluated it in a longitudinal study, where magnetic resonance images of knees were used to quantify the tibial trabecular...... bone in both a marker for OA diagnosis and another marker for prediction of tibial cartilage loss. By multiple-instance learning, we also investigated which region of the tibia provided the best prognosis for cartilage loss. The inferior part of the tibial bone was classified as the most relevant...

  2. Suprapatellar Nailing of Tibial Shaft Fractures in Total Knee Arthroplasty.

    Science.gov (United States)

    Woyski, Dustin; Emerson, Jason

    2016-12-01

    Fractures of the tibial shaft in patients with ipsilateral total knee arthroplasty are rare but difficult to treat. Nonoperative treatment of these fractures with casting or bracing limits weight bearing for an extended period and can result in unacceptable malalignment. Operative fixation with plate and screws also limits early weight bearing and requires healing of soft tissue that is of poor quality. The authors present a method of internal fixation that uses a standard intramedullary tibial nail and suprapatellar instrumentation. This method can easily be performed, avoids the tibial baseplate, and does not require alteration of the instrumentation or intramedullary nail.

  3. Next generation spin torque memories

    CERN Document Server

    Kaushik, Brajesh Kumar; Kulkarni, Anant Aravind; Prajapati, Sanjay

    2017-01-01

    This book offers detailed insights into spin transfer torque (STT) based devices, circuits and memories. Starting with the basic concepts and device physics, it then addresses advanced STT applications and discusses the outlook for this cutting-edge technology. It also describes the architectures, performance parameters, fabrication, and the prospects of STT based devices. Further, moving from the device to the system perspective it presents a non-volatile computing architecture composed of STT based magneto-resistive and all-spin logic devices and demonstrates that efficient STT based magneto-resistive and all-spin logic devices can turn the dream of instant on/off non-volatile computing into reality.

  4. Comparison of glenohumeral contact pressures and contact areas after glenoid reconstruction with latarjet or distal tibial osteochondral allografts.

    Science.gov (United States)

    Bhatia, Sanjeev; Van Thiel, Geoffrey S; Gupta, Deepti; Ghodadra, Neil; Cole, Brian J; Bach, Bernard R; Shewman, Elizabeth; Wang, Vincent M; Romeo, Anthony A; Verma, Nikhil N; Provencher, Matthew T

    2013-08-01

    Glenoid reconstruction with distal tibial allografts offers the theoretical advantage over Latarjet reconstruction of improved joint congruity and a cartilaginous articulation for the humeral head. Hypothesis/ To investigate changes in the magnitude and location of glenohumeral contact areas, contact pressures, and peak forces after (1) the creation of a 30% anterior glenoid defect and subsequent glenoid bone augmentation with (2) a flush Latarjet coracoid graft or (3) a distal tibial osteochondral allograft. It was hypothesized that the distal tibial bone graft would best normalize glenohumeral contact areas, contact pressures, and peak forces. Controlled laboratory study. Eight cadaveric shoulder specimens were dissected free of all soft tissues and randomly tested in 3 static positions of humeral abduction with a 440-N compressive load: 30°, 60°, and 60° of abduction with 90° of external rotation (ABER). Glenohumeral contact area, contact pressure, and peak force were determined sequentially using a digital pressure mapping system for (1) the intact glenoid, (2) the glenoid with a 30% anterior bone defect, and (3) the glenoid after reconstruction with a distal tibial allograft or a Latarjet bone block. Glenoid reconstruction with distal tibial allografts resulted in significantly higher glenohumeral contact areas than reconstruction with Latarjet bone blocks in 60° of abduction (4.87 vs. 3.93 cm2, respectively; P Latarjet reconstruction in the ABER position (2.39 vs. 2.61 N, respectively; P Latarjet reconstruction also followed this same pattern, but differences in contact areas and peak forces between the defect model and Latarjet reconstruction in the ABER position were not statistically significant (P > .05). Reconstruction of anterior glenoid bone defects with a distal tibial allograft may allow for improved joint congruity and lower peak forces within the glenohumeral joint than Latarjet reconstruction at 60° of abduction and the ABER position

  5. Investigation of torque control using a variable slip induction generator

    Energy Technology Data Exchange (ETDEWEB)

    Bossanyi, E.A.; Gamble, C.R.

    1991-07-01

    An investigation of the possibilities of using a variable slip induction generator to control wind turbine transmission torque has been carried out. Such a generator consists of a wound rotor induction generator with its rotor winding connected to an external variable resistance circuit. By controlling the external resistance, the torque-slip characteristic of the generator can be modified, allowing efficient, low-slip operation below rated wind speed and compliant, high-slip operation above rated, where the additional losses are of no consequence but the resulting compliance allows a much reduced duty to be specified for the transmission and gearbox. A number of hardware options have been investigated for the variable resistance rotor circuit, the main options being either a rectifier and DC chopper or an AC regulator. Both of these options use semiconductor switching devices, for which the relative merits of thyristors, MOSFETs, GTOs and transistors have been investigated. A favoured scheme consisting of an AC regulator using GTOs has been provisionally selected. This choice uses some non-standard equipment but is expected to give negligible problems with harmonics. A comprehensive simulation model has been set up and used to investigate the behaviour of the whole system. (author).

  6. Acoustic Interaction Forces and Torques Acting on Suspended Spheres in an Ideal Fluid.

    Science.gov (United States)

    Lopes, J Henrique; Azarpeyvand, Mahdi; Silva, Glauber T

    2016-01-01

    In this paper, the acoustic interaction forces and torques exerted by an arbitrary time-harmonic wave on a set of N objects suspended in an inviscid fluid are theoretically analyzed. We utilize the partial-wave expansion method with translational addition theorem and re-expansion of multipole series to solve the related multiple scattering problem. We show that the acoustic interaction force and torque can be obtained using the farfield radiation force and torque formulas. To exemplify the method, we calculate the interaction forces exerted by an external traveling and standing plane wave on an arrangement of two and three olive-oil droplets in water. The droplets' radii are comparable to the wavelength (i.e., Mie scattering regime). The results show that the acoustic interaction forces present an oscillatory spatial distribution which follows the pattern formed by interference between the external and rescattered waves. In addition, acoustic interaction torques arise on the absorbing droplets whenever a nonsymmetric wavefront is formed by the external and rescattered waves' interference.

  7. Total knee arthroplasty and fractures of the tibial plateau

    Science.gov (United States)

    Softness, Kenneth A; Murray, Ryan S; Evans, Brian G

    2017-01-01

    Tibial plateau fractures are common injuries that occur in a bimodal age distribution. While there are various treatment options for displaced tibial plateau fractures, the standard of care is open reduction and internal fixation (ORIF). In physiologically young patients with higher demand and better bone quality, ORIF is the preferred method of treating these fractures. However, future total knee arthroplasty (TKA) is a consideration in these patients as post-traumatic osteoarthritis is a common long-term complication of tibial plateau fractures. In older, lower demand patients, ORIF is potentially less favorable for a variety of reasons, namely fixation failure and the need for delayed weight bearing. In some of these patients, TKA can be considered as primary mode of treatment. This paper will review the literature surrounding TKA as both primary treatment and as a salvage measure in patients with fractures of the tibial plateau. The outcomes, complications, techniques and surgical challenges are also discussed.

  8. Tibial tubercle osteotomy for patello-femoral joint disorders.

    Science.gov (United States)

    Hall, Matthew J; Mandalia, Vipul I

    2016-03-01

    Tibial tubercle osteotomy has a long history in the management of patella instability and patello-femoral arthritis. This review aims to provide a comprehensive review of the literature describing the biomechanics of the patello-femoral joint and the rationale behind the use of the tibial tubercle osteotomy in modern day practice. Several different tibial tubercle osteotomies are available and we aim to detail the concepts behind their use and the subsequent clinical results. With continued developments of chondrocyte implantation techniques, the potential to fill defects on the chondral surface of either the patella or trochlea in conjunction with a tibial tubercle osteotomy may well become more commonplace in a group that is commonly young and difficult to manage. Level of evidence III.

  9. PHILOS humerus plate for a distal tibial fracture.

    Science.gov (United States)

    Twaij, Haider; Damany, Dev

    2013-01-04

    This report discusses the use of an alternative implant in the emergency fixation of a distal tibial fracture. We planned to fix the shear-type medial malleolar fracture in a closed, tri-malleolar fracture with a locking distal tibial plate. Intra-operatively, it was noted that the required plate was unavailable. A PHILOS humeral plate seemed to fit the contours of the distal tibia. The broad end of the PHILOS, when placed distally, gave options to place locking screws in the medial malleolar fragment. The fracture was stable after fixation. The patient made a full post-operative recovery and follow-up at 4 months was satisfactory. Despite adequate planning, there will be instances where one has to improvise. An understanding of the principles of fracture management can aid in finding solutions. PHILOS humeral plate may be used to stabilize a distal tibial fracture if an appropriate distal tibial locking plate is not available.

  10. Safe surgical technique: intramedullary nail fixation of tibial shaft fractures.

    Science.gov (United States)

    Zelle, Boris A; Boni, Guilherme

    2015-01-01

    Statically locked, reamed intramedullary nailing remains the standard treatment for displaced tibial shaft fractures. Establishing an appropriate starting point is a crucial part of the surgical procedure. Recently, suprapatellar nailing in the semi-extended position has been suggested as a safe and effective surgical technique. Numerous reduction techiques are available to achieve an anatomic fracture alignment and the treating surgeon should be familiar with these maneuvers. Open reduction techniques should be considered if anatomic fracture alignment cannot be achieved by closed means. Favorable union rates above 90 % can be achieved by both reamed and unreamed intramedullary nailing. Despite favorable union rates, patients continue to have functional long-term impairments. In particular, anterior knee pain remains a common complaint following intramedullary tibial nailing. Malrotation remains a commonly reported complication after tibial nailing. The effect of postoperative tibial malalignment on the clinical and radiographic outcome requires further investigation.

  11. Open segmental fractures of the tibia treated by external fixation

    Directory of Open Access Journals (Sweden)

    Golubović Ivan

    2012-01-01

    Full Text Available Introduction. Open segmental fractures of the tibia are rare but severe injuries. In these fractures the wide zone of injury (damage of all structures of the lower leg creates very unsuitable biological conditions for healing of the fracture. Objective. The aim of our work was to present the results of treatment of patients with segmental open fractures of the tibia treated by external fixation. Methods. We analyzed treatment results of 21 patients with open segmental tibial fractures who were treated using the method of external fixation at the Clinical Center Niš from January 1, 1995 to July 31, 2010. The average age of the patients was 53 years; the youngest patient was 27 years and the oldest one 80 years. According to the Gustilo open fracture classification, there were 3 (14.3% type I, 6 (28.6% type II, 8 (38.1% type IIIA, and 4 (19.0% type IIIB. All the patients were treated by a unilateral type Mitković external fixator by Traffix Company. Results. Union was attained in 16 (76.2% fractures without severe complications (pseudoarthrosis, chronic osteitis and angular deformities of over 10 degrees. Among severe complications associated with open segmental tibial fractures, in two cases we registered septic pseudoarthrosis, in one aseptic pseudoarthrosis and in two large angular deformities of the tibia after union, with a valgus of over 10 degrees and extremity shortening of over 2 cm which required additional surgery. Conclusion. External fixation by the use of Mitković external fixator is one of the methods of choice in the treatment of open segmental tibial fractures, which incorporated with antibiotic therapy provides good biomehanical conditions for segmental fracture healing that enables good stability of the segmental tibial fracture and decreases the risk of deep infections. [Projekat Ministarstva nauke Republike Srbije, br. 41017: Virtuelni koštano­zglobni sistem čoveka i njegova primena u pretkliničkoj i kliničkoj praksi

  12. Torque Ripple Reduction of Reluctance Torque Assisted Motors Using Asymmetric Flux Barriers

    Science.gov (United States)

    Hiramoto, Kenji; Takeda, Yoji; Sanada, Masayuki; Morimoto, Shigeo

    Interior permanent magnet synchronous motor (IPMSM) is efficient and can be operated in wide speed region; therefore it is used widely. However, torque ripple of reluctance torque assisted motors, for example IPMSM and synchronous reluctance motor (SynRM), is very large. The skew is known in the prior art as a torque ripple reduction method of AC motors. Although the skew is effective for torque ripple reduction, structure is complicated and it has the disadvantage that average torque will decrease. The discontinuous variation of magnetic resistance between flux barriers and teeth cause the torque ripple. In this paper, in order to ease the discontinuous variation of magnetic resistance, flux barriers are asymmetrically designed so that the relative position relation between flux barriers and teeth may not be in agreement as much as possible. As a result, the torque ripple can be reduced dramatically without the average torque decrease. The experimental motor has been fabricated and the results of measuring torque ripple prove the validity of the torque ripple reduction using asymmetric flux barriers.

  13. The medial tibial stress syndrome. A cause of shin splints.

    Science.gov (United States)

    Mubarak, S J; Gould, R N; Lee, Y F; Schmidt, D A; Hargens, A R

    1982-01-01

    The medial tibial stress syndrome is a symptom complex seen in athletes who complain of exercise-induced pain along the distal posterior-medial aspect of the tibia. Intramuscular pressures within the posterior compartments of the leg were measured in 12 patients with this disorder. These pressures were not elevated and therefore this syndrome is a not a compartment syndrome. Available information suggests that the medial tibial stress syndrome most likely represents a periostitis at this location of the leg.

  14. Patient-specific instrumentation improves tibial component rotation in TKA.

    Science.gov (United States)

    Silva, Alcindo; Sampaio, Ricardo; Pinto, Elisabete

    2014-03-01

    To compare the femoral and tibial components rotational alignment in total knee arthroplasty (TKA) performed either with conventional or with patient-specific instrumentation. Forty-five patients underwent primary TKA and were prospectively randomized into two groups: 22 patients into the conventional instrumentation group (group A) and 23 patients into the Signature™ patient-specific instrumentation group (group B). All patients underwent computed tomography of the operated knee in the first week after surgery to measure the components rotation. The femoral component rotation was 0.0° (-0.25, 1.0) in group A, and 0.0° (0.0, 1.0) in group B. The tibial component rotation was -16.0° (-18.5, 11.8) in group A, and -16.0° (-19.0, -14.0) in group B. There were no significant differences between the two groups in tibial and femoral components rotation. The difference between the tibial component rotation and the neutral tibial rotation was similar in both groups [2.0° (-0.5, 6.3) in group A and 2.0° (-1.0, 4.0) in group B], but the dispersion around the median was different between the two groups. The amplitude of the difference between tibial rotation and neutral position was 27° (-13, 14) in group A and 9° (-3, 6) in group B. There is a smaller chance of internal malrotation of the tibial component with the Signature™ patient-specific instrumentation system, with less dispersion and amplitude of the tibial component rotation around the neutral position. II.

  15. Physeal growth arrest after tibial lengthening in achondroplasia

    Science.gov (United States)

    2012-01-01

    Background and purpose Bilateral tibial lengthening has become one of the standard treatments for upper segment-lower segment disproportion and to improve quality of life in achondroplasia. We determined the effect of tibial lengthening on the tibial physis and compared tibial growth that occurred at the physis with that in non-operated patients with acondroplasia. Methods We performed a retrospective analysis of serial radiographs until skeletal maturity in 23 achondroplasia patients who underwent bilateral tibial lengthening before skeletal maturity (lengthening group L) and 12 achondroplasia patients of similar height and age who did not undergo tibial lengthening (control group C). The mean amount of lengthening of tibia in group L was 9.2 cm (lengthening percentage: 60%) and the mean age at the time of lengthening was 8.2 years. The mean duration of follow-up was 9.8 years. Results Skeletal maturity (fusion of physis) occurred at 15.2 years in group L and at 16.0 years in group C. The actual length of tibia (without distraction) at skeletal maturity was 238 mm in group L and 277 mm in group C (p = 0.03). The mean growth rates showed a decrease in group L relative to group C from about 2 years after surgery. Physeal closure was most pronounced on the anterolateral proximal tibial physis, with relative preservation of the distal physis. Interpretation Our findings indicate that physeal growth rate can be disturbed after tibial lengthening in achondroplasia, and a close watch should be kept for such an occurrence—especially when lengthening of more than 50% is attempted. PMID:22489887

  16. Displaced tibial shaft fractures treated with ASIF compression internal fixation

    DEFF Research Database (Denmark)

    Gebuhr, Peter Henrik; Larsen, T K; Petersen, O C

    1990-01-01

    Fifty-one tibial shaft fractures treated by ASIF compression osteosynthesis were seen at follow-up at a median time of 46 weeks after injury. Twenty-four were open fractures and the patients received prophylactic antibiotics. The median stay in hospital was 15 days for open fractures and 6 days...... for closed fractures. There were complications in 26 cases, with deep infection in 9 cases. At present we cannot advocate the use of ASIF compression osteosynthesis for displaced tibial fractures....

  17. Vascularized fibular graft in infected tibial bone loss

    Directory of Open Access Journals (Sweden)

    C Cheriyan Kovoor

    2011-01-01

    Full Text Available Background : The treatment options of bone loss with infections include bone transport with external fixators, vascularized bone grafts, non-vascularized autogenous grafts and vascularized allografts. The research hypothesis was that the graft length and intact ipsilateral fibula influenced hypertrophy and stress fracture. We retrospectively studied the graft hypertrophy in 15 patients, in whom vascularized fibular graft was done for post-traumatic tibial defects with infection. Materials and Methods : 15 male patients with mean age 33.7 years (range 18 - 56 years of post traumatic tibial bone loss were analysed. The mean bony defect was 14.5 cm (range 6.5 - 20 cm. The mean length of the graft was 16.7 cm (range 11.5 - 21 cm. The osteoseptocutaneous flap (bone flap with attached overlying skin flap from the contralateral side was used in all patients except one. The graft was fixed to the recipient bone at both ends by one or two AO cortical screws, supplemented by a monolateral external fixator. A standard postoperative protocol was followed in all patients. The hypertrophy percentage of the vascularized fibular graft was calculated by a modification of the formula described by El-Gammal. The followup period averaged 46.5 months (range 24 - 164 months. The Pearson correlation coefficient (r was worked out, to find the relationship between graft length and hypertrophy. The t-test was performed to find out if there was any significant difference in the graft length of those who had a stress fracture and those who did not and to find out whether there was any significant difference in hypertrophy with and without ipsilateral fibula union. The Chi square test was performed to identify whether there was any association between the stress fracture and the fibula union. Given the small sample size we have not used any statistical analysis to determine the relation between the percentage of the graft hypertrophy and stress fracture. Results : Graft

  18. Arthrofibrosis of the knee following a fracture of the tibial plateau.

    Science.gov (United States)

    Haller, J M; Holt, D C; McFadden, M L; Higgins, T F; Kubiak, E N

    2015-01-01

    The aim of this study was to report the incidence of arthrofibrosis of the knee and identify risk factors for its development following a fracture of the tibial plateau. We carried out a retrospective review of 186 patients (114 male, 72 female) with a fracture of the tibial plateau who underwent open reduction and internal fixation. Their mean age was 46.4 years (19 to 83) and the mean follow-up was16.0 months (6 to 80). A total of 27 patients (14.5%) developed arthrofibrosis requiring a further intervention. Using multivariate regression analysis, the use of a provisional external fixator (odds ratio (OR) 4.63, 95% confidence interval (CI) 1.26 to 17.7, p = 0.021) was significantly associated with the development of arthrofibrosis. Similarly, the use of a continuous passive movement (CPM) machine was associated with significantly less development of arthrofibrosis (OR = 0.32, 95% CI 0.11 to 0.83, p = 0.024). The effect of time in an external fixator was found to be significant, with each extra day of external fixation increasing the odds of requiring manipulation under anaesthesia (MUA) or quadricepsplasty by 10% (OR = 1.10, p = 0.030). High-energy fracture, surgical approach, infection and use of tobacco were not associated with the development of arthrofibrosis. Patients with a successful MUA had significantly less time to MUA (mean 2.9 months; sd 1.25) than those with an unsuccessful MUA (mean 4.86 months; sd 2.61, p = 0.014). For those with limited movement, therefore, performing an MUA within three months of the injury may result in a better range of movement. Based our results, CPM following operative fixation for a fracture of the tibial plateau may reduce the risk of the development of arthrofibrosis, particularly in patients who also undergo prolonged provisional external fixation. ©2015 The British Editorial Society of Bone & Joint Surgery.

  19. Drag and Torque on Locked Screw Propeller

    Directory of Open Access Journals (Sweden)

    Tomasz Tabaczek

    2014-09-01

    Full Text Available Few data on drag and torque on locked propeller towed in water are available in literature. Those data refer to propellers of specific geometry (number of blades, blade area, pitch and skew of blades. The estimation of drag and torque of an arbitrary propeller considered in analysis of ship resistance or propulsion is laborious. The authors collected and reviewed test data available in the literature. Based on collected data there were developed the empirical formulae for estimation of hydrodynamic drag and torque acting on locked screw propeller. Supplementary CFD computations were carried out in order to prove the applicability of the formulae to modern moderately skewed screw propellers.

  20. Irreducible Salter Harris type II distal tibial physeal fracture secondary to interposition of the posterior tibial tendon: a case report.

    Science.gov (United States)

    Soulier, Robert; Fallat, Lawrence

    2010-01-01

    Pediatric distal tibial fractures generally occur without significant long-term sequelae, and patients are commonly able to return to their preinjury activities after proper management. The literature reports excellent outcomes after anatomical reduction of distal tibial and ankle physeal fractures with closed or open treatment. Treatment options include simple immobilization of nondisplaced fractures, and closed or open reduction for restoration of anatomic alignment of displaced fractures. Soft tissue interposition within the fracture can threaten successful closed reduction, and may warrant open management if closed reduction fails to produce a satisfactory result. Despite the documented possibility of soft tissue interposition preventing closed reduction of pediatric ankle fractures, there is a paucity of literature reporting this complication. We report a unique case of an irreducible Salter-Harris type II distal tibial physeal fracture secondary to interposition of the posterior tibial tendon. Copyright 2010 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  1. Does proximal tibial osteotomy with a novel osteotomy system obtain coronal plane correction without affecting tibial slope and patellar height?

    Science.gov (United States)

    Blackman, Andrew J; Krych, Aaron J; Engasser, William M; Levy, Bruce A; Stuart, Michael J

    2015-12-01

    To determine changes in tibial slope, patellar height, and coronal plane alignment after medial opening wedge proximal tibial osteotomy (PTO) using a modern osteotomy system. Patients undergoing medial opening wedge PTO for any indication with follow-up until radiographic union were identified. Pre- and post-operative tibial slope (referenced off the anterior tibial cortex, proximal tibial anatomic axis, and posterior tibial cortex), patellar height (Caton-Deschamps, Blackburne-Peel, and Insall-Salvati indices), and coronal plane [mechanical axis and weight-bearing line (WBL) ratio] measurements were taken by two observers and compared. Review of 27 patients demonstrated unchanged tibial slope and slightly decreased patellar height post-operatively (Caton-Deschamps: -0.10 ± 0.09; Blackburne-Peel: -0.11 ± 0.10). Coronal plane measurements showed 6.4° ± 1.8° mean change in mechanical axis. Mean post-operative WBL ratio was significantly lower (51.6 ± 11.5 %) than mean goal WBL ratio (62.2 ± 2.5 %). Preoperative mechanical axis >6° varus and osteoarthritis alone as the surgical indication were risk factors for undercorrection >10 %. Medial opening wedge PTO using a recently developed instrumentation system was found to have no effect on tibial slope. Patellar height was decreased after osteotomy using this system, although clinical significance of these findings is unknown. Coronal plane undercorrection of 10.6 % of the target WBL ratio was seen in the group as a whole, although secondary analysis of these results indicated that patients with medial compartment osteoarthritis and/or preoperative mechanical axis of >6° varus accounted for the majority of the cases of undercorrection. Retrospective case series, Level IV.

  2. Frequency control of a spin-torque oscillator using magnetostrictive anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Park, Min Gyu Albert; Lee, Seok-Hee, E-mail: bgpark@kaist.ac.kr, E-mail: shlee@kaist.edu [Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Baek, Seung-heon Chris [Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Park, Byong-Guk, E-mail: bgpark@kaist.ac.kr, E-mail: shlee@kaist.edu [Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2016-01-11

    We report the working principle of a spin-torque oscillator, of which the frequency is efficiently controlled by manipulating the magnetostrictive anisotropy. To justify the scheme, we simulate a conventional magnetic-tunnel junction-based oscillator which is fabricated on a piezoelectric material. By applying mechanical stress to a free layer using a piezoelectric material, the oscillation frequency can be controlled to ensure a broad tuning range without a significant reduction of the dynamic resistance variation. Such controllability, which appears in the absence of an external magnetic field, will not only enable the integration of spin-torque oscillators and conventional complimentary metal-oxide semiconductor technology but will also broaden the applicability of spin-torque oscillators.

  3. The precision and torque production of common hip adductor squeeze tests used in elite football

    DEFF Research Database (Denmark)

    Light, N; Thorborg, K

    2016-01-01

    OBJECTIVES: Decreased hip adductor strength is a known risk factor for groin injury in footballers, with clinicians testing adductor strength in various positions and using different protocols. Understanding how reliable and how much torque different adductor squeeze tests produce will facilitate...... choosing the most appropriate method for future testing. In this study, the reliability and torque production of three common adductor squeeze tests were investigated. DESIGN: Test-retest reliability and cross-sectional comparison. METHODS: Twenty elite level footballers (16-33 years) without previous...... or current groin pain were recruited. Relative and absolute test-retest reliability, and torque production of three adductor squeeze tests (long-lever in abduction, short-lever in adduction and short-lever in abduction/external rotation) were investigated. Each participant performed a series of isometric...

  4. Voltage-driven versus current-driven spin torque in anisotropic tunneling junctions

    KAUST Repository

    Manchon, Aurelien

    2011-10-01

    Nonequilibrium spin transport in a magnetic tunnel junction comprising a single magnetic layer in the presence of interfacial spin-orbit interaction (SOI) is studied theoretically. The interfacial SOI generates a spin torque of the form T=T∥ M×(z× M)+T⊥ z× M, even in the absence of an external spin polarizer. For thick and large tunnel barriers, the torque reduces to the perpendicular component T⊥, which can be electrically tuned by applying a voltage across the insulator. In the limit of thin and low tunnel barriers, the in-plane torque T∥ emerges, proportional to the tunneling current density. Experimental implications on magnetic devices are discussed. © 2011 IEEE.

  5. Interfacial spin-orbit splitting and current-driven spin torque in anisotropic tunnel junctions

    KAUST Repository

    Manchon, Aurelien

    2011-05-17

    Spin transport in magnetic tunnel junctions comprising a single magnetic layer in the presence of interfacial spin-orbit interaction (SOI) is investigated theoretically. Due to the presence of interfacial SOI, a current-driven spin torque can be generated at the second order in SOI, even in the absence of an external spin polarizer. This torque possesses two components, one in plane and one perpendicular to the plane of rotation, that can induce either current-driven magnetization switching from an in-plane to out-of-plane configuration or magnetization precessions, similar to spin transfer torque in spin valves. Consequently, it appears that it is possible to control the magnetization steady state and dynamics by either varying the bias voltage or electrically modifying the SOI at the interface.

  6. Taylor spatial frame in the treatment of open tibial shaft fractures

    Directory of Open Access Journals (Sweden)

    Al-Sayyad Mohammed

    2008-01-01

    Full Text Available Background: The Taylor spatial frame (TSF is a modern multiplanar external fixator that combines the ease of application and computer accuracy in the reduction of fractures. A retrospective review of our prospective TSF database for the use of this device for treating open tibial fractures in pediatric, adolescent, and adult patients was carried out to determine the effectiveness and complications of TSF in the treatment of these fractures. Materials and Methods: Nineteen male patients with open tibial fractures were included. Of these fractures, 10 were Gustilo Type II, five were Gustilo Type IIIA (two had delayed primary closure and three had split thickness skin grafting, and four were Gustilo Type IIIB (all had rotational flaps. Twelve of our patients presented immediately to the emergency room, and the remaining seven cases presented at a mean of 3 months (range, 2.2-4.5 months after the initial injury. The fractures were located in proximal third (n=1, proximal/middle junction (n=2, middle third (n=3, middle/distal junction (n=8, distal third (n=3, and segmental fractures (n=2. Patients were of an average age of 26 years (range, 6-45years. Mean duration of follow-up was 3.5 years. Results: All fractures healed over a mean of 25 weeks (range, 9-46 weeks. All were able to participate in the activities of daily living without any difficulty and most were involved in sports during the last follow-up. Postoperative complications included pin tract infection in 12 patients. Conclusion: The TSF is an effective definitive method of open tibial fracture care with the advantage of early mobilization, ease of soft tissue management through gradual fracture reduction, and the ability to postoperatively manipulate the fracture into excellent alignment.

  7. Results of bypasses to the anterior tibial artery through the interosseous membrane.

    Science.gov (United States)

    Illuminati, G; Calio, F G; Bertagni, A; Martinelli, V

    1998-08-01

    The purpose of the present study was to retrospectively evaluate the results of anatomically tunneled grafts to the anterior tibial artery for distal revascularization in terms of patency and limb salvage rates as well as local morbidity, which can lengthen the postoperative hospital stay. Twenty-three patients received 24 bypasses to the anterior tibial artery, with grafts tunneled through the interosseous membrane. The mean age was 67 years; 10 patients were diabetic, 12 were smokers, 9 presented with significant coronary artery disease, and 2 with chronic renal insufficiency. The donor vessel was the common femoral artery in 17 cases, the superficial femoral artery in 4, and the infra-articular popliteal artery in 3. The graft material consisted in the reversed saphenous vein in 4 cases, the non-reversed devalvulated ex situ saphenous vein in 11, composite polytetrafluoroethylene (PTFE) + inversed saphenous vein in 6, and PTFE alone in 3 cases. No postoperative mortality was observed, nor was there postoperative graft occlusion or need for major amputation. The average postoperative length of stay in the hospital was 9.7 days. Two local surgical wound complications were observed, which did not necessitate a postoperative hospital stay exceeding 15 days. Cumulative primary patency and limb salvage rates at 3 years were 50% and 70%, respectively. Anatomic tunneling of grafts to the anterior tibial artery yields patency and limb salvage rates comparable to those reported in the literature for distal bypasses and, considered overall, an acceptably low local morbidity and short hospital stay. Definitive superiority over externally tunneled grafts, however, is not definitely demonstrated by this study and should be prospectively tested.

  8. Implementing Torque Control with High-Ratio Gear Boxes and without Joint-Torque Sensors

    OpenAIRE

    Del Prete, Andrea; Mansard, Nicolas; Ramos Ponce, Oscar Efrain; Stasse, Olivier; Nori, Francesco

    2016-01-01

    International audience; This paper presents a complete framework (estimation, identification and control) for the implementation of joint-torque control on the humanoid robot HRP-2. While torque control has already been implemented on a few humanoid robots, this is one of the first implementations of torque control on a robot that was originally built to be position controlled (iCub[1] and Asimo[2] being the first two, to the best of our knowledge). The challenge comes from both the hardware,...

  9. Simple Design Approach for Low Torque Ripple and High Output Torque Synchronous Reluctance Motors

    Directory of Open Access Journals (Sweden)

    Mohamed Nabil Fathy Ibrahim

    2016-11-01

    Full Text Available The rotor design of Synchronous Reluctance Motors (SynRMs has a large effect on their efficiency, torque density and torque ripple. In order to achieve a good compromise between these three goals, an optimized rotor geometry is necessary. A finite element method (FEM is a good tool for the optimization. However, the computation time is an obstacle as there are many geometrical parameters to be optimized. The flux-barrier widths and angles are the two most crucial parameters for the SynRM output torque and torque ripple. This paper proposes an easy-to-use set of parametrized equations to select appropriate values for these two rotor parameters. With these equations, the reader can design a SynRM of distributed windings with a low torque ripple and with a better average torque. The methodology is valid for a wide range of SynRMs. To check the validity of the proposed equations, the sensitivity analysis for the variation of these two parameters on the SynRM torque and torque ripple is carried out. In addition, the analysis in this paper gives insight into the behavior of the machine as a function of these two parameters. Furthermore, the torque and torque ripple of SynRMs having a rotor with three, four and five flux-barriers are compared with three literature approaches. The comparison shows that the proposed equations are effective in choosing the flux-barrier angles and widths for low torque ripple and better average torque. Experimental results have been obtained to confirm the FEM results and to validate the methodology for choosing the rotor parameters.

  10. High Torque, Direct Drive Electric Motor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Bear Engineering proposes to advance the development of an innovative high torque, low speed, direct drive motor in order to meet NASA's requirements for such...

  11. High Torque, Direct Drive Electric Motor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Bear Engineering proposes to develop an innovative high torque, low speed, direct drive motor in order to meet NASA's requirements for such devices. Fundamentally,...

  12. Exhaust powered drive shaft torque enhancer

    Energy Technology Data Exchange (ETDEWEB)

    Koch, A.B.

    1986-09-30

    This patent describes a power producing combination including an internal combustion engine and a mounting frame therefor, and power transmission means including rotating drive shaft means connected to the engine. The improvement described here is a drive shaft torque enhancing device, the device comprising: a multiplicity of blades secured to the drive shaft, equally spaced therearound, each generally lying in a plane containing the axis of the drive shaft; torque enhancer feed duct means for selectively directing a stream of exhaust gases from the engine to impact against the blades to impart torque to the drive shaft; and wherein the power producing combination is used in a vehicle, the vehicle having braking means including a brake pedal; and the power producing combination further comprising torque enhancer disengagement means responsive to motion of the brake pedal.

  13. Transmission of torque at the nanoscale

    Science.gov (United States)

    Williams, Ian; Oğuz, Erdal C.; Speck, Thomas; Bartlett, Paul; Löwen, Hartmut; Royall, C. Patrick

    2016-01-01

    In macroscopic mechanical devices, torque is transmitted through gearwheels and clutches. In the construction of devices at the nanoscale, torque and its transmission through soft materials will be a key component. However, this regime is dominated by thermal fluctuations leading to dissipation. Here we demonstrate the principle of torque transmission for a disc-like colloidal assembly exhibiting clutch-like behaviour, driven by 27 particles in optical traps. These are translated on a circular path to form a rotating boundary that transmits torque to additional particles confined to the interior. We investigate this transmission and find that it is determined by solid-like or fluid-like behaviour of the device and a stick-slip mechanism reminiscent of macroscopic gearwheels slipping. The transmission behaviour is predominantly governed by the rotation rate of the boundary and the density of the confined system. We determine the efficiency of our device and thus optimize conditions to maximize power output.

  14. Sensorless vector and direct torque control

    CERN Document Server

    Vas, Peter

    1998-01-01

    This is the first comprehensive book on sensorless high performance a.c. drives. It is essential reading for anyone interested in acquiring a solid background on sensorless torque-controlled drives. It presents a detailed and unified treatment of sensorless vector-controlled and direct-torque controlled drive systems. It also discusses the applications of artificial intelligence to drives. Where possible, space vector theory is used and emphasis is laid on detailed mathematical and physical analysis. Sensorless drive schemes for different types of permanent magnet synchronous motors, synchronous reluctance motors, and induction motors are also presented. These include more than twenty vector drives e.g. five types of MRAS-based vector drives, and eleven types of direct-torque-controlled (DTC) drives, e.g. the ABB DTC drive. However, torque-controlled switched reluctance motor drives are also discussed due to their emerging importance. The book also covers various drive applications using artificial intellige...

  15. Torque Control of Friction Stir Welding Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Longhurst Engineering, PLC and Vanderbilt University propose the innovation of torque control of friction stir welding (FSW) as a replacement to force control of...

  16. Fundamental limits of optical force and torque

    Science.gov (United States)

    Rahimzadegan, A.; Alaee, R.; Fernandez-Corbaton, I.; Rockstuhl, C.

    2017-01-01

    Optical force and torque provide unprecedented control on the spatial motion of small particles. A valid scientific question, that has many practical implications, concerns the existence of fundamental upper bounds for the achievable force and torque exerted by a plane wave illumination with a given intensity. Here, while studying isotropic particles, we show that different light-matter interaction channels contribute to the exerted force and torque, and analytically derive upper bounds for each of the contributions. Specific examples for particles that achieve those upper bounds are provided. We study how and to which extent different contributions can add up to result in the maximum optical force and torque. Our insights are important for applications ranging from molecular sorting, particle manipulation, and nanorobotics up to ambitious projects such as laser-propelled spaceships.

  17. MRI induced torque and demagnetization in retention magnets for a bone conduction implant.

    Science.gov (United States)

    Jansson, Karl-Johan Fredén; Håkansson, Bo; Reinfeldt, Sabine; Taghavi, Hamidreza; Eeg-Olofsson, Måns

    2014-06-01

    Performing magnetic resonance imaging (MRI) examinations in patients who use implantable medical devices involve safety risks both for the patient and the implant. Hearing implants often use two permanent magnets, one implanted and one external, for the retention of the external transmitter coil to the implanted receiver coil to achieve an optimal signal transmission. The implanted magnet is subjected to both demagnetization and torque, magnetically induced by the MRI scanner. In this paper, demagnetization and a comparison between measured and simulated induced torque is studied for the retention magnet used in a bone conduction implant (BCI) system. The torque was measured and simulated in a uniform static magnetic field of 1.5 T. The magnetic field was generated by a dipole electromagnet and permanent magnets with two different types of coercive fields were tested. Demagnetization and maximum torque for the high coercive field magnets was 7.7% ± 2.5% and 0.20 ± 0.01 Nm, respectively and 71.4% ± 19.1% and 0.18 ± 0.01 Nm for the low coercive field magnets, respectively. The simulated maximum torque was 0.34 Nm, deviating from the measured torque in terms of amplitude, mainly related to an insufficient magnet model. The BCI implant with high coercive field magnets is believed to be magnetic resonance (MR) conditional up to 1.5 T if a compression band is used around the skull to fix the implant. This is not approved and requires further investigations, and if removal of the implant is needed, the surgical operation is expected to be simple.

  18. Parameter Analysis on Torque Stabilization for the Eddy Current Brake: A Developed Model, Simulation, and Sensitive Analysis

    Directory of Open Access Journals (Sweden)

    Quan Zhou

    2015-01-01

    Full Text Available Eddy current brake (ECB is an attractive contactless brake whereas it suffers from braking torque attenuation when the rotating speed increases. To stabilize the ECB’s torque generation property, this paper introduces the concept of anti-magneto-motive force to develop the ECB model on the fundamental of magnetic circles. In the developed model, the eddy current demagnetization and the influence of temperature which make the braking torque attenuation are clearly presented. Using the developed model of ECB, the external and internal characteristics of the ECB are simulated through programming by MATLAB. To find the sensibility of the influences on ECB’s torque generation stability, the stability indexes are defined and followed by a sensibility analysis on the internal parameters of an ECB. Finally, this paper indicates that (i the stability of ECB’s torque generating property could be enhanced by obtaining the optimal combination of “demagnetization speed point and the nominal maximum braking torque.” (ii The most remarkable influencing factor on the shifting the demagnetization speed point of ECB was the thickness of the air-gap. (iii The radius of pole shoe’s cross section area and the distance from the pole shoe center to the rotation center are both the most significant influences on the nominal maximum braking torque.

  19. Exact Analytic Solutions for the Rotation of an Axially Symmetric Rigid Body Subjected to a Constant Torque

    CERN Document Server

    Romano, Marcello

    2012-01-01

    New exact analytic solutions are introduced for the rotational motion of a rigid body having two equal principal moments of inertia and subjected to an external torque which is constant in magnitude. In particular, the solutions are obtained for the following cases: (1) Torque parallel to the symmetry axis and arbitrary initial angular velocity; (2) Torque perpendicular to the symmetry axis and such that the torque is rotating at a constant rate about the symmetry axis, and arbitrary initial angular velocity; (3) Torque and initial angular velocity perpendicular to the symmetry axis, with the torque being fixed with the body. In addition to the solutions for these three forced cases, an original solution is introduced for the case of torque-free motion, which is simpler than the classical solution as regards its derivation and uses the rotation matrix in order to describe the body orientation. This paper builds upon the recently discovered exact solution for the motion of a rigid body with a spherical ellipso...

  20. Torque-mixing Magnetic Resonance Spectroscopy

    Science.gov (United States)

    Losby, Joseph; Fani Sani, Fatemeh; Grandmont, Dylan; Diao, Zhu; Belov, Miro; Burgess, Jacob; Compton, Shawn; Hiebert, Wayne; Vick, Doug; Mohammad, Kaveh; Salimi, Elham; Bridges, Gregory; Thomson, Douglas; Freeman, Mark

    A universal, mechanical torque method for magnetic resonance spectroscopy is presented. In analogy to resonance detection by induction, a signal proportional to the transverse component of a precessing dipole moment can be measured as a pure mechanical torque in broadband, frequency-swept spectroscopy. Comprehensive electron spin resonance of a single-crystal, mesoscopic yttrium iron garnet disk at room temperature are presented to demonstrate the method. The rich detail allows analysis of even complex 3D spin textures.

  1. Ultrahigh Casimir interaction torque in nanowire systems.

    Science.gov (United States)

    Morgado, Tiago A; Maslovski, Stanislav I; Silveirinha, Mário G

    2013-06-17

    We study the Casimir torque arising from the quantum electromagnetic fluctuations due to the interaction of two interfaces in a system formed by a dense array of metallic nanorods embedded in dielectric fluids. It is demonstrated that as a consequence of the ultrahigh density of photonic states in the nanowire array it is possible to channel the quantum fluctuations, and thereby boost the Casimir torque by several orders of magnitude as compared to other known systems (e.g., birefringent parallel plates).

  2. Large amplitude oscillation of magnetization in spin-torque oscillator stabilized by field-like torque

    Energy Technology Data Exchange (ETDEWEB)

    Taniguchi, Tomohiro, E-mail: tomohiro-taniguchi@aist.go.jp; Kubota, Hitoshi; Imamura, Hiroshi [National Institute of Advanced Industrial Science and Technology (AIST), Spintronics Research Center, Tsukuba 305-8568 (Japan); Tsunegi, Sumito [Unité Mixte de Physique CNRS/Thales and Université Paris Sud 11, 1 Ave. A. Fresnel, Palaiseau (France)

    2015-05-07

    Oscillation frequency of spin torque oscillator with a perpendicularly magnetized free layer and an in-plane magnetized pinned layer is theoretically investigated by taking into account the field-like torque. It is shown that the field-like torque plays an important role in finding the balance between the energy supplied by the spin torque and the dissipation due to the damping, which results in a steady precession. The validity of the developed theory is confirmed by performing numerical simulations based on the Landau-Lifshitz-Gilbert equation.

  3. Yielding Torque-Tube System Reduces Crash Injuries

    Science.gov (United States)

    Mcsmith, D. G.

    1982-01-01

    Yielding torque-tube system minimizes injuries by limiting load transferred to occupant in crash. When properly integrated into seat structure, torque tube yields in plastic deformation stage of material and maintains a relatively constant resistance to applied torque for many degrees of rotation. Yielding torque-tube system is expected to find application in aircraft and automobile industries.

  4. Influence of Closed Stator Slots on Cogging Torque

    DEFF Research Database (Denmark)

    Ion, Trifu; Leban, Krisztina Monika; Ritchie, Ewen

    2013-01-01

    Cogging torque results due interaction of magnetic field of magnets and stator slots, and have negative effects on permanent magnet machines such as vibrations, noise, torque ripples and problems during turbine start-up and cut-in. In order to reduce cogging torque this paper presents a study...... of influence of closed stator slots on cogging torque using magnetic slot wedges....

  5. Fourth-order acoustic torque in intense sound fields

    Science.gov (United States)

    Wang, T. G.; Kanber, H.; Olli, E. E.

    1978-01-01

    The observation of a fourth-order acoustic torque in intense sound fields is reported. The torque was determined by measuring the acoustically induced angular deflection of a polished cylinder suspended by a torsion fiber. This torque was measured in a sound field of amplitude greater than that in which first-order acoustic torque has been observed.

  6. Evoked EMG-based torque prediction under muscle fatigue in implanted neural stimulation

    Science.gov (United States)

    Hayashibe, Mitsuhiro; Zhang, Qin; Guiraud, David; Fattal, Charles

    2011-10-01

    In patients with complete spinal cord injury, fatigue occurs rapidly and there is no proprioceptive feedback regarding the current muscle condition. Therefore, it is essential to monitor the muscle state and assess the expected muscle response to improve the current FES system toward adaptive force/torque control in the presence of muscle fatigue. Our team implanted neural and epimysial electrodes in a complete paraplegic patient in 1999. We carried out a case study, in the specific case of implanted stimulation, in order to verify the corresponding torque prediction based on stimulus evoked EMG (eEMG) when muscle fatigue is occurring during electrical stimulation. Indeed, in implanted stimulation, the relationship between stimulation parameters and output torques is more stable than external stimulation in which the electrode location strongly affects the quality of the recruitment. Thus, the assumption that changes in the stimulation-torque relationship would be mainly due to muscle fatigue can be made reasonably. The eEMG was proved to be correlated to the generated torque during the continuous stimulation while the frequency of eEMG also decreased during fatigue. The median frequency showed a similar variation trend to the mean absolute value of eEMG. Torque prediction during fatigue-inducing tests was performed based on eEMG in model cross-validation where the model was identified using recruitment test data. The torque prediction, apart from the potentiation period, showed acceptable tracking performances that would enable us to perform adaptive closed-loop control through implanted neural stimulation in the future.

  7. Modelling of a Magnetostrictive Torque Sensor

    Directory of Open Access Journals (Sweden)

    Tsiantos Vasilios

    2016-01-01

    Full Text Available Existing magnetostrictive torque sensor designs typically measure the rotation of the saturation magnetization under an applied torque and their theoretical treatment revolves around the minimization of the free energy equation adapted according to the assumptions considered valid in each design. In the torque measurement design discussed in this paper, Ni-rich NiFe films have been electrodeposited on cylindrical austenitic steel rods. Contrary to existing designs, the excitation field is applied along the axial direction and is low enough to ensure that the resulting magnetization along the same direction remains in the linear region of the M(H characteristic. Assuming homogeneous magnetization, positive magnetostriction constant λ, negligible hysteresis and demagnetizing fields, torque T may be expressed in terms of an effective uniaxial anisotropy constant Ku around 45° to the axial direction. It is shown, that for the proposed arrangement, the resulting M is the linear superposition of the effect of a torque-induced effective field and the excitation field, the applied field accounts for the vertical offset of the magnetization response and the applied torque increases the slope of the M(H characteristic.

  8. Laser-induced torques in metallic ferromagnets

    Science.gov (United States)

    Freimuth, Frank; Blügel, Stefan; Mokrousov, Yuriy

    2016-10-01

    We study laser-induced torques in bcc Fe, hcp Co, and L 10 FePt based on first-principles electronic structure calculations and the Keldysh nonequilibrium formalism. We find that the torques have two contributions, one from the inverse Faraday effect (IFE) and one from the optical spin-transfer torque (OSTT). Depending on the ferromagnet at hand and on the quasiparticle broadening the two contributions may be of similar magnitude, or one contribution may dominate over the other. Additionally, we determine the nonequilibrium spin polarization in order to investigate its relation to the torque. We find the torques and the perpendicular component of the nonequilibrium spin polarization to be odd in the helicity of the laser light, while the spin polarization that is induced parallel to the magnetization is helicity independent. The parallel component of the nonequilibrium spin polarization is orders of magnitude larger than the perpendicular component. In the case of hcp Co we find good agreement between the calculated laser-induced torque and a recent experiment.

  9. Testing the Validity of the Neoclassical Toroidal Viscosity Model of Torque due to 3D Non-Resonant Magnetic Fields

    Science.gov (United States)

    McCubbin, A. J.; Smith, S. P.; Ferraro, N. M.; Callen, J. D.; Meneghini, O.

    2012-10-01

    Understanding the torque applied by resonant and non-resonant magnetic perturbations and its effect on rotation is essential to predict confinement and stability in burning plasmas. Non-axisymmetric 3D fields produced in the DIII-D tokamak apply a torque to the plasma, which can be evaluated through its effect on the plasma rotation. One explanation for this torque is Neoclassical Toroidal Viscosity (NTV) acting through non-resonant field components [1]. We have developed a software framework in which magnetic perturbations calculated by the state of the art two fluid MHD code M3D-C1 can be used in NTV calculations. For discharges with applied external magnetic fields in DIII-D, the experimentally determined torques will be analyzed and compared with NTV models.[4pt] [1] J.D. Callen, Nucl. Fusion 51, 094026 (2011).

  10. Direct Torque Control of a Small Wind Turbine with a Sliding-Mode Speed Controller

    Science.gov (United States)

    Sri Lal Senanayaka, Jagath; Karimi, Hamid Reza; Robbersmyr, Kjell G.

    2016-09-01

    In this paper. the method of direct torque control in the presence of a sliding-mode speed controller is proposed for a small wind turbine being used in water heating applications. This concept and control system design can be expanded to grid connected or off-grid applications. Direct torque control of electrical machines has shown several advantages including very fast dynamics torque control over field-oriented control. Moreover. the torque and flux controllers in the direct torque control algorithms are based on hvsteretic controllers which are nonlinear. In the presence of a sliding-mode speed control. a nonlinear control system can be constructed which is matched for AC/DC conversion of the converter that gives fast responses with low overshoots. The main control objectives of the proposed small wind turbine can be maximum power point tracking and soft-stall power control. This small wind turbine consists of permanent magnet synchronous generator and external wind speed. and rotor speed measurements are not required for the system. However. a sensor is needed to detect the rated wind speed overpass events to activate proper speed references for the wind turbine. Based on the low-cost design requirement of small wind turbines. an available wind speed sensor can be modified. or a new sensor can be designed to get the required measurement. The simulation results will be provided to illustrate the excellent performance of the closed-loop control system in entire wind speed range (4-25 m/s).

  11. Driving torque reduction in linkage mechanisms using joint compliance for robot head

    Science.gov (United States)

    Zhong, Chunhao; Yang, Xiaojun

    2015-09-01

    The conventional linkage mechanisms with compliant joint have been widely studied and implemented for increasing the adaptability of the mechanism to external contacts. However, the analysis of how compliant joints in linkage mechanism can reduce the energy consumption isn't still studied deeply. In a mobile service robot head, the actions of blinking the eyes and moving the eyeballs are realized by the planar linkage mechanism respectively. Therefore, minimizing the driving torques through motion trajectories for the linkage mechanism, which will be beneficial to extend the working time for mobile service robots. The dynamic modeling of the linkage mechanism with springs-loaded compliant joint is established. An optimization procedure for obtaining the optimal parameters of springs is proposed for minimizing the max value of driving torques within a range of desired operating conditions. The Simulations prove that the linkage mechanism with compliant joints can effectively reduce the driving torques, and reduce the energy consumption consequently. The framework can also be applied in other similar applications to reduce the driving torque and save energy. Compared with previous efforts, this is the first attempt that the linkage mechanism with complaint joint is applied in the robot head for reducing the driving torque.

  12. Dynamical corotation torques on low-mass planets

    CERN Document Server

    Paardekooper, Sijme-Jan

    2014-01-01

    We study torques on migrating low-mass planets in locally isothermal discs. Previous work on low-mass planets generally kept the planet on a fixed orbit, after which the torque on the planet was measured. In addition to these static torques, when the planet is allowed to migrate it experiences dynamical torques, which are proportional to the migration rate and whose sign depends on the background vortensity gradient. We show that in discs a few times more massive than the Minimum Mass Solar Nebula, these dynamical torques can have a profound impact on planet migration. Inward migration can be slowed down significantly, and if static torques lead to outward migration, dynamical torques can take over, taking the planet beyond zero-torque lines set by saturation of the corotation torque in a runaway fashion. This means the region in non-isothermal discs where outward migration is possible can be larger than what would be concluded from static torques alone.

  13. Validation of dynamic torque response of an electrorheological (ER) clutch

    Science.gov (United States)

    Tan, K. P.; Stanway, R.; Bullough, W. A.

    2006-02-01

    It is now well established that using actuators, which have faster speeds of response than d.c. servomotors, can solve the positional errors of the robot arms. One of the possible robotic actuators can be an electro-rheological (ER) clutch. To justify this objective, the authors measured the output torque response of a co-axial ER clutch. However, due to the dynamic inefficiency of a torque transducer, the measured torque response is inaccurate for analytical studies. Therefore, this measured torque is signal processed by using the transfer functions of this torque sensor and a filter to yield the ER torque response. The validity of this ER torque is investigated by comparing the numerical errors between the measured torque and its inverse torque response. From the torque error analysis, it is concluded that the ER clutch can be an actuator to improve the positioning accuracies of the robot arms.

  14. Biomechanical analysis of fracture fixation with external fixator in vivo

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: To investigate the different ways of measuring the main axial strain during treatment with an external fixator and to find the suitable compression loaded by the external fixator at an early stage.Methods: Eighteen healthy big-ear rabbits were randomly divided into two groups according to different measuring methods: Group A and Group B. In Group A,a strain gauge was affixed to the external tibial cortex with 502 glue, and in Group B, a bone cement-coated strain gauge was installed on the internal tibial cortex. Groups A and B were divided into two subgroups A1, A2 and B1,B2, respectively, according to the pressure of half of and the same as the body weight. A Z-shaped left mid-shaft tibial osteotomy was performed and fixed by an external fixator. Results: The scaler curves of Group A changed dramatically during the early stage. The trendlines of the internal and external cortex went consistently after reaching the stable stage while the latter strain value was higher than the former. The time for Group B reaching the stable stage was short, but its absolute strain value was less than that of Group A. Before they were pressed to the stable stage, the declined speed of Subgroup A1 was more slowly than that of Subgroup A2 while the results of Subgroups B1 and B2 were same. Group A had an ascending trend after it declined while Group B didn't have. After they reached the stable stage, both Subgroups A1 and A2 had a declining trend while Subgroup A2 was more quickly than Subgroup Al, Subgroup B1 was kept at a definite level while Subgroup B2 fluctuated.Conclusions: The axial strain under external fixator can be measured by bone cement coated-strain gauge in vivo. The data may suggest that half of the body weight load was suitable for external fixator.

  15. Distal tibial fractures are a poorly recognised complication with fibula free flaps.

    Science.gov (United States)

    Durst, A; Clibbon, J; Davis, B

    2015-09-01

    The fibula free flap is ideal for complex jaw reconstructions, with low reported donor and flap morbidity. We discuss a distal tibial stress fracture two months following a vascularised fibula free flap procedure. Despite being an unrecognised complication, a literature review produced 13 previous cases; only two were reported in the reconstructive surgery literature, with the most recent claiming to be the first. The majority of these studies treated this fracture non-operatively; none reported their patient follow-up. Each case presented with ipsilateral leg pain, which has been cited as an early donor site morbidity in as many as 40% of fibula free flap cases. It is known that the fibula absorbs at least 15% of leg load on weight bearing. Studies have shown severe valgus deformities in up to 25% of patients with fibulectomies. We treated our patient operatively, first correcting his worsening valgus deformity with an external fixator, then reinforcing his healed fracture with a long distal tibial plate. We believe that this complication is underreported, unexpected and not mentioned during the consenting process. By highlighting the management of our case and the literature, we aim to increase awareness (and thus further reporting and appropriate management) of this debilitating complication.

  16. Cogging torque reduction for interior permanent magnet synchronous motors

    OpenAIRE

    Tost Candel, Miquel

    2015-01-01

    Interior permanent magnet synchronous machines show a good range of behaviours, which make these kinds of machines good candidates for an electromechanical energy conversion. However, in order to improve their accuracy in their torque responses, the cogging torque and torque ripple phenomena should be mitigated to obtain better performance of the machine. In order to reduce the cogging torque and torque ripple, control techniques as well as geometric parameters of the machine have to be im...

  17. Potentiation increases peak twitch torque by enhancing rates of torque development and relaxation.

    Science.gov (United States)

    Froyd, Christian; Beltrami, Fernando Gabe; Jensen, Jørgen; Noakes, Timothy David

    2013-01-01

    The aim of this study was to measure the extent to which potentiation changes in response to an isometric maximal voluntary contraction. Eleven physically active subjects participated in two separate studies. Single stimulus of electrical stimulation of the femoral nerve was used to measure torque at rest in unpotentiated quadriceps muscles (study 1 and 2), and potentiated quadriceps muscles torque in a 10 min period after a 5 s isometric maximal voluntary contraction of the quadriceps muscles (study 1). Additionally, potentiated quadriceps muscles torque was measured every min after a further 10 maximal voluntary contractions repeated every min (study 2). Electrical stimulation repeated several times without previous maximal voluntary contraction showed similar peak twitch torque. Peak twitch torque 4 s after a 5 s maximal voluntary contraction increased by 45±13% (study 1) and by 56±10% (study 2), the rate of torque development by 53±13% and 82±29%, and the rate of relaxation by 50±17% and 59±22%, respectively, but potentiation was lost already two min after a 5 s maximal voluntary contraction. There was a tendency for peak twitch torque to increase for the first five repeated maximal voluntary contractions, suggesting increased potentiation with additional maximal voluntary contractions. Correlations for peak twitch torque vs the rate of torque development and for the rate of relaxation were r(2)= 0.94 and r(2)=0.97. The correlation between peak twitch torque, the rate of torque development and the rate of relaxation suggests that potentiation is due to instantaneous changes in skeletal muscle contractility and relaxation.

  18. Comparative study of the results of compound tibial shaft fractures treated by Ilizarov ring fixators and limb reconstruction system fixators

    Institute of Scientific and Technical Information of China (English)

    Chandra Prakash Pal; Harish Kumar; Deepak Kumar; K.S.Dinkar; Vivek Mittal; Naveen Kumar Singh

    2015-01-01

    Purpose: Ilizarov ring fixator and limb reconstruction system (LRS) fixators have been used in the management of complex tibial fractures with severe soft tissue injuries, compound tibial fractures, and infected tibial nonunion for which conventional internal fixation cannot be contemplated.Fracture union and distraction osteogenesis can be done simultaneously with these external fixators, allowing early weight bearing.Several previous studies have shown almost equal results of rail and ring fixators for the compound tibial shaft fractures.Thus we performed a prospective study to evaluate the union rate, functional outcome and amount of limb lengthening after the treatment of compound tibial shaft fractures with or without infected nonunion by ring or LRS fixators.Methods: This prospective study was done at Sarojini Naidu Medical College and Hospital, Agra, India and included 32 patients of compound tibial shaft fractures with or without infected nonunion.There were 26 males and 6 females and the average age was 40 years.Patients were randomly divided into two groups (n =16 for each): one underwent Ilizarov fixation and the other received LRS fixation.Cases were followed up for 3-24 months, 6 months on average from September 2012 to October 2014.Functional and radiological outcomes were assessed using the Association for the Study and Application of Methods of Ilizarov (ASAMI) criteria for both rail and ring fixators.Results: Union was achieved in all cases.Radiological outcome was found excellent in 68.75%, good in 18.75% and fair in 12.50% of cases treated by rail fixators whereas it was excellent in 56.25%, good in 18.75%, fair in 12.50% and poor in 12.50% of cases treated by ring fixators.Functional result was satisfactory in 75.00% of cases treated by rail fixator and 68.75% of cases treated by ring fixators whereas the corresponding rate of unsatisfactory was 25.00% vs.31.25%.Conclusion: In our short-term assessment, LRS fixators show a

  19. Treatment of open tibial fracture with bone defect caused by high velocity missiles: a case report.

    Science.gov (United States)

    Golubović, Zoran; Vukajinović, Zoran; Stojiljković, Predrag; Golubović, Ivan; Visnjić, Aleksandar; Radovanović, Zoran; Najman, Stevo

    2013-01-01

    Tibia fracture caused by high velocity missiles is mostly comminuted and followed by bone defect which makes their healing process extremely difficult and prone to numerous complications. A 34-year-old male was wounded at close range by a semi-automatic gun missile. He was wounded in the distal area of the left tibia and suffered a massive defect of the bone and soft tissue. After the primary treatment of the wound, the fracture was stabilized with an external fixator type Mitkovic, with convergent orientation of the pins. The wound in the medial region of the tibia was closed with the secondary stitch, whereas the wound in the lateral area was closed with the skin transplant after Thiersch. Due to massive bone defect in the area of the rifle-missile wound six months after injury, a medical team placed a reconstructive external skeletal fixator type Mitkovic and performed corticotomy in the proximal metaphyseal area of the tibia. By the method of bone transport (distractive osteogenesis), the bone defect of the tibia was replaced. After the fracture healing seven months from the secondary surgery, the fixator was removed and the patient was referred to physical therapy. Surgical treatment of wounds, external fixation, performing necessary debridement, adequate antibiotic treatment and soft and bone tissue reconstruction are essential in achieving good results in patients with the open tibial fracture with bone defect caused by high velocity missiles. Reconstruction of bone defect can be successfully treated by reconstructive external fixator Mitkovic.

  20. Reconstrucción tibial: transferencia sóleo-peroné ipsilateral. Tibialización peroneal Tibial reconstruction: ipsilateral soleus-fibula transfer. Fibular tibialization

    Directory of Open Access Journals (Sweden)

    E. Revelo Jiron

    2009-12-01

    Full Text Available Las transferencias óseas peroneales en forma libre o ipsilateral han sido propuestas para la reconstrucción de grandes defectos tibiales. Están también descritas varias modificaciones al respecto, siendo una de ellas la constitución de un colgajo compuesto soleo-peroné realizado como transferencia libre. En este estudio presentamos nuestra experiencia con esta variante, pero en forma ipsilateral. logrando la reconstrucción del defecto tibial por medio de la tibialización peroneal. Escogimos realizar un colgajo compuesto soleo-peroné ipsilateral a flujo anterógrado o retrogrado para la reconstrucción de una serie personal de 14 pacientes consecutivos, 13 hombre y 1 mujer, con edad media de 30 años, y con amplios defectos tibiales y de tejidos blandos causados por accidentes de transito en 12 casos, 1 por proyectil balístico y 1 por artefacto explosivo artesanal. El promedio de tamaño del defecto tibial fue de 9.4 cm. Elegimos la forma ipsilateral por no disponer de infraestructura adecuada para realizar una transferencia libre. La serie de estudio se realizó durante el periodo comprendido entre Abril de 1995 y Abril del 2005. Todos los colgajos sobrevivieron. Dos pacientes desarrollaron pseudoartrosis. El apoyo completo y la marcha en 12 pacientes, se logró en un periodo promedio de 9 meses. El seguimiento postoperatorio ha sido de 3 a 6 años. Doce pacientes se han incorporado a la vida activa. Discutimos algunos aspectos prácticos de la técnica como resultado de la experiencia quirúrgica obtenida de esta serie personal. Consideramos que el método es fiable, fácil de realizar y proporciona excelentes resultados.Fibular flaps such as in there free form or as ipsilateral transfers have been proposed for reconstruction of large tibial defects. Several modifications have been described for the use of this flap. In this study we will present our experience using the ipsilateral transfer of an osteomuscular soleous fibular flap

  1. Alternative method for direct measurement of tibial slope

    Directory of Open Access Journals (Sweden)

    Stijak Lazar

    2014-01-01

    Full Text Available Background/Aim. The tibial slope is one of the most frequently cited anatomical causes of anterior cruciate ligament trauma. The aim of this study was to determine the possibility of direct measuring of the tibial slope of the knee without prior soft tissue dissection in cadavers. Methods. Measurement was performed on the two groups of samples: osteological and cadaveric. The osteological group consisted of 102 matured tibiae and measurement was performed: indirectly by sagittal photographing of the tibia, and directly by a set of parallel bars. The cadaveric group consisted of 50 cadaveric knees and measurement was performed directly by a set of parallel bars. The difference and correlation between indirect and the direct measurements were observed, which included also measuring of the difference and correlation of the tibial slope on the medial and lateral condyles. Results. A statistically significant difference between the direct and indirect method of measuring (p 0.05. However, the slope on the medial condyle, as well as indirect measurement showed a statistically significant difference (p < 0.01. Conclusion. By the use of a set of parallel bars it is possible to measure the tibial slope directly without removal of the soft tissue. The results of indirect, photographic measurement did not statistically differ from the results of direct measurement of the tibial slope.

  2. Spontaneous collapse of the tibial plateau: radiological staging

    Energy Technology Data Exchange (ETDEWEB)

    Carpintero, P.; Leon, F.; Zafra, M. [University Hospital ' ' Reina Sofia' ' , Orthopaedic Department, Cordoba (Spain); Montero, R.; Carreto, A. [University Hospital ' ' Reina Sofia' ' , Radiology Department, Cordoba (Spain)

    2005-07-01

    This paper proposes a radiological staging system for necrosis of the tibial plateau, similar to those already developed for the hip and the medial femoral condyle. We retrospectively studied the clinical case histories and radiographic findings of 14 patients (15 affected knees) with histologically proven osteonecrosis of the tibial plateau. Stage I was marked by normal radiograph, but increased uptake in bone scan and subchondral areas of abnormal marrow signal intensity in magnetic resonance imaging (MRI), as reported in other osteonecrosis sites. Stage II was characterised by cystic and sclerotic changes, and stage III fracture of the medial rim of the medial tibial plateau and tibial plateau collapse were present. Stage IV was marked by joint narrowing. These changes appeared earlier and were more pronounced when there was genu varum/valgum or involvement of the lateral tibial plateau. The radiological evolution of the disease appears to follow a four-stage course over a period of roughly one year from the onset of symptoms. (orig.)

  3. Tacón de torque. Análisis tensional y deformacional utilizando el Método de Elementos Finitos.

    Directory of Open Access Journals (Sweden)

    R. A. González Carbonell

    2007-05-01

    Full Text Available En este trabajo se aborda la problemática del tratamiento en menores que presentan torsión tibial y la necesidad de un dispositivo ortopédico para su corrección. En particular, se presentan los elementos necesarios para el diseño de un tacón de torque. Se estudiaron los fenómenos no lineales presentes en el diseño mecánico de piezas que no cumplen con la ley de Hooke, específicamente para materiales hiperelásticos. El modelo de las cargas que actúan sobre el tacón de torque fue definido teniendo en cuenta la acción dinámica de las cargas producto de la marcha. Para realizar los cálculos de tensiones y visualizar las deformaciones durante su funcionamiento se utilizó el Método de los Elementos Finitos. Finalmente con los resultados obtenidos fue propuesto un diseño del tacón de torque.In this work a problem of treatment of the internal tibia torsion and the necessity of an orthopedic device were studied. The needed knowledge for design the torque heel was mentioned. The study of non lineal phenomena in mechanical design of elastomers was carried out. The load model of the torque heels was defined taken into account the action of dynamic loads. The Stress and Strain of the torque heel were obtained using the Finite Elements Method. Finally, the results were analyzed and the definitive design of the torque heel was obtained.

  4. A Method to Accurately Estimate the Muscular Torques of Human Wearing Exoskeletons by Torque Sensors

    Directory of Open Access Journals (Sweden)

    Beomsoo Hwang

    2015-04-01

    Full Text Available In exoskeletal robots, the quantification of the user’s muscular effort is important to recognize the user’s motion intentions and evaluate motor abilities. In this paper, we attempt to estimate users’ muscular efforts accurately using joint torque sensor which contains the measurements of dynamic effect of human body such as the inertial, Coriolis, and gravitational torques as well as torque by active muscular effort. It is important to extract the dynamic effects of the user’s limb accurately from the measured torque. The user’s limb dynamics are formulated and a convenient method of identifying user-specific parameters is suggested for estimating the user’s muscular torque in robotic exoskeletons. Experiments were carried out on a wheelchair-integrated lower limb exoskeleton, EXOwheel, which was equipped with torque sensors in the hip and knee joints. The proposed methods were evaluated by 10 healthy participants during body weight-supported gait training. The experimental results show that the torque sensors are to estimate the muscular torque accurately in cases of relaxed and activated muscle conditions.

  5. Decoupled Speed and Torque Control of IPMSM Drives Using a Novel Load Torque Estimator

    Directory of Open Access Journals (Sweden)

    ZAKY, M.

    2017-08-01

    Full Text Available This paper proposes decoupled speed and torque control of interior permanent magnet synchronous motor (IPMSM drives using a novel load torque estimator (LTE. The proposed LTE is applied for computing a load torque and yielding a feed-forward value in the speed controller to separate the torque control from the speed control. Indirect flux weakening using direct current component is obtained for high speed operation of the IPMSM drive, and its value for maximum torque per ampere (MTPA control in constant torque region is also used. LTE uses values of direct and quadrature currents to improve the behavior of the speed controller under the reference tracking and torque disturbances. The complete IPMSM drive by Matlab/Simulink is built. The effectiveness of the proposed control scheme using an experimental setup of the complete drive system implemented on a DSP-DS1102 control board is confirmed. Extensive results over a wide speed range are verified. The efficacy of the proposed method is confirmed in comparison to a conventional PI controller under both the reference speed tracking and load torque disturbance.

  6. A Method to Accurately Estimate the Muscular Torques of Human Wearing Exoskeletons by Torque Sensors

    Science.gov (United States)

    Hwang, Beomsoo; Jeon, Doyoung

    2015-01-01

    In exoskeletal robots, the quantification of the user’s muscular effort is important to recognize the user’s motion intentions and evaluate motor abilities. In this paper, we attempt to estimate users’ muscular efforts accurately using joint torque sensor which contains the measurements of dynamic effect of human body such as the inertial, Coriolis, and gravitational torques as well as torque by active muscular effort. It is important to extract the dynamic effects of the user’s limb accurately from the measured torque. The user’s limb dynamics are formulated and a convenient method of identifying user-specific parameters is suggested for estimating the user’s muscular torque in robotic exoskeletons. Experiments were carried out on a wheelchair-integrated lower limb exoskeleton, EXOwheel, which was equipped with torque sensors in the hip and knee joints. The proposed methods were evaluated by 10 healthy participants during body weight-supported gait training. The experimental results show that the torque sensors are to estimate the muscular torque accurately in cases of relaxed and activated muscle conditions. PMID:25860074

  7. Forces and torques on rigid inclusions in an elastic environment: resulting matrix-mediated interactions, displacements, and rotations

    CERN Document Server

    Puljiz, Mate

    2016-01-01

    Embedding rigid inclusions into elastic matrix materials is a procedure of high practical relevance, for instance for the fabrication of elastic composite materials. We theoretically analyze the following situation. Rigid spherical inclusions are enclosed by a homogeneous elastic medium under stick boundary conditions. Forces and torques are directly imposed from outside onto the inclusions, or are externally induced between them. The inclusions respond to these forces and torques by translations and rotations against the surrounding elastic matrix. This leads to elastic matrix deformations, and in turn results in mutual long-ranged matrix-mediated interactions between the inclusions. Adapting a well-known approach from low-Reynolds-number hydrodynamics, we explicitly calculate the displacements and rotations of the inclusions from the externally imposed or induced forces and torques. Analytical expressions are presented as a function of the inclusion configuration in terms of displaceability and rotateabilit...

  8. Magnetization reversal in ferromagnetic thin films induced by spin-orbit interaction with Slonczewski-like spin transfer torque

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jia, E-mail: lijia@wipm.ac.cn [State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China)

    2014-10-07

    We theoretically investigate the dynamics of magnetization in ferromagnetic thin films induced by spin-orbit interaction with Slonczewski-like spin transfer torque. We reproduce the experimental results of perpendicular magnetic anisotropy films by micromagnetic simulation. Due to the spin-orbit interaction, the magnetization can be switched by changing the direction of the current with the assistant of magnetic field. By increasing the current amplitude, wider range of switching events can be achieved. Time evolution of magnetization has provided us a clear view of the process, and explained the role of minimum external field. Slonczewski-like spin transfer torque modifies the magnetization when current is present. The magnitude of the minimum external field is determined by the strength of the Slonczewski-like spin transfer torque. The investigations may provide potential applications in magnetic memories.

  9. Is device-assisted reduction prior to semi-extended intramedullary nailing of distal tibial fractures necessary?

    Science.gov (United States)

    Mehta, Nisarg; Selvaratnam, Veenesh; Giotakis, Nikolaos; Narayan, Badri

    2017-02-01

    Traditional methods of nailing distal tibial fractures have an unacceptable risk of mal-alignment due to difficulty in obtaining and maintaining reduction intra-operatively. Methods to obtain and maintain reduction when nailing these fractures, and therefore reducing the risk of Mal-alignment include modified external fixators, distractors and commercial reduction tools. Semi-extended intramedullary nailing of distal tibial fractures via a supra-patellar approach is now being used more commonly. The aim of this study was to assess whether a commercial reduction device (Staffordshire Orthopaedic Reduction Machine - STORM, Intelligent Orthopaedics, Stafffordshire, UK) is necessary to reduce the risk of mal-alignment in patients undergoing semi-extended nailing for distal tibial fractures. A case-control study was conducted in 20 patients who had STORM-assisted reduction of distal tibial fractures prior to intramedullary nailing and 20 controls without STORM. The control group was matched for age, sex, fracture type (AO/OTA), ASA and gender. All patients had an intramedullary nail (IMN) using the semi-extended system. Primary outcome measures were coronal and sagittal mal-alignment. Secondary outcome measure was unplanned return to theatre for complications and problems with fracture healing. There was no difference in post-operative mal-alignment in both groups. There was no significant difference in time to union in both groups Both groups had equal number of patients requiring unplanned return to theatre. The STORM group was associated with a significantly increased operative time [p=0.007, 130.3min (SD 49.4) STORM vs 95.6 mins (SD 22.9) Control]. Intraoperative use of STORM significantly increases operative time with no difference in outcome. The superior orthogonal views and manual control obtained during semi-extended nailing via a supra-patellar approach obviate the need for additional methods: of intraoperative reduction for this fracture group. Copyright

  10. Dual Control of Giant Field-like Spin Torque in Spin Filter Tunnel Junctions

    Science.gov (United States)

    Tang, Y.-H.; Chu, F.-C.; Kioussis, Nicholas

    2015-06-01

    We predict a giant field-like spin torque, , in spin-filter (SF) barrier tunnel junctions in sharp contrast to existing junctions based on nonmagnetic passive barriers. We demonstrate that has linear bias behavior, is independent of the SF thickness, and has odd parity with respect to the SF’s exchange splitting. Thus, it can be selectively controlled via external bias or external magnetic field which gives rise to sign reversal of via magnetic field switching. The underlying mechanism is the interlayer exchange coupling between the noncollinear magnetizations of the SF and free ferromagnetic electrode via the nonmagnetic insulating (I) spacer giving rise to giant spin-dependent reflection at the SF/I interface. These findings suggest that the proposed field-like-spin-torque MRAM may provide promising dual functionalities for both ‘reading’ and ‘writing’ processes which require lower critical current densities and faster writing and reading speeds.

  11. Wireless control and selection of forces and torques - towards wireless engines

    Science.gov (United States)

    Boyvat, M.; Hafner, C.; Leuthold, J.

    2014-07-01

    Powering and manipulating translational and rotational motions of objects wirelessly, and controlling several objects independently is of significant importance in numerous fields such as robotics, medicine, biology, fluid dynamics, optics. We propose a method based on coupled LC resonators, to control objects selectively by steering the frequency of an external magnetic field. This concept does not need any magnetic materials and it brings a rich variety of features concerning forces and torques. We theoretically and experimentally show that the forces can be enhanced by the interaction of resonators and that both direction and magnitude of forces can be controlled by the frequency of the applied external magnetic field. Moreover, we demonstrate interesting rotational effects, such as bi-directionally controllable torques, controllable stable orientations, and spinning, which leads to a wirelessly powered motor.

  12. Design, Implementation and Evaluation of a Torque Transducer with Ability of Real-time Torque Monitoring

    Directory of Open Access Journals (Sweden)

    A Zeinali

    2014-04-01

    Full Text Available Torque, speed, and power as mechanical variables are associated with the functional performance of any rotating machinery. The real-time performance and the efficiency of a machine can be determined with on-line measurement of these parameters. In this investigation a rotary torque meter (transducer was constructed from strain gauge sensors for measuring the torque of rotating shafts. The system converts the torque of rotating shaft into voltage signals, based on the principle of strain gauge resistance. The signals are then amplified and converted into digital signals. These digital signals are sent to a RF receiver circuit for displaying and storage. Results of static calibration and a series of dynamic tests confirmed a satisfactory operation of the designed apparatus in various conditions. Also, the torque measuring range, resolution and the accuracy were from 3 to 700 N m, 3 N m and 1%, respectively.

  13. Improved Torque Control Performance of Direct Torque Control for 5-Phase Induction Machine

    Directory of Open Access Journals (Sweden)

    Logan Raj Lourdes Victor Raj

    2013-12-01

    Full Text Available In this paper, the control of five-phase induction machine using Direct Torque Control (DTC is presented. The general D-Q model of five-phase induction machine is discussed. The de-coupled control of stator flux and electromagnetic torque based on hysteresis controller similar to conventional DTC is applied to maintain the simplicity of the system. Three sets of look-up tables consist of voltage vectors with different amplitude that selects the  most optimal voltage vectors according motor operation condition is proposed. This provides excellent torque dynamic control, reduces torque ripple, lower switching frequency (high efficiency and extension of constant torque. Simulation results validate the improvement achieved.

  14. Prevailing Torque Locking Feature Wear-out

    Science.gov (United States)

    Zimandy, Adam J. C.

    This thesis provides much needed representative sample data for reuse life of fully seated and torqued locknuts. Most national requirements for prevailing torque locking fasteners only specify unseated reuse life. This could create a potentially dangerous situation if unseated is misinterpreted for seated. This thesis provides comparative data for seated verses unseated configuration. Six aerospace, 3 all-metal and 3 nylon insert, and one non-aerospace locknuts were tested at preloads levels of unseated, 66%, 75%, and 85% of yield of bolt. The locknuts tested are MS21043-4, NAS1291-4, NAS1805-4, MS17825-4, MS21044D4, NAS1021N4, and Grade 8. A fixture was created in order to allow for the simultaneous data collection of the applied preload and torque, along with the removal of preload without loosening the locknut. The results from testing indicate the number of reuse cycles is greater for nylon locknuts than the all-metal locknuts. Large losses, on the order of 20-50%, in prevailing torque occur between the first and second cycle of each locknut under all preloads. Tightening Torque required to achieve a certain preload was found to increase with reuse. Application of lubrication to nylon locknuts had a significant effect, reducing the reuse life and prevailing torque performance. The testing indicated the effect of preload reduced the number of reuse cycles to failure, failure occurs when the prevailing torque is measured outside the range of 3.5 to 30 in-lb. All locknuts survived unseated and 66% Y preload testing, except MS21043 which lasted about 14.5 reuse cycles at 66% Y and NAS1805 which survived 8 reuse cycles for unseated and 12.67 reuse cycles at 66% Y. NAS1805's loss of reuse life is due to hardness and material compatibility issues. The scatter of the torque measurements was low for the first three to five cycles, then as the coatings and lubrications are worn the scatter increases. The data collected from testing agrees with the torque friction

  15. In vitro comparison of tibial plateau leveling osteotomy with and without use of a tibial plateau leveling jig.

    Science.gov (United States)

    Schmerbach, Kay Ingo; Boeltzig, Christian Konrad Matthias; Reif, Ullrich; Wieser, Jan Carsten; Keller, Thomas; Grevel, Vera

    2007-02-01

    To evaluate the influence of a tibial plateau leveling jig on osteotomy orientation, fragment reduction, and postoperative tibial plateau angle (TPA) during tibial plateau leveling osteotomy (TPLO). In vitro experimental study. Large-breed canine cadavers (n=20). TPLO was performed on 40 hindlimbs using 4 methods. Group 1: Jig; dogs in dorsal recumbency with the osteotomy parallel to the distal jig pin. Groups 2-4: No jig; dogs in lateral recumbency with the osteotomy in a vertical orientation (group 2: tibia parallel to the table top; group 3: controlled superimposition of the femoral condyles; group 4: internal rotation of the tibia). Postoperative TPA, fragment reduction, and osteotomy orientation relative to the tibial plateau were compared. Positive or negative values denoted deviation from parallel relative to the tibial plateau. Postoperative TPA, fragment reduction, and proximodistal osteotomy orientation were not significantly different between groups. Craniocaudal osteotomy orientation was significantly different (Ptable surface. TPLO without use of a jig reduces surgical trauma, is less time consuming, and reduces cost.

  16. [Anatomical quantification of the tibial part of the plantar aponeurosis].

    Science.gov (United States)

    Hiramoto, Y

    1983-03-01

    The metrical analysis of the anatomical characteristics is important because of its objectiveness. As it is concerned with the organs belonging to the locomotor system, the metrical method of the bones has already been systematized by Martin (1928), whereas the same kind of method for use on other organs remains undeveloped. The author aims to establish the metrical method of the plantar aponeurosis. The method for measuring the tibial part of the aponeurosis developed in this paper is sufficiently applicable for obtaining its principal anatomical characteristics. The results show that the tibial portion of the plantar aponeurosis becomes statistically significantly wider and thinner in its anterior part, and that the thickness of the tibial portion of the aponeurosis in the anterior part is larger on the right side than on the left side.

  17. Smooth torque speed characteristic of switched reluctance motors

    DEFF Research Database (Denmark)

    Zeng, Hui; Chen, Zhe; Chen, Hao

    2014-01-01

    of the constraints of the supply voltage and peak current. Based on previous work that sought to expand the STO range, a scheme is developed in this study to determine the maximum smooth torque range at each speed. The relationship between the maximum smooth torque and speed is defined as the smooth torque speed......The torque ripple of switched reluctance motors (SRMs) is the main disadvantage that limits the industrial application of these motors. Although several methods for smooth-toque operation (STO) have been proposed, STO works well only within a certain torque and speed range because...... characteristics (STSC), a concept similar to torque speed characteristics (TSC). STSC can be utilized to evaluate torque utilization by comparing it with TSC. Thus, the concept benefits the special design of SRMs, especially for the generation of smooth torque. Furthermore, the torque sharing function (TSF...

  18. TIBIAL PLATEAU FRACTURES – SURGICAL MANAGEMENT BY MIPPO

    Directory of Open Access Journals (Sweden)

    Bharath Raju

    2014-06-01

    Full Text Available BACKGROUND AND OBJECTIVES: Tibial plateau fractures are one of the most common intra-articular fractures. They are the outcome of indirect coronal or direct compressive forces. The incidence of tibial plateau fractures is 1.3% of all fractures. These fractures have varied degree of fracture configuration involving medial, lateral or both tibial plateaus with varied degree of intra-articular depressions and displacements. Due to speedy vehicles and mechanization there has been increase in the number of tibial plateau fractures. Knee joints being one of the major weight bearing joints of human body, these fractures are of big importance. METHODS: We studied 30 cases of tibial plateau fractures treated by MIPPO at kempegowda institute of medical sciences from June 2012 to April 2014 with minimum follow up of up to 6months. RESULTS: All the selected patients were evaluated both clinically as well as radiologically. The lab investigations were done and then they were taken up for the surgery. The fractures were classified as per schatzker’s classification and treated accordingly. In the post-op period early range of movements were started and the patients were non weight bearing till 6 weeks. Till 12 weeks partial weight bearing was allowed and full weight bearing was allowed after radiological union of the fracture. CONCLUSION: Tibial plateau fractures when treated with MIPPO give articular anatomical reduction, rigid fixation and early mobolisation of the knee joint. This prevents development of osteoarthritis and includes all the advantages of minimally invasive procedure and so better patient compliance.

  19. Emergency department external fixation for provisional treatment of pilon and unstable ankle fractures

    Directory of Open Access Journals (Sweden)

    Craig R Lareau

    2015-01-01

    Full Text Available Unstable ankle fractures and impacted tibial pilon fractures often benefit from provisional external fixation as a temporizing measure prior to definitive fixation. Benefits of external fixation include improved articular alignment, decreased articular impaction, and soft tissue rest. Uniplanar external fixator placement in the Emergency Department (ED ex-fix is a reliable and safe technique for achieving ankle reduction and stability while awaiting definitive fixation. This procedure involves placing transverse proximal tibial and calcaneal traction pins and connecting the pins with two external fixator rods. This technique is particularly useful in austere environments or when the operating room is not immediately available. Additionally, this bedside intervention prevents the patient from requiring general anesthesia and may be a cost-effective strategy for decreasing valuable operating time. The ED ex-fix is an especially valuable procedure in busy trauma centers and during mass casualty events, in which resources may be limited.

  20. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  1. Tacón de torque. Análisis tensional y deformacional utilizando el Método de Elementos Finitos.

    OpenAIRE

    R. A. González Carbonell; E. Álvarez García; Y. Campos Pérez

    2007-01-01

    En este trabajo se aborda la problemática del tratamiento en menores que presentan torsión tibial y la necesidad de un dispositivo ortopédico para su corrección. En particular, se presentan los elementos necesarios para el diseño de un tacón de torque. Se estudiaron los fenómenos no lineales presentes en el diseño mecánico de piezas que no cumplen con la ley de Hooke, específicamente para materiales hiperelásticos. El modelo de las cargas que actúan sobre el tacón de torque fue definido tenie...

  2. Reconstruction of compound tibial and soft tissue loss using a traction histogenesis technique.

    Science.gov (United States)

    Lenoble, E; Lewertowski, J M; Goutallier, D

    1995-08-01

    We used simultaneous bone and soft tissue transport for reconstruction of large compound tissue loss in the lower leg. We report the results and complications of a 12-patient series. The average age of the patients was 31.2 years (range 20 to 48 years). Seven patients had grade IIIB open tibial fractures, three had complications after grade II or IIIA, and two had an en-bloc resection of bone, muscle, and skin for a malignant bone tumor. Arteriography was routinely performed, and demonstrated at least one patent tibial artery. Every patient had normal sensibility of the sole. The first stage of the reconstruction was an aggressive excision of the all necrotic skin, muscle, and bone. The Ilizarov external fixator was applied and wires were secured under a tension of 100 kg, using a dynamometric tensioner. Cutaneous tissue loss was not replaced in 10 patients, when the bone was not exposed. A medial gastrocnemius flap was performed in two patients and lengthened with the bone. Corticotomy was performed 15 days after the first stage with careful respect for the periosteum. Distraction was initiated 15 days after the corticotomy. The average bone defect was 12.5 cm after initial excision. An average of 9 operative procedures and 18 months of treatment were required before bony union. The mean duration of bone transport was 6.5 months, and the mean duration of external fixation was 12 months. The final functional results were fair and only two patients returned to work. One patient had a below-knee amputation after 10 months of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Multidirectional Tibial Tubercle Transfer Technique: Rationale and Biomechanical Investigation.

    Science.gov (United States)

    Sarin, Vineet K; Camisa, William; Leasure, Jeremi M; Merchant, Alan C

    This study describes a new surgical technique to transfer the tibial tubercle, explains the rationale for its development, and reports the results of initial biomechanical testing. The design goals were to create a tibial tubercle osteotomy that would provide equivalent or better initial fixation compared with traditional techniques, yet would be more flexible, reproducible, accurate, less invasive, and safer. The results of the biomechanical analysis suggest that initial fixation with this novel tubercle transfer technique is as strong as traditional Elmslie-Trillat and anteromedialization procedures.

  4. Ischial hypoplasia, tibial hypoplasia and facial abnormalities: a new syndrome?

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, G. [Department of Radiology, Dokkyo University School of Medicine (Japan); Haga, Yoshihiko [Department of Orthopaedics, Shizuoka Children`s Hospital, Shizuoka (Japan); Aoki, Katsuhiko [Department of Radiology, Shizuoka Children`s Hospital, Shizuoka (Japan); Hasegawa, Tomoko [Division of Clinical Genetics, Shizuoka Children`s Hospital, Shizuoka (Japan)

    1998-12-01

    A child with facial abnormalities, short stature and a variety of skeletal alterations is reported. The facial abnormalities comprised low-set ears, short nose with a long philtrum, micrognathia and cleft palate. The skeletal alterations included ischial hypoplasia, malformations of the cervical spine, hypoplasia of the lesser trochanters, tibial hypoplasia with bowing of the lower legs, tibio-fibular diastasis with malformed distal tibial epiphyses, clubfeet and brachymesophalangy. The constellation of clinical and radiological findings in the present patient do not fit any known malformation syndrome. (orig.) With 4 figs., 8 refs.

  5. Tibial and fibular angles in homozygous sickle cell disease

    Energy Technology Data Exchange (ETDEWEB)

    Akamaguna, A.I.; Odita, J.C.; Ugbodaga, C.I.; Okafor, L.A.

    1986-05-01

    Measurements of the tibial and fibular angles made on ankle radiographs of 34 patients with sickle cell disease were compared with those of 36 normal Nigerians. Widening of the fibular angle, which is an indication of tibiotalar slant, was demonstrated in about 79% of sickle cell disease patients. By using fibular angle measurements as an objective method of assessing subtle tibiotalar slant, it is concluded that the incidence of this deformity is much higher among sickle cell disease patients than previously reported. The mean values of tibial and fibular angles in normal Nigerians are higher than has been reported amongst Caucasians.

  6. High tibial osteotomy in Sweden, 1998-2007

    DEFF Research Database (Denmark)

    W-Dahl, Annette; Robertsson, Otto; Lohmander, Stefan

    2012-01-01

    Most studies on high tibial osteotomies (HTOs) have been hospital-based and have included a limited number of patients. We evaluated the use and outcome-expressed as rate of revision to knee arthroplasty-of HTO performed in Sweden with 9 million inhabitants, 1998-2007.......Most studies on high tibial osteotomies (HTOs) have been hospital-based and have included a limited number of patients. We evaluated the use and outcome-expressed as rate of revision to knee arthroplasty-of HTO performed in Sweden with 9 million inhabitants, 1998-2007....

  7. Casimir Torque in Inhomogeneous Dielectric Plates

    CERN Document Server

    Long, William

    2013-01-01

    In this work, we consider a torque caused by the well known quantum mechanical Casimir effect arising from quantized field fluctuations between plates with inhomogeneous, sharply discontinuous, dielectric properties. While the Casimir effect is a relatively well understood phenomenon, systems resulting in lateral or rotational forces are far less developed; to our knowledge, a theoretical study of discontinuous dielectric variants of such systems has not been attempted. We utilize a Proximity Force Approximation in conjunction with the Lifshitz dielectric formula to perform theoretical analyses of resultant torques in systems with bisected and quadrisected dielectric regions. We also develop a high precision Monte Carlo type numerical integrator to approximate our derived expressions. Our calculations of an energy density linear with the alignment angle result in a constant torque and have implications in NEMS (nano electromechanical systems) and MEMS (micro electromechanical systems), including a postulated ...

  8. Torque for an Inertial Piezoelectric Rotary Motor

    Directory of Open Access Journals (Sweden)

    Jichun Xing

    2013-01-01

    Full Text Available For a novel inertial piezoelectric rotary motor, the equation of the strain energy in the piezoceramic bimorph and the equations of the strain energy and the kinetic energy in the rotor are given. Based on them, the dynamic equation of the motor is obtained. Using these equations, the inertial driving torque of the motor is investigated. The results show that the impulsive driving torque changes with changing peak voltage of the excitation signal, the piezoelectric stress constant, the thickness of the piezoceramic bimorph, and the rotor radius obviously. Tests about the motor torque are completed which verifies the theory analysis here in. The results can be used to design the operating performance of the motor.

  9. AX-5 space suit bearing torque investigation

    Science.gov (United States)

    Loewenthal, Stuart; Vykukal, Vic; Mackendrick, Robert; Culbertson, Philip, Jr.

    1990-01-01

    The symptoms and eventual resolution of a torque increase problem occurring with ball bearings in the joints of the AX-5 space suit are described. Starting torques that rose 5 to 10 times initial levels were observed in crew evaluation tests of the suit in a zero-g water tank. This bearing problem was identified as a blocking torque anomaly, observed previously in oscillatory gimbal bearings. A large matrix of lubricants, ball separator designs and materials were evaluated. None of these combinations showed sufficient tolerance to lubricant washout when repeatedly cycled in water. The problem was resolved by retrofitting a pressure compensated, water exclusion seal to the outboard side of the bearing cavity. The symptoms and possible remedies to blocking are discussed.

  10. RFID Torque Sensing Tag System for Fasteners

    Science.gov (United States)

    Fink, Patrick W. (Inventor); Lin, Gregory Y. (Inventor); Ngo, Phong H. (Inventor); Kennedy, Timothy F. (Inventor)

    2016-01-01

    The present invention provides an RFID-based torque sensor that can be used to quickly monitor off the shelf fasteners including fasteners that are used in expensive satellites or other uses where fastener failure can be very costly. In one embodiment, an antenna, RFID ring and spring comprise a sensor tag that can be interrogated with an interrogation signal produced by an interrogator device. When sufficient torque is applied to the fastener, an RFID circuit is connected, and produces a radio frequency (RF) signal that can be read by the interrogator. In one embodiment, the RFID circuit does not transmit when the spring member is not compressed, thereby indicating insufficient tensioning of the fastener. The present invention offers the ability to remotely, quickly, and inexpensively verify that any number of fasteners are torqued properly upon initial installation. Where applicable, the present invention allows low cost monitoring over the life of the fastener.

  11. Fundamental Limits of Optical Force and Torque

    CERN Document Server

    Rahimzadegan, Aso; Fernandez-Corbaton, Ivan; Rockstuhl, Carsten

    2016-01-01

    Optical force and torque provide unprecedented control on the spatial motion of small particles. A valid scientific question, that has many practical implications, concerns the existence of fundamental upper bounds for the achievable force and torque exerted by a plane wave illumination with a given intensity. Here, while studying isotropic particles, we show that different light-matter interaction channels contribute to the exerted force and torque and analytically derive upper bounds for each of the contributions. Specific examples for particles that achieve those upper bounds are provided. We study how and to which extent different contributions can be made to add up. Our insights are important for applications ranging from molecular sorting, particle manipulation, nanorobotics up to ambitious projects such as laser-propelled spaceships.

  12. Cogging Torque Minimization in Transverse Flux Machines

    Energy Technology Data Exchange (ETDEWEB)

    Husain, Tausif; Hasan, Iftekhar; Sozer, Yilmaz; Husain, Iqbal; Muljadi, Eduard

    2017-02-16

    This paper presents the design considerations in cogging torque minimization in two types of transverse flux machines. The machines have a double stator-single rotor configuration with flux concentrating ferrite magnets. One of the machines has pole windings across each leg of an E-Core stator. Another machine has quasi-U-shaped stator cores and a ring winding. The flux in the stator back iron is transverse in both machines. Different methods of cogging torque minimization are investigated. Key methods of cogging torque minimization are identified and used as design variables for optimization using a design of experiments (DOE) based on the Taguchi method. A three-level DOE is performed to reach an optimum solution with minimum simulations. Finite element analysis is used to study the different effects. Two prototypes are being fabricated for experimental verification.

  13. Visual influence on haptic torque perception.

    Science.gov (United States)

    Xu, Yangqing; O'Keefe, Shélan; Suzuki, Satoru; Franconeri, Steven L

    2012-01-01

    The brain receives input from multiple sensory modalities simultaneously, yet we experience the outside world as a single integrated percept. This integration process must overcome instances where perceptual information conflicts across sensory modalities. Under such conflicts, the relative weighting of information from each modality typically depends on the given task. For conflicts between visual and haptic modalities, visual information has been shown to influence haptic judgments of object identity, spatial features (e.g., location, size), texture, and heaviness. Here we test a novel instance of haptic-visual conflict in the perception of torque. We asked participants to hold a left-right unbalanced object while viewing a potentially left-right mirror-reversed image of the object. Despite the intuition that the more proximal haptic information should dominate the perception of torque, we find that visual information exerts substantial influences on torque perception even when participants know that visual information is unreliable.

  14. Novel torque ripple minimization algorithm for direct torque control of induction motor drive

    Institute of Scientific and Technical Information of China (English)

    LONG Bo; GUO Gui-fang; HAO Xiao-hong; LI Xiao-ning

    2009-01-01

    To elucidate the principles of notable torque and flux ripple during the steady state of the conventional direct torque control (DTC) of induction machines, the factors of influence torque variation are examined. A new torque ripple minimization algorithm is proposed. The novel method eradicated the torque ripple by imposing the required stator voltage vector in each control cycle. The M and T axial components of the stator voltage are accomplished by measuring the stator flux error and the expected incremental value of the torque at every sampling time. The maximum angle rotation allowed is obtained. Experimental results showed that the proposed method combined with the space vector pulse width modulation(SVPWM) could be implemented in most existing digital drive controllers, offering high performance in both steady and transient states of the induction drives at full speed range. The result of the present work imphes that torque fluctuation could be eliminated by imposing proper stator voltage, and the proposed scheme could not only maintain constant switching frequency for the inverter, but also solve the heating problem and current harmonics in traditional induction motor drives.

  15. Avaliação do torque de resistência passiva em atletas femininas com entorse de tornozelo

    Directory of Open Access Journals (Sweden)

    Márcia Barbanera

    2012-04-01

    Full Text Available INTRODUÇÃO: A entorse de tornozelo é uma das lesões mais comuns em atletas. Uma forma de avaliar a frouxidão ligamentar pode ser através da medida da amplitude passiva dos movimentos de inversão e eversão do pé para estimar a resistência passiva das estruturas capsuloligamentares do tornozelo, o qual pode ser chamado de torque de resistência passiva. Existem poucos estudos que utilizam a avaliação do torque passivo do tornozelo para avaliar a resistência da cápsula e dos ligamentos. OBJETIVO: O objetivo deste estudo foi comparar o torque passivo dos movimentos de inversão e eversão do pé em atletas com e sem história de entorse de tornozelo. MÉTODO: Participaram do estudo 32 atletas de basquetebol e voleibol feminino (16,06 ± 0,8 anos, 67,63 ± 8,17kg, 177,8 ± 6,47cm. Seus tornozelos foram divididos em dois grupos: grupo controle (29, composto por tornozelos sem sintomas, e grupo entorse de tornozelo, composto por tornozelos que sofreram lesão (29. O torque dos movimentos passivos do tornozelo foi registrado por um dinamômetro isocinético, e a atividade dos músculos fibular longo e tibial anterior foi medida por um eletromiógrafo. As atletas realizaram duas repetições do movimento de inversão e eversão, nas velocidades de 5, 10 e 20°/s e, em seguida, o mesmo protocolo foi repetido apenas para o movimento de inversão máxima do pé. RESULTADOS: O torque de resistência passiva durante os movimentos de inversão e eversão do pé foi menor no grupo com entorse do tornozelo. Este grupo também mostrou menor torque durante o movimento de inversão máxima do pé. Não foram observadas diferenças entre o movimento de inversão e eversão. CONCLUSÕES: A entorse de tornozelo leva a um menor torque de resistência passiva, indicando redução da resistência dos ligamentos colaterais do tornozelo e uma frouxidão articular mecânica.

  16. The role of interaction torque and muscle torque in the control of downward squatting

    OpenAIRE

    Fujisawa, Hiroyuki; Suzuki, Hiroto; Murakami, Kenichi; Kawakami, Shingo; Suzuki, Makoto

    2016-01-01

    [Purpose] The purposes of this study were first to analyze the multijoint dynamics of downward squatting, and to examine the contribution of interaction torque and muscle torque to net torque, and second, to examine mechanisms of movement control. [Subjects] The subjects were 31 healthy men with a mean age of 21.0 ± 1.2 years (range, 19–24 years). [Methods] Squatting tasks with the trunk in two positions, an erect and anterior tilt position, were performed by the subjects. Net, interaction, m...

  17. Muscle synergy control model-tuned EMG driven torque estimation system with a musculo-skeletal model.

    Science.gov (United States)

    Min, Kyuengbo; Shin, Duk; Lee, Jongho; Kakei, Shinji

    2013-01-01

    Muscle activity is the final signal for motion control from the brain. Based on this biological characteristic, Electromyogram (EMG) signals have been applied to various systems that interface human with external environments such as external devices. In order to use EMG signals as input control signal for this kind of system, the current EMG driven torque estimation models generally employ the mathematical model that estimates the nonlinear transformation function between the input signal and the output torque. However, these models need to estimate too many parameters and this process cause its estimation versatility in various conditions to be poor. Moreover, as these models are designed to estimate the joint torque, the input EMG signals are tuned out of consideration for the physiological synergetic contributions of multiple muscles for motion control. To overcome these problems of the current models, we proposed a new tuning model based on the synergy control mechanism between multiple muscles in the cortico-spinal tract. With this synergetic tuning model, the estimated contribution of multiple muscles for the motion control is applied to tune the EMG signals. Thus, this cortico-spinal control mechanism-based process improves the precision of torque estimation. This system is basically a forward dynamics model that transforms EMG signals into the joint torque. It should be emphasized that this forward dynamics model uses a musculo-skeletal model as a constraint. The musculo-skeletal model is designed with precise musculo-skeletal data, such as origins and insertions of individual muscles or maximum muscle force. Compared with the mathematical model, the proposed model can be a versatile model for the torque estimation in the various conditions and estimates the torque with improved accuracy. In this paper, we also show some preliminary experimental results for the discussion about the proposed model.

  18. Avaliação radiográfica da osteotomia proximal de abertura gradual da tíbia Radiographic assessment of the opening wedge proximal tibial osteotomy

    Directory of Open Access Journals (Sweden)

    Carlos Francisco Bittencourt Silva

    2010-01-01

    Full Text Available OBJETIVO: Avaliar radiograficamente indivíduos submetidos à osteotomia de abertura gradual da tíbia proximal com o objetivo de analisar a inclinação tibial proximal no plano frontal e no plano sagital e a altura patelar. MÉTODO: Foram incluídos no estudo 22 indivíduos operados no Instituto Nacional de Traumatologia e Ortopedia (INTO para correção do desvio angular em varo da tíbia pela técnica de osteotomia de abertura gradual (OAG com fixador externo monolateral da Orthofix. Foram analisados pacientes submetidos à OAG com término de tratamento entre janeiro de 2000 e dezembro de 2006. A técnica utilizada para a mensuração dos valores foi obtida através de radiografias em AP com carga e perfil com flexão a 30º dos joelhos operados. RESULTADOS: Não houve diferenças entre os valores dos índices de altura patelar e inclinação tibial pré-operatórios e pós-operatórios de significância estatística nos pacientes avaliados. CONCLUSÃO: A osteotomia tibial de abertura gradual representa uma técnica que evita os problemas apresentados pela osteotomia tibial proximal alta, pois ela é realizada sem promover alterações do mecanismo extensor, desequilíbrio ligamentar ou distorções na tíbia proximal.OBJETIVO: To radiographically evaluate patients who underwent opening wedge proximal tibial osteotomy in order to analyze the proximal tibial slope in the frontal plane, sagittal plane, and patellar height. METHOD: The study included 22 patients operated on at the Instituto Nacional de Traumatologia e Ortopedia (INTO for the correction of varus angular tibial deviation using the opening wedge osteotomy (OWO technique with the Orthofix monolateral external fixator. We analyzed patients with OWO having completed treatment between January 2000 and December 2006. Values were measured by using X-rays of the anteroposterior profile with load and lateral profile with 30º flexion of the operated knees. RESULTS: No statistically

  19. Age variations in the properties of human tibial trabecular bone

    DEFF Research Database (Denmark)

    Ding, Ming; Dalstra, M; Danielsen, CC;

    1997-01-01

    We tested in compression specimens of human proximal tibial trabecular bone from 31 normal donors aged from 16 to 83 years and determined the mechanical properties, density and mineral and collagen content. Young's modulus and ultimate stress were highest between 40 and 50 years, whereas ultimate...

  20. Aetiology, imaging and treatment of medial tibial stress syndrome

    NARCIS (Netherlands)

    Moen, M.H.

    2012-01-01

    The work contained is this thesis discusses aetiology, imaging and treatment of a common leg injury: medial tibial stress syndrome (MTSS). Although a common injury, the number of scientific articles on this topic is relatively low as is explained in chapter 1. This chapter also highlights that the m

  1. Tibial inlay for posterior cruciate ligament reconstruction: a systematic review.

    Science.gov (United States)

    Papalia, Rocco; Osti, Leonardo; Del Buono, Angelo; Denaro, Vincenzo; Maffulli, Nicola

    2010-08-01

    Although no consensus has been reached regarding the management of PCL deficiency, in vitro and in vivo studies have investigated whether the tibial inlay technique restores the anatomical site of insertion of the PCL, prevents elongation, stretching, graft failure, and improves long-term PCL stability. A systematic search using PubMed, Ovid, the Cochrane Reviews, and Google Scholar databases using 'posterior cruciate ligament tear', 'Tibial inlay technique' and 'posterior cruciate ligament reconstruction' as keywords identified 71 publications, of which 10 were relevant to the topic, and included a total of 255 patients. The tibial inlay technique restores the anatomic insertion site of the PCL, eliminates the killer turn effect, and places the graft at lower potential risk for abrasion and subsequent rupture. It has the disadvantages of increased operating time and risk to the posterior neurovascular structures. There was no evidence of an association between outcome results and Coleman methodology score, but the Coleman methodology scores correlated positively with the level-of-evidence rating. The methodological quality of the studies included has not improved over the years. Given the few reported published findings, we cannot ascertain whether this procedure may provide a consistent alternative to commonly used PCL surgical strategies. The lack of published randomized clinical trials and few reported findings did not allow to ascertain whether the tibial inlay for posterior cruciate ligament reconstruction may provide a consistent alternative to commonly used PCL surgical strategies and to demonstrate procedure efficacy.

  2. Contact Stress Generation on the UHMWPE Tibial Insert

    Directory of Open Access Journals (Sweden)

    S. Petrović Savić

    2014-12-01

    Full Text Available Total knee replacement (TKR is considered, during last years, as a very successful surgical technique for removing knee joint deformities and eliminating pain caused by cartilage damage. In literature, as primary causes for knee joint endoprothesis damage are cited complex movements which cause occurrences of complex stress conditions, sagital radius conformity, sliding, types of materials etc. Aim of this study is analysis of contact stresses that occur on tibial implant for 15°, 45° and 60° knee flexion and 50 kg, 75 kg, 100 kg and 125 kg weight. Knee joint prosthesis model and finite elements method (FEM analysis are done in software Catia V5. For this analysis we used ultra-high molecular weight polyethylene (UHMWPE for tibial implant material and AISI 316, AISI 317, AISI 321, 17-4PH, CoCrMo, Ti6Al4V and SAE A-286 for femoral component materials. Results show that area of maximal contact stress is identified in medial and lateral part of tibial implant. Von Mises stress values vary regarding of flexion degree and weight, but values are approximate for types of chosen materials. Contact stress location corresponds to damage that occur on tibial implant during exploitation.

  3. Osteoarthritis Imaging by Quantification of Tibial Trabecular Bone

    DEFF Research Database (Denmark)

    Marques, Joselene

    The pathogenesis of osteoarthritis (OA) includes complex events in the whole joint. In this project, we combined machine-learning techniques in a texture analysis framework and evaluated it in a longitudinal study, where magnetic resonance images of knees were used to quantify the tibial trabecul...

  4. Anterior cruciate ligament reconstruction failure after tibial shaft malunion.

    Science.gov (United States)

    LaFrance, Russell M; Gorczyca, John T; Maloney, Michael D

    2012-02-17

    Anterior cruciate ligament (ACL) reconstruction is common, with >100,000 procedures performed each year in the United States. Several factors are associated with failure, including poor surgical technique, graft incorporation failure, overly aggressive rehabilitation, and trauma. Tibial shaft fracture is also common and frequently requires operative intervention. Failure to reestablish the anatomic alignment of the tibia may cause abnormal forces across adjacent joints, which can cause degenerative joint disease or attritional failure of the surrounding soft tissues. This article describes a case of ACL reconstruction failure after a tibial fracture that resulted in malunion. Excessive force across the graft from lower-extremity malalignment and improper tunnel placement likely contributed to the attritional failure of the graft. This patient required a staged procedure for corrective tibial osteotomy followed by revision ACL reconstruction. This article describes ACL reconstruction failure, tibial shaft malunions, their respective treatments, the technical details of each procedure, and the technical aspects that must be considered when these procedures are done in a staged manner by 2 surgeons.

  5. Olanzapine-induced tender pitting pre-tibial edema

    Directory of Open Access Journals (Sweden)

    Kaliaperumal Mathan

    2015-01-01

    Full Text Available Antipsychotic-induced edema is uncommonly encountered in clinical practice. We report a case of tender pitting pre-tibial edema with olanzapine in a woman with no medical comorbidities. The peculiar distribution of edema resulted in diagnostic confusion necessitating specific investigations. Eventually, the edema resolved following complete stoppage of the drug, but caused distress to the patient and the caregiver.

  6. Total knee arthroplasty after high tibial osteotomy. A systematic review

    NARCIS (Netherlands)

    T.M. van Raaij (Tom); M. Reijman (Max); A. Furlan (Alessandro); J.A.N. Verhaar (Jan)

    2009-01-01

    textabstractBackground: Previous osteotomy may compromise subsequent knee replacement, but no guidelines considering knee arthroplasty after prior osteotomy have been developed. We describe a systematic review of non-randomized studies to analyze the effect of high tibial osteotomy on total knee art

  7. Preliminary evaluation of the tibial tuberosity-trochlear groove measurement

    DEFF Research Database (Denmark)

    Miles, James Edward; Kirpensteijn, Jolle; Svalastoga, Eiliv Lars

    guide surgical treatment. The TTTG measures tibial tuberosity position relative to the axis of the femoral trochlea. A preliminary investigation of TTTG measurement was performed using the red fox (Vulpes vulpes) cadavers as a morphologically similar and homogenous substitute for dog cadavers. CT...

  8. Asymmetry in gait pattern following tibial shaft fractures

    DEFF Research Database (Denmark)

    Larsen, Peter; Læssøe, Uffe; Rasmussen, Sten

    2017-01-01

    INTRODUCTION: Despite the high number of studies evaluating the outcomes following tibial shaft fractures, the literature lacks studies including objective assessment of patients' recovery regarding gait pattern. The purpose of the present study was to evaluate whether gait patterns at 6 and 12 m...

  9. MR imaging findings of medial tibial crest friction

    Energy Technology Data Exchange (ETDEWEB)

    Klontzas, Michail E., E-mail: miklontzas@gmail.com; Akoumianakis, Ioannis D., E-mail: ioannis.akoumianakis@gmail.com; Vagios, Ilias, E-mail: iliasvagios@gmail.com; Karantanas, Apostolos H., E-mail: akarantanas@gmail.com

    2013-11-01

    Objective: Medial tibial condyle bone marrow edema (BME), associated with soft tissue edema (STe) surrounding the medial collateral ligament, was incidentally observed in MRI examinations of young and athletic individuals. The aim of the present study was to 1. Prospectively investigate the association between these findings and coexistence of localized pain, and 2. Explore the possible contribution of the tibial morphology to its pathogenesis. Methods: The medial tibial condyle crest was evaluated in 632 knee MRI examinations. The angle and depth were measured by two separate evaluators. The presence of STe and BME was recorded. A third evaluator blindly assessed the presence of pain at this site. Results: BME associated with STe was found in 24 patients (with no history of previous trauma, osteoarthritis, tumor or pes anserine bursitis). The mean crest angle was 151.3° (95%CI 147.4–155.3°) compared to 159.4° (95%CI 158.8–160°) in controls (Mann–Whitney test, P < 0.0001). MRI findings were highly predictive of localized pain (sensitivity 92% specificity 99%, Fisher's exact test, P < 0.0001). Conclusion: Friction at the medial tibial condyle crest is a painful syndrome. MRI is a highly specific and sensitive imaging modality for its diagnosis.

  10. Multichannel recording of tibial-nerve somatosensory evoked potentials

    NARCIS (Netherlands)

    de Wassenberg, W. J. G. van; Kruizinga, W. J.; van der Hoeven, J. H.; Leenders, K. L.; Maurits, N. M.

    2008-01-01

    Study aims. -The topography of the peaks of tibial.-nerve somatosensory evoked potential (SEP) varies among healthy subjects, most likely because of differences in position and orientation of their cortical generator(s). Therefore, amplitude estimation with a standard one- or two-channel derivation

  11. Optimizing Casimir torque between corrugated metallic plates

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Robson B. [Universidade Federal Fluminense, Niteroi, RJ (Brazil); Maia Neto, Paulo A. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, RJ (Brazil)

    2013-07-01

    Full text: The Casimir effect plays a major role in micro- and nano-electromechanical systems (MEMS and NEMS). Besides the normal Casimir force between metallic or dielectric plates, the observation of the lateral Casimir force between corrugated plates opens novel possibilities of micro-mechanical control. The lateral force results from breaking the translational symmetry along directions parallel to the plates by imprinting periodic corrugations on both metallic plates. As the rotational symmetry is broken by this geometry, a Casimir torque arises when the corrugations are not aligned. We calculate the Casimir torque between two parallel metallic plates with surface profiles in the form of 'fans' with arbitrary relative spatial orientation. As compared to the case of anisotropic dielectric plates, the torque per unit area is increased by up to three orders of magnitude for a given separation distance. The experiment proposed here can be performed with torsion pendulum techniques for separation distances as large as 1 μm. From the point of view of fundamental physics, this torque makes possible a precise experimental investigation of the non-trivial geometry dependence of the Casimir effect. We follow the scattering approach and calculate the Casimir energy up to second order in the corrugation amplitudes, taking into account nonspecular reflections, polarization mixing and the finite conductivity of the metals. We investigate the experimental conditions that optimize the effect. (author)

  12. Planetary Torque in 3D Isentropic Disks

    Science.gov (United States)

    Fung, Jeffrey; Masset, Frédéric; Lega, Elena; Velasco, David

    2017-03-01

    Planetary migration is inherently a three-dimensional (3D) problem, because Earth-size planetary cores are deeply embedded in protoplanetary disks. Simulations of these 3D disks remain challenging due to the steep resolution requirements. Using two different hydrodynamics codes, FARGO3D and PEnGUIn, we simulate disk–planet interaction for a one to five Earth-mass planet embedded in an isentropic disk. We measure the torque on the planet and ensure that the measurements are converged both in resolution and between the two codes. We find that the torque is independent of the smoothing length of the planet’s potential (r s), and that it has a weak dependence on the adiabatic index of the gaseous disk (γ). The torque values correspond to an inward migration rate qualitatively similar to previous linear calculations. We perform additional simulations with explicit radiative transfer using FARGOCA, and again find agreement between 3D simulations and existing torque formulae. We also present the flow pattern around the planets that show active flow is present within the planet’s Hill sphere, and meridional vortices are shed downstream. The vertical flow speed near the planet is faster for a smaller r s or γ, up to supersonic speeds for the smallest r s and γ in our study.

  13. Are torque values of preadjusted brackets precise?

    Directory of Open Access Journals (Sweden)

    Alessandra Motta Streva

    Full Text Available OBJECTIVE: The aim of the present study was to verify the torque precision of metallic brackets with MBT prescription using the canine brackets as the representative sample of six commercial brands. MATERIAL AND METHODS: Twenty maxillary and 20 mandibular canine brackets of one of the following commercial brands were selected: 3M Unitek, Abzil, American Orthodontics, TP Orthodontics, Morelli and Ortho Organizers. The torque angle, established by reference points and lines, was measured by an operator using an optical microscope coupled to a computer. The values were compared to those established by the MBT prescription. RESULTS: The results showed that for the maxillary canine brackets, only the Morelli torque (-3.33º presented statistically significant difference from the proposed values (-7º. For the mandibular canines, American Orthodontics (-6.34º and Ortho Organizers (-6.25º presented statistically significant differences from the standards (-6º. Comparing the brands, Morelli presented statistically significant differences in comparison with all the other brands for maxillary canine brackets. For the mandibular canine brackets, there was no statistically significant difference between the brands. CONCLUSIONS: There are significant variations in torque values of some of the brackets assessed, which would clinically compromise the buccolingual positioning of the tooth at the end of orthodontic treatment.

  14. Planetary Torque in 3D Isentropic Disks

    CERN Document Server

    Fung, Jeffrey; Lega, Elena; Velasco, David

    2016-01-01

    Planet migration is inherently a three-dimensional (3D) problem, because Earth-size planetary cores are deeply embedded in protoplanetary disks. Simulations of these 3D disks remain challenging due to the steep requirement in resolution. Using two different hydrodynamics code, FARGO3D and PEnGUIn, we simulate disk-planet interaction for a 1 to 5 Earth-mass planet embedded in an isentropic disk. We measure the torque on the planet and ensure that the measurements are converged both in resolution and between the two codes. We find that the torque is independent of the smoothing length of the planet's potential ($r_{\\rm s}$), and that it has a weak dependence on the adiabatic index of the gaseous disk ($\\gamma$). The torque values correspond to an inward migration rate qualitatively similar to previous linear calculations. We perform additional simulations with explicit radiative transfer using FARGOCA, and again find agreement between 3D simulations and existing torque formulae. We also present the flow pattern...

  15. Are torque values of preadjusted brackets precise?

    Directory of Open Access Journals (Sweden)

    Alessandra Motta Streva

    2011-08-01

    Full Text Available OBJECTIVE: The aim of the present study was to verify the torque precision of metallic brackets with MBT prescription using the canine brackets as the representative sample of six commercial brands. MATERIAL AND METHODS: Twenty maxillary and 20 mandibular canine brackets of one of the following commercial brands were selected: 3M Unitek, Abzil, American Orthodontics, TP Orthodontics, Morelli and Ortho Organizers. The torque angle, established by reference points and lines, was measured by an operator using an optical microscope coupled to a computer. The values were compared to those established by the MBT prescription. RESULTS: The results showed that for the maxillary canine brackets, only the Morelli torque (-3.33º presented statistically significant difference from the proposed values (-7º. For the mandibular canines, American Orthodontics (-6.34º and Ortho Organizers (-6.25º presented statistically significant differences from the standards (-6º. Comparing the brands, Morelli presented statistically significant differences in comparison with all the other brands for maxillary canine brackets. For the mandibular canine brackets, there was no statistically significant difference between the brands. CONCLUSIONS: There are significant variations in torque values of some of the brackets assessed, which would clinically compromise the buccolingual positioning of the tooth at the end of orthodontic treatment.

  16. Contributory factors to the results of gravity-assisted pivot-shift test for anterior cruciate ligament injury: the significance of muscle torque around the knee.

    Science.gov (United States)

    Hiraoka, Hisatada; Yashiki, Motohisa; Sakai, Hiroya

    2008-03-01

    Gravity-assisted pivot-shift (GAPS) test is a newly advocated test for anterior cruciate ligament (ACL) injury. It induces anterolateral rotatory instability with valgus stress to the knee applied by gravitational force during patient's active knee motion. We investigated prospectively the relationships between the results of the GAPS test and the possible contributory factors and sought to clarify the determinant factors of the GAPS test. A total of 54 knee joints of 54 patients with unilateral ACL injury (29 males, 25 females, average 23.4 +/- 9.0 years old) were enrolled in this study and were divided into two groups, i.e., positive GAPS test group and negative GAPS test group. Muscle torque around the knee joints measured before surgery, configuration of the femoral condyle and tibial posterior slope angle measured on lateral radiograph, and other clinical factors were compared between the two groups using Mann-Whitney U test or chi-square test. According to the results of these analyses, factors having a statistically significant difference were additionally evaluated using multiple logistic regression analysis to reveal items with strong relevance to a positive GAPS test. The results of the multiple logistic regression analysis showed that the flexor/extensor peak torque ratio of contralateral uninjured knees and sex had a significant correlation with the results of the GAPS test. The relatively less flexor muscle torque compared with extensor muscle torque, and being a female patient were considered to be the determinant factors of a positive GAPS test.

  17. Do ethnicity and gender influence posterior tibial slope?

    Science.gov (United States)

    Bisicchia, Salvatore; Scordo, Gavinca M; Prins, Johan; Tudisco, Cosimo

    2017-02-02

    Ethnicity and gender can affect posterior tibial slope; however, studies on this topic have limitations and are in disagreement. The aim of the present study was to evaluate posterior tibial slope in a large group of consecutive patients, determining whether ethnicity and gender can influence its value. Secondly, to determine intra- and inter-rater reliability of the two radiographic methods adopted. Posterior tibial slope was calculated (rater 1) in lateral view X-rays of the knee according to the posterior tibial cortex (PTC) and tibial proximal anatomical axis (TPAA) methods. Data were matched with ethnicity and gender. For determination of intra- and inter-rater reliability, 50 random X-rays were selected, and blindly measured by two other raters (2 and 3). A total of 581 radiographs were included (413 white and 168 black knees). Comparing white and black subjects, a statistically significant difference was found for both PTC (4.9 ± 1.2 vs 7.1 ± 2.9, p < 0.0001), and for TPAA (7.7 ± 1.1 vs 10.2 ± 3.0, p < 0.0001). In white subjects, an influence of gender was found only for TPAA (6.4 ± 1.1 in males vs 7.6 ± 1.1 in females, p < 0.0001). In black subjects, an influence of gender was found only for PTC (7.4 ± 3.0 in males vs 6.2 ± 2.9 in females, p = 0.01). Intra-rater reliability was good for both methods for rater 1, and very good for rater 2. Inter-rater reliability among the 3 raters was very good for both methods. Differences in posterior tibial slope between different ethnic groups exist. Differences observed between genders are conflicting and might be too small to have implications in clinical practice. The TPAA method is recommended for the evaluation of posterior tibial slope because of higher intra- and inter-rater reliability. Level of evidence 3 Case-control study.

  18. Direct Torque Control of IPMSM to Improve Torque ripple and Efficiency based on Fuzzy Controller

    Directory of Open Access Journals (Sweden)

    B. Mirzaeian Dehkordi

    2012-09-01

    Full Text Available In this paper, a stator-flux-reference frame control method is proposed in order to control the speed and torque of an Interior Permanent Magnet Synchronous Machine (IPMSM in different loads condition. Direct Torque Control method (DTC based on Space Vector Modulation (SVM is used for control of IPMSM. In the proposed control method, conventional PI controller is used for controlling the stator flux, and torque of the motor. Also, a fuzzy controller is considered to improve the dynamic performance of DTC technique for speed control. In comparison to the conventional reference flux controller methods, this method, in addition, improves the torque profile of the motor drive. Moreover, it reduces copper losses. Simulation results for a 240V, 120A, 2500rpm, IPMSM confirm the appropriate performances of the method.

  19. Tacón de torque. Análisis tensional y deformacional utilizando el Método de Elementos Finitos. // Torque heel: Tensional and deformational analysis using the Finite Elements Method.

    OpenAIRE

    R. A. González Carbonell; E. Álvarez García; Y. Campos Pérez

    2007-01-01

    En este trabajo se aborda la problemática del tratamiento en menores que presentan torsión tibial y la necesidad de undispositivo ortopédico para su corrección. En particular, se presentan los elementos necesarios para el diseño de un tacón detorque. Se estudiaron los fenómenos no lineales presentes en el diseño mecánico de piezas que no cumplen con la ley deHooke, específicamente para materiales hiperelásticos. El modelo de las cargas que actúan sobre el tacón de torque fuedefinido teniendo ...

  20. Analysis of Knee Joint Line Obliquity after High Tibial Osteotomy.

    Science.gov (United States)

    Oh, Kwang-Jun; Ko, Young Bong; Bae, Ji Hoon; Yoon, Suk Tae; Kim, Jae Gyoon

    2016-11-01

    The aim of this study was to evaluate which lower extremity alignment (knee and ankle joint) parameters affect knee joint line obliquity (KJLO) in the coronal plane after open wedge high tibial osteotomy (OWHTO). Overall, 69 knees of patients that underwent OWHTO were evaluated using radiographs obtained preoperatively and from 6 weeks to 3 months postoperatively. We measured multiple parameters of knee and ankle joint alignment (hip-knee-ankle angle [HKA], joint line height [JLH], posterior tibial slope [PS], femoral condyle-tibial plateau angle [FCTP], medial proximal tibial angle [MPTA], mechanical lateral distal femoral angle [mLDFA], KJLO, talar tilt angle [TTA], ankle joint obliquity [AJO], and the lateral distal tibial ground surface angle [LDTGA]; preoperative [-pre], postoperative [-post], and the difference between -pre and -post values [-Δ]). We categorized patients into two groups according to the KJLO-post value (the normal group [within ± 4 degrees, 56 knees] and the abnormal group [greater than ± 4 degrees, 13 knees]), and compared their -pre parameters. Multiple logistic regression analysis was used to examine the contribution of the -pre parameters to abnormal KJLO-post. The mean HKA-Δ (-9.4 ± 4.7 degrees) was larger than the mean KJLO-Δ (-2.1 ± 3.2 degrees). The knee joint alignment parameters (the HKA-pre, FCTP-pre) differed significantly between the two groups (p knee joint alignment and knee joint convergence angle evaluated by HKA-pre and FCTP-pre angle, respectively, were significant predictors of abnormal KJLO after OWHTO. However, -pre ankle joint parameters were not significantly associated with abnormal KJLO after OWHTO.

  1. Tracking control of time-varying knee exoskeleton disturbed by interaction torque.

    Science.gov (United States)

    Li, Zhan; Ma, Wenhao; Yin, Ziguang; Guo, Hongliang

    2017-08-16

    Knee exoskeletons have been increasingly applied as assistive devices to help lower-extremity impaired people to make their knee joints move through providing external movement compensation. Tracking control of knee exoskeletons guided by human intentions often encounters time-varying (time-dependent) issues and the disturbance interaction torque, which may dramatically put an influence up on their dynamic behaviors. Inertial and viscous parameters of knee exoskeletons can be estimated to be time-varying due to unexpected mechanical vibrations and contact interactions. Moreover, the interaction torque produced from knee joint of wearers has an evident disturbance effect on regular motions of knee exoskeleton. All of these points can increase difficultly of accurate control of knee exoskeletons to follow desired joint angle trajectories. This paper proposes a novel control strategy for controlling knee exoskeleton with time-varying inertial and viscous coefficients disturbed by interaction torque. Such designed controller is able to make the tracking error of joint angle of knee exoskeletons exponentially converge to zero. Meanwhile, the proposed approach is robust to guarantee the tracking error bounded when the interaction torque exists. Illustrative simulation and experiment results are presented to show efficiency of the proposed controller. Additionally, comparisons with gradient dynamic (GD) approach and other methods are also presented to demonstrate efficiency and superiority of the proposed control strategy for tracking joint angle of knee exoskeleton. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  2. Localização do ponto de entrada tibial Localization of the tibial entry point

    Directory of Open Access Journals (Sweden)

    Pedro José Labronici

    2010-01-01

    Full Text Available OBJETIVO: Verificar, através de um questionário, o ponto de entrada da haste intramedular na região proximal da tíbia. Métodos: 230 participantes que tratam fraturas da tíbia foram entrevistados. O questionário foi formulado com três segmentos que poderiam ser respondidos com um formato "sim" ou "não" e um quarto, com duas figuras que representavam uma radiografia em anteroposterior (AP e lateral que poderiam ser respondidas com um formato "A", "B" ou "C". RESULTADOS: A razão mais frequente foi a "facilidade de acesso" (67,8%, seguida do "melhor acesso para inserção da haste" (60,9% e em terceiro "prevenir a dor no joelho" (27,4%. Existiu relação significativa entre as razões de escolha do acesso como "prevenir dor no joelho" e "evitar tendinites" com os pontos A e C da figura esquemática de radiografia em AP, principalmente o ponto C (crista tibial medial. Observou-se que não existiu diferença significativa nos tipos de acesso em relação ao ligamento patelar, nas figuras esquemáticas de radiografia em AP e perfil entre as faixas etárias. CONCLUSÃO: Observou-se que quanto maior a faixa etária maior a proporção de escolher a pergunta "evitar deformidade em valgo". As razões de aspecto médico (prático foram relacionadas com o tipo de acesso no ligamento transpatelar, enquanto que as razões de aspecto paciente (funcional foram relacionadas com o acesso parapatelar medial. O acesso transpatelar foi escolhido pela maioria dos participantes (66,5%.OBJETIVE: To assess, through a questionnaire, the intramedullary nail entry point in the proximal aspect of the tibia. Me-thods: 230 attendees who treat tibial fractures were interviewed. The questionnaire was created with three sections that could be answered with "Yes" or "No" answers and a fourth section that had two figures representing anteroposterior (AP and lateral view x-rays that could be answered with a format "A, "B" or "C". RESULTS: The most frequent reason was "ease

  3. Potentiation Increases Peak Twitch Torque by Enhancing Rates of Torque Development and Relaxation

    OpenAIRE

    Froyd, Christian; Beltrami, Fernando Gabe; Jensen, Jørgen; Noakes, Timothy David

    2013-01-01

    The aim of this study was to measure the extent to which potentiation changes in response to an isometric maximal voluntary contraction. Eleven physically active subjects participated in two separate studies. Single stimulus of electrical stimulation of the femoral nerve was used to measure torque at rest in unpotentiated quadriceps muscles (study 1 and 2), and potentiated quadriceps muscles torque in a 10 min period after a 5 s isometric maximal voluntary contraction of the quadriceps muscle...

  4. Evaluation of torque within manual preparation with root canal instruments

    OpenAIRE

    Gorski, Christof

    2016-01-01

    Used root canal instruments are often deformed; they can fracture, persist and reinfect teeth. There are no evident studies consulting torque and manual preparation of root canals. Thus, the purpose of this study is the evaluation of torque within manual preparation in connection with its impact on file deformation. With the aid of torque measurement a change in dental education could potentially be achieved.

  5. Frictional torque numbers for ball cup and journal bearings

    OpenAIRE

    Ligterink, D.J.

    1982-01-01

    Plastic bearing material wears in ball cup and journal bearings. Contact areas in the ball cup and the journal bearing increase. The frictional torque needed to rotate the ball or journal also increases. When the coefficient of friction is assumed to be constant during wearing out, the frictional torque increases to a maximum of 1.273 times the frictional torque at zero wear.

  6. Research on Torque Ratio Based on the Steering Wheel Torque Characteristic for Steer-by-Wire System

    Directory of Open Access Journals (Sweden)

    Yandong Han

    2014-01-01

    Full Text Available Steer-by-wire system can improve the performance of vehicle handling stability. Removing the mechanical linkages between the front wheels and the steering wheel leads to a key technique of force feedback for steer-by-wire system. In view of the characteristic of variable torque transmission ratio for steer-by-wire system, this paper proposes a method for designing torque ratio based on the steering wheel torque characteristic for steer-by-wire system. It converts the torque ratio design into equivalent assist torque design by analyzing their relationship. It achieves the torque ratio design at different conditions based on the negative equivalent assist torque characteristic curve. Simulations and vehicle experiments are conducted by the proposed method, and the results show that the design goal has been achieved and the steering wheel torque characteristic obtained is very similar to that of the reference car.

  7. Cogging Torque and Acoustic Noise Reduction in High Torque BLDC Motors by Teeth Pairings

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Min [Halla Climate Control Co. (Korea, Republic of); Hwang, Sang Moon [Pusan National University (Korea, Republic of)

    1999-03-01

    This paper investigates reduction of acoustic noise and cogging torque in a BLDC motor with larger stator slot open width. Using energy method, cogging torque is analytically determined with airgap MMF function and airgap permeance function and confirmed by FEM analysis. It show that the cogging torque is firstly governed by N{sub L} G{sub NL} B{sub NL} with the fundamental period of N{sub L}, where N{sub L} is the least common multiple of the number of slots and the number of poles, G{sub NL}, airgap permeance function and B{sub NL}, airgap MMF function. It also shows that there exist several tooth width which minimizes the cogging torque, for the motors that smaller slot open width or stator teeth notching is not available. And it proposes a teeth pairing with two different tooth width which can effectively eliminate the cogging torque and thus the acoustic noise. Experimental results show that the proposed teeth pairing reduces the cogging torque by 85% and the acoustic noise by 3.1 dB. (author). 9 refs., 13 figs., 1 tab.

  8. Performances improvements and torque ripple minimization for VSI fed induction machine with direct control torque.

    Science.gov (United States)

    Abdelli, R; Rekioua, D; Rekioua, T

    2011-04-01

    This paper describes a torque ripple reduction technique with constant switching frequency for direct torque control (DTC) of an induction motor (IM). This method enables a minimum torque ripple control. In order to obtain a constant switching frequency and hence a torque ripple reduction, we propose a control technique for IM. It consists of controlling directly the electromagnetic torque by using a modulated hysteresis controller. The design methodology is based on space vector modulation (SVM) of electrical machines with digital vector control. MATLAB simulations supported with experimental study are used. The simulation and experimental results of this proposed algorithm show an adequate dynamic to IM; however, the research can be extended to include synchronous motors as well. The implementation of the proposed algorithm is described. It doesn't require any PI controller in the torque control loop. The hardware inverter is controlled digitally using a Texas Instruments TMS320F240 digital signal processor (DSP) with composed C codes for generating the required references. The results obtained from simulation and experiments confirmed the feasibility of the proposed strategy compared to the conventional one.

  9. Uncertainty of knee joint muscle activity during knee joint torque exertion: the significance of controlling adjacent joint torque.

    Science.gov (United States)

    Nozaki, Daichi; Nakazawa, Kimitaka; Akai, Masami

    2005-09-01

    In the single-joint torque exertion task, which has been widely used to control muscle activity, only the relevant joint torque is specified. However, the neglect of the neighboring joint could make the procedure unreliable, considering our previous result that even monoarticular muscle activity level is indefinite without specifying the adjacent joint torque. Here we examined the amount of hip joint torque generated with knee joint torque and its influence on the activity of the knee joint muscles. Twelve healthy subjects were requested to exert various levels of isometric knee joint torque. The knee and hip joint torques were obtained by using a custom-made device. Because no information about hip joint torque was provided to the subjects, the hip joint torque measured here was a secondary one associated with the task. The amount of hip joint torque varied among subjects, indicating that they adopted various strategies to achieve the task. In some subjects, there was a considerable internal variability in the hip joint torque. Such variability was not negligible, because the knee joint muscle activity level with respect to the knee joint torque, as quantified by surface electromyography (EMG), changed significantly when the subjects were requested to change the strategy. This change occurred in a very systematic manner: in the case of the knee extension, as the hip flexion torque was larger, the activity of mono- and biarticular knee extensors decreased and increased, respectively. These results indicate that the conventional single knee joint torque exertion has the drawback that the intersubject and/or intertrial variability is inevitable in the relative contribution among mono- and biarticular muscles because of the uncertainty of the hip joint torque. We discuss that the viewpoint that both joint torques need to be considered will bring insights into various controversial problems such as the shape of the EMG-force relationship, neural factors that help

  10. External Otitis (Swimmer's Ear)

    Science.gov (United States)

    ... to Pneumococcal Vaccine Additional Content Medical News External Otitis (Swimmer's Ear) By Bradley W. Kesser, MD, Associate ... the Outer Ear Ear Blockages Ear Tumors External Otitis (Swimmer's Ear) Malignant External Otitis Perichondritis External otitis ...

  11. Somatotype-variables related to muscle torque and power output in female volleyball players.

    Science.gov (United States)

    Buśko, Krzysztof; Lewandowska, Joanna; Lipińska, Monika; Michalski, Radosław; Pastuszak, Anna

    2013-01-01

    The purpose of this study was to investigate the relationship between somatotype, muscle torque, maximal power output and height of rise of the body mass centre measured in akimbo counter movement jump (ACMJ), counter movement jump (CMJ) and spike jump (SPJ), and power output measured in maximal cycle ergometer exercise bouts in female volleyball players. Fourteen players participated in the study. Somatotype was determined using the Heath-Carter method. Maximal muscle torque was measured under static conditions. Power output was measured in 5 maximal cycle ergometer exercise bouts, 10 s each, at increasing external loads equal to 2.5, 5.0, 7.5, 10.0 and 12.5% of body weight (BW). All jump trials (ACMJ, SPJ and CMJ) were performed on a force plate. The mean somatotype of volleyball players was: 4.9-3.5-2.5. The value of the sum of muscle torque of the left upper extremities was significantly correlated only with mesomorphic component. Mesomorphic and ectomorphic components correlated significantly with values of maximal power measured during ACMJ and CMJ. Power output measured in maximal cycle ergometer exercise bouts at increasing external loads equal to 2.5, 5.0 and 7.5% of BW was significantly correlated with endomorphy, mesomorphy and ectomorphy.

  12. ROLE OF LOW PROFILE PRECONTOURED DISTAL TIBIAL LOCKING PLATE USING MIPPO TECHNIQUE IN PILON FRACTURE

    Directory of Open Access Journals (Sweden)

    Isaac Sunder

    2015-10-01

    Full Text Available : Tibial pilon fracture – Spectrum of injury ranging from fractures caused by low energy rotational foces to fractures caused by high energy axial compression forces due to RTA/ fall from height with significant metaphyseal communition articular communition with diaphyseal extension. Almost 80% patients will have fibula fracture. The aim of the study is study the efficacy of LP PD DTP in the management of closed pilon fractures (OTA type A Type B and Type C 1 and open pilon fractures (Grade 1 Grade II Grade III A (Gustilo Anterson grading. 1. I have studied 21 patients of pilon fracture classified using AO/OTA classification Type A-metaphyseal; Type B–Partially articular; Type C Metaphyseal fracture with articular involvement. 2. Used LP/ PC/ Distal tibial plate using MIPPO technique in OTA–A, B and C 1 closed & grade I II Grade III A compound fractures. OBSERVATIONS: 1. In contrary to stages protocol (Ist external fixation with fibular plating after 2-3 Weeks ORIF/MIPPO with/Without bone grafting, it is done percutaneously or minimally invasive and it can be done on day 1 without any major soft tissue problem & post-operative infection. 2. Duration of stay in the hospital can be reduced. 3. Since it is done through calcaneal traction or femoral distractor – fibula length restored & plating may not be necessary all the time and fibula plating can be avoid if the soft tissue condition is not favorable for plating laterally. 4. Since it is done through calcaneal traction/femoral distractor inspite of ground glass communition–good reduction is almost always possible. 5. Since MIPPO–need for bone grafting in less. 6. As in staged protocol more time is spent in soft tissue healing and after 2–3 weeks, fractures reduction if difficult and almost impossible with indirect reduction and may warrant open reduction. I conclude that LP PC distal tibial plate using MIPPO technique offers several advantages over two staged protocol and improved

  13. Tailoring spin-orbit torque in diluted magnetic semiconductors

    KAUST Repository

    Li, Hang

    2013-05-16

    We study the spin orbit torque arising from an intrinsic linear Dresselhaus spin-orbit coupling in a single layer III-V diluted magnetic semiconductor. We investigate the transport properties and spin torque using the linear response theory, and we report here: (1) a strong correlation exists between the angular dependence of the torque and the anisotropy of the Fermi surface; (2) the spin orbit torque depends nonlinearly on the exchange coupling. Our findings suggest the possibility to tailor the spin orbit torque magnitude and angular dependence by structural design.

  14. Methods of torque ripple reduction for flux reversal motor

    Science.gov (United States)

    Vakil, Gaurang; Sheth, N. K.; Miller, David

    2009-04-01

    This paper presents two-dimensional finite element based results for various methods of torque ripple reduction in flux-reversal motors. The effects of variation in magnet and rotor pole heights, rotor pole skewing, and multiple teeth per rotor pole on the cogging torque, developed torque, torque ripple, and phase inductance and also an optimum value of the magnet and rotor pole heights, skew angle, and choice of teeth per rotor pole with the teeth depth resulting in torque ripple reduction are presented.

  15. Research on Drag Torque Prediction Model for the Wet Clutches

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Considering the surface tension effect and centrifugal effect, a mathematical model based on Reynolds equation for predicting the drag torque of disengage wet clutches is presented. The model indicates that the equivalent radius is a function of clutch speed and flow rate. The drag torque achieves its peak at a critical speed. Above this speed, drag torque drops due to the shrinking of the oil film. The model also points out that viscosity and flow rate effects on drag torque. Experimental results indicate that the model is reasonable and it performs well for predicting the drag torque peak.

  16. Stability at the half pin–frame interface on external fixation constructs

    OpenAIRE

    Alexios Dimitrios Iliadis; Parag Kumar Jaiswal; Jay Meswania; Gordon Blunn; David Goodier; Peter Calder

    2016-01-01

    Abstract A mechanical study investigating the use of two different methods (grub and bolt screws) to secure external fixation half pins to circular frames. A four part experiment: (1) Grub and bolt screws were used to secure half pins in Taylor Spatial frames. Loosening torques were measured using a calibrated torque wrench. (2) Using universal testing machine (UTM), axial loading was applied to establish thresholds for loosening in grub and bolt screw constructs. (3) We established the appli...

  17. Displaceable spur gear torque controlled driver and method

    Science.gov (United States)

    Cook, Joseph S., Jr. (Inventor)

    1994-01-01

    Methods and apparatus are provided for a torque driver including a laterally displaceable gear support member to carry an output spur gear. A biasing assembly biases the output spur gear into engagement with a pinion to which is applied an input torque greater than a desired output torque limit for a threaded fastener such as a nut or screw. A coiled output linkage connects the output spur gear with a fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. A gauged selector mechanism is provided to laterally displace multiple driver members for fasteners arranged in differing configurations. The torque limit is selectably adjustable and may be different for fasteners within the same fastener configuration.

  18. Surface Roughness Effects on Vortex Torque of Air Supported Gyroscope

    Institute of Scientific and Technical Information of China (English)

    LIANG Yingchun; LIU Jingshi; SUN Yazhou; LU Lihua

    2011-01-01

    In order to improve the drift precision of air supported gyroscope, effects of surface roughness magnitude and direction on vortex torque of air supported gyroscope are studied. Based on Christensen's rough surface stochastic model and consistency transformation method, Reynolds equation of air supported gyroscope containing surface roughness information is established.Also effects of mathematical models of main machining errors on vortex torque are established. By using finite element method,the Reynolds equation is solved numerically and the vortex torque in the presence of machining errors and surface roughness is calculated. The results show that surface roughness of slit has a significant effect on vortex torque. Transverse surface roughness makes vortex torque greater, while longitudinal surface roughness makes vortex torque smaller. The maximal difference approaches 11.4% during the range analyzed in this article. However surface roughness of journal influences vortex torque insignificantly. The research is of great significance for designing and manufacturing air supported gyroscope and predicting its performance.

  19. Fast Estimation of Strains for Cross-Beams Six-Axis Force/Torque Sensors by Mechanical Modeling

    Directory of Open Access Journals (Sweden)

    Junqing Ma

    2013-05-01

    Full Text Available Strain distributions are crucial criteria of cross-beams six-axis force/torque sensors. The conventional method for calculating the criteria is to utilize Finite Element Analysis (FEA to get numerical solutions. This paper aims to obtain analytical solutions of strains under the effect of external force/torque in each dimension. Genetic mechanical models for cross-beams six-axis force/torque sensors are proposed, in which deformable cross elastic beams and compliant beams are modeled as quasi-static Timoshenko beam. A detailed description of model assumptions, model idealizations, application scope and model establishment is presented. The results are validated by both numerical FEA simulations and calibration experiments, and test results are found to be compatible with each other for a wide range of geometric properties. The proposed analytical solutions are demonstrated to be an accurate estimation algorithm with higher efficiency.

  20. Spin diffusion and torques in disordered antiferromagnets

    KAUST Repository

    Manchon, Aurelien

    2017-02-01

    We have developed a drift-diffusion equation of spin transport in collinear bipartite metallic antiferromagnets. Starting from a model tight-binding Hamiltonian, we obtain the quantum kinetic equation within Keldysh formalism and expand it to the lowest order in spatial gradient using Wigner expansion method. In the diffusive limit, these equations track the spatio-temporal evolution of the spin accumulations and spin currents on each sublattice of the antiferromagnet. We use these equations to address the nature of the spin transfer torque in (i) a spin-valve composed of a ferromagnet and an antiferromagnet, (ii) a metallic bilayer consisting of an antiferromagnet adjacent to a heavy metal possessing spin Hall effect, and in (iii) a single antiferromagnet possessing spin Hall effect. We show that the latter can experience a self-torque thanks to the non-vanishing spin Hall effect in the antiferromagnet.

  1. Treatment of open tibial fracture with bone defect caused by high velocity missiles: A case report

    Directory of Open Access Journals (Sweden)

    Golubović Zoran

    2013-01-01

    Full Text Available Introduction .Tibia fracture caused by high velocity missiles is mostly comminuted and followed by bone defect which makes their healing process extremely difficult and prone to numerous complications. Case Outline. A 34-year-old male was wounded at close range by a semi-automatic gun missile. He was wounded in the distal area of the left tibia and suffered a massive defect of the bone and soft tissue. After the primary treatment of the wound, the fracture was stabilized with an external fixator type Mitkovic, with convergent orientation of the pins. The wound in the medial region of the tibia was closed with the secondary stitch, whereas the wound in the lateral area was closed with the skin transplant after Thiersch. Due to massive bone defect in the area of the rifle-missile wound six months after injury, a medical team placed a reconstructive external skeletal fixator type Mitkovic and performed corticotomy in the proximal metaphyseal area of the tibia. By the method of bone transport (distractive osteogenesis, the bone defect of the tibia was replaced. After the fracture healing seven months from the secondary surgery, the fixator was removed and the patient was referred to physical therapy. Conclusion. Surgical treatment of wounds, external fixation, performing necessary debridement, adequate antibiotic treatment and soft and bone tissue reconstruction are essential in achieving good results in patients with the open tibial fracture with bone defect caused by high velocity missiles. Reconstruction of bone defect can be successfully treated by reconstructive external fixator Mitkovic. [Projekat Ministarstva nauke Republike Srbije, br. III 41017 i br. III 41004

  2. Measurement of edgewise torque force in vitro.

    Science.gov (United States)

    Steyn, C L

    1977-05-01

    The construction of a model for the measurement of palatal root torque is described. It was demonstrated that: 1. Halfway between the apex of a tooth and the arch wire the force was double that which was delivered at the apex. 2. The lateral incisors were subjected to appreciably more force than the central incisors. 3. The smaller the number of teeth acted upon, the greater the force they received.

  3. An ironless armature brushless torque motor

    Science.gov (United States)

    Studer, P. A.

    1973-01-01

    A high torque motor with improved servo mechanism is reported. Armature windings are cast into an epoxy cylinder and armature conductors are integrally cast with an aluminum mounting ring which provides thermal conductance directly into the structure. This configuration eliminates magnetic hysteresis because there is no relative motion between the rotating magnetic field and any stationary iron. The absence of destabilization forces provides a fast electrical response compared with a typical torquer of conventional construction.

  4. Torque Control of Electrorheological Fluidic Actuators

    OpenAIRE

    Vitrani, Marie-Aude; Nikitczuk, Jason; Morel, Guillaume; Mavroidis, Constantinos

    2004-01-01

    International audience; In this paper, the experimental closed loop torque control of electro-rheological fluids (ERF) based actuators for haptic applications is performed. ERFs are liquids that respond mechanically to electric fields by changing their properties, such as viscosity and shear stress, electroactively. Using the electrically controlled rheological properties of ERFs, we developed actuators for haptic devices that can resist human operator forces in a controlled and tunable fashi...

  5. Non-adiabatic spin transfer torque investigated using thermally activated magnetic domain walls in permalloy wires

    Energy Technology Data Exchange (ETDEWEB)

    Eltschka, Matthias; Krzyk, Stephen; Nowak, Ulrich; Klaeui, Mathias [Fachbereich Physik, Universitaet Konstanz, Universitaetsstrasse 10, 78457 Konstanz (Germany); Woetzel, Mathias [Fachbereich Physik, Universitaet Konstanz, Universitaetsstrasse 10, 78457 Konstanz (Germany); Center for Electron Nanoscopy, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark); Kasama, Takeshi; Dunin-Borkowski, Rafal [Center for Electron Nanoscopy, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark); Rhensius, Jan [Fachbereich Physik, Universitaet Konstanz, Universitaetsstrasse 10, 78457 Konstanz (Germany); Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Heyderman, Laura [Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland)

    2010-07-01

    The understanding of the interplay between spin-polarized currents and magnetization as well as the determination of the spin torque terms are of scientific interest and essential for many proposed applications. Using transmission electron microscopy we investigate thermally activated domain walls (DWs) jumping back and forth between two pinning sites in permalloy wires at room temperature. The motion is of pure thermal origin without the influence of external magnetic fields or electron currents. Considering the DW as a quasi particle in a local potential with two metastable states we show that this DW movement can be described by an Arrhenius law. Subsequently, we investigate the change of the local potential by constant currents which are far below the threshold values needed for DW propagation and do not induce significant heating. Based on a 1D description of the spin transfer torque effect and the Arrhenius law we derive the non-adiabatic coefficient {beta} for a transverse and a vortex DW.

  6. Gravitational torques in spiral galaxies gas accretion as a driving mechanism of galactic evolution

    CERN Document Server

    Block, D L; Combes, F; Puerari, I; Buta, R J; Block, David L.; Bournaud, Frederic; Combes, Francoise; Puerari, Ivanio; Buta, Ron

    2002-01-01

    The distribution of gravitational torques and bar strengths in the local Universe is derived from a detailed study of 163 galaxies observed in the near-infrared. The results are compared with numerical models for spiral galaxy evolution. It is found that the observed distribution of torques can be accounted for only with external accretion of gas onto spiral disks. Accretion is responsible for bar renewal - after the dissolution of primordial bars - as well as the maintenance of spiral structures. Models of isolated, non-accreting galaxies are ruled out. Moderate accretion rates do not explain the observational results: it is shown that galactic disks should double their mass in less than the Hubble time. The best fit is obtained if spiral galaxies are open systems, still forming today by continuous gas accretion, doubling their mass every 10 billion years.

  7. A Non-Unity Torque Sharing Function for Torque Ripple Minimization of Switched Reluctance Generators in Wind Power Systems

    Directory of Open Access Journals (Sweden)

    Hye-Ung Shin

    2015-10-01

    Full Text Available This paper deals with a new torque ripple minimization method for a Switched Reluctance Generator (SRG. Although, the SRG has many advantages including simple and robust construction, and high power density as a generator, it has not been widely employed in the industry. One of the major drawbacks of the SRG is its high torque ripple that results in high noise operation of the generator. In this paper, a non-unity Torque Sharing Function (TSF is proposed to minimize the torque ripple over a wide speed range of operation. Simulations as well as experimental results are presented to verify the effectiveness of the proposed torque ripple minimization technique.

  8. Fixator-assisted tibial lengthening over a plate in a patient with sequelae of poliomyelitis.

    Science.gov (United States)

    Tosun, Haci Bayram; Serbest, Sancar; Uludag, Abuzer; Gumustas, Seyitali; Celik, Suat

    2016-11-01

    There are many techniques for limb lengthening. Lengthening over a plate is an alternative choice of fixation in children or when nailing is difficult. We present a new technique for tibial lengthening with using a monolateral external fixator over a lengthening plate.Lengthening over an intramedullary nail is a commonly used method in patients with short stature or limb-length discrepancy. However, in patients with a narrow and excessively sclerotic intramedullary cavity in the pediatric age group where the skeletal system has not yet fully developed, difficulties have been observed in lengthening methods with nailing.Therefore, in these cases, the use of lengthening techniques over a plate is an alternative treatment option. Nevertheless, in lengthening techniques over a plate, if one side of the osteotomy area cannot be fixed, associated mechanical axis problems have been reported.We applied tibia lengthening with external fixator assistance over a custom-made lengthening plate in a patient with sequelae of poliomyelitis. This new lengthening technique applied over a plate could be the solution to the problems observed in other lengthening techniques over a plate.

  9. Dynamics of a split torque helicopter transmission

    Science.gov (United States)

    Rashidi, Majid; Krantz, Timothy

    A high reduction ratio split torque gear train has been proposed as an alternative to a planetary configuration for the final stage of a helicopter transmission. A split torque design allows a high ratio of power-to-weight for the transmission. The design studied in this work includes a pivoting beam that acts to balance thrust loads produced by the helical gear meshes in each of two parallel power paths. When the thrust loads are balanced, the torque is split evenly. A mathematical model was developed to study the dynamics of the system. The effects of time varying gear mesh stiffness, static transmission errors, and flexible bearing supports are included in the model. The model was demonstrated with a test case. Results show that although the gearbox has a symmetric configuration, the simulated dynamic behavior of the first and second compound gears are not the same. Also, results show that shaft location and mesh stiffness tuning are significant design parameters that influence the motions of the system.

  10. Mode coupling in spin torque oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Steven S.-L., E-mail: ZhangShule@missouri.edu [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States); Zhou, Yan, E-mail: yanzhou@hku.hk [Department of Physics, The University of Hong Kong, Hong Kong (China); Center of Theoretical and Computational Physics, University of Hong Kong, Hong Kong (China); Li, Dong, E-mail: geodesic.ld@gmail.com [Department of Physics, Centre for Nonlinear Studies, and Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Systems, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China); Heinonen, Olle, E-mail: heinonen@anl.gov [Material Science Division, Argonne National Laboratory, Lemont, IL 60439 (United States); Northwestern-Argonne Institute of Science and Technology, 2145 Sheridan Road, Evanston, IL 60208 (United States); Computation Institute, The Unversity of Chicago, 5735 S Ellis Avenue, Chicago, IL 60637 (United States)

    2016-09-15

    A number of recent experimental works have shown that the dynamics of a single spin torque oscillator can exhibit complex behavior that stems from interactions between two or more modes of the oscillator, such as observed mode-hopping or mode coexistence. There has been some initial work indicating how the theory for a single-mode (macro-spin) spin torque oscillator should be generalized to include several modes and the interactions between them. In the present work, we rigorously derive such a theory starting with the Landau–Lifshitz–Gilbert equation for magnetization dynamics by expanding up to third-order terms in deviation from equilibrium. Our results show how a linear mode coupling, which is necessary for observed mode-hopping to occur, arises through coupling to a magnon bath. The acquired temperature dependence of this coupling implies that the manifold of orbits and fixed points may shift with temperature. - Highlights: • Deriving equations for coupled modes in spin torque oscillators. • Including Hamiltonian formalism and elimination of three–magnon processes. • Thermal bath of magnons central to mode coupling. • Numerical examples of circular and elliptical devices.

  11. Posterior Tibial Tendon Dysfunction: An Overlooked Cause of Foot Deformity

    Science.gov (United States)

    Bubra, Preet Singh; Keighley, Geffrey; Rateesh, Shruti; Carmody, David

    2015-01-01

    Posterior tibial tendon dysfunction is the most common cause of adult acquired flatfoot. Degenerative changes in this tendon, lead to pain and weakness and if not identified and treated will progress to deformity of the foot and degenerative changes in the surrounding joints. Patients will complain of medial foot pain, weakness, and a slowly progressive foot deformity. A “too many toes” sign may be present and patients will be unable to perform a single heal raise test. Investigations such X-ray, ultrasound and magnetic resonance imaging will help stage the disease and decide on management. The optimal manage may change based on the progression of deformity and stage of disease. Early identification and prompt initiation of treatment can halt progression of the disease. The purpose of this article is to examine the causes, signs, symptoms, examinations, investigations and treatment options for posterior tibial tendon dysfunction. PMID:25810985

  12. MR evaluation of femoral neck version and tibial torsion

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-01-15

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

  13. High tibial osteotomy in varus knees: indications and limits

    Science.gov (United States)

    LOIA, MARCO CORGIAT; VANNI, STEFANIA; ROSSO, FEDERICA; BONASIA, DAVIDE EDOARDO; BRUZZONE, MATTEO; DETTONI, FEDERICO; ROSSI, ROBERTO

    2016-01-01

    Opening wedge high tibial osteotomy (OWHTO) is a surgical procedure that aims to correct the weight-bearing axis of the knee, moving the loads laterally from the medial compartment. Conventional indications for OWHTO are medial compartment osteoarthritis and varus malalignment of the knee; recently OWHTO has been used successfully in the treatment of double and triple varus. OWHTO, in contrast to closing wedge high tibial osteotomy, does not require fibular osteotomy or peroneal nerve dissection, or lead to disruption of the proximal tibiofibular joint and bone stock loss. For these reasons, interest in this procedure has grown in recent years. The aim of this study is to review the literature on OWHTO, considering indications and prognostic factors (body mass index, grade of osteoarthritis, instability, range of movement and age), outcomes at mid-term follow-up, and limits of the procedure (slope modifications, patellar height changes and difficulties in conversion to a total knee arthroplasty). PMID:27602350

  14. Roentgen stereogrammetry in high tibial osteotomy for gonarthrosis

    Energy Technology Data Exchange (ETDEWEB)

    Tjoernstrand, B.; Selvik, G.; Egund, N.; Lingstrand, A.

    1981-01-01

    In three cases operated with high tibial osteotomy for medial gonarthrosis the exact method of roentgen stereophotogrammetry with tantalum balls as bone markers was used to study angular and translational movements in three dimensions at the operation and during the healing period. Tibial osteotomy caused angular and translational movements even in planes where correction was not intended, and the stereo technique revealed that stability was not present when knee mobilisation started. Correlation between the stereo values and conventional radiographic measurements were best in the frontal plane (root mean square value of discrepancies 1.3/sup 0/). Roentgen stereophotogrammetry gives superior information compared with the conventional radiographic technique, but it is concluded that the latter has sufficient accuracy for the clinical assessment of corrections in the frontal plane.

  15. Open tibial shaft fractures: II. Definitive management and limb salvage.

    Science.gov (United States)

    Melvin, J Stuart; Dombroski, Derek G; Torbert, Jesse T; Kovach, Stephen J; Esterhai, John L; Mehta, Samir

    2010-02-01

    Definitive treatment of open fractures of the tibial diaphysis is challenging. The high-energy nature of these fractures, as well as the contamination of the fracture site and devitalization of the soft-tissue envelope, greatly increases the risk of infection, nonunion, and wound complications. The goals of definitive treatment include wound coverage or closure; prevention of infection; restoration of length, alignment, rotation, and stability; fracture healing; and return of function. Advances in orthobiologics, modern plastic surgical techniques, and fracture stabilization methods, most notably locked intramedullary nailing, have led to improved prognosis for functional recovery and limb salvage. Despite improved union and limb salvage rates, the prognosis for severe type III open fracture of the tibial shaft remains guarded, and outcomes are often determined by patient psychosocial variables.

  16. Asymmetry in gait pattern following tibial shaft fractures

    DEFF Research Database (Denmark)

    Larsen, Peter; Læssøe, Uffe; Rasmussen, Sten

    2017-01-01

    INTRODUCTION: Despite the high number of studies evaluating the outcomes following tibial shaft fractures, the literature lacks studies including objective assessment of patients' recovery regarding gait pattern. The purpose of the present study was to evaluate whether gait patterns at 6 and 12...... months post-operatively following intramedullary nailing of a tibial shaft fracture are different compared with a healthy reference population. PATIENTS AND METHODS: The study design was a prospective cohort study. The primary outcome measurement was the gait patterns at 6 and 12 months post...... fracture, gait asymmetry accompanied with slower speed and cadence are common during the first 6 months and become normalized compared with a healthy reference population between 6 and 12 months post-operatively....

  17. The Spin Torque Lego - from spin torque nano-devices to advanced computing architectures

    Science.gov (United States)

    Grollier, Julie

    2013-03-01

    Spin transfer torque (STT), predicted in 1996, and first observed around 2000, brought spintronic devices to the realm of active elements. A whole class of new devices, based on the combined effects of STT for writing and Giant Magneto-Resistance or Tunnel Magneto-Resistance for reading has emerged. The second generation of MRAMs, based on spin torque writing : the STT-RAM, is under industrial development and should be out on the market in three years. But spin torque devices are not limited to binary memories. We will rapidly present how the spin torque effect also allows to implement non-linear nano-oscillators, spin-wave emitters, controlled stochastic devices and microwave nano-detectors. What is extremely interesting is that all these functionalities can be obtained using the same materials, the exact same stack, simply by changing the device geometry and its bias conditions. So these different devices can be seen as Lego bricks, each brick with its own functionality. During this talk, I will show how spin torque can be engineered to build new bricks, such as the Spintronic Memristor, an artificial magnetic nano-synapse. I will then give hints on how to assemble these bricks in order to build novel types of computing architectures, with a special focus on neuromorphic circuits. Financial support by the European Research Council Starting Grant NanoBrain (ERC 2010 Stg 259068) is acknowledged.

  18. Posterior Tibial Tendon Dysfunction and Flatfoot: Analysis with Simulated Walking

    OpenAIRE

    Watanabe, Kota; Kitaoka, Harold B; Fujii, Tadashi; Crevoisier, Xavier M.; Berglund, Lawrence J.; Zhao, Kristin D.; Kaufman, Kenton R.; An, Kai-Nan

    2012-01-01

    Many biomechanical studies investigated pathology of flatfoot and effects of operations on flatfoot. The majority of cadaveric studies are limited to the quasistatic response to static joint loads. This study examined the unconstrained joint motion of the foot and ankle during stance phase utilizing a dynamic foot-ankle simulator in simulated stage 2 posterior tibial tendon dysfunction (PTTD). Muscle forces were applied on the extrinsic tendons of the foot using six servo-pneumatic cylinders ...

  19. Human tibial torsion - Morphometric assessment and clinical relevance

    Directory of Open Access Journals (Sweden)

    Swati Gandhi

    2014-02-01

    Full Text Available Background: Tibial torsion is an important anatomical parameter in clinical practice and displays variability among individuals. These variations are extremely significant in view of alignment guides such as those related to rotational landmarks of tibia in total knee arthroplasty. Further, precise knowledge and information pertaining to angle of tibial torsion also helps in correction of traumatic malunion or congenital maltorsion of tibia. Methods: The present study was carried out to determine the angle of tibial torsion in 100 adult dry tibia bones in the Department of Anatomy, Government Medical College, Amritsar. The study group comprised 50 males and 50 females with equal number of right- and left-sided bones. The measurements were meticulously recorded and the data were subjected to statistical analysis. The results were analyzed and discussed in the light of existing literature. Results: On the right side, it was found to be 29.84° ± 4.86°° (range = 22.00° -38.00° in males and 28.92° ± 5.10°° (range = 15.00°-38.00° in females. On the left side, it was found to be 28.00° ± 4.94°° (range = 20.00°-40.00°° in males and 28.12° ± 4.28°° (range = 20.00°-37.00°° in females. Conclusion: The present study is an endeavor to provide baseline data with reference to the angle of tibial torsion in the Indian population. The results of the study assume special importance in view of the technical advancements in reconstructive surgical procedures in orthopedic practice.

  20. Aetiology, imaging and treatment of medial tibial stress syndrome

    OpenAIRE

    Moen, M.H.

    2012-01-01

    The work contained is this thesis discusses aetiology, imaging and treatment of a common leg injury: medial tibial stress syndrome (MTSS). Although a common injury, the number of scientific articles on this topic is relatively low as is explained in chapter 1. This chapter also highlights that the most probable cause of MTSS is bone overload and not traction induced periostitis. In chapter 2 a review of the literature on MTSS is provided until 2009. Chapters 3 and 4 discuss different common a...

  1. Pigmented villonodular synovitis after TKA associated with tibial component loosening.

    Science.gov (United States)

    Chung, Byung June; Park, Yong Bum

    2011-08-08

    There is no known causal link between total knee arthroplasty (TKA) and pigmented villonodular synovitis (PVNS). There also is no known relationship between PVNS and implant loosening after TKA in the literature. This article presents a case of PVNS in a patient undergoing revision TKA for tibial component loosening. A 74-year-old woman who had undergone cemented bilateral TKA 5 years earlier presented with painful swelling in her right knee. At the time of the primary TKA, no abnormal signs were found in the synovial membrane. Routine follow-up radiographs did not indicate implant loosening. At the patient's final follow-up examination before revision surgery, a radiolucent lesion was found below the tibial component. During revision surgery, there was focal proliferation of the synovial tissue with heavy pigmentation around the anteromedial part of the tibial component. The abnormal tissue was removed, and the tibial component was exchanged. The articular surface of the polyethylene was not damaged, and backside wear was not found. For the revision surgery, 5-mm thick medial metal block and extension stem were used. Histological analysis of the resected tissue revealed the typical appearance of PVNS. We present a typical case of PVNS found during revision TKA 5 years after primary TKA. It is hoped this report will encourage surgeons to consider PVNS in the differential diagnosis of patients who present with painful swelling of the knee and to consider PVNS as one of the causes of implant loosening after TKA. Further research about causal factors between PVNS and implant loosening are needed. Copyright 2011, SLACK Incorporated.

  2. Tibial acceleration profiles during the menstrual cycle in female athletes.

    Science.gov (United States)

    Hohmann, Erik; Bryant, Adam L; Livingstone, Elisabeth; Reaburn, Peter; Tetsworth, Kevin; Imhoff, Andreas

    2015-10-01

    Fluctuating levels of endogenous estrogen are thought to have an adverse effect on lower limb biomechanics, given the observed higher rate of ACL injury at certain phases of the menstrual cycle. The purpose of this study was to investigate the effects of fluctuating endogenous estrogen levels during the menstrual cycle on acceleration transients at the proximal tibia in young physically active females. Eleven females aged 16-18 years participated in this study and were compared to a male control group. Female subjects were tested at each of the four phases of the menstrual cycle: menses, follicular, ovulation and luteal. On each test occasion, acceleration transients at the proximal tibia were measured while subjects performed an abrupt deceleration task (simulated netball landing). No significant differences were found between the different phases of the menstrual cycle for peak tibial acceleration (PTA; P = 0.57), and time to zero tibial acceleration (TZTA; P = 0.59). However, there was a significant difference for time to peak tibial acceleration (TPTA) between menstruation and follicular (P = 0.04), menstruation and ovulation (P = 0.001), menstruation and luteal phase (P = 0.002), and follicular phase and ovulation (P = 0.007). In the male control group, no significant between-test session differences were observed for PTA (P = 0.48), TZTA (P = 0.08) and TPTA (P = 0.29). While there were no significant between-group differences for PTA (P = 0.21) and TZTA (P = 0.48), significant between-group differences were observed for TPTA (P = 0.001). The results of this project strongly suggest that serum estrogen fluctuations have an effect on tibial acceleration profiles in young female athletes during different phases of the menstrual cycle.

  3. Safe surgical technique: intramedullary nail fixation of tibial shaft fractures

    OpenAIRE

    Zelle, Boris A.; Boni, Guilherme

    2015-01-01

    Statically locked, reamed intramedullary nailing remains the standard treatment for displaced tibial shaft fractures. Establishing an appropriate starting point is a crucial part of the surgical procedure. Recently, suprapatellar nailing in the semi-extended position has been suggested as a safe and effective surgical technique. Numerous reduction techiques are available to achieve an anatomic fracture alignment and the treating surgeon should be familiar with these maneuvers. Open reduction ...

  4. Heel and foot reconstruction using reverse-flow posterior tibial flap.

    Science.gov (United States)

    Satoh, K; Sakai, M; Hiromatsu, N; Ohsumi, N

    1990-04-01

    Island flaps supplied by the intermuscular cutaneous perforator (IMCP) from a deep vessel, such as the peroneal flap pedicled by IMCP from the peroneal vessel or the anterior tibial flap supplied by IMCP from the anterior tibial vessel, are reported to be useful in reconstructive procedures for soft-tissue defects of the lower leg. However, the posterior tibial flap, pedicled by IMCP from the posterior tibial vessel, has not yet been fully described. The posterior tibial flap can be used either as a normal-flow or as a reverse-flow flap. It is particularly versatile as a reverse-flow flap for reconstruction of soft-tissue defects of the heel and foot. Three reverse-flow posterior tibial flaps were clinically applied, without venous anastomosis, to reconstruct heel and foot defects, and all three survived completely. The operative procedure and its characteristics are described.

  5. Bilateral synchronous tibial periosteal osteosarcoma with familial incidence.

    Science.gov (United States)

    Maheshwari, Aditya V; Jelinek, James S; Seibel, Nita L; Meloni-Ehrig, Aurelia M; Kumar, Dhruv; Henshaw, Robert M

    2012-08-01

    Multifocal or multicentric osteosarcoma (OS) has been described as tumor occurrence at two or more sites in a patient without visceral metastasis. These may be synchronous (more than one lesion at presentation) or metachronous (new tumor developing after the initial treatment). The incidence of multifocal OS has ranged from 1.5 to 5.4% in large series, with the synchronous type being rarer. Similarly, periosteal OS is another rare subtype of surface OS and constitutes less than 2% of all OS. An 11-year-old female was diagnosed with bilateral synchronous tibial periosteal OS, which were confirmed by CT-guided biopsies. After neoadjuvant chemotherapy, the patient underwent a staged wide local resection of the tumors. The defect was reconstructed with a proximal tibial replacement on the left side and autologous bone grafting on the right side. The patient did well after surgery and is free of disease at 5.5 years of follow-up. However, her brother also developed a right tibial periosteal osteosarcoma 4 years after her index surgery. Genetic analysis of blood sample from both patients showed a similar missense mutation in at least one allele of TP53 gene (exon 8). To the best of our knowledge, a case of bilateral 'synchronous' periosteal OS with a familial incidence has not been reported before.

  6. Suprapatellar nailing of tibial fractures-Indications and technique.

    Science.gov (United States)

    Franke, J; Hohendorff, B; Alt, V; Thormann, U; Schnettler, R

    2016-02-01

    Intramedullary nailing is the standard procedure for surgical treatment of closed and Gustilo-Anderson Grade I-II° open fractures of the tibial shaft. The use of intramedullary nailing for the treatment of proximal metaphyseal tibia fractures is frequently followed by postoperative malalignment, whereas plate osteosynthesis is associated with higher rates of postoperative infection. Intramedullary nailing of tibial fractures is generally performed through an infrapatellar approach. The injured extremity must be positioned at a minimum of 90° of flexion in the knee joint to achieve optimal exposure of the correct entry point. The tension of the quadriceps tendon causes a typical apex anterior angulation of the proximal fragment. The suprapatellar approach improves reduction of the fracture and reduces the occurrence of malalignment during intramedullary nailing of extra-articular proximal tibial fractures. The knee is positioned in 20° of flexion to neutralise traction forces secondary to the quadriceps muscle, thus preventing an apex anterior angulation of the proximal fragment. An additional advantage of the technique is that it allows the surgeon to avoid or minimise further soft tissue damage because of the distance between the optimal incision point and the usual area of soft tissue damage.

  7. State diagram of spin-torque oscillator with perpendicular reference layer and planar field generation layer

    Directory of Open Access Journals (Sweden)

    Mengwei Zhang

    2015-06-01

    Full Text Available The state diagram of spin-torque oscillator (STO with perpendicular reference layer (REF and planar field generation layer (FGL was studied by a macrospin model and a micro-magnetic model. The state diagrams are calculated versus the current density, external field and external field angle. It was found that the oscillation in FGL could be controlled by current density combined with external field so as to achieve a wide frequency range. An optimized current and applied field region was given for microwave assisted magnetic recording (MAMR, considering both frequency and output field oscillation amplitude. The results of the macro-spin model were compared with those of the micro-magnetic model. The macro-spin model was qualitatively different from micro-magnetics and experimental results when the current density was large and the FGL was non-uniform.

  8. Torque Ripple Reduction in Direct Torque Control Based Induction Motor using Intelligent Controllers

    Science.gov (United States)

    Sudhakar, Ambarapu; Vijaya Kumar, M.

    2015-09-01

    This paper presents intelligent control scheme together with conventional control scheme to overcome the problems with uncertainties in the structure encountered with classical model based design of induction motor drive based on direct torque control (DTC). It allows high dynamic performance to be obtained with very simple hysteresis control scheme. Direct control of the torque and flux is achieved by proper selection of inverter voltage space vector through a lookup table. This paper also presents the application of intelligent controllers like neural network and fuzzy logic controllers to control induction machines with DTC. Intelligent controllers are used to emulate the state selector of the DTC. With implementation of intelligent controllers the system is also verified and proved to be operated stably with reduced torque ripple. The proposed method validity and effectiveness has been verified by computer simulations using Matlab/Simulink®. These results are compared with the ones obtained with a classical DTC using proportional integral speed controller.

  9. Improved Torque Control Performance in Direct Torque Control using Optimal Switching Vectors

    Directory of Open Access Journals (Sweden)

    Muhd Zharif Rifqi Zuber Ahmadi

    2015-02-01

    Full Text Available This paper presents the significant improvement of Direct Torque Control (DTC of 3-phases induction machine using a Cascaded H-Bidge Multilevel Inverter (CHMI. The largest torque ripple and variable switching frequency are known as the major problem founded in DTC of induction motor. As a result, it can diminish the performance induction motor control. Therefore, the conventional 2-level inverter has been replaced with CHMI the in order to increase the performance of the motor either in dynamic or steady-state condition. By using the multilevel inverter, it can produce a more selection of the voltage vectors. Besides that, it can minimize the torque ripple output as well as increase the efficiency by reducing the switching frequency of the inverter. The simulation model of the proposed method has been developed and tested by using Matlab software. Its improvements were also verified via experimental results.

  10. Role of the fibula in the stability of diaphyseal tibial fractures fixed by intramedullary nailing

    OpenAIRE

    John G. Galbraith; Daly, Charles J.; Harty, James A; Dailey, Hannah L.

    2016-01-01

    Background: For tibial fractures, the decision to fix a concomitant fibular fracture is undertaken on a case-by-case basis. To aid in this clinical decision-making process, we investigated whether loss of integrity of the fibula significantly destabilises midshaft tibial fractures, whether fixation of the fibula restores stability to the tibia, and whether removal of the fibula and interosseous membrane for expediency in biomechanical testing significantly influences tibial interfragmentary m...

  11. Osteotomia tibial alta em pacientes com artrose do joelho High tibial osteotomy in patients with knee arthrosis

    Directory of Open Access Journals (Sweden)

    Roger Avakian

    2008-01-01

    Full Text Available OBJETIVO: Avaliar o tratamento da gonartrose medial com osteotomia tibial tipo cunha de fechamento lateral associado à liberação da articulação tibiofibular proximal. MÉTODOS: Realizamos esta técnica associado com liberação da articulação tibiofibular proximal no tratamento da gonartrose medial em 36 pacientes (41 joelhos de janeiro de 1995 a abril de 2003, com idade de 53,4 anos (média, seguidos por 51,6 meses (média. RESULTADOS: Na avaliação notamos que as osteotomias tibiais com cunha de fechamento lateral permitem correção satisfatória da deformidade fêmorotibial, com angulação femorotibial final em torno de 7º de valgo; o eixo mecânico foi desviado da região tibial medial (posição 1,2% para o centro do joelho (posição 50,5%; a inclinação tibial na incidência perfil pré-operatória de 9,8º foi corrigida para 6,5º (média; a mobilidade articular apresentou perda de 2,3º na extensão (média. CONCLUSÃO: A técnica permite correção satisfatória da deformidade em varo fêmorotibial, porém não é isenta de complicações (14,6%. O grau de satisfação (Lysholm dos pacientes teve incremento de 27,3 para 89. Assim, constitui uma parte essencial no arsenal de tratamento da gonartrose.PURPOSE: To assess medial gonarthrosis treatment with wedge-like side-closed tibial osteotomy combined with proximal tibial-fibular joint release. METHODS: we employed this technique combined with proximal tibial-fibular joint release in the treatment of medial gonarthrosis in 36 patients (41 knees, from January 1995 to April 2003, with mean age of 53.4 years, followed-up for 51.6 months (in average. RESULTS: In the assessment, we noticed that wedge-like side-closed tibial osteotomies allow for a satisfactory repair of the femorotibial deformity, with end femorotibial angle of about 7° valgus; the mechanical axis was dislocated from the medial region of the tibia (position: 1.2% to knee center (position: 50.5%; the 9.8° tibial

  12. Aneurisma verdadeiro bilateral de artéria tibial posterior True bilateral aneurysm of the posterior tibial artery

    Directory of Open Access Journals (Sweden)

    Silvio Romero de Barros Marques

    2006-03-01

    Full Text Available Neste artigo, faz-se o relato de um caso de aneurisma verdadeiro bilateral da artéria tibial posterior em paciente de 57 anos. Os aneurismas surgiram em épocas diferentes. Os aspectos clínicos, diagnósticos e terapêuticos deste caso são discutidos. Este relato é importante, pois os autores não têm conhecimento de caso semelhante na literatura consultada.This article reports a case of true bilateral aneurysm of the tibial posterior artery in a 57 year-old patient. The aneurysms occurred at different times. The clinical, diagnostic and therapeutic aspects of this case are discussed. This report is important because the authors did not find a similar description in the literature.

  13. Bevel gear driver and method having torque limit selection

    Science.gov (United States)

    Cook, Joseph S., Jr. (Inventor)

    1994-01-01

    This invention comprises a torque drive mechanism utilizing axially translatable, mutually engageable transmission members having mating crown gears, driven and driving members with a three-element drive train being biased together by resilient means or by a fluid actuator system, the apparatus being operable to transmit a precisely controlled degree of torque to a driven member. The apparatus is applicable for use in hand tools and as a replacement for impact torque drivers, torque wrenches, motorized screw drivers, or the like, wherein the applied torque must be precisely controlled or limited. The bevel torque drive includes a drive gear which is axially displaceable and rotatable within cylindrical driver housing, a rotatable intermediate gear, and an output gear. Key rotationally secures displaceable gear with respect to input shaft but permits axial movement therebetween. A thrust bearing is preferably connected to the lower end of shaft for support to reduce play and friction between shaft and a transmission joint disc during rotation of the gear train. Coaxially mounted coiled spring is footed against displaceable gear for biasing the displaceable gear toward and into engagement with the intermediate gear for driving intermediate gear and output gear. Torque control is achieved by the use of straight or spiral beveled gears which are of configurations adapted to withdraw from mutual engagement upon the torque exceeding a predetermined limit. The novel, advantageous features of the invention include the configuration of the mating, crown gear sets and the axially translatable, slidable drive gear. The mechanism is capable of transmitting a high degree of torque within a narrow, compact transmission housing. The compact size and narrow, elongated configuration of the housing is particularly applicable for use in hand tools and in multiple torque driver mechanisms in which it is necessary to drive multiple fasteners which are located in close proximity. Prior

  14. Local and Widespread Hyperalgesia After Isolated Tibial Shaft Fractures Treated with Intramedullary Nailing

    DEFF Research Database (Denmark)

    Larsen, Peter; Elsøe, Rasmus; Graven-Nielsen, Thomas

    2016-01-01

    OBJECTIVES: Knee pain is accepted as a common complication to intramedullary nailing of tibial fractures. However, no studies have systematically studied the pain sequel following tibial fractures. The objective of this study was to assess pain and hyperalgesia from 6 weeks to 12 months postopera......OBJECTIVES: Knee pain is accepted as a common complication to intramedullary nailing of tibial fractures. However, no studies have systematically studied the pain sequel following tibial fractures. The objective of this study was to assess pain and hyperalgesia from 6 weeks to 12 months...

  15. Pseudoarthrosis of medial tibial plateau fracture——role of alignment procedure

    Institute of Scientific and Technical Information of China (English)

    Ashish Devgan; Pradeep Kamboj; Vinay Gupta; Narender K Magu; Rajesh Rohilla

    2013-01-01

    Nonunion in tibial plateau fractures is very rare.Limited literature is available on Pubmed search on intraarticular tibial nonunion.Most of the cases reported have been following failed surgical treatment and none was neglected fractures.Three patients of isolated and neglected medial tibial plateau nonunion with almost similar demographic profile are reported in this paper.All the three patients were managed by minimally invasive compression fixation using lag screws supplemented with limb realignme nt procedure of high tibial osteotomy.We discussed theinjury mechanism,management and rehabilitation in such cases and reviewed the available literature regarding such a presentation.

  16. Stress analysis of the tibial plateau according to the difference of blade path entry in opening wedge high tibial osteotomy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jun Woo; Xin, YuanZhu; Yang, Seok Jo [Chungnam National University, Daejeon (Korea, Republic of); Ji, Jong Hun; Panchal, Karnav; Kwon, Oh Soo [The Catholic University of Korea, Daejeon (Korea, Republic of)

    2015-03-15

    High tibial osteotomy (HTO) has been used to successfully treat patients with genu varus deformities that can improve mechanical function and condition in the knee joint. Clinical studies have reported that bow legs often occur with a concentrated load on the varus of the tibia. This study aimed to analyze and verify the clinical test data result by utilizing the three-dimensional (3D) static finite element method (FEM). The 3D model of lower extremities, which include the femur, tibia, meniscus, and knee articular cartilage, was created using the images from a computer tomography scan and magnetic resonance imaging. In this report, we compared changes in stress distribution and force reaction on the tibial plateau because of critical problems caused by unexpected changes in the tibial posterior-slope angle because of HTO. The results showed that the 5 .deg. wedge-angle virtual opening wedge HTO without and with the posterior-slope angle shows has a load concentration of approximately 60% and 45% in the medial region, respectively.

  17. Effect of fatigue on hamstring reflex responses and posterior-anterior tibial translation in men and women.

    Directory of Open Access Journals (Sweden)

    Martin Behrens

    Full Text Available Anterior cruciate ligament (ACL rupture ranks among the most common injuries in sports. The incidence of ACL injuries is considerably higher in females than in males and the underlying mechanisms are still under debate. Furthermore, it has been suggested that muscle fatigue can be a risk factor for ACL injuries. We investigated gender differences in hamstring reflex responses and posterior-anterior tibial translation (TT before and after fatiguing exercise. We assessed the isolated movement of the tibia relative to the femur in the sagittal plane as a consequence of mechanically induced TT in standing subjects. The muscle activity of the hamstrings was evaluated. Furthermore, isometric maximum voluntary torque (iMVT and rate of torque development (RTD of the hamstrings (H and quadriceps (Q were measured and the MVT H/Q as well as the RTD H/Q ratios were calculated. After fatigue, reflex onset latencies were enhanced in women. A reduction of reflex responses associated with an increased TT was observed in females. Men showed no differences in these parameters. Correlation analysis revealed no significant associations between parameters for TT and MVT H/Q as well as RTD H/Q. The results of the present study revealed that the fatigue protocol used in this study altered the latency and magnitude of reflex responses of the hamstrings as well as TT in women. These changes were not found in men. Based on our results, it is conceivable that the fatigue-induced decrease in neuromuscular function with a corresponding increase in TT probably contributes to the higher incidence of ACL injuries in women.

  18. Medial opening wedge high tibial osteotomy alters knee moments in multiple planes during walking and stair ascent.

    Science.gov (United States)

    Leitch, Kristyn M; Birmingham, Trevor B; Dunning, Cynthia E; Giffin, J Robert

    2015-07-01

    Medial opening wedge high tibial osteotomy is a surgical procedure intended to redistribute loads on the knee in patients with medial compartment knee osteoarthritis (OA). The surgery may affect moments in multiple planes during ambulation, with potential beneficial or detrimental effects on joint loads. The objective of this study was to investigate three-dimensional external knee moments before and after medial opening wedge high tibial osteotomy during level walking and during stair ascent. Fourteen patients with varus alignment and osteoarthritis primarily affecting the medial compartment of the tibiofemoral joint were assessed. Three-dimensional motion analyses during level walking and stair ascent was evaluated using inverse dynamics before, 6 and 12 months after surgery. Mean changes at 12 months suggested decreases in the peak knee adduction, flexion and internal rotation moments, with standardized response means ranging from 0.15 to 2.54. These decreases were observed despite increases in speed. Changes in alignment were associated with changes in the adduction and internal rotation moments, but not the flexion moment. Both pre- and postoperatively, the peak knee adduction moment was significantly lower (p=0.001) during stair ascent than during level walking, while the flexion and internal rotation moments were significantly higher (pplanes of motion during ambulation, suggesting substantial alterations of the loads on the knee during ambulation.

  19. Robust spin transfer torque in antiferromagnetic tunnel junctions

    KAUST Repository

    Saidaoui, Hamed Ben Mohamed

    2017-04-18

    We theoretically study the current-induced spin torque in antiferromagnetic tunnel junctions, composed of two semi-infinite antiferromagnetic layers separated by a tunnel barrier, in both clean and disordered regimes. We find that the torque enabling electrical manipulation of the Néel antiferromagnetic order parameter is out of plane, ∼n×p, while the torque competing with the antiferromagnetic exchange is in plane, ∼n×(p×n). Here, p and n are the Néel order parameter direction of the reference and free layers, respectively. Their bias dependence shows behavior similar to that in ferromagnetic tunnel junctions, the in-plane torque being mostly linear in bias, while the out-of-plane torque is quadratic. Most importantly, we find that the spin transfer torque in antiferromagnetic tunnel junctions is much more robust against disorder than that in antiferromagnetic metallic spin valves due to the tunneling nature of spin transport.

  20. COMMUTATION TIME ESTIMATOR FOR PM BLDC MOTOR TORQUE SIGNATURE ENHANCEMENT

    Directory of Open Access Journals (Sweden)

    WAEL A. SALAH

    2014-12-01

    Full Text Available This paper presents the development of the commutation time estimator (CTE for PM BLDC motor drives. The proposed scheme is aimed to enhance motor output torque by minimizing the generated torque ripples. The torque ripples originating from commutation instances cause spikes and dips in the motor output torque. The motor output torque could be enhanced by mitigating the phase current mismatch rate during phase current commutation period. This rate could be almost matched by introducing the commutation time estimator (CTE in order to control the rate of the energized phase current to be matched with the de-energized phase rate. Results obtained have validated and verified the proposed CTE effectiveness with a 50% average reduction of the generated torque ripples in PM BLDC motor.

  1. The effect of knee joint angle on torque control.

    Science.gov (United States)

    Sosnoff, Jacob J; Voudrie, Stefani J; Ebersole, Kyle T

    2010-01-01

    The purpose of the author's investigation was to examine the effect of knee joint angle on torque control of the quadriceps muscle group. In all, 12 healthy adults produced maximal voluntary contractions and submaximal torque (15, 30, and 45% MVC [maximal voluntary contraction]) at leg flexion angles of 15 degrees , 30 degrees , 60 degrees , and 90 degrees below the horizontal plane. As expected, MVC values changed with respect to joint angle with maximum torque output being greatest at 60 degrees and least at 15 degrees . During the submaximal tasks, participants appropriately scaled their torque output to the required targets. Absolute variability (i.e., standard deviation) of torque output was greatest at 60 degrees and 90 degrees knee flexion. However, relative variability as indexed by coefficient of variation (CV) decreased as joint angle increased, with the greatest CV occurring at 15 degrees . These results are congruent with the hypothesis that joint angle influences the control of torque.

  2. Displacement of the medial meniscus within the passive motion characteristics of the human knee joint: an RSA study in human cadaver knees.

    Science.gov (United States)

    Tienen, T G; Buma, P; Scholten, J G F; van Kampen, A; Veth, R P H; Verdonschot, N

    2005-05-01

    The objective of this study was to validate an in vitro human cadaver knee-joint model for the evaluation of the meniscal movement during knee-joint flexion. The question was whether our model showed comparable meniscal displacements to those found in earlier meniscal movement studies in vivo. Furthermore, we determined the influence of tibial torque on the meniscal displacement during knee-joint flexion. Three tantalum beads were inserted in the medial meniscus of six human-cadaver joints. The knee joints were placed and loaded in a loading apparatus, and the movements of the beads were determined by means of RSA during knee-joint flexion and extension with and without internal tibial (IT) and external tibial (ET) torque. During flexion without tibial torque, all menisci moved in posterior and lateral direction. The anterior horn showed significantly greater excursions than the posterior horn in both posterior and lateral direction. Internal tibial torque caused an anterior displacement of the pathway on the tibial plateau. External tibial torque caused a posterior displacement of the pathway. External tibial torque restricted the meniscal displacement during the first 30 degrees of knee-joint flexion. The displacements of the meniscus in this experiment were similar to the displacements described in the in vivo MRI studies. Furthermore, the application of tibial torque confirmed the relative immobility of the posterior horn of the meniscus. During external tibial torque, the posterior displacement of the pathway on the tibial plateau during the first 30 degrees of flexion might be restricted by the attached knee-joint capsule or the femoral condyle. This model revealed representative meniscal displacements during simple knee-joint flexion and also during the outer limits of passive knee-joint motion.

  3. Torque Anomaly in Quantum Field Theory

    CERN Document Server

    Fulling, S A; Trendafilova, C S

    2012-01-01

    The expectation values of energy density and pressure of a quantum field inside a wedge-shaped region appear to violate the expected relationship between torque and total energy as a function of angle. In particular, this is true of the well-known Deutsch--Candelas stress tensor for the electromagnetic field, whose definition requires no regularization except possibly at the vertex. Unlike a similar anomaly in the pressure exerted by a reflecting boundary against a perpendicular wall, this problem cannot be dismissed as an artifact of an ad hoc regularization.

  4. Motor Torque Calculations For Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Saurabh Chauhan

    2015-08-01

    Full Text Available Abstract It is estimated that 25 of the total cars across the world will run on electricity by 2025. An important component that is an integral part of all electric vehicles is the motor. The amount of torque that the driving motor delivers is what plays a decisive role in determining the speed acceleration and performance of an electric vehicle. The following work aims at simplifying the calculations required to decide the capacity of the motor that should be used to drive a vehicle of particular specifications.

  5. Calculation of the torque on dielectric elliptical cylinders

    OpenAIRE

    Rockstuhl, Carsten; Herzig, Hans-Peter

    2008-01-01

    We present our investigation of the torque exerted on dielectric elliptical cylinders by highly focused laser beams. The calculations are performed with rigorous diffraction theory, and the size-dependent torque is analyzed as a function of the axis ratio. It is found that highly elongated particles will experience a reversal of the torque for a radius that is approximately one third of the wavelength. This effect is attributed to interference effects inside the structure due to multiple refl...

  6. Electronic measurement of variable torques in precision work technology

    Science.gov (United States)

    Maehr, M.

    1978-01-01

    Approaches for the determination of torques on the basis of length measurements are discussed. Attention is given to torque determinations in which the deformation of a shaft is measured, an electric measurement of the torsion angle, and an approach proposed by Buschmann (1970). Methods for a torque determination conducted with the aid of force measurements make use of piezoelectric approaches. The components used by these methods include a quartz crystal and a charge amplifier.

  7. Transient Effects on Dynamic Torque for Butterfly Valves

    OpenAIRE

    Price, Trevor N.

    2013-01-01

    Butterfly valves are versatile components widely used in hydraulic systems as shutoff and throttling valves. Butterfly valve components must be able to withstand the forces and torques that are generated with use. Dynamic torque data are usually obtained in a test lab for a variety of steady state flow conditions; however the dynamic torque under transient (unsteady flow) conditions may be significantly different than that found in the laboratory. If a valve is closed too fast, especially in ...

  8. DIRECT TORQUE CONTROL FOR INDUCTION MOTOR USING INTELLIGENT TECHNIQUES

    Directory of Open Access Journals (Sweden)

    R.Toufouti

    2007-09-01

    Full Text Available In this paper, we propose two approach intelligent techniques of improvement of Direct Torque Control (DTC of Induction motor such as fuzzy logic (FL and artificial neural network (ANN, applied in switching select voltage vector .The comparison with conventional direct torque control (DTC, show that the use of the DTC_FL and DTC_ANN, reduced the torque, stator flux, and current ripples. The validity of the proposed methods is confirmed by the simulative results.

  9. Robot Vibrations Caused by Torque Ripples in Power Transmission Mechanisms

    OpenAIRE

    小島, 宏行; 田口, 和哉; 辻, 浩明

    1989-01-01

    When an industrial robot with a power transmission mechanism such as a harmonic drive gear is operated, vibrations resulting from the torque ripple of the power transmission mechanism are frequently generated. However, few studies on robot vibration characteristics owing to torque ripples have been reported. In this paper, the vibrations of a horizontal two-link robot are investigated with consideration given to the torque ripple and the nonlinearity of the power transmission mechanism. In th...

  10. The Torque of High Speed Scanning Micromirrors with Vertical Combdrives

    Science.gov (United States)

    Wada, Hiroyuki; Lee, Daesung; Zappe, Stefan; Solgaard, Olav

    2003-12-01

    200 μm by 200 μm scanning micromirror actuated by vertical combdrives was fabricated. It is important to estimate the torque in order to know the tilt angle. We propose a way to estimate the torque by using the capacitance derived from the overlap area between the upper and lower comb teeth. The tilt angle that was estimated using the calculated torque was about 80% of the measured tilt.

  11. Control of fracture reduction robot using force/torque measurement.

    Science.gov (United States)

    Douke, T; Nakajima, Y; Mori, Y; Onogi, S; Sugita, N; Mitsuishi, M; Bessho, M; Ohhashi, S; Tobita, K; Ohnishi, I; Sakuma, I; Dohi, T; Maeda, Y; Koyama, T; Sugano, N; Yonenobu, K; Matsumoto, Y; Nakamura, K

    2008-01-01

    We have developed a surgical robotic system for femoral fracture reduction employing indirect traction. Indirect traction in fracture reduction is a generally used surgical method for preventing complications such as bone splits caused by high stress on bones. For traction, a patient's foot is gripped by a jig and pulled to the distal side. Indirect traction has the advantage of distributing bone stress by utilizing a strong traction force; however, this procedure does not accurately control the proper positioning of fractured fragments when a surgical robot is used. The human leg has knee and an ankle joints, and thus robotic motion presents problems in not being able to directly propagate reduction motion to a fractured femoral fragment, rendering control of bone position difficult. We propose a control method for fracture reduction robots using external force/torque measurements of the human leg to achieve precise fracture reduction. Results showed that the proposed method reduced repositioning error from 6.8 mm and 15.9 degrees to 0.7 mm and 5.3 degrees, respectively.

  12. Modeling Grain Alignment by Radiative Torques and Hydrogen Formation Torques in Reflection Nebula

    CERN Document Server

    Hoang, Thiem; Andersson, B-G

    2014-01-01

    Reflection nebulae--dense cores--illuminated by surrounding stars offer a unique opportunity to directly test our quantitative model of grain alignment based on radiative torques (RATs) and to explore new effects arising from additional torques. In this paper, we first perform detailed modeling of grain alignment by RATs for the IC 63 reflection nebula illuminated both by a nearby $\\gamma$ Cas star and the diffuse interstellar radiation field. We calculate linear polarization $p$ of background stars by radiatively aligned grains and explore the variation of fractional polarization (p/A$_V)$ with visual extinction $A_{V}$ across the cloud. We show that the variation of $p/A_{V}$ from the surface of the dayside toward the IC 63 center can be described by a power law $p/A_{V}\\propto A_{V}^{\\eta}$, having a shallow slope $\\eta \\sim- 0.1$ for $A_{V} 4$. We then consider the effects of additional torques due to H$_{2}$ formation and model grain alignment by joint action of RATs and H$_2$ torques. We find that p/A$_...

  13. A New Circuit Model for Spin-Torque Oscillator Including Perpendicular Torque of Magnetic Tunnel Junction

    Directory of Open Access Journals (Sweden)

    Hyein Lim

    2013-01-01

    Full Text Available Spin-torque oscillator (STO is a promising new technology for the future RF oscillators, which is based on the spin-transfer torque (STT effect in magnetic multilayered nanostructure. It is expected to provide a larger tunability, smaller size, lower power consumption, and higher level of integration than the semiconductor-based oscillators. In our previous work, a circuit-level model of the giant magnetoresistance (GMR STO was proposed. In this paper, we present a physics-based circuit-level model of the magnetic tunnel junction (MTJ-based STO. MTJ-STO model includes the effect of perpendicular torque that has been ignored in the GMR-STO model. The variations of three major characteristics, generation frequency, mean oscillation power, and generation linewidth of an MTJ-STO with respect to the amount of perpendicular torque, are investigated, and the results are applied to our model. The operation of the model was verified by HSPICE simulation, and the results show an excellent agreement with the experimental data. The results also prove that a full circuit-level simulation with MJT-STO devices can be made with our proposed model.

  14. Cogging Torque Characteristics of a Magnetic-Geared Motor

    Science.gov (United States)

    Niguchi, Noboru; Hirata, Katsuhiro

    This paper describes the cogging torque characteristics of a magnetic-geared motor with permanent magnets only on the high-speed rotor. The operational principle, which is different from that of the magnetic-geared motor with permanent magnets on the high-speed rotor and stator, is described. The torque characteristics, especially the order of the cogging torque, are mathematically formulated and verified by conducting 3-D finite element analysis and carrying out measurements on a prototype. Furthermore, a novel cogging torque reduction method is proposed and verified as well.

  15. Effect of antagonist muscle fatigue on knee extension torque.

    Science.gov (United States)

    Beltman, J G M; Sargeant, A J; Ball, D; Maganaris, C N; de Haan, A

    2003-09-01

    The effect of hamstring fatigue on knee extension torque was examined at different knee angles for seven male subjects. Before and after a dynamic flexion fatigue protocol (180 degrees s(-1), until dynamic torque had declined by 50%), maximal voluntary contraction extension torque was measured at four knee flexion angles (90 degrees, 70 degrees, 50 degrees and 30 degrees ). Maximal torque generating capacity and voluntary activation of the quadriceps muscle were determined using electrical stimulation. Average rectified EMG of the biceps femoris was determined. Mean dynamic flexion torque declined by 48+/-11%. Extensor maximal voluntary contraction torque, maximal torque generating capacity, voluntary activation and average rectified EMG at the four knee angles were unaffected by the hamstring fatigue protocol. Only at 50 degrees knee angle was voluntary activation significantly lower (15.7%) after fatigue ( P<0.05). In addition, average rectified EMG before fatigue was not significantly influenced by knee angle. It was concluded that a fatigued hamstring muscle did not increase the maximal voluntary contraction extension torque and knee angle did not change coactivation. Three possible mechanisms may explain the results: a potential difference in recruited fibre populations in antagonist activity compared with the fibres which were fatigued in the protocol, a smaller loss in isometric torque generating capacity of the hamstring muscle than was expected from the dynamic measurements and/or a reduction in voluntary activation.

  16. Analytical studies of torque motor tape active element

    Directory of Open Access Journals (Sweden)

    Dolgih Antonina

    2016-01-01

    Full Text Available The paper presents analytical studies of the torque motor tape active element. The tape active element is a novel type of a motor’s stator organization, where the conventional winding is replaced by a tape winding. Given the operation principle of proposed active element; its torque characteristics are then computationally found with using the finite element method (FEM. The results show the possibility of the optimal value of the relative electrode width, when the torque will be maximal. The analytical studies of the motor’s torque over the number of tape winding coils allowed to receive the recommendations on choosing the number of coils.

  17. Are joint torque models limited by an assumption of monoarticularity?

    Science.gov (United States)

    Lewis, Martin G C; King, Mark A; Yeadon, Maurice R; Conceição, Filipe

    2012-11-01

    This study determines whether maximal voluntary ankle plantar flexor torque could be more accurately represented using a torque generator that is a function of both knee and ankle kinematics. Isovelocity and isometric ankle plantar flexor torques were measured on a single participant for knee joint angles of 111° to 169° (approximately full extension) using a Contrex MJ dynamometer. Maximal voluntary torque was represented by a 19-parameter two-joint function of ankle and knee joint angles and angular velocities with the parameters determined by minimizing a weighted root mean square difference between measured torques and the two-joint function. The weighted root mean square difference between the two-joint function and the measured torques was 10 N-m or 3% of maximum torque. The two-joint function was a more accurate representation of maximal voluntary ankle plantar flexor torques than an existing single-joint function where differences of 19% of maximum torque were found. It is concluded that when the knee is flexed by more than 40°, a two-joint representation is necessary.

  18. Spin-torque switching of a nano-magnet using giant spin hall effect

    Directory of Open Access Journals (Sweden)

    Ashish V. Penumatcha

    2015-10-01

    Full Text Available The Giant Spin Hall Effect(GSHE in metals with high spin-orbit coupling is an efficient way to convert charge currents to spin currents, making it well-suited for writing information into magnets in non-volatile magnetic memory as well as spin-logic devices. We demonstrate the switching of an in-plane CoFeB magnet using a combination of GSHE and an external magnetic field. The magnetic field dependence of the critical current is used to estimate the spin hall angle with the help of a thermal activation model for spin-transfer torque switching of a nanomagnet.

  19. Development and Calibration of a Hyperstatic Six-component Force/Torque Sensor

    Institute of Scientific and Technical Information of China (English)

    HOU Yulei; YAO Jiantao; ZENG Daxing; CHEN Jie; ZHAO Yongsheng

    2009-01-01

    The six-component force/torque sensor has become one kind of the most important sensors with the ability of measuring all the external forces and torques. A novel hyperstatic six-component force/torque sensor based on the Stewart platform structure, which can be used for the force measurement of the robot wrist, is proposed, and its structural optimal design, finite element analysis and calibration experimentation is presented. The characteristic of the sensor structure is analyzed in comparison with the traditional Stewart platform-based sensor. The mathematical expression of the sensor's force mapping matrix is introduced. The condition number and generalized amplifying coefficient defined by singular values of force Jacobian matrix are used to evaluate the performances of isotropy and sensitivity of the sensor respectively. The optimal design of the sensor structure is performed with the objective of achieving high measurement sensitivity and good isotropy. The sensor prototype is fabricated, and the static and dynamic characteristics of the sensor are analyzed with finite element analysis software package ANSYS. The calibration device is manufactured, and the data acquisition and processing system is developed. The theoretical and experimental study of the static calibration of the sensor prototype is carried out. The results of simulation analysis and calibration experimentation prove the feasibility of the hyperstatic sensor structure, and the contents of this paper possess theoretical significance and engineering value for the further research and practical application of the six-component force sensor.

  20. Spin-orbit torques for current parallel and perpendicular to a domain wall

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Tomek; Lee, Kyujoon; Karnad, Gurucharan V. [Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudinger Weg 7, 55128 Mainz (Germany); Alejos, Oscar [Departamento de Electricidad y Electrónica, Universidad de Valladolid, Paseo de Belen, 7, E-47011 Valladolid (Spain); Martinez, Eduardo; Moretti, Simone [Departamento Fisica Aplicada, Universidad de Salamanca, Plaza de los Caidos s/n, E-38008 Salamanca (Spain); Hals, Kjetil M. D. [Niels Bohr International Academy and the Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen (Denmark); Garcia, Karin; Ravelosona, Dafiné [Institut d' Electronique Fondamentale, UMR CNRS 8622, Université Paris Sud, 91405 Orsay Cedex (France); Vila, Laurent [Institut Nanosciences et Cryogénie, Université Grenoble Alpes, F-38000 Grenoble (France); Institut Nanosciences et Cryogénie, CEA, F-38000 Grenoble (France); Lo Conte, Roberto; Kläui, Mathias [Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudinger Weg 7, 55128 Mainz (Germany); Graduate School of Excellence “Materials Science in Mainz” (MAINZ), Staudinger Weg 9, 55128 Mainz (Germany); Ocker, Berthold [Singulus Technologies AG, 63796 Kahl am Main (Germany); Brataas, Arne [Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway)

    2015-09-21

    We report field- and current-induced domain wall (DW) depinning experiments in Ta\\Co{sub 20}Fe{sub 60}B{sub 20}\\MgO nanowires through a Hall cross geometry. While purely field-induced depinning shows no angular dependence on in-plane fields, the effect of the current depends crucially on the internal DW structure, which we manipulate by an external magnetic in-plane field. We show depinning measurements for a current sent parallel to the DW and compare its depinning efficiency with the conventional case of current flowing perpendicularly to the DW. We find that the maximum efficiency is similar for both current directions within the error bars, which is in line with a dominating damping-like spin-orbit torque (SOT) and indicates that no large additional torques arise for currents perpendicular to the DW. Finally, we find a varying dependence of the maximum depinning efficiency angle for different DWs and pinning levels. This emphasizes the importance of our full angular scans compared with previously used measurements for just two field directions (parallel and perpendicular to the DW) to determine the real torque strength and shows the sensitivity of the SOT to the precise DW structure and pinning sites.

  1. On the torque mechanism of Savonius rotors

    Energy Technology Data Exchange (ETDEWEB)

    Fujisawa, N. (Dept. of Mechanical Univ., Kiryu (Japan))

    1992-07-01

    The aerodynamic performance and the flow fields of Savonius rotors at various overlap ratios have been investigated by measuring the pressure distributions on the blades and by visualizing the flow fields in and around the rotors with and without rotation. Experiments have been performed on four rotors having two semicircular blades but with different overlap ratios ranging 0 to 0.5. The static torque performance is improved by increasing the overlap ratio especially on the returning blade, which is due to the pressure recovery effect by the flow through the overlap. On the other hand, the torque and the power performance of the rotating rotor reaches a maximum at an overlap of 0.15. This effect is largely created by the Coanda-like flow on the convex side of the advancing blade, which is strengthened by the flow through the overlap at this small overlap ratio. However, this phenomena is weakened as the overlap ratio is further increased, suggesting a deteriorated performance of the rotor. Observations of the flow inside the rotor indicate an increased recirculation region at such large overlap ratios, which also suggests a reduced aerodynamic efficiency for rotors with large overlap. 11 figs., 16 refs.

  2. Radiative torques: Analytical Model and Basic Properties

    CERN Document Server

    Lazarian, Alex

    2007-01-01

    We attempt to get a physical insight into grain alignment processes by studying basic properties of radiative torques (RATs). For this purpose we consider a simple toy model of a helical grain that reproduces well the basic features of RATs. The model grain consists of a spheroidal body with a mirror attached at an angle to it. Being very simple, the model allows analytical description of RATs that act upon it. We show a good correspondence of RATs obtained for this model and those of irregular grains calculated by DDSCAT. Our analysis of the role of different torque components for grain alignment reveals that one of the three RAT components does not affect the alignment, but induces only for grain precession. The other two components provide a generic alignment with grain long axes perpendicular to the radiation direction, if the radiation dominates the grain precession, and perpendicular to magnetic field, otherwise. We study a self-similar scaling of RATs as a function of $\\lambda/a_{eff}$. We show that th...

  3. Dynamics of a split torque helicopter transmission

    Science.gov (United States)

    Krantz, Timothy L.

    1994-06-01

    Split torque designs, proposed as alternatives to traditional planetary designs for helicopter main rotor transmissions, can save weight and be more reliable than traditional designs. This report presents the results of an analytical study of the system dynamics and performance of a split torque gearbox that uses a balance beam mechanism for load sharing. The Lagrange method was applied to develop a system of equations of motion. The mathematical model includes time-varying gear mesh stiffness, friction, and manufacturing errors. Cornell's method for calculating the stiffness of spur gear teeth was extended and applied to helical gears. The phenomenon of sidebands spaced at shaft frequencies about gear mesh fundamental frequencies was simulated by modeling total composite gear errors as sinusoid functions. Although the gearbox has symmetric geometry, the loads and motions of the two power paths differ. Friction must be considered to properly evaluate the balance beam mechanism. For the design studied, the balance beam is not an effective device for load sharing unless the coefficient of friction is less than 0.003. The complete system stiffness as represented by the stiffness matrix used in this analysis must be considered to precisely determine the optimal tooth indexing position.

  4. Torque generation mechanism of ATP synthase

    Science.gov (United States)

    Miller, John; Maric, Sladjana; Scoppa, M.; Cheung, M.

    2010-03-01

    ATP synthase is a rotary motor that produces adenosine triphosphate (ATP), the chemical currency of life. Our proposed electric field driven torque (EFT) model of FoF1-ATP synthase describes how torque, which scales with the number of c-ring proton binding sites, is generated by the proton motive force (pmf) across the mitochondrial inner membrane. When Fo is coupled to F1, the model predicts a critical pmf to drive ATP production. In order to fully understand how the electric field resulting from the pmf drives the c-ring to rotate, it is important to examine the charge distributions in the protonated c-ring and a-subunit containing the proton channels. Our calculations use a self-consistent field approach based on a refinement of reported structural data. The results reveal changes in pKa for key residues on the a-subunit and c-ring, as well as titration curves and protonation state energy diagrams. Health implications will be briefly discussed.

  5. Research on Torque Ratio Based on the Steering Wheel Torque Characteristic for Steer-by-Wire System

    OpenAIRE

    Yandong Han; Lei He; Xiang Wang; Changfu Zong

    2014-01-01

    Steer-by-wire system can improve the performance of vehicle handling stability. Removing the mechanical linkages between the front wheels and the steering wheel leads to a key technique of force feedback for steer-by-wire system. In view of the characteristic of variable torque transmission ratio for steer-by-wire system, this paper proposes a method for designing torque ratio based on the steering wheel torque characteristic for steer-by-wire system. It converts the torque ratio design into ...

  6. Medial tibial pain: a dynamic contrast-enhanced MRI study.

    Science.gov (United States)

    Mattila, K T; Komu, M E; Dahlström, S; Koskinen, S K; Heikkilä, J

    1999-09-01

    The purpose of this study was to compare the sensitivity of different magnetic resonance imaging (MRI) sequences to depict periosteal edema in patients with medial tibial pain. Additionally, we evaluated the ability of dynamic contrast-enhanced imaging (DCES) to depict possible temporal alterations in muscular perfusion within compartments of the leg. Fifteen patients with medial tibial pain were examined with MRI. T1-, T2-weighted, proton density axial images and dynamic and static phase post-contrast images were compared in ability to depict periosteal edema. STIR was used in seven cases to depict bone marrow edema. Images were analyzed to detect signs of compartment edema. Region-of-interest measurements in compartments were performed during DCES and compared with controls. In detecting periosteal edema, post-contrast T1-weighted images were better than spin echo T2-weighted and proton density images or STIR images, but STIR depicted the bone marrow edema best. DCES best demonstrated the gradually enhancing periostitis. Four subjects with severe periosteal edema had visually detectable pathologic enhancement during DCES in the deep posterior compartment of the leg. Percentage enhancement in the deep posterior compartment of the leg was greater in patients than in controls. The fast enhancement phase in the deep posterior compartment began slightly slower in patients than in controls, but it continued longer. We believe that periosteal edema in bone stress reaction can cause impairment of venous flow in the deep posterior compartment. MRI can depict both these conditions. In patients with medial tibial pain, MR imaging protocol should include axial STIR images (to depict bone pathology) with T1-weighted axial pre and post-contrast images, and dynamic contrast enhanced imaging to show periosteal edema and abnormal contrast enhancement within a compartment.

  7. High-resolution axial MR imaging of tibial stress injuries

    Directory of Open Access Journals (Sweden)

    Mammoto Takeo

    2012-05-01

    Full Text Available Abstract Purpose To evaluate the relative involvement of tibial stress injuries using high-resolution axial MR imaging and the correlation with MR and radiographic images. Methods A total of 33 patients with exercise-induced tibial pain were evaluated. All patients underwent radiograph and high-resolution axial MR imaging. Radiographs were taken at initial presentation and 4 weeks later. High-resolution MR axial images were obtained using a microscopy surface coil with 60 × 60 mm field of view on a 1.5T MR unit. All images were evaluated for abnormal signals of the periosteum, cortex and bone marrow. Results Nineteen patients showed no periosteal reaction at initial and follow-up radiographs. MR imaging showed abnormal signals in the periosteal tissue and partially abnormal signals in the bone marrow. In 7 patients, periosteal reaction was not seen at initial radiograph, but was detected at follow-up radiograph. MR imaging showed abnormal signals in the periosteal tissue and entire bone marrow. Abnormal signals in the cortex were found in 6 patients. The remaining 7 showed periosteal reactions at initial radiograph. MR imaging showed abnormal signals in the periosteal tissue in 6 patients. Abnormal signals were seen in the partial and entire bone marrow in 4 and 3 patients, respectively. Conclusions Bone marrow abnormalities in high-resolution axial MR imaging were related to periosteal reactions at follow-up radiograph. Bone marrow abnormalities might predict later periosteal reactions, suggesting shin splints or stress fractures. High-resolution axial MR imaging is useful in early discrimination of tibial stress injuries.

  8. Posterior cruciate ligament reconstruction by means of tibial tunnel: anatomical study on cadavers for tunnel positioning

    Directory of Open Access Journals (Sweden)

    Antônio Altenor Bessa de Queiroz

    2014-08-01

    Full Text Available Objective:To determine the reference points for the exit of the tibial guidewire in relation to the posterior cortical bone of the tibia.Methods:Sixteen knees from fresh cadavers were used for this study. Using a viewing device and a guide marked out in millimeters, three guidewires were passed through the tibia at 0, 10 and 15 mm distally in relation to the posterior crest of the tibia. Dissections were performed and the region of the center of the tibial insertion of the posterior cruciate ligament (PCL was determined in each knee. The distances between the center of the tibial insertion of the PCL and the posterior tibial border (CB and between the center of the tibial insertion of the PCL and wires 1, 2 and 3 (CW1, CW2 and CW3 were measured.Results:In the dissected knees, we found the center of the tibial insertion of the PCL at 1.09 ± 0.06 cm from the posterior tibial border. The distances between the wires 1, 2 and 3 and the center of the tibial insertion of the PCL were respectively 1.01 ± 0.08, 0.09 ± 0.05 and 0.5 ± 0.05 cm.Conclusion:The guidewire exit point 10 mm distal in relation to the posterior crest of the tibia was the best position for attempting to reproduce the anatomical center of the PCL.

  9. Immediate weight-bearing after osteosynthesis of proximal tibial fractures may be allowed

    DEFF Research Database (Denmark)

    Haak, Karl Tobias; Palm, Henrik; Holck, Kim;

    2012-01-01

    Immediate weight-bearing following osteosynthesis of proximal tibial fractures is traditionally not allowed due to fear of articular fracture collapse. Anatomically shaped locking plates with sub-articular screws could improve stability and allow greater loading forces. The purpose of this study...... was to investigate if immediate weight-bearing can be allowed following locking plate osteosynthesis of proximal tibial fractures....

  10. Arthroscopically assisted osteosynthesis of tibial plateau fractures in patients older than 55 years

    NARCIS (Netherlands)

    Roerdink, WH; Oskam, J; Vierhout, PAM

    2001-01-01

    Purpose: To evaluate the end results of arthroscopically assisted osteosynthesis of tibial plateau fractures in patients older than 55 years of age. Type of Study: Case series. Methods: Over a 5-year period, 201 consecutive patients presented with tibial plateau fracture; 131 of these patients were

  11. Chemotherapy affects the pattern of failure after shear loading of the proximal tibial growth plate.

    NARCIS (Netherlands)

    Leeuwen, B.L.; Hartel, R.M.; Jansen, H.W.B.; Verkerke, G.J.; Veth, R.P.H.; Kamps, W.A.; Hoekstra, H.J.

    2004-01-01

    INTRODUCTION: Tibial bones are shorter and less resistant to shear forces after treatment with doxorubicin, methotrexate, or cisplatin. We investigated the pattern of failure after shear loading of the proximal tibial growth plate in rats treated with these chemotherapeutic agents. MATERIALS AND MET

  12. Tibial slope in total ankle arthroplasty: Anterior or lateral approach.

    Science.gov (United States)

    Usuelli, Federico Giuseppe; Maccario, Camilla; Indino, Cristian; Manzi, Luigi; Gross, Christopher Edward

    2017-06-01

    A new total ankle arthroplasty (TAA) system performed through a lateral approach provides direct visualization of the centre of rotation, allowing for accurate reconstruction of the joint alignment and less bone resection. Radiographic references are needed to describe deformities and plan the surgical procedures. The tibial slope is an important factor when treating malalignment. The aim of this study is to show if there is any difference regarding the post-operative tibial slope (β angle) measurement comparing a fixed-bearing TAA through a lateral approach and a mobile-bearing TAA through an anterior approach. The study included 217 ankles. Between May 2011 and April 2015, 77 patients underwent a TAA with a mobile-bearing implant through an anterior approach and 45 with a fixed-bearing implant through a lateral approach: in these patients the β angle was measured 2 and 12 months postoperatively. 95 subjects with unilateral post-traumatic ankle arthritis composed the control group: in these patients we measured the anterior distal tibial angle (ADTA) of the controlateral, non arthritic tibiotalar joint. In the mobile-bearing group, the mean β angle at 2 and 12 months postoperatively was 86.4±3.1 and 86.8±3.1 (p-value=0.12). In the fixed-bearing group, the mean β angle at 2 and 12 months postoperatively was 83.1±5.4 and 83.9±6.5 (p-value=0.26). A statistically significant difference was found between the β angle of the two groups. In the control group the mean ADTA was 84.9±2.5. A non-statistically significant difference was observed only between β angle of the fixed-bearing group and the ADTA of the control group. Regarding the tibial slope, fixed-bearing TAA through a lateral approach showed a more anatomic placement. In contrast, β angle in mobile-bearing group appeared more reproducible than fixed-bearing group. Copyright © 2016 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  13. Expected long-term outcome after a tibial shaft fracture

    DEFF Research Database (Denmark)

    Faergemann, C; Frandsen, P A; Röck, N D

    1999-01-01

    these expectations with the outcome measured in patients. METHODS: There were five groups of nonpatients: (1) 42 orthopedic surgeons, (2) 36 physiotherapists, (3) 42 students, (4) 49 white collar workers, and (5) 38 blue collar workers. Outcome was measured by Sickness Impact Profile (SIP). The SIP scores were...... compared with SIP scores obtained from 33 patients with a unilateral tibial fracture. RESULTS: Marked variation was observed between the groups. CONCLUSION: Physiotherapists expected the lowest degree of disability and orthopedic surgeons the highest. In the three groups of students, white collar workers...

  14. Double segmental tibial fractures——an unusual fracture pattern

    Institute of Scientific and Technical Information of China (English)

    Kamal Bali; Vishal Kumar; Sandeep Patel; Sameer Aggarwal

    2011-01-01

    A case of a 50-year-old pedestrian who was hit by a bike and suffered fractures of both bones of his right leg was presented. Complete clinical and radiographic assessment showed double segmental fractures of the tibia and multisegmental fractures of the fibula. Review of the literature revealed that this fracture pattern was unique and only a single case was reported so far. Moreover, we discussed the possible mechanisms which can lead to such an injury. We also discussed the management of segmental tibial fracture and the difficulties encountered with them. This case was managed by modern osteosynthesis tech nique with a pleasing outcome.

  15. Chronic venous disease as a clinical manifestation of tibial osteochondroma

    Directory of Open Access Journals (Sweden)

    Marcelo Fernandes Lima

    2013-06-01

    Full Text Available Osteochondromas are the most common type of benign tumor of the skeleton. They most frequently affect the distal extremity of the femur, with the tibia being the second most commonly affected long bone. Vascular complications of these lesions are rare, but pseudoaneurysm formation is the most frequently reported of them. In this case report, we describe a case of compression of the popliteal neurovascular bundle by a tibial osteochondroma in a diabetic patient who had been admitted to hospital to treat an infected lesion on his left foot and complained of edema and paresthesia of the left lower limb.

  16. Computational modelling of ovine critical-sized tibial defects with implanted scaffolds and prediction of the safety of fixator removal.

    Science.gov (United States)

    Doyle, Heather; Lohfeld, Stefan; Dürselen, Lutz; McHugh, Peter

    2015-04-01

    Computational model geometries of tibial defects with two types of implanted tissue engineering scaffolds, β-tricalcium phosphate (β-TCP) and poly-ε-caprolactone (PCL)/β-TCP, are constructed from µ-CT scan images of the real in vivo defects. Simulations of each defect under four-point bending and under simulated in vivo axial compressive loading are performed. The mechanical stability of each defect is analysed using stress distribution analysis. The results of this analysis highlights the influence of callus volume, and both scaffold volume and stiffness, on the load-bearing abilities of these defects. Clinically-used image-based methods to predict the safety of removing external fixation are evaluated for each defect. Comparison of these measures with the results of computational analyses indicates that care must be taken in the interpretation of these measures.

  17. Towards a naturalistic brain-machine interface: hybrid torque and position control allows generalization to novel dynamics.

    Directory of Open Access Journals (Sweden)

    Pratik Y Chhatbar

    Full Text Available Realization of reaching and grasping movements by a paralytic person or an amputee would greatly facilitate her/his activities of daily living. Towards this goal, control of a computer cursor or robotic arm using neural signals has been demonstrated in rodents, non-human primates and humans. This technology is commonly referred to as a Brain-Machine Interface (BMI and is achieved by predictions of kinematic parameters, e.g. position or velocity. However, execution of natural movements, such as swinging baseball bats of different weights at the same speed, requires advanced planning for necessary context-specific forces in addition to kinematic control. Here we show, for the first time, the control of a virtual arm with representative inertial parameters using real-time neural control of torques in non-human primates (M. radiata. We found that neural control of torques leads to ballistic, possibly more naturalistic movements than position control alone, and that adding the influence of position in a hybrid torque-position control changes the feedforward behavior of these BMI movements. In addition, this level of control was achievable utilizing the neural recordings from either contralateral or ipsilateral M1. We also observed changed behavior of hybrid torque-position control under novel external dynamic environments that was comparable to natural movements. Our results demonstrate that inclusion of torque control to drive a neuroprosthetic device gives the user a more direct handle on the movement execution, especially when dealing with novel or changing dynamic environments. We anticipate our results to be a starting point of more sophisticated algorithms for sensorimotor neuroprostheses, eliminating the need of fully automatic kinematic-to-dynamic transformations as currently used by traditional kinematic-based decoders. Thus, we propose that direct control of torques, or other force related variables, should allow for more natural

  18. The External Degree.

    Science.gov (United States)

    Houle, Cyril O.

    This book examines the external degree in relation to the extremes of attitudes, myths, and data. Emphasis is placed on the emergence of the American external degree, foreign external-degree programs, the purpose of the external degree, the current scene, institutional issues, and problems of general policy. (MJM)

  19. Clinical features of a rare anatomical variation of the posterior tibial and fibular arteries

    Directory of Open Access Journals (Sweden)

    Pedro Oliveira Portilho

    Full Text Available Abstract The posterior tibial artery normally arises from tibial-fibular trunk at the popliteal fossa, together with the fibular artery. The classic course of the posterior tibial artery is to run between the triceps surae muscle and muscles of the posterior compartment of the leg before continuing its course posteriorly to the medial malleolus, while the fibular artery runs through the lateral margin of the leg. Studies of both arteries are relevant to the fields of angiology, vascular surgery and plastic surgery. To the best of our knowledge, we report the first case of an anastomosis between the posterior tibial artery and the fibular artery in their distal course. The two arteries joined in an unusual “X” format, before division of the posterior tibial artery into plantar branches. We also provide a literature review of unusual variations and assess the clinical and embryological aspects of both arteries in order to contribute to further investigations regarding these vessels.

  20. A Patient with Unilateral Tibial Aplasia and Accessory Scrotum: A Pure Coincidence or Nonfortuitous Association?

    Directory of Open Access Journals (Sweden)

    Zoran Gucev

    2010-01-01

    Full Text Available Tibial aplasia is an uncommon lower limb malformation that can occur isolated or be part of a more complex malformation pattern. We describe a 9-year-old boy born after uneventful pregnancy and delivery. Family history was negative for maternal diabetes and other malformations. The patient presented with left tibial aplasia and homolateral prexial foot polydactyly. He also displayed enamel dysplasia and bifid scotum with cryptorchidism. Literature review failed to identify a significant syndromic association between lower limb defects of the tibial type and the genital anomalies reported here. The combination of tibial aplasia with midline genital malformations further supports the hypothesis that the tibial ray development mirrors the morphogenetic process of the radial structures. Accordingly, the malformation pattern observed in the present patient may be pathogenetically explained by an insult occurring during late blastogenesis.

  1. Pseudoarthrosis of medial tibial plateau fracture-role of alignment procedure

    Directory of Open Access Journals (Sweden)

    Devgan Ashish

    2013-04-01

    Full Text Available 【Abstract】 Nonunion in tibial plateau fractures is very rare. Limited literature is available on Pubmed search on intraarticular tibial nonunion. Most of the cases reported have been following failed surgical treatment and none was neglected fractures. Three patients of isolated and neglected medial tibial plateau nonunion with almost similar demo-graphic profile are reported in this paper. All the three pa-tients were managed by minimally invasive compression fixation using lag screws supplemented with limb realign-ment procedure of high tibial osteotomy. We discussed the injury mechanism, management and rehabilitation in such cases and reviewed the available literature regarding such a presentation. Key words: Fracture healing; Tibial fractures; Frac-ture fixation; Osteotomy

  2. Tibial tunnel and pretibial cysts following ACL graft reconstruction: MR imaging diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Ghazikhanian, Varand [Brigham and Women' s Hospital, Musculoskeletal Imaging and Intervention, Department of Radiology, Boston, MA (United States); Beltran, Javier [Maimonides Medical Center, Brooklyn, NY (United States); Nikac, Violeta [Maimonides Medical Center, Department of Radiology, Brooklyn, NY (United States); Bencardino, Jenny T. [NYU Hospital for Joint Diseases, New York, NY (United States); Feldman, Marina

    2012-11-15

    Tunnel cyst formation is a rare complication after anterior cruciate ligament reconstruction, usually occurring 1-5 years post-operatively, which may occasionally be symptomatic. There are multiple proposed theories regarding the etiology of tunnel cysts. Theories include necrosis, foreign-body reaction, lack of complete graft osteo-integration, and intravasation of articular fluid. It is important to know if the tunnel cysts are communicating or not communicating with the joint, as surgical management may be different. Imaging characteristics on magnetic resonance images (MRI) include tibial tunnel widening, multilocular or unilocular cyst formation in the graft or tibial tunnel, with possible extension into the pretibial space, intercondylar notch, and/or popliteal fossa. The MR imaging differential diagnosis of tibial tunnel cysts includes infection, foreign-body granuloma, or tibial screw extrusion. Importantly, to the best of our knowledge, graft failure or instability has not been reported in association with tibial tunnel cysts. (orig.)

  3. Tibial lead determination by 99Tcm radiopharmaceutical x-ray fluorescence.

    Science.gov (United States)

    Mountford, P J; Green, S; Bradley, D A; Lewis, A D; Morgan, W D

    1994-04-01

    The feasibility of measuring tibial lead concentration by x-ray fluorescence with an internal 99Tcm labelled bone-seeking radiopharmaceutical was investigated using phantoms containing known values of lead concentration and 99Tcm activity. The minimum detectable concentration (MDC) at two standard deviations based on the counts in the Kalpha1 peak of 10.9 microg Pb ml(-1) was estimated to correspond to an MDC for an individual within a range of approximately 8-15 microg Pb (g bone mineral)(-1) if the counts from all four K x-ray peaks were included. Due to its much greater dose compared to an external source, the MDC of this internal source technique would have to be reduced before it could be used for measurements of occupationally or environmentally exposed individuals other than as an adjunct for a patient undergoing a bone scan. Methods of achieving such a reduction include increasing the acquisition time and the number of HPGE detectors, and optimizing the design of their collimators.

  4. Ilizarov fixator in management of nonunited and infected tibial shaft fractures

    Directory of Open Access Journals (Sweden)

    Abhinay Singh

    2015-01-01

    Full Text Available Background: Management of nonunion with bony defect and infection in long bones is a challenging problem for orthopedic surgeons. Objectives: Evaluation of Ilizarov circular fixation method of treatment for the management of nonunited and infected fractures of tibia. Materials and Methods: This prospective study was conducted in a tertiary care hospital of eastern region of India on 30 subjects in a time span of 3 years after taking clearance of the Institutional Ethical Committee and informed consent of the patients. Results: All the patients had infected nonunion before undergoing Ilizarov procedure. Following initial injury, 22 patients were treated with external fixation and 8 cases were treated with internal fixation. At the time of presentation, 18 patients had infected gap nonunion, 5 patients had infected hypertrophic and 2 patients had atrophic nonunion. The Ilizarov fixator was kept for an average period of 303.7 days. Based on Association for the Study and Application of Methods of Ilizarov scoring system, bony and functional results were assessed. The bony result was excellent in 16 patients, good in eight, fair in four and poor in two. The functional result was excellent in 10 patients, good in 16, fair in two, poor in two. Conclusion: Ilizarov ring fixator still remains an excellent treatment modality for tibial nonunion with a defect, regarding bone union, deformity correction, infection eradication, limb-length achievement, and limb function.

  5. Correção da falha óssea femoral e tibial pelo método do transporte ósseo de Ilizarov Femoral and tibial bone loss correction using Ilizarov's bone transport

    Directory of Open Access Journals (Sweden)

    Celso Herminio Ferraz Picado

    2000-12-01

    pacientes ficaram satisfeitos com o resultado do tratamento. Concluímos que a resposta biológica ao transporte ósseo é formidável, com a formação do regenerado reparando grandes falhas ósseas. Entretanto, consideramos que o aparelho circular externo preconizado por Ilizarov traz consigo diversas complicações principalmente relacionadas a presença dos fios transfixantes, causando sofrimento para os pacientes, principalmente quando instalados no fêmur.Eleven patients carrying diaphyseal bone fissure secondary to ressection of infected bone segments, 5 in the femur and 6 in the tibia, submitted to the Ilizarov bone transport technique were retrospectively analyzed. In the group of patients with femoral lesion the bone fissure varied from 7 cm to 12 cm, and in two there was a 2 cm shortening of the limb. In the group with tibial lesion the bone fissure varied from 2.5 cm to 10 cm, with limb shortening in two patients, respectively 1.5 cm and 2 cm. The mean follow-up period since the end of the treatment until evaluation was 49 months for the femoral lesion patients and 28.3 months for the tibial lesion patients. The femoral transports were bifocal and the tibial transports were bifocal in 4 patients and trifocal in 2. In all, patients formation of regenerate occurred. Consolidation of the target focus was naturally obtained in 7 patients; one patient needed bone grafting to obtain the focus consolidation. In three patients the nonunion of the target focus demanded modification of the treatment method with the external circular fixator withdrawal. In all the patients infection adjacent to the wires was observed. There was rupture of the wires in all assemblies made in the thigh. All the wires lost the tension initially imposed to them. Two patients submitted to femoral transport evolved with septic arthritis of the knee. Mobility of the knee was severely impaired in the patients submitted to femoral transport, and the same was observed in relation to the ankle of

  6. Very simple torque magnetometer for measuring magnetic thin films

    Energy Technology Data Exchange (ETDEWEB)

    Tejedor, M.; Fernandez, A.; Hernando, B.; Carrizo, J.

    1985-11-01

    A new torque magnetometer has been developed and built in order to measure magnetization saturation and perpendicular anisotropy of magnetic thin films. Its main characteristic is that it employs for counteraction the torque exerted on the sample in the same field used for exciting it. This gives rise to a great simplicity and sensitivity of the measuring system.

  7. Spin-torque generation in topological insulator based heterostructures

    KAUST Repository

    Fischer, Mark H.

    2016-03-11

    Heterostructures utilizing topological insulators exhibit a remarkable spin-torque efficiency. However, the exact origin of the strong torque, in particular whether it stems from the spin-momentum locking of the topological surface states or rather from spin-Hall physics of the topological-insulator bulk, remains unclear. Here, we explore a mechanism of spin-torque generation purely based on the topological surface states. We consider topological-insulator-based bilayers involving ferromagnetic metal (TI/FM) and magnetically doped topological insulators (TI/mdTI), respectively. By ascribing the key theoretical differences between the two setups to location and number of active surface states, we describe both setups within the same framework of spin diffusion of the nonequilibrium spin density of the topological surface states. For the TI/FM bilayer, we find large spin-torque efficiencies of roughly equal magnitude for both in-plane and out-of-plane spin torques. For the TI/mdTI bilayer, we elucidate the dominance of the spin-transfer-like torque. However, we cannot explain the orders of magnitude enhancement reported. Nevertheless, our model gives an intuitive picture of spin-torque generation in topological-insulator-based bilayers and provides theoretical constraints on spin-torque generation due to topological surface states.

  8. Sagittal osteotomy inclination in medial open-wedge high tibial osteotomy.

    Science.gov (United States)

    Lee, Seung-Yup; Lim, Hong-Chul; Bae, Ji Hoon; Kim, Jae Gyoon; Yun, Se-Hyeok; Yang, Jae-Hyuk; Yoon, Jung-Ro

    2017-03-01

    Unlike postoperative changes in posterior tibial slope after medial open-wedge high tibial osteotomy, sagittal osteotomy inclination has not been examined. It has been recommended that the osteotomy line in the sagittal plane be parallel to the medial posterior tibial slope. The purpose of this study was to determine the frequency of parallel osteotomy in medial open-wedge high tibial osteotomy. To determine the sagittal osteotomy inclination, the angle between the medial joint line and the osteotomy line was measured in the lateral radiograph. A positive angle value indicates that the osteotomy is anteriorly inclined relative to the medial posterior tibial slope. Correlation between the sagittal osteotomy inclination and posterior tibial slope was also evaluated. The mean sagittal osteotomy inclination was 15.1 ± 7.5°. The majority 87.1 % of knees showed an anterior-inclined osteotomy. There was a significantly positive correlation between the postoperative posterior tibial slope and the sagittal osteotomy inclination (r, 0.33; 95 % confidence interval (CI) 0.19-0.46; P osteotomy inclination (r, 0.35; 95 % CI 0.21-0.47; P osteotomy in the sagittal plane relative to the medial joint line was planned, only 12.9 % of cases achieved osteotomy parallel to the medial posterior tibial slope in the sagittal plane. Because of high rate of the anterior-inclined osteotomy and their correlations with posterior tibial slope, surgeons should make all efforts to perform parallel osteotomy relative to medial posterior tibial slope. IV.

  9. Magnon-mediated Dzyaloshinskii-Moriya torque in homogeneous ferromagnets

    KAUST Repository

    Manchon, Aurelien

    2014-12-01

    In thin magnetic layers with structural inversion asymmetry and spin-orbit coupling, the Dzyaloshinskii-Moriya interaction arises at the interface. When a spin-wave current jm flows in a system with a homogeneous magnetization m, this interaction produces an effective fieldlike torque of the form TFLm×(z×jm) as well as a dampinglike torque, TDLm×[(z×jm)×m], the latter only in the presence of spin-wave relaxation (z is normal to the interface). These torques mediated by the magnon flow can reorient the time-averaged magnetization direction and display a number of similarities with the torques arising from the electron flow in a magnetic two-dimensional electron gas with Rashba spin-orbit coupling. This magnon-mediated spin-orbit torque can be efficient in the case of magnons driven by a thermal gradient.

  10. Active element influence on the motor’s torque

    Directory of Open Access Journals (Sweden)

    Dolgih Antonina

    2017-01-01

    Full Text Available The paper presents the numerical and experimental studies of the influence of the torque motor active element on the motor’s torque. The tape active element is a novel type of a motor’s stator organization, where the conventional winding is replaced by a tape winding. The force (torque dependence over the rotor pole position using COMSOL is given; the tape winding resistance and the turns number are defined. The relative motor’s characteristics are investigated and the maximum torque over the certain poles pair number is obtained. The application of the proposed active element in brushless DC motor is considered. The results show the possibility of the further synthesis of the torque motor.

  11. Approaching the Standard Quantum Limit of Mechanical Torque Sensing

    CERN Document Server

    Kim, P H; Doolin, C; Souris, F; Davis, J P

    2016-01-01

    Mechanical transduction of torque has been key to probing a number of physical phenomena, such as gravity, the angular momentum of light, the Casimir effect, magnetism, and quantum oscillations. Following similar trends as mass and force sensing, mechanical torque sensitivity can be dramatically improved by scaling down the physical dimensions, and therefore moment of inertia, of a torsional spring. Yet now, through precision nanofabrication and sub-wavelength cavity optomechanics, we have reached a point where geometric optimization can only provide marginal improvements to torque sensitivity. Instead, nanoscale optomechanical measurements of torque are overwhelmingly hindered by thermal noise. Here we present cryogenic measurements of a cavity-optomechanical torsional resonator cooled in a dilution refrigerator to a temperature of 25 mK, corresponding to an average phonon occupation of = 35, that demonstrate a record-breaking torque sensitivity of 2.9 yNm/Hz^{1/2}. This a 270-fold improvement over previous...

  12. Direct Torque Control With Feedback Linearization for Induction Motor Drives

    DEFF Research Database (Denmark)

    Lascu, Cristian Vaslie; Jafarzadeh, Saeed; Fadali, Sami M.

    2017-01-01

    This paper describes a direct-torque-controlled (DTC) induction motor (IM) drive that employs feedback linearization and sliding-mode control (SMC). A new feedback linearization approach is proposed, which yields a decoupled linear IM model with two state variables: torque and stator flux magnitude....... This intuitive linear model is used to implement a DTC-type controller that preserves all DTC advantages and eliminates its main drawback, the flux and torque ripple. Robust, fast, and ripple-free control is achieved by using SMC with proportional control in the vicinity of the sliding surface. SMC assures...... robustness as in DTC, while the proportional component eliminates the torque and flux ripple. The torque time response is similar to conventional DTC and the proposed solution is flexible and highly tunable due to the P component. The controller design is presented, and its robust stability is analyzed...

  13. Approaching the standard quantum limit of mechanical torque sensing

    Science.gov (United States)

    Kim, P. H.; Hauer, B. D.; Doolin, C.; Souris, F.; Davis, J. P.

    2016-10-01

    Reducing the moment of inertia improves the sensitivity of a mechanically based torque sensor, the parallel of reducing the mass of a force sensor, yet the correspondingly small displacements can be difficult to measure. To resolve this, we incorporate cavity optomechanics, which involves co-localizing an optical and mechanical resonance. With the resulting enhanced readout, cavity-optomechanical torque sensors are now limited only by thermal noise. Further progress requires thermalizing such sensors to low temperatures, where sensitivity limitations are instead imposed by quantum noise. Here, by cooling a cavity-optomechanical torque sensor to 25 mK, we demonstrate a torque sensitivity of 2.9 yNm/. At just over a factor of ten above its quantum-limited sensitivity, such cryogenic optomechanical torque sensors will enable both static and dynamic measurements of integrated samples at the level of a few hundred spins.

  14. Special-Purpose High-Torque Permanent-Magnet Motors

    Science.gov (United States)

    Doane, George B., III

    1995-01-01

    Permanent-magnet brushless motors that must provide high commanded torques and satisfy unusual heat-removal requirement are developed. Intended for use as thrust-vector-control actuators in large rocket engines. Techniques and concepts used to design improved motors for special terrestrial applications. Conceptual motor design calls for use of rotor containing latest high-energy-product rare-earth permanent magnets so that motor produces required torque while drawing smallest possible currents from power supply. Torque generated by electromagnetic interaction between stator and permanent magnets in rotor when associated electronic circuits applied appropriately temporally and spatially phased currents to stator windings. Phase relationships needed to produce commanded torque computed in response to torque command and to electronically sensed angular position of rotor relative to stator.

  15. Optical Torque from Enhanced Scattering by Multipolar Plasmonic Resonance

    CERN Document Server

    Lee, Yoonkyung E; Jin, Dafei; Fang, Nicholas

    2014-01-01

    We present a theoretical study of the optical angular momentum transfer from a circularly polarized plane wave to thin metal nanoparticles of different rotational symmetries. While absorption has been regarded as the predominant mechanism of torque generation on the nanoscale, we demonstrate numerically how the contribution from scattering can be enhanced by using multipolar plasmon resonance. The multipolar modes in non-circular particles can convert the angular momentum carried by the scattered field, thereby producing scattering-dominant optical torque, while a circularly symmetric particle cannot. Our results show that the optical torque induced by resonant scattering can contribute to 80% of the total optical torque in gold particles. This scattering-dominant torque generation is extremely mode-specific, and deserves to be distinguished from the absorption-dominant mechanism. Our findings might have applications in optical manipulation on the nanoscale as well as new designs in plasmonics and metamateria...

  16. Torque Characteristics of Saturated Permanent-Magnet Synchronous Motors

    Science.gov (United States)

    Takahashi, Akeshi; Kikuchi, Satoshi; Wakui, Shinichi; Mikami, Hiroyuki; Ide, Kazumasa; Shima, Kazuo

    The evaluation of torque characteristics in a saturated magnetic field for permanent-magnet (PM) synchronous motors is presented. The torque saturation characteristics of non-salient and salient pole machines are investigated by finite element analysis and measurement. Thus, it is found that the torque saturation originates in the magnetic saturation in both the stator teeth, which are located on the leading position toward the direct axis, and in the stator back yoke, which is located on the lagging position toward the direct axis. This mechanism can also explain the reason for the significant torque saturation in the salient-pole machine; the higher inductance of the quadrature axis of the salient-pole machine causes a significant magnetic saturation in the stator back yoke. Therefore, less saliency or a wider back yoke can improve the torque saturation.

  17. Radiative torques on interstellar grains; 1, superthermal spinup

    CERN Document Server

    Draine, B T; Weingartner, Joseph C

    1996-01-01

    Irregular dust grains are subject to radiative torques when irradiated by interstellar starlight. It is shown how these radiative torques may be calculated using the discrete dipole approximation. Calculations are carried out for one irregular grain geometry, and three different grain sizes. It is shown that radiative torques can play an important dynamical role in spinup of interstellar dust grains, resulting in rotation rates which may exceed even those expected from H_2 formation on the grain surface. Because the radiative torque on an interstellar grain is determined by the overall grain geometry rather than merely the state of the grain surface, the resulting superthermal rotation is expected to be long-lived. By itself, long-lived superthermal rotation would permit grain alignment by normal paramagnetic dissipation on the "Davis-Greenstein" timescale. However, radiative torques arising from anisotropy of the starlight background can act directly to alter the grain alignment on much shorter timescales, a...

  18. The fate of fibular osteotomies performed during high tibial osteotomy.

    Science.gov (United States)

    Bicer, Elcil Kaya; Basa, Can Doruk; Gunay, Huseyin; Aydogdu, Semih; Sur, Hakki

    2016-08-01

    High tibial osteotomy (HTO) is an important treatment alternative in isolated single compartment knee osteoarthritis. To achieve adequate mechanical axis corrections in the lower extremity fibula is also osteotomized concomitantly. The aim of this study was to compare the union rates of proximal and diaphyseal fibular osteotomies accompanying high tibial osteotomies. Sixty-seven knees of sixty-three patients who had undergone HTO were retrospectively evaluated. The patients were grouped according to the level of the fibular osteotomy (FO). In group I, the level of FO was proximal, and in group II, it was at the level of junction of middle and distal third of diaphysis. The union rates of FOs at two different levels were compared. The influence of the presence of displacement at the osteotomy site and apposition between bone ends on union was also evaluated. Fifty-nine of sixty-seven FOs (88.06 %) were united. The union rate of proximal FOs was significantly greater than diaphyseal osteotomies (p < 0.0001); 97.9 % of proximal FOs were united, whereas this ratio was 65 % for the diaphyseal FOs. The presence of displacement at the FO and apposition between bone ends significantly influenced the bony union rate (p values 0.035 and <0.0001, respectively). Union rates and nonunion characteristics of FO might differ according to its level, apposition of bone ends, and contact area. The fate of FO might also affect the union of HTO.

  19. Posterior coronal plating for tibial fractures: technique and advantages

    Directory of Open Access Journals (Sweden)

    Montu Jain

    2014-04-01

    Full Text Available Objective:Tibial shaft fractures are straightforward to treat but when associated with soft tissue injury particularly at the nail entry/plate insertion site or there is significant comminution proximally or a large butterfly fragment/a second split component in the posterior coronal plane, it is a challenge to the treating surgeon. The aim of the present report is to describe the technique of posterior coronal plating in such a scenario and its advantages. Methods:Between July 2008 and June 2011, 12 patients were pro spectively treated by this approach using 4.5 mm broad dynamic compression plates. Results:The time of bony consolidation and full weight bearing averaged 21.7 weeks (range, 16-26 weeks. Patients were followed up for at least 24 months (range, 24-48 months. At 1 year postoper atively, no loss in reduction or alignment was observed. Mean Hospital for Lower Extremity Measurement Functional Score was 72.8 (range, 64-78. All patients were satisfied with their treatment outcomes. Conclusion:Direct posterior approach and fixation using prone position helps to visualise the fracture fragments and provide rigid fixation. The approach is simple and extensile easily, apart from advantages of less soft tissue and hardware problems compared to standard medial or lateral plating. Key words: Tibial fractures; Bone plates; Orthopedic procedures

  20. Anterior and posterior tibial anesthetic block in diabetic foot surgery.

    Directory of Open Access Journals (Sweden)

    José Julio Ojeda González

    2004-12-01

    Full Text Available Fundament: Diabetes Mellitus is a disease of high and increasing prevalence and its complications follow a parallel course. Its morbidity is derived from its own complications which are produced at a long or short term and peripheral vascular disease hihglights among them.Objective: to check the usefulness of the anterior and posterior blockade of the tibia for the surgery of the diabetic foot. Method: Prospective study carried out from January to December 2003 at the University Hospital ¨Dr. Gustavo Aldereguía Lima¨ to patients who are carriers of a diabetic foot and who were initially assisted at the service of Angiology and later at the service of Anesthesiology when the surgical procedures were decided. All the patients were applied an anterior and posterior blockade of the tibial nerve . The variables measured were: age, weight, height, surgical time, type of surgery, cardiac frequency medium arterial pressure, and classification of patients according to the American Association of Anesthesiology All the patients were applied a scale for assessing pain in three different moments.Result: There was a predominance of females . The blockade of the posterior tibial nerve with lidocaine 1 % in different points permitted the performance of the surgical techniques proposed. The anesthetic procedure was favorable, and economic since the patients did not requiere of the use of analgesic in the post operatory stage.

  1. Radiographic predictors of compartment syndrome in tibial plateau fractures.

    Science.gov (United States)

    Ziran, Bruce H; Becher, Stephen John

    2013-11-01

    The purpose of this article was to evaluate the relationship of radiographic features of tibial plateau fractures to the development of compartment syndrome. We hypothesized that the direction and degree of initial displacement of the femur on the tibia, and the amount of tibial widening (TW), were correlated with the development of compartment syndrome. Retrospective case-control study. Single level 1 trauma center. Retrospective evaluation of 158 patients with 162 plateau fractures. Grouping with and without compartment syndrome. The following data were obtained: age, sex, Schatzker and OTA/AO classification, open/closed status, TW, and femoral displacement (FD). A univariate statistical and a logistical regression analysis were performed to determine significance. The overall rate of compartment syndrome was 11%. Univariate analysis found both the TW and FD to be significant with respect to development of compartment syndrome (P compartment syndrome. Logistic regression found FD and Schatzker grade to be significant. Our study is the first to identify easily obtained radiographic parameters that correlate to the occurrence compartment syndrome. There may also be a relationship between TW and FD, as noted by regression result. This study helps to assess which patients with a fracture are at higher risk for developing a compartment syndrome. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

  2. Effect of interstitial low level laser therapy on tibial defect

    Science.gov (United States)

    Lee, Sangyeob; Ha, Myungjin; Hwang, Donghyun; Yu, Sungkon; Jang, Seulki; Park, Jihoon; Radfar, Edalat; Kim, Hansung; Jung, Byungjo

    2016-03-01

    Tibial defect is very common musculoskeletal disorder which makes patient painful and uncomfortable. Many studies about bone regeneration tried to figure out fast bone healing on early phase. It is already known that low level laser therapy (LLLT) is very convenient and good for beginning of bone disorder. However, light scattering and absorption obstruct musculoskeletal therapy which need optimal photon energy delivery. This study has used an interstitial laser probe (ILP) to overcome the limitations of light penetration depth and scattering. Animals (mouse, C57BL/6) were divided into three groups: laser treated test group 1 (660 nm; power 10 mW; total energy 5 J) and test group 2 (660 nm; power 20 mW; total energy 10 J); and untreated control group. All animals were taken surgical operation to make tibial defect on right crest of tibia. The test groups were treated every 48 hours with ILP. Bone volume and X-ray attenuation coefficient were measured on 0, 14th and 28th day with u-CT after treatment and were used to evaluate effect of LLLT. Results show that bone volume of test groups has been improved more than control group. X-ray attenuation coefficients of each groups have slightly different. The results suggest that LLLT combined with ILP may affect on early phase of bone regeneration and may be used in various musculoskeletal disease in deep tissue layer.

  3. Nanocavity optomechanical torque magnetometry and RF susceptometry

    CERN Document Server

    Wu, Marcelo; Firdous, Tayyaba; Sani, Fatemeh Fani; Losby, Joseph E; Freeman, Mark R; Barclay, Paul E

    2016-01-01

    Nanophotonic optomechanical devices allow observation of nanoscale vibrations with sensitivity that has dramatically advanced metrology of nanomechanical structures [1-9] and has the potential to similarly impact studies of nanoscale physical systems [10, 11]. Here we demonstrate this potential with a nanophotonic optomechanical torque magnetometer and radio-frequency (RF) magnetic susceptometer. Exquisite readout sensitivity provided by a nanocavity integrated within a torsional nanomechanical resonator enables observations of the unique net magnetization and RF driven responses of single mesoscopic magnetic structures in ambient conditions. The magnetic moment resolution is sufficient for observation of Barkhausen steps in the magnetic hysteresis of a lithographically-patterned permalloy island [12]. In addition, significantly enhanced RF susceptibility is found over narrow field ranges and attributed to thermally-assisted driven hopping of a magnetic vortex core between neighboring pinning sites [13]. The ...

  4. Torque Splitting by a Concentric Face Gear Transmission

    Science.gov (United States)

    Filler, Robert R.; Heath, Gregory F.; Slaughter, Stephen C.; Lewicki, David G.

    2002-01-01

    Tests of a 167 Kilowatt (224 Horsepower) split torque face gearbox were performed by the Boeing Company in Mesa, Arizona, while working under a Defense Advanced Research Projects Agency (DARPA) Technology Reinvestment Program (TRP). This paper provides a summary of these cooperative tests, which were jointly funded by Boeing and DARPA. Design, manufacture and testing of the scaled-power TRP proof-of-concept (POC) split torque gearbox followed preliminary evaluations of the concept performed early in the program. The split torque tests were run using 200 N-m (1767 in-lbs) torque input to each side of the transmission. During tests, two input pinions were slow rolled while in mesh with the two face gears. Two idler gears were also used in the configuration to recombine torque near the output. Resistance was applied at the output face gear to create the required loading conditions in the gear teeth. A system of weights, pulleys and cables were used in the test rig to provide both the input and output loading. Strain gages applied in the tooth root fillets provided strain indication used to determine torque splitting conditions at the input pinions. The final two pinion-two idler tests indicated 52% to 48% average torque split capabilities for the two pinions. During the same tests, a 57% to 43% average distribution of the torque being recombined to the upper face gear from the lower face gear was measured between the two idlers. The POC split torque tests demonstrated that face gears can be applied effectively in split torque rotorcraft transmissions, yielding good potential for significant weight, cost and reliability improvements over existing equipment using spiral bevel gearing.

  5. Dynamic output feedback linearizing control of saturated induction motors with torque per ampere ratio maximization

    OpenAIRE

    Peresada, Sergei; Kovbasa, Serhii; Dymko, Serhii; BOZHKO, Serhiy

    2016-01-01

    The paper presents a novel maximum torque per Ampere (MTA) controller for induction motor (IM) drives. The proposed controller exploits the concept of direct (observer based) field orientation and guarantees asymptotic torque tracking of smooth reference trajectories and maximizes the torque per Ampere ratio when the developed torque is constant or slowly varying. A dynamic output-feedback linearizing technique is employed for the torque subsystem design. In order to improve torque tracking a...

  6. Functional torque ratios and torque curve analysis of shoulder rotations in overhead athletes with and without impingement symptoms.

    Science.gov (United States)

    Zanca, Gisele G; Oliveira, Ana B; Saccol, Michele F; Ejnisman, Benno; Mattiello-Rosa, Stela M

    2011-12-01

    In this study, we evaluated the peak torque, functional torque ratios, and torque curve profile of the shoulder rotators in overhead athletes with impingement symptoms so as to examine possible alterations in response to sports training and shoulder pain. Twenty-one overhead athletes with impingement symptoms were compared with 25 overhead athletes and 21 non-athletes, none of whom were symptomatic for impingement. The participants performed five maximal isokinetic concentric and eccentric contractions of medial and lateral shoulder rotations at 1.57 rad · s(-1) and 3.14 rad · s(-1). Isokinetic peak torque was used to calculate the eccentric lateral rotation-to-concentric medial rotation and the eccentric medial rotation-to-concentric lateral rotation ratios. An analysis of the torque curve profiles was also carried out. The eccentric lateral rotation-to-concentric medial rotation torque ratio of asymptomatic athletes was lower than that of non-athletes at both test velocities. The concentric medial rotation isokinetic peak torque of the asymptomatic athletes, at 3.14 rad · s(-1), was greater than that of the non-athletes, and the peak appeared to occur earlier in the movement for athletes than non-athletes. These findings suggest that there may be adaptations to shoulder function in response to throwing practice. The eccentric medial rotation-to-concentric lateral rotation torque ratio was altered neither by the practice of university-level overhead sports nor impingement symptoms.

  7. A New Fixed Switching Frequency Direct Torque Controlled PMSM Drives with Low Ripple in Flux and Torque

    Directory of Open Access Journals (Sweden)

    Tole Sutikno

    2011-11-01

    Full Text Available Direct Torque Control (DTC has gained popularity for development of advanced motor control due to its simplicity and offers fast instantaneous torque and flux controls. However, the conventional DTC which is based on hysteresis controller has major drawbacks, namely high torque ripple and variable inverter switching frequency. This paper presents an improved switching strategy for reducing flux and torque ripples in DTC of PMSM drives; wherein the torque hysteresis controller and the look-up table used in the conventional DTC are replaced with a constant frequency torque controller (CFTC and an optimized look-up table, respectively. It can be shown that a constant switching frequency is established due to the use of the CFTC while the reduction of torque and flux ripples is achieved mainly because of the selection of optimized voltage vector (i.e. with an optimized look-up table. This paper also will explain the construction of DTC schemes implemented using MATLAB-Simulink blocks. Simulation results were shown that a significant reduction of flux and torque ripples which is about 90% can be achieved through the proposed DTC scheme.

  8. Ankle fusion stability: a biomechanical comparison of external versus internal fixation.

    Science.gov (United States)

    Hoover, Justin R; Santrock, Robert D; James, William C

    2011-04-11

    This biomechanical study compares bimalleolar external fixation to conventional crossed-screw construct in terms of stability and compression for ankle arthrodesis. The goals of the study were to determine which construct is more stable with bending and torsional forces, and to determine which construct achieves more compression.Fourth-generation bone composite tibia and talocalcaneal models were made to 50th percentile anatomic specifications. Fourteen ankle fusion constructs were created with bimalleolar external fixators and 14 with crossed-screw constructs. Ultimate bend, torque, and compression testing were completed on the external fixator and crossed-screw constructs using a multidirectional Materials Testing Machine (MTS Systems Corp, Eden Prairie, Minnesota). Ultimate bend testing revealed a statistically significant difference (P=.0022) with the mean peak load to failure for the external fixator constructs of 973.2 N compared to 612.5 N for the crossed-screw constructs. Ultimate torque testing revealed the mean peak torque to failure for the external fixator construct was 80.2 Nm and 28.1 Nm for the crossed-screw construct, also a statistically significant difference (P=.0001). The compression testing yielded no statistically significant difference (P=.9268) between the average failure force of the external fixator construct (81.6 kg) and the crossed-screw construct (81.2 kg).With increased stiffness in both bending and torsion and comparable compressive strengths, bimalleolar external fixation is an excellent option for tibiotalar ankle arthrodesis.

  9. Analysis of Primary Stability of Dental Implants Inserted in Different Substrates Using the Pullout Test and Insertion Torque

    Directory of Open Access Journals (Sweden)

    Nathalia Ferraz Oliscovicz

    2013-01-01

    Full Text Available The aim of the study was to evaluate mechanical behavior of implants inserted in three substrates, by measuring the pullout strength and the relative stiffness. 32 implants (Master Porous-Conexao, cylindrical, external hexagon, and surface treatment were divided into 4 groups (n=8: pig rib bone, polyurethane Synbone, polyurethane Nacional 40 PCF, and pinus wood. Implants were installed with the exact distance of 5 mm of another implant. The insertion torque (N·cm was quantified using the digital Kratos torque meter and the pullout test (N was performed by an axial traction force toward the long axis of the implant (2 min/mm through mount implant devices attached to a piece adapted to a load cell of 200 Kg of a universal testing machine (Emic DL10000. Data of insertion torque and maximum pullout force were submitted to one-way ANOVA and Bonferroni tests (α=0.05. Polyurethane Nacional 40 PCF and pinus wood showed the highest values of insertion torque and pullout force, with significant statistical difference (P<0.05 with other groups. The analysis showed stiffness materials with the highest values for primary stability.

  10. A Novel Direct Torque Control for Induction Machine Drive System with Low Torque And Flux Ripples using XSG

    Directory of Open Access Journals (Sweden)

    Souha Boukadida

    2014-12-01

    Full Text Available The conventional Direct Torque Control (DTC is known to produce a quick and robust response in AC drives. However, during steady state, stator flux and electromagnetic torque which results in incorrect speed estimations and acoustical noise. A modified Direct Torque Control (DTC by using Space Vector Modulation (DTC-SVM for induction machine is proposed in this paper. Using this control strategy, the ripples introduced in torque and flux are reduced. This paper presents a novel approach to design and implementation of a high perfromane torque control (DTC-SVM of induction machine using Field Programmable gate array (FPGA.The performance of the proposed control scheme is evaluated through digital simulation using Matlab\\Simulink and Xilinx System Generator. The simulation results are used to verify the effectiveness of the proposed control strategy.

  11. Large amplitude spin torque vortex oscillations at zero external field using a perpendicular spin polarizer

    Energy Technology Data Exchange (ETDEWEB)

    Dussaux, A.; Rache Salles, B.; Jenkins, A. S.; Bortolotti, P.; Grollier, J.; Cros, V.; Fert, A. [Unité Mixte de Physique CNRS/Thales and Université Paris Sud 11, 1 Ave. A. Fresnel, 91767 Palaiseau (France); Grimaldi, E., E-mail: eva.grimaldi@thalesgroup.com [Unité Mixte de Physique CNRS/Thales and Université Paris Sud 11, 1 Ave. A. Fresnel, 91767 Palaiseau (France); CNES, 1 Avenue Edouard Belin, 31400 Toulouse (France); Khvalkovskiy, A. V. [Unité Mixte de Physique CNRS/Thales and Université Paris Sud 11, 1 Ave. A. Fresnel, 91767 Palaiseau (France); A.M. Prokhorov General Physics Institute of RAS, Vavilova Str. 38, 119991 Moscow (Russian Federation); Kubota, H.; Fukushima, A.; Yakushiji, K.; Yuasa, S. [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan)

    2014-07-14

    We investigate the microwave response of a spin transfer vortex based oscillator in a magnetic tunnel junction with an in-plane reference layer combined with a spin valve with an out-of-plane magnetization spin polarizing layer. The main advantage of this perpendicular spin polarizer is to induce a large spin transfer force even at zero magnetic field, thus leading to a record emitted power (up to 0.6 μW) associated to a very narrow spectral linewidth of a few hundreds of kHz. The characteristics of this hybrid vortex based spin transfer nano-oscillator obtained at zero field and room temperature are of great importance for applications based on rf spintronic devices as integrated and tunable microwave source and/or microwave detector.

  12. External fixation combined with limited internal fixation in the treatment of pilon tibia fractures

    Directory of Open Access Journals (Sweden)

    Golubović Zoran

    2007-01-01

    Full Text Available Background/Aim. Intraarticular fractures of the tibial plafond (pilon fractures belong to the group of most severe fractures. They are usually caused by high-energy trauma and frequently associated with a marked soft-tissue damage. Surgical treatment has replaced the traditional nonoperative treatment. The aim of this study was to present the results of the treatment of distal tibial intraarticular fracture by the use of internal fixation, as well as the combination of minimal internal fixation and external fixation. Methods. The study included 47 patients with pilon tibia fractures who went through at the Clinic for Orthopedics and Traumatology, School of Medicine, Niš (1995-2004. Within the analyzed group there were 33 (70.2% males and 14 (29.8% females. The patients mean age was 45.8 years. In the first group, which consisted of 22 patients, open reduction and internal fixation of both the tibia and the fibula was performed in the two separate incisions. The second group consisted of 25 patients managed with external fixation by external fixator "Mitković" with limited internal fixation. Besides external fixation, a minimal internal fixation was performed by the use of Kirschner wires and screws. The patients were followed-up inside a 24-months-period. Results. The obtained was a substantially high number of complications after open reduction and internal fixation in the group of patients. There was no difference in a long-term clinical outcome. Postoperative osteitis, as the most severe complication in the management of closed pilon tibia fractures, was not registered in the second group. Conclusion. Considering the results obtained in this study, it can be concluded that external fixation by the "Mitković" external fixator with the minimal internal fixation is a satisfactory method for the treatment of fractures of the tibial plafond causing less complications than internal fixation. .

  13. Temperature dependence of spin-orbit torques in Cu-Au alloys

    KAUST Repository

    Wen, Yan

    2017-03-07

    We investigated current driven spin-orbit torques in Cu40Au60/Ni80Fe20/Ti layered structures with in-plane magnetization. We have demonstrated a reliable and convenient method to separate dampinglike torque and fieldlike torque by using the second harmonic technique. It is found that the dampinglike torque and fieldlike torque depend on temperature very differently. Dampinglike torque increases with temperature, while fieldlike torque decreases with temperature, which are different from results obtained previously in other material systems. We observed a nearly linear dependence between the spin Hall angle and longitudinal resistivity, suggesting that skew scattering may be the dominant mechanism of spin-orbit torques.

  14. Immediate compensation for variations in self-generated Coriolis torques related to body dynamics and carried objects.

    Science.gov (United States)

    Pigeon, Pascale; Dizio, Paul; Lackner, James R

    2013-09-01

    shoulder and 34% at the elbow. In accordance with Sainburg's dynamic dominance hypothesis, the right arm exhibited an advantage for coordinating intersegmental dynamics, showing a more stable finger velocity in relation to the torso across targets, decreasing error variability with movement speed, and more synchronized peaks of finger relative and torso angular velocities in conditions with greater joint torque requirements. The arm used had little effect on the movement path and the magnitude of the joint torques in any of the conditions. These results indicate that compensations for forthcoming Coriolis torque variations take into account the dynamic properties of the body and of external objects, as well as the planned velocities of the torso and arm.

  15. Regulating multiple externalities

    DEFF Research Database (Denmark)

    Waldo, Staffan; Jensen, Frank; Nielsen, Max

    2016-01-01

    Open access is a well-known externality problem in fisheries causing excess capacity and overfishing. Due to global warming, externality problems from CO2 emissions have gained increased interest. With two externality problems, a first-best optimum can be achieved by using two regulatory instrume......Open access is a well-known externality problem in fisheries causing excess capacity and overfishing. Due to global warming, externality problems from CO2 emissions have gained increased interest. With two externality problems, a first-best optimum can be achieved by using two regulatory...

  16. Interaction torque contributes to planar reaching at slow speed

    Directory of Open Access Journals (Sweden)

    Hoshi Fumihiko

    2008-10-01

    Full Text Available Abstract Background How the central nervous system (CNS organizes the joint dynamics for multi-joint movement is a complex problem, because of the passive interaction among segmental movements. Previous studies have demonstrated that the CNS predictively compensates for interaction torque (INT which is arising from the movement of the adjacent joints. However, most of these studies have mainly examined quick movements, presumably because the current belief is that the effects of INT are not significant at slow speeds. The functional contribution of INT for multijoint movements performed in various speeds is still unclear. The purpose of this study was to examine the contribution of INT to a planer reaching in a wide range of motion speeds for healthy subjects. Methods Subjects performed reaching movements toward five targets under three different speed conditions. Joint position data were recorded using a 3-D motion analysis device (50 Hz. Torque components, muscle torque (MUS, interaction torque (INT, gravity torque (G, and net torque (NET were calculated by solving the dynamic equations for the shoulder and elbow. NET at a joint which produces the joint kinematics will be an algebraic sum of torque components; NET = MUS - G - INT. Dynamic muscle torque (DMUS = MUS-G was also calculated. Contributions of INT impulse and DMUS impulse to NET impulse were examined. Results The relative contribution of INT to NET was not dependent on speed for both joints at every target. INT was additive (same direction to DMUS at the shoulder joint, while in the elbow DMUS counteracted (opposed to INT. The trajectory of reach was linear and two-joint movements were coordinated with a specific combination at each target, regardless of motion speed. However, DMUS at the elbow was opposed to the direction of elbow movement, and its magnitude varied from trial to trial in order to compensate for the variability of INT. Conclusion Interaction torque was important at

  17. BIOMECHANICAL STUDY ON UNILATERAL SINGLE-PLANE EXTERNAL FIXER

    Institute of Scientific and Technical Information of China (English)

    刘国平; 杜靖远; 徐兆雄

    1995-01-01

    Six tibias removed from 30-40 years old males,who died in an accident for in less than 12 hours,were cateotomised at one-third supra-medium segment.They were fixed by an unilateral adjustable external fixer (UAEF),to be used as a model of external fixation of tibial fracture (MEFTF).The compression,tension,torsion,antero-posterior and lateral bending strength,and the strength for vertically extracting the pins from the tibia were determined in the MEFTF.Within a certain range of foad,the correlation of strain to stress was basically a linear relationship.These data provide a theoretical basis of biomechanjcs for the improvement of UAEF and for early exercises of fracture patients,such as extend-bending of the joint,raising the limb and walking with a walking stick.

  18. ExternE National Implementation Finland

    Energy Technology Data Exchange (ETDEWEB)

    Pingoud, K.; Maelkki, H.; Wihersaari, M.; Pirilae, P. [VTT Energy, Espoo (Finland); Hongisto, M. [Imatran Voima Oy, Vantaa (Finland); Siitonen, S. [Ekono Energy Ltd, Espoo (Finland); Johansson, M. [Finnish Environment Institute, Helsinki (Finland)

    1999-07-01

    ExternE National Implementation is a continuation of the ExternE Project, funded in part by the European Commission's Joule III Programme. This study is the result of the ExternE National Implementation Project for Finland. Three fuel cycles were selected for the Finnish study: coal, peat and wood-derived biomass, which together are responsible for about 40% of total electricity generation in Finland and about 75% of the non-nuclear fuel based generation. The estimated external costs or damages were dominated by the global warming (GW) impacts in the coal and peat fuel cycles, but knowledge of the true GW impacts is still uncertain. From among other impacts that were valued in monetary terms the human health damages due to airborne emissions dominated in all the three fuel cycles. Monetary valuation for ecosystem impacts is not possible using the ExternE methodology at present. The Meri-Pori power station representing the coal fuel cycle is one of the world's cleanest and most efficient coal-fired power plants with a condensing turbine. The coal is imported mainly from Poland. The estimated health damages were about 4 mECU/kWh, crop damages an order of magnitude lower and damages caused to building materials two orders of magnitude lower. The power stations of the peat and biomass fuel cycles are of CHP type, generating electricity and heat for the district heating systems of two cities. Their fuels are of domestic origin. The estimated health damages allocated to electricity generation were about 5 and 6 mECU/kWh, respectively. The estimates were case-specific and thus an generalisation of the results to the whole electricity generation in Finland is unrealistic. Despite the uncertainties and limitations of the methodology, it is a promising tool in the comparison of similar kinds of fuel cycles, new power plants and pollution abatement technologies and different plant locations with each other. (orig.)

  19. Radiographic study on the tibial insertion of the posterior cruciate ligament

    Directory of Open Access Journals (Sweden)

    Julio Cesar Gali

    2015-06-01

    Full Text Available OBJECTIVE: To establish the radiographic distances from posterior cruciate ligament (PCL tibial insertions centers to the lateral and medial tibial cortex in the anteroposterior view, and from these centers to the PCL facet most proximal point on the lateral view, in order to guide anatomical tunnels drilling in PCL reconstruction and for tunnel positioning postoperative analysis.STUDY DESIGN: Controlled laboratory study.METHODS: Twenty cadaver knees were evaluated. The PCL's bundles tibial insertions were identified and marked out using metal tags, and the knees were radiographed. On these radiographs, the bundles insertion sites center location relative to the tibial mediolateral measure, and the distances from the most proximal PCL facet point to the bundle's insertion were determined. All measures were calculated using the ImageJ software.RESULTS: On the anteroposterior radiographs, the mean distance from the anterolateral (AL bundle insertion center to the medial tibial edge was 40.68 ± 4.10 mm; the mean distance from the posteromedial (PM bundle insertion center to the medial tibial edge was 38.74 ± 4.40 mm. On the lateral radiographs, the mean distances from the PCL facet most proximal point to AL and PM bundles insertion centers were 5.49 ± 1.29 mm and 10.53 ± 2.17 mm respectively.CONCLUSIONS: It was possible to establish a radiographic pattern for PCL tibial bundles insertions, which may be useful for intraoperative tunnels locations control and for postoperative tunnels positions analysis.

  20. Impact of Fixed-Bearing and Mobile-Bearing Tibial Insert in Unicondylar Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    Mehmet Faruk Çatma

    2016-06-01

    Full Text Available INTRODUCTION: The aim of the study is to investigate the impact of fixed or mobile-bearing tibial inserts on patellofemoral arthrosis and evaluate which one to be preferred for patients with patellofemoral arthrosis. METHODS: Operated in our clinic between January 2009 and February 2013, 33 with patellofemoral arthritis together with anteromedial compartment arthritis were included in the study. Patellofemoral joints of patients were evaluated according to the scoring system defined by Fulkerson-Shea. RESULTS: Unicondylar knee arthroplasty with fixed-bearing tibial insertsand 22 (66,6% (male: 3, female: 19 and unicondylar knee arthroplasty with mobile-bearing tibial inserts 11 (33,9 % (male: 2, female: 9 were implanted.Average knee flexion was found to be 116,5 (100-135 degrees in 22 patients with mobile-bearing tibial inserts, and 114,5 (95-135 in 11 patients with fixed-bearing tibial inserts. DISCUSSION AND CONCLUSION: Patellofemoral arthrosis is an important factor for unicondylar knee arthroplasty prognosis and one of the determinants of patient satisfaction. Significantly less patellofemoral complaints were seen with UKA with fixed-bearing tibial insert compared to mobile-bearing tibial insert.

  1. Modified retro-tubercle opening-wedge versus conventional high tibial osteotomy.

    Science.gov (United States)

    Keyhani, Sohrab; Abbasian, Mohammad Reza; Kazemi, Seyed Morteza; Esmailiejah, Ali Akbar; Seyed Hosseinzadeh, Hamid Reza; Shahi, Alisina; Shahi, Ali Sina; Firouzi, Farzad

    2011-01-01

    Despite the fact that common surgical techniques for the treatment of genu varum usually correct the malalignment in the affected knee, these methods have significant complications and cause problems in the long term. Retro-tubercle opening-wedge high tibial osteotomy is among the newer techniques for the treatment of genu varum. The goal of this study was to compare the results of retro-tubercle opening-wedge high tibial osteotomy with those of medial opening-wedge osteotomy. In a randomized, controlled trial, 72 patients with varus knees who were scheduled for surgery were assigned into either the retro-tubercle opening-wedge high tibial osteotomy (n=34) or medial opening-wedge osteotomy groups (n=38). Groups were matched for age and sex. The position of the patella was compared with respect to the tuberosity and the upper tibial slope pre- and postoperatively. Patients were followed for an average of 13 months (range, 10-21 months). In the retro-tubercle opening-wedge high tibial osteotomy group, the length of the patellar tendon did not significantly differ pre- and postoperatively (P≥.5); however, in the medial opening-wedge osteotomy group, a statistically significant shortening was noted in patellar tendon postoperatively (P≤.05). Similarly, the tibial plateau inclination showed a statistically significant difference postoperatively in the medial opening-wedge osteotomy group, while the difference in the retro-tubercle opening-wedge high tibial osteotomy group did not reach statistical significance.

  2. [Suprapatellar approach to tibial medullary nailing with electromagnetic field-guided distal locking].

    Science.gov (United States)

    Rueger, J M; Rücker, A H; Hoffmann, M

    2015-04-01

    Closed tibial shaft fractures are the domain of intramedullary nailing. With the introduction of new nail designs and technologies, even small, dislocated distal fragments can be anatomically aligned and safely fixed. Unsolved or to a lesser degree controlled are the problems of distal locking in the freehand technique, which can still be difficult and can lead to a significant radiation exposure, and how to control very short proximal tibial fragments in metaphyseal tibial fractures or tibial segmental fractures, where the proximal fracture line also runs through the metaphysis.By using a suprapatellar approach, i.e. a skin incision proximal to the patella with an entry point into the tibial bone from within the knee at the same site as for a standard infrapatellar approach, and then nailing the tibia in a semi-extended position, i.e. the knee is only flexed 10-20°, the intraoperative dislocation of a short proximal fragment can be avoided. The main indications for semi-extended tibial nailing are a short diaphyseal fragment in an isolated tibial shaft fracture, a segmental fracture where the proximal fracture line is metaphyseal and in patients where infrapatellar soft tissues are compromised.The use of the electromagnetic guidance system SureShot® generates reliable and reproducible results, reduces the operating time and is independent from radiation for distal locking.

  3. Study on Monitoring Rock Burst through Drill Pipe Torque

    Directory of Open Access Journals (Sweden)

    Zhonghua Li

    2015-01-01

    Full Text Available This paper presents a new method to identify the danger of rock burst from the response of drill pipe torque during drilling process to overcome many defects of the conventional volume of drilled coal rubble method. It is based on the relationship of rock burst with coal stress and coal strength. Through theoretic analysis, the change mechanism of drill pipe torque and the relationship of drill pipe torque with coal stress, coal strength, and drilling speed are investigated. In light of the analysis, a new device for testing drill pipe torque is developed and a series of experiments is performed under different conditions; the results show that drill pipe torque linearly increases with the increase of coal stress and coal strength; the faster the drilling speed, the larger the drill pipe torque, and vice versa. When monitoring rock burst by drill pipe torque method, the index of rock burst is regarded as a function in which coal stress index and coal strength index are principal variables. The results are important for the forecast of rock burst in coal mine.

  4. Current-induced torques and interfacial spin-orbit coupling

    KAUST Repository

    Haney, Paul M.

    2013-12-19

    In bilayer systems consisting of an ultrathin ferromagnetic layer adjacent to a metal with strong spin-orbit coupling, an applied in-plane current induces torques on the magnetization. The torques that arise from spin-orbit coupling are of particular interest. Here we use first-principles methods to calculate the current-induced torque in a Pt-Co bilayer to help determine the underlying mechanism. We focus exclusively on the analog to the Rashba torque, and do not consider the spin Hall effect. The details of the torque depend strongly on the layer thicknesses and the interface structure, providing an explanation for the wide variation in results found by different groups. The torque depends on the magnetization direction in a way similar to that found for a simple Rashba model. Artificially turning off the exchange spin splitting and separately the spin-orbit coupling potential in the Pt shows that the primary source of the “fieldlike” torque is a proximate spin-orbit effect on the Co layer induced by the strong spin-orbit coupling in the Pt.

  5. Standard practice for torque calibration of testing machines and devices

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This practice covers procedures and requirements for the calibration of torque for static and quasi-static torque capable testing machines or devices. These may, or may not, have torque indicating systems and include those devices used for the calibration of hand torque tools. Testing machines may be calibrated by one of the three following methods or combination thereof: 1.1.1 Use of standard weights and lever arms. 1.1.2 Use of elastic torque measuring devices. 1.1.3 Use of elastic force measuring devices and lever arms. 1.1.4 Any of the methods require a specific uncertainty of measurement and a traceability derived from national standards of mass and length. 1.2 The procedures of 1.1.1, 1.1.2, and 1.1.3 apply to the calibration of the torque-indicating systems associated with the testing machine, such as a scale, dial, marked or unmarked recorder chart, digital display, etc. In all cases the buyer/owner/user must designate the torque-indicating system(s) to be calibrated and included in the repor...

  6. Towards Scalable Strain Gauge-Based Joint Torque Sensors

    Science.gov (United States)

    D’Imperio, Mariapaola; Cannella, Ferdinando; Caldwell, Darwin G.; Cuschieri, Alfred

    2017-01-01

    During recent decades, strain gauge-based joint torque sensors have been commonly used to provide high-fidelity torque measurements in robotics. Although measurement of joint torque/force is often required in engineering research and development, the gluing and wiring of strain gauges used as torque sensors pose difficulties during integration within the restricted space available in small joints. The problem is compounded by the need for a scalable geometric design to measure joint torque. In this communication, we describe a novel design of a strain gauge-based mono-axial torque sensor referred to as square-cut torque sensor (SCTS), the significant features of which are high degree of linearity, symmetry, and high scalability in terms of both size and measuring range. Most importantly, SCTS provides easy access for gluing and wiring of the strain gauges on sensor surface despite the limited available space. We demonstrated that the SCTS was better in terms of symmetry (clockwise and counterclockwise rotation) and more linear. These capabilities have been shown through finite element modeling (ANSYS) confirmed by observed data obtained by load testing experiments. The high performance of SCTS was confirmed by studies involving changes in size, material and/or wings width and thickness. Finally, we demonstrated that the SCTS can be successfully implementation inside the hip joints of miniaturized hydraulically actuated quadruped robot-MiniHyQ. This communication is based on work presented at the 18th International Conference on Climbing and Walking Robots (CLAWAR). PMID:28820446

  7. Synovial C-Shaped Tibial Footprint of the Anterior Cruciate Ligament

    Science.gov (United States)

    Janovsky, César; Kaleka, Camila Cohen; Alves, Maria Teresa Seixas; Ferretti, Mario; Cohen, Moises

    2016-01-01

    Background: Although numerous anatomic studies about the anterior cruciate ligament (ACL) structure and attachments have been performed, these studies have not reached consensus on the ACL footprint. Purpose: To investigate the existing controversy regarding the morphology of the tibial ACL insertion (footprint) and confirm histologically that the tibial ACL footprint is not completely filled with ligament tissue. Study Design: Descriptive laboratory study. Methods: The tibial ACL footprint was dissected from 20 different fresh-frozen cadaveric knees (all males; mean age, 68.8 ± 5.4 years [range, 55-80 years]; mean weight, 78 ± 6.6 kg [range, 45-93 kg]). Two knees, 1 with severe osteoarthritis and 1 with previous knee surgery, were excluded. The tibial ACL insertion was observed, and this area was longitudinally divided into 4 parallel slices (0%-25%, 25-50%, 50%-75%, and 75%-100%), embedded in paraffin wax, and stained with hematoxylin-eosin, alcian blue, and picrosirius-polarization. The specimens were measured using a microscope to determine the distances from the anterior to the posterior border of the ACL ligament tibial insertion and the distance from the posterior border to the end of the ligament fibers of the ACL ligament tibial insertions. Results: The 18 evaluated knee specimens confirmed the finding of a C-shaped tibial insertion of the ACL. The measurements showed that the ligament (vertical parallel collagen fibers) occupied only 30.8% of the complete insertion. The remaining area was filled with synovial tissue, demonstrating histologically the “C” shape. Conclusion: This study confirms macroscopically the C-shaped tibial insertion of the ACL and shows histologically that synovial tissue is an indirect insertion filling the major part of the footprint. Clinical Relevance: This anatomic study suggests a different shape of the ACL tibial footprint, which may be useful for new perspectives regarding ACL reconstruction surgery research. PMID

  8. The accuracy of intramedullary tibial guide of sagittal alignment of PCL-substituting total knee arthroplasty.

    Science.gov (United States)

    Han, Hyuk-Soo; Kang, Seung-Baik; Jo, Chris H; Kim, Sun-Hong; Lee, Jung-Ha

    2010-10-01

    Experimental and clinical studies on the accuracy of the intramedullary alignment method have produced different results, and few have addressed accuracy in the sagittal plane. Reported deviations are not only attributable to the alignment method but also to radiological errors. The purpose of this study was to evaluate the accuracy of the intramedullary alignment method in the sagittal plane using computed tomography (CT) and 3-dimensional imaging software. Thirty-one TKAs were performed using an intramedullary alignment method involving the insertion of a long 8-mm diameter rod into the medullary canal to the distal metaphysis of the tibia. All alignment instruments were set to achieve an ideal varus/valgus angle of 0° in the coronal plane and a tibial slope of 0° in the sagittal plane. The accuracy of the intramedullary alignment system was assessed by measuring the coronal tibial component angle and sagittal tibial slope angles, i.e., angles between the tibial anatomical axis and the tangent to the medial and lateral tibial plateau or the cut-surface. The mean coronal tibial component angle was 88.5° ± 1.2° and the mean tibial component slope in the sagittal plane was 1.6° ± 1.2° without anterior slope. Our intramedullary tibial alignment method, which involves passing an 8-mm diameter long rod through the tibial shaft isthmus, showed good accuracy (less than 3 degrees of variation and no anterior slope) in the sagittal plane in neutral or varus knees.

  9. Clock face model applied to tibial intraneural ganglia in the popliteal fossa

    Energy Technology Data Exchange (ETDEWEB)

    Spinner, Robert J. [Mayo Clinic, Department of Neurologic Surgery, Rochester, MN (United States); Mayo Clinic, Department of Orthopedics, Rochester, MN (United States); Mayo Clinic, Rochester, MN (United States); Hebert-Blouin, Marie-Noelle [Mayo Clinic, Department of Neurologic Surgery, Rochester, MN (United States); Maniker, Allen H. [Beth Israel Hospital, Department of Neurosurgery, New York, NY (United States); Amrami, Kimberly K. [Mayo Clinic, Department of Neurologic Surgery, Rochester, MN (United States); Mayo Clinic, Department of Radiology, Rochester, MN (United States)

    2009-07-15

    Tibial intraneural ganglia occurring in the popliteal fossa are often misdiagnosed because of their relative rarity. Their joint connection is typically not recognized and therefore not treated, leading to recurrence. This is a retrospective clinical study. Magnetic resonance images (MRIs) of six patients with confirmed tibial intraneural ganglia arising from the superior tibiofibular joint were analyzed and were compared to ten individuals with normal tibial nerves who were imaged with MRI. All studies were interpreted as left-sided. A previously designed clock face model introduced for peroneal intraneural ganglia was used to describe the superior tibiofibular joint connection (tail sign). A single axial image was sought to determine the normal anatomic and pathologic relationships of the tibial nerve and tibial articular branch to the superior tibiofibular joint. In all patients with intraneural ganglia, a single conventional axial image at the mid-fibular head level could reliably demonstrate: (1) intraneural cyst within the articular branch at the superior tibiofibular joint connection (tail sign) between 8 and 9 o'clock and intraneural cyst within the tibial nerve, (2) the central location of the tibial nerve posterior to the tibia, and (3) popliteus muscle denervation changes and atrophy (popliteus sign). This technique can provide radiologists and surgeons with rapid and reproducible information for diagnosis and treatment planning of tibial intraneural ganglia. Similar to its use with the clock face model in peroneal intraneural ganglia, a standard axial image at the mid-fibular head level can be used to interpret key features of tibial intraneural ganglia and identify the joint connection. Improved identification of the presence of a joint connection will change the therapeutic approach of this pathology and reduce cyst recurrences. (orig.)

  10. Direct contribution of axial impact compressive load to anterior tibial load during simulated ski landing impact.

    Science.gov (United States)

    Yeow, C H; Lee, P V S; Goh, J C H

    2010-01-19

    Anterior tibial loading is a major factor involved in the anterior cruciate ligament (ACL) injury mechanism during ski impact landing. We sought to investigate the direct contribution of axial impact compressive load to anterior tibial load during simulated ski landing impact of intact knee joints without quadriceps activation. Twelve porcine knee specimens were procured. Four specimens were used as non-impact control while the remaining eight were mounted onto a material-testing system at 70 degrees flexion and subjected to simulated landing impact, which was successively repeated with incremental actuator displacement. Four specimens from the impacted group underwent pre-impact MRI for tibial plateau angle measurements while the other four were subjected to histology and microCT for cartilage morphology and volume assessment. The tibial plateau angles ranged from 29.4 to 38.8 degrees . There was a moderate linear relationship (Y=0.16X; R(2)=0.64; p<0.001) between peak axial impact compressive load (Y) and peak anterior tibial load (X). The anterior and posterior regions in the impacted group sustained surface cartilage fraying, superficial clefts and tidemark disruption, compared to the control group. MicroCT scans displayed visible cartilage deformation for both anterior and posterior regions in the impacted group. Due to the tibial plateau angle, increased axial impact compressive load can directly elevate anterior tibial load and hence contribute to ACL failure during simulated landing impact. Axial impact compressive load resulted in shear cartilage damage along anterior-posterior tibial plateau regions, due to its contribution to anterior tibial loading. This mechanism plays an important role in elevating ACL stress and cartilage deformation during impact landing.

  11. Preoperative determination of tibial nail length: An anthropometric study

    Institute of Scientific and Technical Information of China (English)

    Renjit Thomas Issac; Hitesh Gopalan; Mathew Abraham; Cherian John; Sujith Mathew Issac; Diju Jacob

    2016-01-01

    Objective:To assess the correlation between five anthropometric parameters and the distance from tibial tuberosity to medial malleolus in 100 volunteers.Methods:Six anthropometric parameters were measured in 50 male and 50 female medical students using a metallic scale:medial knee joint line to ankle joint line (K-A),medial knee joint line to medial malleolus (K-MM),tibial tuberosity to ankle joint (TT-A),tibial tuberosity to medial malleolus (TT-MM),olecranon to 5th metacarpal head (O-MH) and body height (BH).Nail size predicted based upon TT-MM measurement was chosen as ideal nail size.A constant was derived for each of the six anthropometric parameters which was either added or subtracted to each measurement to derive nail size.A regression equation was applied to BH measurements.Nail sizes calculated were compared with that obtained from TT-MM measurement and accuracy was evaluated.Accuracy of O-MH and BH regression equations recommended by other authors were calculated in our data.Results:Adding 11 mm to TT-A distance had highest accuracy (81%) and correlation (0.966) in predicting nails correctly.Subtracting 33 mm from K-MM measurement and 25 mm from K-A distance derived accurate sizes in 69% and 76% respectively.Adding 6 mm to O-MH distance had a poor accuracy of 51%.Nail size prediction based upon body height regression equation derived correct nail sizes in only 34% of the cases.Regression equation analysis by other authors based on O-MH and BH distances yielded correct sizes in 11% and 5% of the cases respectively.Conclusion:TT-A,K-A and K-MM measurements can be used simultaneously to increase accuracy of nail size prediction.This method would be helpful in determining nail size preoperatively especially when one anatomic landmark is difficult to palpate.

  12. Sagittal patellar tilt and concomitant quadriceps hypotrophy after tibial nailing.

    Science.gov (United States)

    Aksahin, Ertugrul; Yilmaz, Serdar; Karasoy, Ismail; Duran, Semra; Yuksel, H Yalcin; Dogan, Ozgur; Yildirim, A Ozgur; Bicimoglu, Ali

    2016-09-01

    The aim of the study was to analyse the patellofemoral alignment in the sagittal plane following tibial fracture surgery with intramedullary nailing and its relationship to parapatellar muscle status. The patellofemoral MRI results of 27 patients (15 males and 12 females) treated with locked intramedullary nailing following tibia shaft fracture were reviewed. The mean age of the patients was 41.8 (±15) years. The patella-patellar tendon angle (P-PT) and the distance between the inferior patellar pole and the tibial tubercle (DP-TT) were evaluated for both the operated extremity and the contralateral normal side. MRI assessment of the infrapatellar fat pad, quadriceps, sartorius, gracilis, semi-membranosus muscles and biceps muscles was also carried out. The correlation between the changes in skeletal muscle mass, the volume of the infrapatellar fat pad and the alterations in the DP-TT distances and P-PT angles were analysed. The quadriceps muscle cross-sectional diameter had a mean of 157.2 mm(2) (115.6/319.5) in the operated extremity, and it was 193 mm(2) (77.6/282.2) in the non-operated normal side (p = 0.001). For the Gracilis muscle, the mean was 84.4 mm(2) (19.7/171) at the operated extremity and 75.7 mm(2) (26.9/238.2) on the normal side (p = 0.05). The cross-sectional areas of the semi-membranosus, sartorius and biceps muscles in the operated and non-operated extremity were not noticeably different (n.s). The P-PT angle was 153° (129.7/156.4) in the operated extremity and 145.7° (137.6/163.4) in the non-operated normal extremity (p hypotrophy negatively correlated (r = -0.4, p = 0.02) with the P-PT angle but positively correlated with the increase in gracilis muscle volume (r = 0.4, p = 0.03). This study revealed that patellofemoral joint kinematics in the operated extremity was diminished in the sagittal plane correlating with the quadriceps muscle volume loss and gracilis muscle hypertrophy. The modalities focused on both preventing

  13. Analyzing the installation angle error of a SAW torque sensor

    Science.gov (United States)

    Fan, Yanping; Ji, Xiaojun; Cai, Ping

    2014-09-01

    When a torque is applied to a shaft, normal strain oriented at ±45° direction to the shaft axis is at its maximum, which requires two one-port SAW resonators to be bonded to the shaft at ±45° to the shaft axis. In order to make the SAW torque sensitivity high enough, the installation angle error of two SAW resonators must be confined within ±5° according to our design requirement. However, there are few studies devoted to the installation angle analysis of a SAW torque sensor presently and the angle error was usually obtained by a manual method. Hence, we propose an approximation method to analyze the angle error. First, according to the sensitive mechanism of the SAW device to torque, the SAW torque sensitivity is deduced based on the linear piezoelectric constitutive equation and the perturbation theory. Then, when a torque is applied to the tested shaft, the stress condition of two SAW resonators mounted with an angle deviating from ±45° to the shaft axis, is analyzed. The angle error is obtained by means of the torque sensitivities of two orthogonal SAW resonators. Finally, the torque measurement system is constructed and the loading and unloading experiments are performed twice. The torque sensitivities of two SAW resonators are obtained by applying average and least square method to the experimental results. Based on the derived angle error estimation function, the angle error is estimated about 3.447°, which is close to the actual angle error 2.915°. The difference between the estimated angle and the actual angle is discussed. The validity of the proposed angle error analysis method is testified to by the experimental results.

  14. Influence of externally applied magnetic perturbations on neoclassical tearing modes at ASDEX Upgrade

    NARCIS (Netherlands)

    Fietz, S.; Bergmann, A.; Classen, I.; Maraschek, M.; M. García-Muñoz,; Suttrop, W.; Zohm, H.; ASDEX Upgrade team,

    2015-01-01

    The influence of externally applied magnetic perturbations (MPs) on neoclassical tearing modes (NTM) and the plasma rotation in general is investigated at the ASDEX Upgrade tokamak (AUG). The low n resonant components of the applied field exert local torques and influence the stability of NTMs. The

  15. ASH External Web Portal (External Portal) -

    Data.gov (United States)

    Department of Transportation — The ASH External Web Portal is a web-based portal that provides single sign-on functionality, making the web portal a single location from which to be authenticated...

  16. Arthroscopic and computer-assisted high tibial osteotomy using standard total knee arthroplasty navigation software.

    Science.gov (United States)

    Thompson, Stephen R; Zabtia, Nazar; Weening, Bradley; Zalzal, Paul

    2013-05-01

    Opening-wedge high tibial osteotomy is an increasingly performed procedure for treatment of varus gonarthrosis and correction of malalignment during meniscal transplantation or cartilage restoration. Precise preoperative planning and meticulous surgical technique are required to achieve an appropriate mechanical axis correction. We describe our technique of arthroscopic and computer-assisted high tibial osteotomy using commonly available total knee arthroplasty navigation software as an intraoperative goniometer. We believe that our technique, by providing intraoperative real-time guidance of the degree of correction that is accurate and reliable, represents a useful tool for the surgeon who uncommonly performs high tibial osteotomy.

  17. Medial tibial pain. A prospective study of its cause among military recruits.

    Science.gov (United States)

    Milgrom, C; Giladi, M; Stein, M; Kashtan, H; Margulies, J; Chisin, R; Steinberg, R; Swissa, A; Aharonson, Z

    1986-12-01

    In a prospective study of 295 infantry recruits during 14 weeks of basic training, 41% had medial tibial pain. Routine scintigraphic evaluation in cases of medial tibial bone pain showed that 63% had abnormalities. A stress fracture was found in 46%. Only two patients had periostitis. None had ischemic medial compartment syndrome. Physical examination could not differentiate between cases with medial tibial bone pain secondary to stress fractures and those with scintigraphically normal tibias. When both pain and swelling were localized in the middle one-third of the tibia, the lesion most likely proved to be a stress fracture.

  18. Osteotomía tibial valguizante: análisis de supervivencia

    OpenAIRE

    Modrego Aranda, Francisco Javier

    2005-01-01

    Presentamos un estudio retrospectivo de 38 osteotomías tibiales valguizantes, en 32 pacientes con "genu-varo" artrósico. La supervivencia a los 180 meses fue del 58%. Cuando el paciente presentaba un peso mayor 1,32 veces al peso ideal la supervivencia disminuía al 53%. Y cuando la corrección angular en ángulo femoro-tibial era menor de 6º la supervivencia disminuía al 33% We evaluated the results in thirty-two patients (thirty-eight knees) who had had a high tibial osteotomy for var...

  19. Accurate torque-speed performance prediction for brushless dc motors

    Science.gov (United States)

    Gipper, Patrick D.

    Desirable characteristics of the brushless dc motor (BLDCM) have resulted in their application for electrohydrostatic (EH) and electromechanical (EM) actuation systems. But to effectively apply the BLDCM requires accurate prediction of performance. The minimum necessary performance characteristics are motor torque versus speed, peak and average supply current and efficiency. BLDCM nonlinear simulation software specifically adapted for torque-speed prediction is presented. The capability of the software to quickly and accurately predict performance has been verified on fractional to integral HP motor sizes, and is presented. Additionally, the capability of torque-speed prediction with commutation angle advance is demonstrated.

  20. Antiferromagnetic domain wall motion driven by spin-orbit torques

    Science.gov (United States)

    Shiino, Takayuki; Oh, Se-Hyeok; Haney, Paul M.; Lee, Seo-Won; Go, Gyungchoon; Park, Byong-Guk; Lee, Kyung-Jin

    2016-01-01

    We theoretically investigate dynamics of antiferromagnetic domain walls driven by spin-orbit torques in antiferromagnet/heavy metal bilayers. We show that spin-orbit torques drive antiferromagnetic domain walls much faster than ferromagnetic domain walls. As the domain wall velocity approaches the maximum spin-wave group velocity, the domain wall undergoes Lorentz contraction and emits spin-waves in the terahertz frequency range. The interplay between spin-orbit torques and the relativistic dynamics of antiferromagnetic domain walls leads to the efficient manipulation of antiferromagnetic spin textures and paves the way for the generation of high frequency signals from antiferromagnets. PMID:27588878

  1. Spin transfer torque with spin diffusion in magnetic tunnel junctions

    KAUST Repository

    Manchon, Aurelien

    2012-08-09

    Spin transport in magnetic tunnel junctions in the presence of spin diffusion is considered theoretically. Combining ballistic tunneling across the barrier and diffusive transport in the electrodes, we solve the spin dynamics equation in the metallic layers. We show that spin diffusion mixes the transverse spin current components and dramatically modifies the bias dependence of the effective spin transfer torque. This leads to a significant linear bias dependence of the out-of-plane torque, as well as a nonconventional thickness dependence of both spin torque components.

  2. Intrinsic nonadiabatic topological torque in magnetic skyrmions and vortices

    KAUST Repository

    Akosa, Collins Ashu

    2017-03-01

    We propose that topological spin currents flowing in topologically nontrivial magnetic textures, such as magnetic skyrmions and vortices, produce an intrinsic nonadiabatic torque of the form Tt∼[(∂xm×∂ym)·m]∂ym. We show that this torque, which is absent in one-dimensional domain walls and/or nontopological textures, is responsible for the enhanced nonadiabaticity parameter observed in magnetic vortices compared to one-dimensional textures. The impact of this torque on the motion of magnetic skyrmions is expected to be crucial, especially to determine their robustness against defects and pinning centers.

  3. High torque DC motor fabrication and test program

    Science.gov (United States)

    Makus, P.

    1976-01-01

    The testing of a standard iron and standard alnico permanent magnet two-phase, brushless dc spin motor for potential application to the space telescope has been concluded. The purpose of this study was to determine spin motor power losses, magnetic drag, efficiency and torque speed characteristics of a high torque dc motor. The motor was designed and built to fit an existing reaction wheel as a test vehicle and to use existing brass-board commutation and torque command electronics. The results of the tests are included in this report.

  4. Combined use of Ilizarov external fixation and Papineau technique for septic pseudoarthrosis of the distal tibia in a patient with diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Stefanos D. Koutsostathis

    2014-02-01

    Full Text Available The surgical treatment of open pilon fractures has a high complication rate especially in diabetic patients. In this article, we present a case of an infected tibial non-union after an open reduction and internal fixation in a diabetic patient, treated with Ilizarov external fixation combined with Papineau technique. Combined use of external fixation and Papineau technique can provide an alternative option for the treatment of septic pseudoarthrosis of the distal tibia.

  5. Risk Factors of Medial Tibial Stress Syndrome(MTSS)

    Institute of Scientific and Technical Information of China (English)

    Sae Yong Lee

    2009-01-01

    @@ Background According to Mubarak[1,2],who first coined the term medial tibial stress syndrome (MTSS)in 1982,the definition of MTSS is " a symptom complex in athletes who experience exercise-induced pain along thedistalposteromedialaspectofthetibia."Previous studies have shown that MTSS accounts for 6 to 15 percent of running related injuries [3-9] and has an incidence among certain populations (ie,military recruits) of up to 35 percent [10].The etiology of MTSS is not well known,but it is commonly believed that the cause is inflammation and possibly an avulsion of the origins of the posterior tibialis and/or the soleus from the periosteum of the posteromedial tibia [10].Traction at the periosteal interface is thought to lead to inflammation and pain at the periosteal-fascial junction.The location of the pain is usually localized over the posterior medial edge of the distal third of the tibia.

  6. Elephantiasis nostras verrucosa complicated with chronic tibial osteomyelitis.

    Science.gov (United States)

    Turhan, Egemen; Ege, Ahmet; Keser, Selcuk; Bayar, Ahmet

    2008-10-01

    Elephantiasis nostras verrucosa represents an infrequent clinical entity with cutaneous changes characterized by dermal fibrosis, hyperkeratotic verrucous and papillamotous lesions resulting from chronic non-filarial lymphedema secondary to infections, surgeries, tumor obstruction, radiation, congestive heart failure, and obesity. Although recurrent streptococcal lymphangitis is believed to play a critical role in the origin of elephantiasis nostras verrucosa, the exact pathogenesis of the disorder is not yet clear. Therapeutic efforts should aim to reduce lymph stasis, which will also lead to improvement of the cutaneous changes but unfortunately there is no specific treatment for advanced cases. In this report, we present a patient who was treated by below knee amputation as a result of elephantiasis nostras verrucosa complicated with chronic tibial osteomyelitis.

  7. Expected long-term outcome after a tibial shaft fracture

    DEFF Research Database (Denmark)

    Faergemann, C; Frandsen, P A; Röck, N D

    1999-01-01

    these expectations with the outcome measured in patients. METHODS: There were five groups of nonpatients: (1) 42 orthopedic surgeons, (2) 36 physiotherapists, (3) 42 students, (4) 49 white collar workers, and (5) 38 blue collar workers. Outcome was measured by Sickness Impact Profile (SIP). The SIP scores were...... compared with SIP scores obtained from 33 patients with a unilateral tibial fracture. RESULTS: Marked variation was observed between the groups. CONCLUSION: Physiotherapists expected the lowest degree of disability and orthopedic surgeons the highest. In the three groups of students, white collar workers...... and blue collar workers only minor variations were observed and their SIP scores showed better correlation with the SIP scores obtained from the patients than those of orthopedic surgeons and physiotherapists....

  8. Double segmental tibial fractures - an unusual fracture pattern

    Directory of Open Access Journals (Sweden)

    Bali Kamal

    2012-02-01

    Full Text Available 【Abstract】A case of a 50-year-old pedestrian who was hit by a bike and suffered fractures of both bones of his right leg was presented. Complete clinical and radiographic assessment showed double segmental fractures of the tibia and multisegmental fractures of the fibula. Review of the literature revealed that this fracture pattern was unique and only a single case was reported so far. Moreover, we discussed the possible mechanisms which can lead to such an injury. We also discussed the management of segmental tibial fracture and the difficulties encountered with them. This case was managed by modern osteosynthesis tech- nique with a pleasing outcome. Key words: Fracture, bone; Tibia; Fibula; Nails

  9. Research on a direct torque control for an electrically excited synchronous motor drive with low ripple in flux and torque

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yangzhong; HU Yuwen; HUANG Wenxin; ZHONG Tianyun

    2007-01-01

    The electrically excited synchronous motor (ESM)has typically small synchronous inductance values and quite low transient values because of the damper windings mounted on the rotor.Therefore,the torque and stator flux linkage ripples are high in the direct torque control(DTC)drive of the ESM with a torque and flux linkage hysteresis controller (basic DTC).A DTC scheme with space vector modulation(SVM)for the ESM was investigated in this paper.It is based on the compensation of the stator flux linkage vector error using the space vector modulation in order to decrease the torque and flux linkage ripples and produce fixed switching frequency under the principle that the torque is controlled by the torque angle in the ESM.Compared with the basic DTC,the results of the simulation and experiment show that the torque and flux linkage rippies are reduced,the maximum current value is decreased during the startup,and the current distortion is much smaller in the steady-state under the SVM-DTC.The field-weakening control is incorporated with the SVM-DTC successfully.

  10. Absolute reliability of hamstring to quadriceps strength imbalance ratios calculated using peak torque, joint angle-specific torque and joint ROM-specific torque values.

    Science.gov (United States)

    Ayala, F; De Ste Croix, M; Sainz de Baranda, P; Santonja, F

    2012-11-01

    The main purpose of this study was to determine the absolute reliability of conventional (H/Q(CONV)) and functional (H/Q(FUNC)) hamstring to quadriceps strength imbalance ratios calculated using peak torque values, 3 different joint angle-specific torque values (10°, 20° and 30° of knee flexion) and 4 different joint ROM-specific average torque values (0-10°, 11-20°, 21-30° and 0-30° of knee flexion) adopting a prone position in recreational athletes. A total of 50 recreational athletes completed the study. H/Q(CONV) and H/Q(FUNC) ratios were recorded at 3 different angular velocities (60, 180 and 240°/s) on 3 different occasions with a 72-96 h rest interval between consecutive testing sessions. Absolute reliability was examined through typical percentage error (CVTE), percentage change in the mean (CM) and intraclass correlations (ICC) as well as their respective confidence limits. H/Q(CONV) and H/Q(FUNC) ratios calculated using peak torque values showed moderate reliability values, with CM scores lower than 2.5%, CV(TE) values ranging from 16 to 20% and ICC values ranging from 0.3 to 0.7. However, poor absolute reliability scores were shown for H/Q(CONV) and H/Q(FUNC) ratios calculated using joint angle-specific torque values and joint ROM-specific average torque values, especially for H/Q(FUNC) ratios (CM: 1-23%; CV(TE): 22-94%; ICC: 0.1-0.7). Therefore, the present study suggests that the CV(TE) values reported for H/Q(CONV) and H/Q(FUNC) (≈18%) calculated using peak torque values may be sensitive enough to detect large changes usually observed after rehabilitation programmes but not acceptable to examine the effect of preventitive training programmes in healthy individuals. The clinical reliability of hamstring to quadriceps strength ratios calculated using joint angle-specific torque values and joint ROM-specific average torque values are questioned and should be re-evaluated in future research studies.

  11. Sagittal accuracy of tibial osteotomy position during in vivo tibial plateau levelling osteotomy performed without an alignment jig and cutting guide.

    Science.gov (United States)

    Craig, Andrew; Witte, Philip Georg; Scott, Harry William

    2017-01-16

    To assess the accuracy of tibial osteotomy location for tibial plateau levelling osteotomy (TPLO) in the sagittal plane and its effect on the postoperative tibial plateau angle (TPA), when performed without an alignment jig and saw guide. Also, to document the improvement gained with experience. Medical records and stifle radiographs of dogs undergoing TPLO, without the use of an alignment jig and saw guide, by one surgeon were reviewed (2010-2014). Postoperative radiographs were reviewed to record the distance and direction of eccentricity. Postoperative TPA was also recorded. In a series of 401 TPLO procedures, 231 met the inclusion criteria. The absolute distance of eccentricity (DOE) for all dogs was 3.0 ± 1.6 mm. When evaluating surgical experience, the DOE for the final 77 cases (2.72 ± 1.43 mm), the middle 77 cases (3.18 ± 1.49 mm), and the first 77 cases (3.24 ± 1.7 mm) were not significantly different (p = 0.07157). There was a very weak correlation between DOE and postoperative TPA (R = 0.029). The location of the tibial osteotomy when performing TPLO without an alignment jig and saw guide compared favourably with previously documented use of an alignment jig and saw guide. Whilst the location of the tibial osteotomy has a theoretical impact on the postoperative TPA, other factors appear to be of greater importance. Surgeon experience did not result in significant improvement in accuracy up to 231 procedures.

  12. Torque Production in a Halbach Machine

    Science.gov (United States)

    Eichenberg, Dennis J.; Gallo, Christopher A.; Thompson, William K.; Vrnak, Daniel R.

    2006-01-01

    The NASA John H. Glenn Research Center initiated the investigation of torque production in a Halbach machine for the Levitated Ducted Fan (LDF) Project to obtain empirical data in determining the feasibility of using a Halbach motor for the project. LDF is a breakthrough technology for "Electric Flight" with the development of a clean, quiet, electric propulsor system. Benefits include zero emissions, decreased dependence on fossil fuels, increased efficiency, increased reliability, reduced maintenance, and decreased operating noise levels. A commercial permanent magnet brushless motor rotor was tested with a custom stator. An innovative rotor utilizing a Halbach array was designed and developed to fit directly into the same stator. The magnets are oriented at 90deg to the adjacent magnet, which cancels the magnetic field on the inside of the rotor and strengthens the field on the outside of the rotor. A direct comparison of the commercial rotor and the Halbach rotor was made. In addition, various test models were designed and developed to validate the basic principles described, and the theoretical work that was performed. The report concludes that a Halbach array based motor can provide significant improvements in electric motor performance and reliability.

  13. Spin orbit torque based electronic neuron

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, Abhronil, E-mail: asengup@purdue.edu; Choday, Sri Harsha; Kim, Yusung; Roy, Kaushik [School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

    2015-04-06

    A device based on current-induced spin-orbit torque (SOT) that functions as an electronic neuron is proposed in this work. The SOT device implements an artificial neuron's thresholding (transfer) function. In the first step of a two-step switching scheme, a charge current places the magnetization of a nano-magnet along the hard-axis, i.e., an unstable point for the magnet. In the second step, the SOT device (neuron) receives a current (from the synapses) which moves the magnetization from the unstable point to one of the two stable states. The polarity of the synaptic current encodes the excitatory and inhibitory nature of the neuron input and determines the final orientation of the magnetization. A resistive crossbar array, functioning as synapses, generates a bipolar current that is a weighted sum of the inputs. The simulation of a two layer feed-forward artificial neural network based on the SOT electronic neuron shows that it consumes ∼3× lower power than a 45 nm digital CMOS implementation, while reaching ∼80% accuracy in the classification of 100 images of handwritten digits from the MNIST dataset.

  14. Radiative torque alignment: Essential Physical Processes

    CERN Document Server

    Hoang, Thiem

    2007-01-01

    We study physical processes that affect the alignment of grains subject to radiative torques (RATs). To describe the action of the RATs we use the analytical model (AMO) of RATs introduced in Paper I, namely, in Lazarian & Hoang (2007). We focus our discussion on the RAT alignment by anisotropic radiation flux in respect to magnetic field. Such an alignment does not invoke paramagnetic, i.e. Davis-Greenstein, dissipation, but, nevertheless, grains tend to align with long axes perpendicular to magnetic field. We use phase space trajectory maps to describe the alignment. When we account for thermal fluctuations within grain material, we show that for grains, which are characterized by a triaxial ellipsoid of inertia, the zero-J attractor point obtained in our earlier study develops into a low-J attractor point. Value at the latter point is the order of thermal angular momentum corresponding to the grain temperature. We show that the alignment of grains with long axes parallel to magnetic field (``wrong alig...

  15. Electromagnetic force and torque in ponderable media

    CERN Document Server

    Mansuripur, Masud

    2014-01-01

    Maxwell's macroscopic equations combined with a generalized form of the Lorentz law of force are a complete and consistent set of equations. Not only are these five equations fully compatible with special relativity, they also conform with conservation laws of energy, momentum, and angular momentum. We demonstrate consistency with the conservation laws by showing that, when a beam of light enters a magnetic dielectric, a fraction of the incident linear (or angular) momentum pours into the medium at a rate determined by the Abraham momentum density, ExH/c^2, and the group velocity V_g of the electromagnetic field. The balance of the incident, reflected, and transmitted momenta is subsequently transferred to the medium as force (or torque) at the leading edge of the beam, which propagates through the medium with velocity V_g. Our analysis does not require "hidden" momenta to comply with the conservation laws, nor does it dissolve into ambiguities with regard to the nature of electromagnetic momentum in ponderab...

  16. Evaluation of toroidal torque by non-resonant magnetic perturbations in tokamaks for resonant transport regimes using a Hamiltonian approach

    CERN Document Server

    Albert, Christopher G; Kapper, Gernot; Kasilov, Sergei V; Kernbichler, Winfried; Martitsch, Andreas F

    2016-01-01

    Toroidal torque generated by neoclassical viscosity caused by external non-resonant, non-axisymmetric perturbations has a significant influence on toroidal plasma rotation in tokamaks. In this article, a derivation for the expressions of toroidal torque and radial transport in resonant regimes is provided within quasilinear theory in canonical action-angle variables. The proposed approach treats all low-collisional quasilinear resonant NTV regimes including superbanana plateau and drift-orbit resonances in a unified way and allows for magnetic drift in all regimes. It is valid for perturbations on toroidally symmetric flux surfaces of the unperturbed equilibrium without specific assumptions on geometry or aspect ratio. The resulting expressions are shown to match existing analytical results in the large aspect ratio limit. Numerical results from the newly developed code NEO-RT are compared to calculations by the quasilinear version of the code NEO-2 at low collisionalities. The importance of the magnetic shea...

  17. Efficient spin transfer torque in La2/3Sr1/3MnO3 nanostructures

    Science.gov (United States)

    Foerster, Michael; Peña, Luis; Vaz, C. A. F.; Heinen, Jan; Finizio, Simone; Schulz, Tomek; Bisig, André; Büttner, Felix; Eisebitt, Stefan; Méchin, Laurence; Hühn, Sebastian; Moshnyaga, Vasily; Kläui, Mathias

    2014-02-01

    We carry out low temperature magnetotransport measurements on nanostructured La2/3Sr1/3MnO3 wires to study the interaction between spin-polarized current and magnetization in this half metallic material. We selectively position domain walls by applying external fields. The domain wall resistance is found to be positive, in contrast to conventional 3d metals. The depinning field is reduced when current pulses are injected into the wire. By comparing measurements for both current polarities, we can disentangle heating and spin transfer torque effects. The determined spin transfer torque efficiency is of the order of 4 × 10-14 Tm2/A, which is significantly higher than in permalloy.

  18. Torque and power characteristics of a helium charged Stirling engine with a lever controlled displacer driving mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Karabulut, H.; Cinar, C.; Oztuerk, E.; Yuecesu, H.S. [Department of Mechanical Technology, Faculty of Technical Education, Gazi University, 06500 Teknikokullar, Ankara (Turkey)

    2010-01-15

    This study presents test results of a Stirling engine with a lever controlled displacer driving mechanism. Tests were conducted with helium and the working fluid was charged into the engine block. The engine was loaded by means of a prony type micro dynamometer. The heat was supplied by a liquefied petroleum gas (LPG) burner. The engine started to run at 118 C hot end temperature and the systematic tests of the engine were conducted at 180 C, 220 C and 260 C hot end external surface temperatures. During the test, cold end temperature was kept at 27 C by means of water circulation. Variation of the shaft torque and power with respect to the charge pressure and hot end temperature were examined. The maximum torque and power were measured as 3.99 Nm and 183 W at 4 bars charge pressure and 260 C hot end temperature. Maximum power corresponded to 600 rpm speed. (author)

  19. An improved torque density Modulated Pole Machine for low speed high torque applications

    DEFF Research Database (Denmark)

    Washington, J. G.; Atkinson, G. J.; Baker, N. J.;

    2012-01-01

    - dimensional Finite Element calculations are used to compare performance of the machines under the same conditions, it is shown that the new Combined Phase topology produces a greater torque whilst reducing the number of components required to assemble the machine and increasing its mechanical integrity.......This paper presents a new topology for three-phase Modulated Pole Machines. This new topology the “Combined Phase Modulated Pole Machine” is analysed and compared to the more traditional technology of three separate single phase units stacked axially with a separation between phases. Three...

  20. Long-term results and comparison of the three different high tibial osteotomy and fixation techniques in medial compartment arthrosis.

    Science.gov (United States)

    Polat, Gökhan; Balcı, Halil İbrahim; Çakmak, Mehmet Fevzi; Demirel, Mehmet; Şen, Cengiz; Aşık, Mehmet

    2017-03-16

    The purpose of this study is to report and analyze the long-term outcomes of the patients who underwent high tibial osteotomy (HTO) with three different techniques for the treatment of medial compartment arthrosis. A total of 187 patients (195 knees) who underwent HTO between 1990 and 2010 were retrospectively evaluated. Eighty-eight knees, opening-wedge osteotomy with Puddu plate (group A); 51 knees, transverse osteotomy below the tubercle with external fixator (group B); and 29 knees, closing-wedge osteotomy with staple fixation (group C) were included in the study. The patients (mean age 44.9 ± 10.6 years, mean follow-up of 12.4 ± 3.2 years) were called for final controls and survival rates of the knees, and functional evaluations of the patients were performed using Knee Society Score (KSS) and Hospital for Special Surgery (HSS) knee score assessments. In the comparison of the three groups, there were no differences regarding the mean age, preoperative arthrosis levels, or preoperative deformity analyses (n.s.). The main finding of these comparisons showed that the closing-wedge osteotomy has the greatest lateralization effect on mechanical axis deviation (MAD) (p = 0.024), the greatest valgization effect on medial proximal tibial angles (MPTA) (p = 0.026), and the lowest posterior tibial slope (PTS) angles (p = 0.032) in comparison to the other groups. There were no functional differences between the three groups in the long-term assessment of patients with KSS and HSS knee scores. According to the Kaplan-Meier survival analysis, the probability of the survival of the native knee joint after HTO was 93.4% in 5 years and 71.2% in 10 years in our study group. During the follow-up of the 168 knees, revision surgery with total knee replacement was needed in 27 knees (16%). The mean time from HTO to total knee replacement was 8.9 years in these patients. HTO has acceptable long-term clinical and functional results that should not be